Western ragweed (Ambrosia psilostachya DC.) top growth and rhizome extracts were inhibitory to germination and growth of seedling shoots and roots of test plants in almost all cases. Germination of all plants tested was reduced an average of 19.5% by the ragweed extracts. Shoot and root growth of plants tested was reduced an average of 56.8% by the ragweed extracts.
R. L. Dalrymple; J. L. Rogers
Many ecological studies have pointed out maternal effects in plants and shown that plant maternal environment influences germination of their seed and subsequent seedling growth. However, few have tested for maternal effects induced by soil macroorganisms. We tested whether two earthworm species (Aporrectodea caliginosa and Lumbricus terrestris) trigger such maternal effects on seed germination and seedling growth of three plant
Kam-Rigne Laossi; Diana-Cristina Noguera; Sébastien Barot
Western ragweed (Ambrosia psilostachya DC.) top growth and rhizome extracts were inhibitory to germination and growth of seedling shoots and roots of test plants in almost all cases. Germination of all plants tested was reduced an average of 19.5% by the ragweed extracts. Shoot and root growth of plants tested was reduced an average of 56.8% by the ragweed extracts. The combined effects of germination plus growth reductions resulted in the tested plants producing only 34.8% in the extracts compared to production in distilled water. PMID:24407801
Dalrymple, R L; Rogers, J L
The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three salt- marsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable
J. L. Espinar; L. V. Garcia; L. Clemente
Phytotoxic activity of Ocimum tenuiflorum (Lamiaceae) plant extracts was investigated against the germination and seedling growth of cress (Lepidium sativum), lettuce (Lactuca sativa), alfalfa (Medicago sativa), Italian ryegrass (Lolium multiflorum), barnyard grass (Echinochloa crus-galli), and timothy (Phleum pratense) at four different concentrations. The plant extracts at concentrations greater than 30?mg dry weight equivalent extract mL(-1) reduced significantly the total germination percent (GP), germination index (GI), germination energy (GE), speed of emergence (SE), seedling vigour index (SVI), and coefficient of the rate of germination (CRG) of all test species except barnyard grass and GP of lettuce. In contrast, time required for 50% germination (T 50) and mean germination time (MGT) were increased at the same or higher than this concentration. The increasing trend of T 50 and MGT and the decreasing trend of other indices indicated a significant inhibition or delay of germination of the test species by O. tenuiflorum plant extracts and vice versa. In addition, the shoot and root growth of all test species were significantly inhibited by the extracts at concentrations greater than 10?mg dry weight equivalent extract mL(-1). The I 50 values for shoot and root growth were ranged from 26 to 104?mg dry weight equivalent extract mL(-1). Seedling growth was more sensitive to the extracts compared to seed germination. Results of this study suggest that O. tenuiflorum plant extracts have phytotoxic properties and thus contain phytotoxic substances. Isolation and characterization of those substances from this plant may act as a tool for new natural, biodegradable herbicide development to control weeds. PMID:25032234
Islam, A K M Mominul; Kato-Noguchi, Hisashi
The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three saltmarsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable conditions for germination were restored. Tolerance of the germination process was related to the average salinity level measured during the growth/germination season at sites where established individuals of each species dominated the species cover. No relationship was found between salinity tolerance of the germination process and seed response to extended exposure to flooding and salinity conditions. The salinity response was significantly related to the conditions prevailing in the habitats of the respective species during the unfavorable (nongrowth/nongermination) season. Our results indicate that changes in salinity and hydrology while seeds are dormant affect the outcome of the seed-bank response, even when conditions at germination are identical. Because these environmental-history-dependent responses differentially affect seed germination, seedling density, and probably sexual recruitment in the studied and related species, these influences should be considered for wetland restoration and management.
Espinar, J.L.; Garcia, L.V.; Clemente, L.
The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three salt-marsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable conditions for germination were restored. Tolerance of the germination process was related to the average salinity level measured during the growth/germination season at sites where established individuals of each species dominated the species cover. No relationship was found between salinity tolerance of the germination process and seed response to extended exposure to flooding and salinity conditions. The salinity response was significantly related to the conditions prevailing in the habitats of the respective species during the unfavorable (nongrowth/nongermination) season. Our results indicate that changes in salinity and hydrology while seeds are dormant affect the outcome of the seed-bank response, even when conditions at germination are identical. Because these environmental-history-dependent responses differentially affect seed germination, seedling density, and probably sexual recruitment in the studied and related species, these influences should be considered for wetland restoration and management. PMID:21646131
Espinar, José L; García, Luis V; Clemente, Luis
A brief summary of the effects of light on plant germination, growth and development, including photoperiodism and pigment formation, introduces 18 experiments and demonstrations which illustrate aspects of these effects. Detailed procedures for each exercise are given, the expected results outlined, and possible sources of difficulty discussed.…
Downs, R. J.; And Others
The effects of wastewater from olive processing on seed germination and early plant growth of different vegetable species were examined. Three types of wastewater at different concentrations were tested: raw wastewater, wastewater with organic matter removed and deionized wastewater.Results generally indicate an inhibitory effect on seed germination and early plant growth by all treatments containing any kind of wastewater. Of
J. D. Perez; E. Esteban; M. Gomez
Aqueous extracts of Artemisia frigida leaf and stem and soils beneath A. frigida were used to test their allelopathic effects on the seed germination and seedling growth of three Poaceae plants (Leymus chinensis, Stipa krylovii, and Cleistogenes squarrosa) on Leymus chinensis grassland. The aqueous extracts of A. frigida leaf and stem decreased the seed germination index of test plants and prolonged their seed germination time, and inhibited the shoot growth of the three plants and the root growth of S. krylovii. The aqueous extracts at concentration > or = 0.075 g x ml(-1) presented a strong inhibition on the root growth of L. chinensis, while those at concentration < or = 0.05 g x ml(-1) had less effects. For the root growth of C. squarrosa, the aqueous extracts showed a "low-promotion and high-inhibition effect". Under the effects of A. frigida soil, the seedling growth of test plants was inhibited. The sensitivity of test plants to the allelopathic effects of A. frigida was in the order of S. krylovii > L. chinense > C. squarrosa, with a higher sensitivity of root growth than shoot growth. PMID:20879526
Li, Xue-feng; Wang, Jian; Xu, Wen-bo; Wang, Kun
The increasing commercial production of engineered nanoparticles (ENPs) has led to concerns over the potential adverse impacts of these ENPs on biota in natural environments. Silver nanoparticles (AgNPs) are one of the most widely used ENPs and are expected to enter natural ecosystems. Here we examined the effects of AgNPs on germination and growth of eleven species of common wetland plants. We examined plant responses to AgNP exposure in simple pure culture experiments (direct exposure) and for seeds planted in homogenized field soils in a greenhouse experiment (soil exposure). We compared the effects of two AgNPs–20-nm polyvinylpyrrolidine-coated silver nanoparticles (PVP-AgNPs) and 6-nm gum arabic coated silver nanoparticles (GA-AgNPs)–to the effects of AgNO3 exposure added at equivalent Ag concentrations (1, 10 or 40 mg Ag L?1). In the direct exposure experiments, PVP-AgNP had no effect on germination while 40 mg Ag L?1 GA-AgNP exposure significantly reduced the germination rate of three species and enhanced the germination rate of one species. In contrast, 40 mg Ag L?1 AgNO3 enhanced the germination rate of five species. In general root growth was much more affected by Ag exposure than was leaf growth. The magnitude of inhibition was always greater for GA-AgNPs than for AgNO3 and PVP-AgNPs. In the soil exposure experiment, germination effects were less pronounced. The plant growth response differed by taxa with Lolium multiflorum growing more rapidly under both AgNO3 and GA-AgNP exposures and all other taxa having significantly reduced growth under GA-AgNP exposure. AgNO3 did not reduce the growth of any species while PVP-AgNPs significantly inhibited the growth of only one species. Our findings suggest important new avenues of research for understanding the fate and transport of NPs in natural media, the interactions between NPs and plants, and indirect and direct effects of NPs in mixed plant communities. PMID:23091638
Yin, Liyan; Colman, Benjamin P.; McGill, Bonnie M.; Wright, Justin P.; Bernhardt, Emily S.
This study presents a novel way of enhancing plant growth through the use of a non-petroleum based product. We report here that exposing either roots or seeds of multicellular plants to extremely low concentrations of dissolved hydrogen sulfide at any stage of life causes statistically significant increases in biomass including higher fruit yield. Individual cells in treated plants were smaller (~13%) than those of controls. Germination success and seedling size increased in, bean, corn, wheat, and pea seeds while time to germination decreases. These findings indicated an important role of H2S as a signaling molecule that can increase the growth rate of all species yet tested. The increased crop yields reported here has the potential to effect the world's agricultural output. PMID:23614010
Dooley, Frederick D; Nair, Suven P; Ward, Peter D
This study presents a novel way of enhancing plant growth through the use of a non-petroleum based product. We report here that exposing either roots or seeds of multicellular plants to extremely low concentrations of dissolved hydrogen sulfide at any stage of life causes statistically significant increases in biomass including higher fruit yield. Individual cells in treated plants were smaller (?13%) than those of controls. Germination success and seedling size increased in, bean, corn, wheat, and pea seeds while time to germination decreases. These findings indicated an important role of H2S as a signaling molecule that can increase the growth rate of all species yet tested. The increased crop yields reported here has the potential to effect the world's agricultural output. PMID:23614010
Dooley, Frederick D.; Nair, Suven P.; Ward, Peter D.
We describe a simple, inexpensive, but remarkably versatile and controlled growth environment for the observation of plant germination and seedling root growth on a flat, horizontal surface over periods of weeks. The setup provides to each plant a controlled humidity (between 56% and 91% RH), and contact with both nutrients and atmosphere. The flat and horizontal geometry of the surface supporting the roots eliminates the gravitropic bias on their development and facilitates the imaging of the entire root system. Experiments can be setup under sterile conditions and then transferred to a non-sterile environment. The system can be assembled in 1-2 minutes, costs approximately 8.78$ per plant, is almost entirely reusable (0.43$ per experiment in disposables), and is easily scalable to a variety of plants. We demonstrate the performance of the system by germinating, growing, and imaging Wheat (Triticum aestivum), Corn (Zea mays), and Wisconsin Fast Plants (Brassica rapa). Germination rates were close to those expected for optimal conditions. PMID:24806462
Sizmur, Tom; Lind, Kara R; Benomar, Saida; VanEvery, Hannah; Cademartiri, Ludovico
This study aims to investigate effects of diesel and kerosene on seed germination and seedling growth among coastal wetland plants to select species that can be used for the restoration and revegetation of oil-polluted habitats. Tests on 51 species were performed in Petri dishes containing 0 %, 6 %, 12 %, and 18 % diesel, 20 %, 40 %, and 60 % kerosene; each treatment combination was replicated five times with 20 seeds in each Petri dish. All dishes were held in a growth chamber with 20°C day of 12 h/15°C night of 12 h in 80 % humidity for 20 days for calculating the germination percentage, seedling weight, and seedling vitality. The germination percentage of Rumex stenophyllus decreased significantly in diesel and kerosene treatments. The weights of seedlings treated with diesel and kerosene either increased or decreased in comparison with controls depending on the species. Vitality percentage values were high for seedlings of Chenopodium ficifolium. Thus, herbaceous plant responses to oil treatments are species-specific. PMID:25138038
Kim, Kee Dae
Responses to increasing salinity, during seed germination and vegetative plant growth, were studied in two related species of Juncus, J. maritimus and J. acutus. In both species, germination was optimal in the absence of salt, reduced by about 50% in the presence of 200 mM NaCl, and completely inhibited by NaCl concentrations above 300 mM. Previous exposure of the seeds to salt,
Monica Boscaiu; Genoveva Ballesteros; Miguel A. Naranjo; Oscar Vicente; Herminio Boira
Increasing use of nanoparticles in daily products is of great concern today, especially when their positive and negative impact on environment is not known. Hence, in current research, we have studied the impact of silver nanoparticle (AgNPs) and silver nitrate (AgNO3) application on seed germination, root, and shoot length of castor bean, Ricinus communis L. plant. Silver nanoparticles had no significant effects on seedling growth even at higher concentration of 4,000 mg L(-1), while the silver in bulk form as AgNO3 applied on the castor bean seeds inhibited the seed germination. Silver uptake in seedlings of the castor seeds on treatment with both the forms of silver was confirmed through atomic absorption spectroscopy studies. The silver nanoparticle and silver nitrate application to castor seeds also caused an enhanced enzymatic activity of ROS enzymes and phenolic content in castor seedlings. High-performance liquid chromatography analysis of individual phenols indicated enhanced content of parahydroxy benzoic acid. These kinds of studies are of great interest in order to unveil the movement and accumulation of nanoparticles in plant tissues for assessing future applications in the field or laboratory. PMID:23702569
Yasur, Jyothsna; Rani, Pathipati Usha
Mycorrhizal fungi are essential for the germination of orchid seeds. However, the specificity of orchids for their mycorrhizal fungi and the effects of the fungi on orchid growth are controversial. Mycorrhizal fungi have been studied in some tem- perate and tropical, epiphytic orchids, but the symbionts of tropical, terrestrial orchids are still unknown. Here we study diversity, specificity and function
Andrea Porras-Alfaro; Paul Bayman
The n-hexane-, acetone- and water-soluble fractions obtained from an aqueous acetone extract of lemon balm (Melissa officinalis L.) shoots inhibited the germination and the growth of roots and shoots of cockscomb (Amaranthus caudatus L.), cress (Lepidium sativum L.), crabgrass (Digitaria sanguinalis L.), timothy (Phleum pratense L.), lettuce (Lactuca sativa L.) and ryegrass (Lolium multiflorum Lam.). The inhibitory activity of the
The effect of a hydrocarbon mixture (HCM) of three polycyclic aromatic hydrocarbons (PAH) and Maya crude oil on germination, growth and survival of four grasses (Bouteloua curtipendula, Cenchrus ciliaris, Echinochloa crusgalli and Rhynchelytrum repens) was studied and compared to a control (Festuca arundinacea) under in vitro conditions. The species were cultured on MS medium with different HCM initial concentrations. Germination was not affected for any assayed concentration; however, the length of the stems and roots decreased when HCM increased and the survival of the four species also diminished. Except for F. arundinacea, a direct link between hydrocarbon concentration and plant survival was observed. In vitro studies are clean and easy to handle techniques allowing isolation of the plant activity from that derived from associations with microorganisms in non-sterile cultures. To our knowledge, this is the first work towards phytoremediation assisted by in vitro plant cultivation. PMID:18222086
Reynoso-Cuevas, L; Gallegos-Martínez, M E; Cruz-Sosa, F; Gutiérrez-Rojas, M
Because of its prolific growth, oilseed rape (Brassica napus L.) can be grown advantageously for phytoremediation of the lands contaminated by industrial wastes. Therefore, toxic effect\\u000a of cadmium on the germination of oilseed rape, the capability of plants for cadmium phytoextraction, and the effect of exogenous\\u000a application of plant growth regulators to mitigate phytotoxicity of cadmium were investigated. For the
Huabing Meng; Shujin Hua; Imran Haider Shamsi; Ghulam Jilani; Yuanlong Li; Lixi Jiang
Orobanche and Phelipanche species (the broomrapes) are root parasitic plants, some of which cause heavy yield losses on important crops. The development of herbicides based on natural metabolites from microbial and plant origin, targeting early stages on parasitic plant development, might contribute to the reduction of broomrape seed bank in agricultural soils. Therefore, the effect of metabolites belonging to different classes of natural compounds on broomrape seed germination and radicle development was assayed in vitro. Among the metabolites tested, epi-sphaeropsidone, cyclopaldic acid, and those belonging to the sesquiterpene class induced broomrape germination in a species-specific manner. epi-Epoformin, sphaeropsidin A, and cytochalasans inhibited germination of GR24-treated broomrape seeds. The growth of broomrape radicle was strongly inhibited by sphaeropsidin A and compounds belonging to cyclohexene epoxide and cytochalasan classes. Broomrape radicles treated with epi-sphaeropsidone developed a layer of papillae while radicles treated with cytochalasans or with sphaeropsidin A turned necrotic. These findings allow new lead natural herbicides for the management of parasitic weeds to be identified. PMID:25272312
Cimmino, Alessio; Fernández-Aparicio, Mónica; Andolfi, Anna; Basso, Sara; Rubiales, Diego; Evidente, Antonio
Major oil sands industrial companies are located in the Athabasca Oil Sands Deposit in northeastern Alberta, Canada. During the process used to extract light crude oil (via hot water digestion and flotation), gypsum is usually added to produce consolidated tails (CT) and CT release water. The vast volumes of process-treated waters (effluent) are held within large dyked tailings ponds. Toward testing viable options for reclamation, various hummock-wetlands systems have been constructed; in addition, natural wetlands (inhabited by obligate wetland plant species) have become established as a result of seeping of the effluents held within the large dyked ponds. Vegetation surveys conducted on and around the industrial site revealed that the constructed wetlands associated with the dyke drainage (effluent treated with phosphorous) and consolidated tails (CT; effluent treated with gypsum) had low biodiversity and were not invaded by many aquatic plants. Although the natural wetland was also not invaded by many aquatic species, it was found to be as diverse as the reference wetlands (i.e. off-site wetlands not exposed to the effluents). Exposure to oil sands effluents had an inhibitory effect on the germination (percent and/or rate) of several plant species (tomato, clover, wheat, rye, pea, reed canary grass, loblolly pine); clover and tomato seed germination were most affected. Two treatments in particular (effluents from the natural on-site wetland and the CT constructed wetland), delayed germination, and also led to reduced fresh weight of seedlings of tomato, wheat, clover and loblolly pine. The osmolarities of the effluents associated with the natural on-site wetland and CT constructed wetland were 712 and 728 mOs/kg, respectively; substituting these effluents with solutions of polyethylene glycol of the same osmotic potentials had a greater inhibitory effect on germination rate. The negative effects of the effluents on seed germination may account for the paucity of aquatic species that invaded the oil sands impacted wetlands. This factor will also be critical in determining the long-term feasibility of hummock-wetland systems. PMID:11843534
Crowe, A U; Plant, A L; Kermode, A R
Ceratoides lanata (Pursh) J.T. Howell is a shrub with numerous annual branchlets from the family Chenopodiaceae and is widely distributed in brackish water playas of northern Utah. Seeds had no dormancy, and about 90% of the seeds germinated in nonsaline control. Seed germination decreased with the increase in salinity, and more than 10% of the seeds germinated at 900 mmol\\/L
M. Ajmal Khan; Bilquees Gul; Darrell J. Weber
We have conducted an investigation on the effects that the extracts of a non-carbonaceous meteorite could have on the germination and growth of plants and the ability of non-carbonaceous meteoritic resource to serve as nutrient source for young plants of edible types. Selected plants were two dicotyledons ( Lycopersicon esculentum and Daucus carota) and one monocotyledon ( Zea mays). Solution cultures were developed using seeds, seedlings and seed-embryos. Meteoritic powder was obtained from the Vigirima mesosiderite, which was analyzed by X-ray diffraction and atomic absorption spectrometry (AAS). Results showed that extracts having variable concentrations of meteoritic matter favored an earlier germination in some plant species but the increase of the concentrations produced a decreased germination. However, total germination rate was higher in the presence of meteoritic extracts than in the presence of controls in the all species. A high metabolic yield in the protein synthesis was seen in dicotyledons utilizing Type-A and B extracts having concentrations of 4.16-8.33×10 3 mg l -1. Phaeophytinization index and chlorophyll a/b ratio, suggesting a negative effect of the heavy metals or acidic ions over the photosynthetic activity when extracts having high meteoritic concentrations were utilized. However, a higher chlorophyll (a) production in comparison to that of chlorophyll (b) was seen in extracts (Type-A and -B) with low concentrations of meteoritic matter. On the other hand, Z. mays seed-embryos growing in extracts (Type-D) having 3.53×10 4 mg l -1 of meteoritic matter showed a protein production (9.81×10 -2 mg protein mg wet wt -1) higher than that observed in seed-embryos coming from extracts having lower concentrations. However, in Murashige medium, the seed-embryos exhibited a enhanced growth and a relatively higher protein production (10.3×10 -2 mg protein mg wet wt. -1). Further, chlorophyll (a+b) synthesis was higher in Murashige medium than in meteoritic extracts but chlorophyll a/b ratio was <1 in all extracts and controls. Our results suggest the usefulness of the non-carbonaceous meteoritic resource as a complementary soil component or fertilizers for culture of edible plants in space settlements and mainly for the production of young plants due to the positive metabolic effects on the chlorophyll synthesis, mitochondrial metabolism and cellular division caused by PO 43-, Fe 2+, Cu 2+ and Ca 2+ ions. Earlier germination responses obtained in the present experiments demonstrated the possibility to utilize germination chambers in space having wet substrates containing meteoritic-powder solutions to obtain a higher number of seedlings in a minimum degree of time. These results also reveal the biological potential of this non-carbonaceous meteoritic matter for the growth of organisms in the early Earth, Mars, and probably in other planetary bodies beyond our Solar system.
Marcano, Vicente; Matheus, Paula; Cedeño, Cesyen; Falcon, Nelson; Palacios-Prü, Ernesto
The effects of sucrose on maturation and of plant growth regulators on germination of soybean somatic embryos were investigated for the purpose of developing an efficient culture method for plant recovery. Somatic embryos produced on medium with a low sucrose concentration (5 gl-1), less than 1 mm in length, 0.6 mg in fresh weight, and green in color, were grown
Takao Komatsuda; Wenbin Lee; Seibi Oka
The effect of a hydrocarbon mixture (HCM) of three polycyclic aromatic hydrocarbons (PAH) and Maya crude oil on germination, growth and survival of four grasses (Bouteloua curtipendula, Cenchrus ciliaris, Echinochloa crusgalli and Rhynchelytrum repens) was studied and compared to a control (Festuca arundinacea) under in vitro conditions. The species were cultured on MS medium with different HCM initial concentrations. Germination
L. Reynoso-Cuevas; M. E. Gallegos-Martínez; F. Cruz-Sosa; M. Gutiérrez-Rojas
Allenrolfea occidentalis, a perennial halophytic shrub in the family Chenopodiaceae is widely distributed in the inland salt marshes and salt playas of western United States. Experiments were conducted to determine the influence of compatible osmotica (betaine and proline) and growth regulators (gibberellic acid and kinetin) in alleviating salinity stress on the seed germination of A. occidentalis. Seed germination decreased with
BILQUEES GUL; M. AJMAL KHAN
Plants need to be included to develop a comprehensive toxicity profile for nanoparticles. Effects of five types of nanoparticles (multi-walled carbon nanotube, aluminum, alumina, zinc, and zinc oxide) on seed germination and root growth of six higher plant species (radish, rape, ryegrass, lettuce, corn, and cucumber) were investigated. Seed germination was not affected except for the inhibition of nanoscale zinc
Daohui Lin; Baoshan Xing
Shimizuomyces paradoxus showed no inhibitory effect against plant pathogen fungi, such as Fusarium oxysporum f. sp. lycopersici and Alternaria solani. The S. paradoxus culture filtrate showed higher seed germination and seedling growth rates in canola than distilled water and potato-dextrose broth. A conidial suspension of 1.0×10(4)/mL resulted in the highest growth stimulating effects on total plant length, and fresh and dry weight of shoots and roots in cucumber, when compared to the highest suspension concentration. Total plant length and shoot weight increased with the foliar spray treatment, and root length and root weight increased by simultaneous treatments of soil drenching and foliar spray in cucumber. Lower concentrations of the S. paradoxus conidial suspension increased the harvest of tomato fruit. PMID:22783066
Sung, Gi-Ho; Shrestha, Bhushan; Park, Ki-Byung; Han, Sang-Kuk; Sung, Jae-Mo
Seagrass meadows play an important role in marine ecosystems. A part of seagrass production is also exported to adjacent coastal terrestrial systems, possibly influencing their functioning. In this work we experimentally analyzed the effect of Posidonia oceanica beach-cast on plant germination, growth, and nutrient uptake of two plant species (Cakile maritima and Elymus farctus) that grow on upper beaches and fore dunes along the Mediterranean coasts. We compared plants growing in simple sand (control) with those growing in a substrate enriched with P. oceanica wrack (treatment) in laboratory. P. oceanica wrack doubled the N substrate pool and kept the substrate humid. Plants growing in the treated substrate grew faster, were twice as large as those growing in the control substrate, while tissues were enriched in N and P (Cakile by the 1.3 fold in N and 2.5 fold in P; Elymus by 1.5 fold in N and 2 fold in P). Our results suggest a positive effect of seagrass litter for the enhancing of dune species, highlighting its role for the conservation of coastal dune ecosystems. PMID:23894678
Del Vecchio, Silvia; Marbà, Núria; Acosta, Alicia; Vignolo, Clara; Traveset, Anna
Seagrass meadows play an important role in marine ecosystems. A part of seagrass production is also exported to adjacent coastal terrestrial systems, possibly influencing their functioning. In this work we experimentally analyzed the effect of Posidonia oceanica beach-cast on plant germination, growth, and nutrient uptake of two plant species (Cakile maritima and Elymus farctus) that grow on upper beaches and fore dunes along the Mediterranean coasts. We compared plants growing in simple sand (control) with those growing in a substrate enriched with P. oceanica wrack (treatment) in laboratory. P. oceanica wrack doubled the N substrate pool and kept the substrate humid. Plants growing in the treated substrate grew faster, were twice as large as those growing in the control substrate, while tissues were enriched in N and P (Cakile by the 1.3 fold in N and 2.5 fold in P; Elymus by 1.5 fold in N and 2 fold in P). Our results suggest a positive effect of seagrass litter for the enhancing of dune species, highlighting its role for the conservation of coastal dune ecosystems. PMID:23894678
Del Vecchio, Silvia; Marbà, Núria; Acosta, Alicia; Vignolo, Clara; Traveset, Anna
1. We examined the effect of soil organic content (1.4, 3.6, 7.2% soil C), water level (+2, -1, -4 cm from soil surface) and duration (13 or 33 days) on 10 species that varied in abundance during succession in freshwater marshes. We also determined the effect of shade (0, 40, 80% shade) and soil organic content (1.4 and 7.2% soil C) on germination of six species over 62 days with water 0.5 cm below the soil surface. 2. Water level consistently affected species germination on both dates. Above-ground biomass was generally higher with increasing organic content of soil, but shade had little effect on germination or height. 3 The hydrologic zone in which species were found in the field was a good indicator of the response of germination to hydrology. Both early successional species and species wide-spread across the successional gradient show similar germination on all organic contents, while later successional species appear to germinate best at higher organic contents. 4. Successional changes in soils are capable of affecting plant community development, independent of disturbance.
Kellogg, C.H.; Bridgham, S.D.; Leicht, S.A.
In perhaps the first-ever study of its kind, the effect of vermicompost, derived solely from an allelopathic weed, on the germination, growth, and yield of a botanical species, has been carried out. In test plots, the soil was treated with the vermicompost of lantana (Lantana camara) at the rates of 5, 7.5, and 10 t ha(-1), and cluster bean (Cyamopsis tetragonoloba) was grown on it. The performance of these systems was compared with the systems in which the soil was fortified with inorganic fertilizers (IFs) in concentrations equivalent to those present in the respective vermicompost (VC) treatments. Additionally, a set of control was studied in which the soil was used without fortification by either VC or IF. It was seen that up to 51.5 % greater germination success occurred in the VC treatments compared to controls. VC also supported better plant growth in terms of stem diameter, shoot length, shoot mass, number of leaves, and leaf pigments. The positive impact extended up to fruit yield. In addition, vermicast application enhanced root nodule formation, reduced disease incidence, and allowed for a smaller number of stunted plants. The results indicate that allelopathic ingredients of lantana seem to have been totally eliminated during the course of its vermicomposting and that lantana vermicompost has the potential to support germination, growth, and fruit yield better than equivalent quantities of IFs. PMID:24946699
Karthikeyan, M; Hussain, N; Gajalakshmi, S; Abbasi, S A
Bioassay experiments were used to assess the allelopathic potential of nodding thistle seeds on cumulative germination, speed of germination, and radicle elongation of five test species i.e., cocksfoot, perennial ryegrass, white clover, subterranean clover, and nodding thistle. Nodding thistle seeds inhibited germination of all species except subterranean clover in at least one of the bioassays used. Radicle elongation of all
D. A. Wardle; M. Ahmed; K. S. Nicholson
Mitochondria occupy a central role in the eukaryotic cell. In addition to being major sources of cellular energy, mitochondria are also involved in a diverse range of functions including signalling, the synthesis of many essential organic compounds and a role in programmed cell death. The active proliferation and differentiation of mitochondria is termed mitochondrial biogenesis and necessitates the coordinated communication of mitochondrial status within an integrated cellular network. Two models of mitochondrial biogenesis have been defined previously, the growth and division model and the maturation model. The former describes the growth and division of pre-existing mature organelles through a form of binary fission, while the latter describes the propagation of mitochondria from structurally and biochemically simple promitochondrial structures that upon appropriate stimuli, mature into fully functional mitochondria. In the last decade, a number of studies have utilised seed germination in plants as a platform for the examination of the processes occurring during mitochondrial biogenesis. These studies have revealed many new aspects of the tightly regulated procession of events that define mitochondrial biogenesis during this period of rapid development. A model for mitochondrial biogenesis that supports the maturation of mitochondria from promitochondrial structures has emerged, where mitochondrial signalling plays a crucial role in the early steps of seed germination. PMID:24727594
Law, Simon R; Narsai, Reena; Whelan, James
Four synthetic multiring analogs of strigol, a naturally occurring sesquiterpene lactone that promotes germination of dormant seeds ofStriga (witchweed), were found to stimulate germination of dormantLactuca (lettuce) seeds. The effects on light-sensitive and light-insensitive lettuce seeds were concentration-dependent and exceeded those produced by equimolar (0.1 mM) solutions of gibberellic acid. Strigol and epistrigol promoted lettuce seed germination to a lesser
Judith M. Bradow; William J. Connick; Armand B. Pepperman
Monoterpenes, the chemical constituents of essential oils found in plants, are known biologically active compounds. The present study was conducted to investigate the inhibitory effects of 30 monoterpenes including monoterpene hydrocarbons and oxygenated monoterpenes on seed germination and seedling growth of Amaranthus retroflexus, Chenopodium album and Rumex crispus under laboratory conditions. The monoterpenes were applied at contents of 10 and 20 microl for liquid compounds and 10 and 20 microg for solid compounds. The results show that most of the monoterpenes significantly inhibited seed germination and seedling growth of the tested plants. Oxygenated monoterpenes including beta-citronellol, nerol and terpinen-4-ol completely inhibited seed germination and seedling growth of all tested plants. Their inhibitory effects were also stronger than that of the herbicide 2,4-D. In general, monoterpenes were less effective against seed germination and seedling growth of C. album as compared with R. crispus and A. retroflexus. Phytotoxic effects of monoterpene hydrocarbons were found to be lower than those of oxygenated monoterpenes. The alcohol derivatives of oxygenated monoterpenes were also found to be more phytotoxic as compared with their acetate derivatives. Based on the present results, it can be concluded that the oxygenated monoterpenes can be used as potential bio-herbicides. PMID:17542486
Kordali, Saban; Cakir, Ahmet; Sutay, Sunay
In Vivo Cell Wall Loosening by Hydroxyl Radicals during Cress Seed Germination and Elongation, including seed germination, elongation growth, and fruit ripening. Here, we report direct in vivo evidence for hydroxyl radical (Ã?OH)-mediated cell wall loosening during plant seed germination and seedling growth. We
Embryos isolated from dormant apple seeds were treated with jasmonic acid (JA), gibberellin A3 (GA3), abscisic acid (ABA) and hydrogen cyanide in darkness and in light. The chemicals were present in the culture medium continuously and simultaneously or applied for 2 days and in different sequences. All treatments stimulated embryo germination except ABA, which was strongly inhibitory. Additive effects of
Rajiv Ranjan; Stanislaw Lewak
Environmental stressors such as salinity may affect plant germination and early growth, eventually impacting the distribution and abundance of more mature individuals. In a lab study we evaluated germination sensitivity to salinity in 13 tidal wetland species found in the Pacific...
Summary Wheat proembryos were excised 7 days after anthesis and germinated to normal fertile plants with an efficiency of 90%. These embryos had clearly differentiated shoot apical meristems and represent an interesting model system for studies of meristem biology. A combination of two media with different osmolarities allowed the continued development of the embryos before induction of germination. Normal germination occurred
Victor A. Iglesias; Andreas Gisel; Ingo Potrykus; Christof Sautter
Seeds from 10 prairie plant species of burned and unburned portions of three tallgrass prairies were collected and tested for germinability. Germination of big bluestem (Andropogon gerardii Vitman) consistently averaged higher with burning. Indiangrass (Sorghastrum nutans L.) and sideoats grama [Bouteloua curtipendula (Michx.) Torr.] averaged 5% higher with burning on two of the three sites, although for indiangrass average germination
Sherry R. Rohn; Thomas B. Bragg
The chemical interaction between plants, which is referred to as allelopathy, may result in the inhibition of plant growth and development. The objective of this research was to determine the impact of kenaf (Hibiscus cannabinus L.) plant extracts on the germination and post-germination development ...
Poor germination and seedling establishment are major problems in arid and semi-arid environments, and these characteristics are considered to be important factors in later plant growth and yield. Laboratory experiments were conducted on freshly harvested pyrethrum (Tanacetum cinerariifolium) seeds to investigate the effects of light (influenced by the seeding method) and seed hydropriming on germination, and shoot and root growth
J. Li; L. Y. Yin; M. A. Jongsma; C. Y. Wang
The phytotoxicity of 5 pharmaceuticals detected in Italian rivers, atorvastatin (7-[2-(4-fluorophenyl)-3-phenyl-4-(phenylcarbamoyl)-5-propan-2-yl-pyrrol-1-yl]-3,5-dihydroxy-heptanoic acid), gemfibrozil (5-(2,5-dimethylphenoxy)-2,2-dimethyl-pentanoic acid), tamoxifene (2-[4-(1,2-diphenylbut-1-enyl)phenoxy]-N,N-dimethyl-ethanamine), ethinyl estradiol (17-ethynyl-13-methyl-7,8,9,11, 12,13,14,15,16,17-decahydro-6H-cyclopenta[a]phenanthrene-3,17-diol) and sildenafil (methyl-9-propyl-2,4,7,8-tetrazabicyclo[4.3.0] nona-3,8,10-trien-5-one), has been assessed in a laboratory model. The treatment system consists of three main successive sections. The first one includes the phytotoxic evaluation of the single compounds on crops, Lactuca sativa (lettuce), Dacus carota subsp. sativa (carrot), and Lycopersicon esculentum (tomato), until the 10(-9) M, concentration lower then the environmental amounts. The second section includes the phytotoxicity assessment of all the selected chemicals on wild species, Avena fatua (wild oats), Amaranthus retroflexus (redroot pigweed), Lolium perenne (perennial ryegrass), Taraxacum officinale (common dandelion), and Chenopodium album (lambsquarter), at the same concentration as previously used. The third section of the procedure includes the evaluation of the effects of the five pharmaceuticals, at 1 microM and 1 nM environmental concentrations, on the metabolism of L. sativa. The variation of the composition of the photosynthetic pigments, sugars, lipids, phenols, fatty acids and flavonoids in lettuce seedlings exposed to the pollutants in respect to the blank was evaluated. The results of the phytotoxicity assays showed the possibility of a notable impact on the different vegetal communities and evidenced different sensitivity among cultivated and wild species, probably due to the different plant physiology. PMID:18205060
D'Abrosca, Brigida; Fiorentino, Antonio; Izzo, Angelina; Cefarelli, Giuseppe; Pascarella, Maria Teresa; Uzzo, Piera; Monaco, Pietro
Presented is one of a series of articles designed to help science teachers keep current on ideas in specific areas in biology. Contained is information on how plants use light for growth, seed germination, and flowering. (PB)
Kendrick, R. E.
Rhizoremediation is a complex type of green clean-up technology that involves both plants and the rhizosphere-associated microorganisms to decompose hazardous compounds. The success of the strategy strongly depends on plant tolerance towards the pollutant, as well as plant's interactions with the rhizospheric microbes. The microorganisms may be stimulated by the secreted root exudates, which results in an increased breakdown of contaminants in the rhizosphere. The main goal of this study was to establish a potential rhizoremediation combination for a diesel-polluted site. Inoculation of plant roots or seeds with indigenous rhizospheric populations is a common approach in the rhizoremediation. However, we introduced hydrocarbon-degrading consortia (M10, R3, and K52) that were previously isolated from crude oil-contaminated soil instead of indigenous microbes. Bioaugmentation with these petroleum degraders was applied to screen four high biomass crop species (Indian mustard, alfalfa, high erucic acid rapeseed, HEAR, and low erucic acid rapeseed, LEAR) for their tolerance towards diesel oil. At no pollution, a promoting effect of M10 bacteria could be observed on germination and root elongation of all plant species. Moreover, M10 consortiums increased the germination index at 6,000 mg diesel oil per kilogram dry soil in the case of Indian mustard, alfalfa, and HEAR. The latter species was found to increment its dry weight upon bioaugmentation with M10 bacteria and all diesel oil treatments (6,000 and 24,000 mg diesel oil per kilogram dry soil). The initial results indicate HEAR and the M10 bacterial consortium as a promising plant-microbe tandem for a long-term rhizoremediation process. PMID:24078757
Graj, Weronika; Lisiecki, Piotr; Szulc, Alicja; Chrzanowski, Lukasz; Wojtera-Kwiczor, Joanna
The decline of many arable weed species in Northern Europe has been attributed to the intensification of modern agriculture and in particular, increasing pesticide use. In this study, we examined the effect of two insecticides, dimethoate and deltamethrin, on the germination and seedling growth of six arable weed species. Although germination was unaffected by insecticide application, seedling growth of four species was decreased by exposure to deltamethrin (Capsella bursa-pastoris and Poa annua), dimethoate (Agrostemma githago), or by both insecticides together (Urtica urens). While increased herbicide use, seed cleaning, and changing sowing times may be of primary importance in explaining the reduction of northern Europe's arable weed flora, our results indicate that insecticide use may also be a contributory factor. Moreover, those species that exhibit apparent tolerance of the insecticides tested, particularly the grass Avena fatua, may benefit from continued insecticide use. The ability to tolerate these agrochemicals, in tandem with reduced herbivory and competition from plants, whose growth is reduced by insecticide application, is likely to confer a significant competitive advantage on insecticide-resistant weed species. PMID:16385742
Hanley, M E; Whiting, M D
The effects of maternal salinity and seed environment on germination and growth in Iris hexagona hexagona occupy saline habitats and plant performance is strongly impacted by salinity stress. We examined. hexagona by (1) growing plants in three different maternal salinity levels in a common garden, (2
Van Zandt, Peter
The effect of 100 ppm solution of each of kinetin, adenine, uracil and thymine on the vegetative and reproductive growth of Cucumis sativus, phaseolus mungo, Oryza sativus, Raphanus sativus and Lycopersicum esculentum plants were studied. The rate of vegetative growth was found to be more in the Cucumis sativus, Raphanus sativus and Lycopersicum esculentum plants treated with all the chemicals mentioned above over that of the controls. Phaseolus mungo and Oryza sativa plants shows almost the same growth rate with that of the control plants. So far the reproductive phase is concerned, measured as the size of fruit and number of fruit and seed, Cucumis sativus plants produced about same number of fruits in all the treatments but fruit size varied greatly along with the number of seeds in kinetin and adenine treated plants. PMID:22557413
Majumdar, A. K.; Boissya, C. L.
Seven plant species including three chenopods:Suaeda fruticosa, Kochia indica, Atriplex crassifolia and four grasses:Sporobolus arabicus, Cynodon dactylon, Polypogon monspeliensis, Desmostachya bipinnata, varied greatly in their seed germination and growth responses to soil moisture or salinity. The germination percentage of\\u000a each species was significantly lower at soil moisture level of 25 % of water holding capacity than at the levels ranging
K. Mahmood; K. A. Malik; M. A. K. Lodhi; K. H. Sheikh
Two complex physiological processes, with opposite positions in the plant's life-cycle, seed and pollen germination, are vital to the accomplishment of successful plant growth and reproduction. This review summarizes the current state of knowledge of the intersection of NO signalling with the signalling pathways of ABA, GA, and ethylene; plant hormones that control the release of plant seeds from dormancy and germination. The cross-talk of NO and ROS is involved in the light- and hormone-specific regulation of seeds' developmental processes during the initiation of plant ontogenesis. Similarly to seed germination, the mechanisms of plant pollen hydration, germination, tube growth, as well as pollen-stigma recognition are tightly linked to the proper adjustment of NO and ROS levels. The interaction of NO with ROS and secondary messengers such as Ca(2+), cAMP and cGMP discovered in pollen represent a common mechanism of NO signalling. The involvement of NO in both breakpoints of plant physiology, as well as in the germination of spores within fungi and oomycetes, points toward NO as a component of an evolutionary conserved signalling pathway. PMID:21893253
Šírová, Jana; Sedlá?ová, Michaela; Piterková, Jana; Luhová, Lenka; Pet?ivalský, Marek
Elemental allelopathy suggests that nickel (Ni)-rich leaves shed by hyperaccumulators inhibit the germination and growth of nearby plant species. Here, the germination of eight herbaceous species following addition of Alyssum murale biomass or Ni(NO3)2, with the same Ni level added to soil, was ass...
Plant volatile compounds have been shown to affect microbial growth and seed germination. Here two fruity volatiles found in strawberry ( Fragaria × ananassa ), ?-decalactone ("peachlike" aroma) and methyl anthranilate ("grapelike" aroma), were tested for effects on relevant pathogens and seedling emergence. Significant growth reduction was observed for Botrytis cinerea , Colletotrichum gloeosporioides , Colletotrichum acutatum , Phomopsis obscurans , and Gnomonia fragariae at 1 mM ?-decalactone or methyl anthranilate, and 5 mM ?-decalactone or methyl anthranilate supplemented medium resulted in complete cessation of fungal growth. Phytophthora cactorum was especially sensitive to 1 mM ?-decalactone, showing complete growth inhibition. Bacteriostatic effects were observed in Xanthamonas cultures. Postharvest infestations on store-bought strawberries were inhibited with volatile treatment. The ?-decalactone volatile inhibited strawberry and Arabidopsis thaliana germination. These findings show that two compounds contributing to strawberry flavor may also contribute to shelf life and suggest that ?-decalactone may play an ecological role by preventing premature germination. PMID:24328200
Chambers, Alan H; Evans, Shane Alan; Folta, Kevin M
Poor establishment of forage legumes may result when they are sown with annual grasses in mixtures. Our objective was to determine the importance of allelopathy as a mechanism of interference between seed germination and seedling growth. Laboratory studies were conducted using two grasses (donor plants): oat (Avena sativa L.) and Italian ryegrass (Lolium multiflorum Lam.) and five annual legumes (target
A simple, low-cost experimental system can be used to demonstrate the "in vivo" effects of barbituates on seed germination and seedling growth behavior in different plant species. Lipid solubility and concentration of individual barbituates both affect the response. List of materials needed, procedures used, and typical results obtained are…
Kordan, H. A.
With regards to importance and abundance of Amaranthus retroflexus weed in fields an experiment was conducted using CRD based factorial design with three replications to study the allelopathic effects of sorghum extracts on germination and growth of Amaranthus retroflexus in 2008-2009. Treatments were: harvesting stage of extracted sorghum (vegetative, flowering and seed filling stage), extracted plant part (leaf, stem, root
M. Yarnia; M. B. Khorshidi Benam; E. Farajzadeh Memari Tabrizi
Suaeda salsa, a leaf succulent shrub in the family Chenopodiaceae, is one of the most important halophytes in China. Suaeda salsa produces dimorphic seeds (soft brown seeds and hard black seeds). Seeds of S. salsa were collected from the coastal salt flats near Huanghua City, China. Experiments were conducted to determine the salinity-alleviating effect of plant growth regulators, nitric oxide,
Weiqiang LiXiaojing; Xiaojing Liu; M. Ajmal Khan; Shinjiro Yamaguchi
Several studies have indicated that pollen germination and tube growth are adversely affected by air pollutants. Pollutants may inhibit the function of pollen by reducing the number of pollen grains which germinate, by reducing the maximum length to which the pollen tubes grow, or by interfering with the formation of the generative cell. The paper reports on studies that are attempting to determine the effects acid rain may have on these crucial stages in the life histories of northeastern tree species. The first stage of this work assessed the effects of acidity in the growth medium on in vitro pollen germination for four deciduous forest species common to central New York State, Betula lutea (yellow birch), B. lenta (black birch), Acer saccharum (sugar maple), and Cornus florida (flowering dogwood). Measurements were taken at the end of the growth period to determine the percentage of grains which had germinated, and to estimate the average tube length. To determine the effects of pollen on the growth medium, the pH of the germination drop was measured at the end of the growth period.
Jacobson, J.S.; Van Rye, D.M.; Lassoie, J.P.
The effect of heavy metals (Cd, Cu, Pb, Zn) on seed germination and root growth in Pimpinella anisum L. (anise), Carum carvi L. (caraway), and Foeniculum vulgare L. (fennel) was evaluated on randomly selected samples of 50 seeds in three replicates from each of the plant species. Heavy metal test solutions were prepared from each metal at two concentrations, the
E. A. Jeliazkova; L. E. Craker
Background and aims The pollination to fertilization process (progamic phase) is thought to have become greatly abbreviated with the origin of flowering plants. In order to understand what developmental mechanisms enabled the speeding of fertilization, comparative data are needed from across the group, especially from early-divergent lineages. I studied the pollen germination process of Austrobaileya scandens, a perennial vine endemic to the Wet Tropics area of northeastern Queensland, Australia, and a member of the ancient angiosperm lineage, Austrobaileyales. Methodology I used in vivo and in vitro hand pollinations and timed collections to study development from late pollen maturation to just after germination. Then I compared the contribution of pollen germination timing to progamic phase duration in 131 angiosperm species (65 families). Principal findings Mature pollen of Austrobaileya was bicellular, starchless and moderately dehydrated—water content was 31.5 % by weight and volume increased by 57.9 % upon hydration. A callose layer in the inner intine appeared only after pollination. In vivo pollen germination followed a logarithmic curve, rising from 28 % at 1 hour after pollination (hap) to 97 % at 12 hap (R2 = 0.98). Sufficient pollen germination to fertilize all ovules was predicted to have occurred within 62 min. Across angiosperms, pollen germination ranged from 1 min to >60 h long and required 8.3 ± 9.8 % of the total duration of the progamic phase. Significance Pollen of Austrobaileya has many plesiomorphic features that are thought to prolong germination. Yet its germination is quite fast for species with desiccation-tolerant pollen (range: <1 to 60 h). Austrobaileya and other early-divergent angiosperms have relatively rapid pollen germination and short progamic phases, comparable to those of many insect-pollinated monocots and eudicots. These results suggest that both the pollen germination and pollen tube growth periods were marked by acceleration of developmental processes early in angiosperm history. PMID:22567221
Williams, Joseph H.
An axis clinostat was constructed to create micro and negative gravity also a rotated flat disk was constructed with different rotation rates to give increased gravity, by centrifugal force up to 48g. Rice seeds were grown on agar in tubes at the constant air temperature of 20 degC under an average light condition of 110 mumol/m^2/sec(PPF). Humidity was not controlled but was maintained above 90%. Since the tube containers were not large enough for long cultivation, shoot and root growth were observed every 12 hours until the sixth day from seeding. The lengths of shoots and roots for each individual plant were measured on the last day. The stem lengths were increased by microgravity but the root lengths were not. Under the negative gravity, negative orthogeotropism and under micro gravity, diageotropism was observed. No significant effect of increased gravity was observed on shoot and root growth.
Takakura, T.; Goto, E.; Tanaka, M.
Colonisation of plant roots by some arbuscular mycorrhizal (AM) fungi is reduced in the presence of sodium chloride (NaCl), probably due to a direct effect of NaCl on the fungi. However, there appear to be differences between the fungi in their ability to colonise plants in the presence of NaCl. This experiment tested the hypothesis that propagules of different isolates and species of AM fungi from saline and nonsaline soils would differ in their ability to germinate and grow in the presence of NaCl in the soil solution. Spores or pieces of root colonised by a range of AM fungi were incubated between filters buried in soil to which NaCl had been added at concentrations of 0, 150 or 300 mM in the soil solution. At regular intervals, filters were removed from the soil and both the percentage of propagules which had germinated and the length of proliferating hyphae were determined. Germination of spores of AM fungi studied was delayed in the presence of NaCl, but the fungi differed in the extent to which germination was inhibited. Two isolates of Scutellospora calospora reached maximum germination in 300 mM NaCl, but neither of two isolates of Acaulospora laevis germinated in the presence of NaCl. Germination of spores of the other fungi, including some isolated from saline soil, fell between these extremes. For some fungi, the specific rate of hyphal extension was reduced by NaCl. For others, the specific rate of growth was similar in the presence of NaCl to that in the control treatment, but overall production of hyphae was reduced in the NaCl treatments because germination was reduced. PMID:16525784
Juniper, S; Abbott, L K
Plant growth regulators, including auxin, gibberellin, cytokinin, abscisic acid, and ethylene, are investigated in this learning activity to demonstrate how these chemicals (hormones) affect plant growth and development.
This page authored by Jim Bidlack, University of Central Oklahoma, based on original activities by Long Ashton Research Station, KScience, Cynthia Herbrandson, Kellogg Community College, Ross Koning, Eastern Connecticut State University, and A.G. Scientific, Inc.
Recent evidence associates the persistence of invasive plant species with disturbance and fluctuations in distinct forms of mineral N in soils. We conducted soil and hydroponic experi- ments to investigate the influence of N form and availability on germination and seedling development of 2 invasive annual grasses, cheatgrass (Bromus tectorum) and medusahead (Taeniatherum caput-medusae) and 6 perennial grasses, blue- bunch
THOMAS A. MONACO; CHARLES T. MACKOWN; DOUGLAS A. JOHNSON; THOMAS A. JONES; JEANETTE M. NORTON; JAY B. NORTON; MARGARET G. REDINBAUGH
This study investigated the effect of cold helium plasma treatment on seed germination, growth and yield of wheat. The effects of different power of cold plasma on the germination of treated wheat seeds were studied. We found that the treatment of 80 W could significantly improve seed germination potential (6.0%) and germination rate (6.7%) compared to the control group. Field experiments were carried out for wheat seeds treated with 80 W cold plasma. Compared with the control, plant height (20.3%), root length (9.0%) and fresh weight (21.8%) were improved significantly at seedling stage. At booting stage, plant height, root length, fresh weight, stem diameter, leaf area and leaf thickness of the treated plant were respectively increased by 21.8%, 11.0%, 7.0%, 9.0%, 13.0% and 25.5%. At the same time, the chlorophyll content (9.8%), nitrogen (10.0%) and moisture content (10.0%) were higher than those of the control, indicating that cold plasma treatment could promote the growth of wheat. The yield of treated wheat was 7.55 t · ha-1, 5.89% more than that of the control. Therefore, our results show that cold plasma has important application prospects for increasing wheat yield.
Jiang, Jiafeng; He, Xin; Li, Ling; Li, Jiangang; Shao, Hanliang; Xu, Qilai; Ye, Renhong; Dong, Yuanhua
More than thirty rhizobacterial isolates from two ecologically important plant species of Thar Desert were evaluated for their plant growth promontory effects in terms of seed germination, shoot and root length elongation and total biomass production. Isolates T-1 from Calligonum polygonoides and TS-2 from Lasiurus sindicus respectively were observed as effective seed germination inducers. Up to 37.5% increase over control
R. K. Gothwal; V. K. Nigam; M. K. Mohan; D. Sasmal; P. Ghosh
\\u000a Parasitic plants are among the most problematic pests of agricultural crops worldwide. Effective means of control are generally\\u000a lacking, in part because of the close physiological connection between the established parasite and host plant hindering efficient\\u000a control using traditional methods. Seed germination and host location are critical early-growth stages that occur prior to\\u000a host attachment, and provide promising targets for
Justin B. Runyon; John F. Tooker; Mark C. Mescher; Consuelo M. De Moraes
To characterize and dissect genetic variation for salinity tolerance, we assessed variation in salinity tolerance during germination and seedling growth for a worldwide sample of Arabidopsis thaliana accessions. By combining QTL mapping, association mapping and expression data, we identified genomic regions involved in salinity response. Among the worldwide sample, we found germination ability within a moderately saline environment (150 mM NaCl) varied considerable, from >90% among the most tolerant lines to complete inability to germinate among the most susceptible. Our results also demonstrated wide variation in salinity tolerance within A. thaliana RIL populations and identified multiple genomic regions that contribute to this variation. These regions contain known candidate genes, but at least four of the regions contain loci not yet associated with salinity tolerance response phenotypes. Our observations suggest A. thaliana natural variation may be an underutilized resource for investigating salinity stress response. PMID:21857956
DeRose-Wilson, Leah; Gaut, Brandon S.
Switchgrass is a perennial C4 plant with great potential as a bioenergy source and, thus, a high demand for establishment from seed. This research investigated the effects of ultrasound treatment on germination and seedling growth in switchgrass. Using an orthogonal matrix design, conditions for the ultrasound pretreatment in switchgrass seed, including sonication time (factor A), sonication temperature (factor B) and ultrasound output power (factor C), were optimized for germinating and stimulating seedling growth (indicated as plumular and radicular lengths) through modeling analysis. The results indicate that sonication temperature (B) was the most effective factor for germination, whereas output power (C) had the largest effect on seedling growth when ultrasound treatment was used. Combined with the analyses of range, variance and models, the final optimal ultrasonic treatment conditions were sonication for 22.5 min at 39.7°C and at an output power of 348 W, which provided the greatest germination percentage and best seedling growth. For this study, the orthogonal matrix design was an efficient method for optimizing the conditions of ultrasound seed treatment on switchgrass. The electrical conductivity of seed leachates in three experimental groups (control, soaked in water only, and ultrasound treatment) was determined to investigate the effects of ultrasound on seeds and eliminate the effect of water in the ultrasound treatments. The results showed that the electrical conductivity of seed leachates during either ultrasound treatment or water bath treatment was significantly higher than that of the control, and that the ultrasound treatment had positive effects on switchgrass seeds. PMID:23071756
Wang, Quanzhen; Chen, Guo; Yersaiyiti, Hayixia; Liu, Yuan; Cui, Jian; Wu, Chunhui; Zhang, Yunwei; He, Xueqing
In this study we describe the selection and characterization of barnyard grass (Echinochloa crusgalli L.) mutants (fows B) with vegetative salt tolerance as compared to a previously described mutant with salt tolerant germination (fows A3). Salt tolerance of both types of mutants was characterized in two distinctive stages of plant development, germination\\u000a and vegetative growth. About 46% of fows A3
Gaber M. AbogadallahMamdouh; Mamdouh M. Serag; Taha M. El-Katouny; W. Paul Quick
Genetic variation in plant response to atmospheric carbon dioxide (CO2) may have influenced paleo-vegetation dynamics and could determine how future elevated CO2 drives plant evolution and ecosystem productivity. We established how levels of relatedness - the maternal family, population, and provenance - affect variation in the CO2 response of a species. This 2-year growth chamber experiment focused on the germination,
JACQUELINE E. M OHAN; J AMES S. C LARK
Suppressant foams used to fight forest fires may leave residual effects on surviving biota that managers need to consider prior to using them. We examined how three fire-suppressant foams (FSFs) (Forexpan S, Phos-Chek-WD881, and Silv-ex) affected seed germination and physiological responses of three plant species. Exposure to FSFs, whether in diluted concentrations or those typical in the field, reduced final germination percentages of seeds grown in petri dishes and within growth chambers. However, the FSFs did not cause total germination failure in any treatment. Inhibition of germination increased with longer exposure times, but only to diluted FSF solutions. Unlike in the laboratory experiments, none of the three FSFs affected seedling emergence when tested in field conditions. Further, we found no evidence of long-term phytotoxic effects on antioxidant enzyme activity nor chlorophyll content of the plant saplings. Therefore, although the three FSFs showed evidence of phytotoxicity to plants in laboratory tests, their actual impact on terrestrial ecosystems may be minimal. We suggest that the benefits of using these FSFs to protect plants in threatened forest ecosystems outweigh their minor risks.
Song, Uhram; Mun, Saeromi; Waldman, Bruce; Lee, Eun Ju
The impact of a variable magnetic field, magnetically treated water and a combination of both these factors on the germination of seeds and the final mass at the initial stage of growth sunflower plants was presented. Investigations were carried out in pots filled with sand, tin an air-conditioned plant house with no access to daylight using fluorescent light as illumination. A statistical significance positive impact was achieved for the samples subjected to the interaction of both stimulating factors simultaneously, the magnetic field and the impact of treated water several times on the speed of seed germination and final plant mass. Negative impacts were obtained for the majority of the test cases, for the magnetically treated water, the short duration of activity of the magnetic field and for the connection of the magnetic field and low-flow times.
Matwijczuk, A.; Kornarzy?ski, K.; Pietruszewski, S.
Using low power continuous wave He–Ne laser irradiation of seeds, the germination characteristics, thermodynamic changes and enzyme activities as well as changes in morphological attributes were explored for wheat (Triticum aestivum L. cv. S-24) cultivar. The changes in thermodynamic properties such as change in enthalpy (?H), entropy generation [(?Se)], entropy flux [(?Sc)], entropy generation ratio [(?S)e/?t], and entropy flux ratio [(?S)c/?t] showed significant (P < 0.05) changes at an energy level of 500 mJ. The germination energy (GE), germination percentage (G%), germination index (GI) as well as ?-amylase and protease activities was also found to be higher at 500 mJ, while the mean emergence time (MET) and time for 50% germination (E50) decreased for 300 mJ irradiance. The internal energy of the seeds increased significantly at all laser energy levels, but was highest for 500 mJ 72 h after sowing. The enzyme activities increased up to 24 h after sowing and then declined. The activities of ?-amylase and protease were found to be positively correlated with the plant physiological attributes. These results indicate that low power continuous wave He–Ne laser (632 nm) treatment has considerable biological effects on seed metabolism during germination as well as on later vegetative growth.
Jamil, Yasir; Perveen, Rashida; Ashraf, Muhammad; Ali, Qasim; Iqbal, Munawar; Ahmad, Muhammad Raza
Rice is characterized by a broad range of metabolic and morphological adaptations to flooding, such as germination and mobilization of stored nutrients under submergence until seedlings reach the water surface to carry out photosynthesis, and sustainable growth of mature plants for long durations under partial submergence. The underlying mechanisms of the molecular basis of adaptation to anaerobic germination and seedling growth in rice are being uncovered. Induction of an ensemble of hydrolases to mobilize endosperm nutrient reserves is one of the key factors for successful germination and coleoptile elongation in rice under submergence. To compensate for reduced efficiency of Tricarboxylic Acid cycle and oxidative respiration in mitochondria under O2 deficient conditions, ?-amylases play a central role in the hydrolysis of starch to provide sugar substrates for glycolysis and alcohol fermentation for generating ATP. We review the progress on the molecular mechanism regulating ?-amylase expression that involves the integration of signals generated by the hormone gibberellin (GA), sugar starvation and O2 deprivation that results in germination and sustainable seedling growth in rice under anaerobic conditions. Comparisons are also made between dicots and monocots for the molecular mechanism of induction of genes involved in alcohol fermentation and sugar/O2 deficiency sensing system. PMID:24575721
Lee, Kuo-Wei; Chen, Peng Wen; Yu, Su-May
The plant cell wall is a dynamic structure whose constant modification is necessary for plant cells to grow and divide. In the cell walls of chickpea (Cicer arietinum) there are at least four ?-galactosidases, whose presence and location in embryonic axes during the first 48 h of seed imbibition are discussed in this paper. We examined their roles as cell wall-modifying enzymes in germinative and/or post-germinative events. At the start of germination, only ?V-Gal, and to a lesser extent ?IV-Gal, appear in the axes before rupture of the testa, suggesting they are related to germination sensu stricto. Once the testa has broken, the four ?-galactosidases are involved in growth and differentiation of the axes. Immunolocation of the different proteins in axes, which in part confirms previous results in seedlings and plants, allows assignment of post-germinative roles to ?I-Gal and ?III-Gal as cell wall modifiers in vascular tissue elements. ?IV-Gal and ?V-Gal participate in the initial events of germination in which cell walls are involved: ?V-Gal in cell proliferation, detachment of root cap cells and initial vascular tissue differentiation; both of them in xylem maturation; and ?IV-Gal in thickening of the primary cell wall. Together with other cell wall-modifying enzymes, such as expansins and XTH, chickpea galactosidases might function in a sequential order in turnover of the primary cell wall, allowing the elongation of embryonic axes during seed germination. PMID:23731125
Hernández-Nistal, J; Martín, I; Dopico, B; Labrador, E
BTF3 has been recognized to be involved in plant growth and development. But its function remains mostly unknown during seed germination and seedling stage. Here, we have analyzed OsBTF3-related sequences in Oryza sativa L. subspecies, japonica, which resembles with the conserved domain of a nascent polypeptide associated complex (NAC) with different homologs of OsBTF3 and human BTF3. Inhibition of Osj10gBTF3 has led to considerable morphological changes during seed germination and seedling growth. Germination percentage was not influenced by the application of GA3, ABA, and NaCl but all concentrations caused wild-type (WT) seeds to germinate more rapidly than the RNAi (Osj10gBTF3Ri) transgenic lines. Seedling inhibition was more severe in the Osj10gBTF3Ri seedlings compared with their WT especially when treated with 100 or 200??M GA3; 50% reduction in shoots was observed in Osj10gBTF3Ri seedlings. The expression of Osj3g1BTF3, Osj3g2BTF3 and Osj10gBTF3 was primarily constitutive and generally modulated by NaCl, ABA, and GA3 stresses in both Osj10gBTF3Ri lines and WT at the early seedling stage, suggesting that Osj3g1BTF3 and Osj10gBTF3 are much similar but different from Osj3g2BTF3 in biological function. These results show that OsBTF3 plays an important role in seed germination and seedling growth gives a new perception demonstrating that more multifaceted regulatory functions are linked with BTF3 in plants. PMID:24971328
Wang, Wenyi; Xu, Mengyun; Wang, Ya
Effects of cold plasma treatment on soybean (Glycine max L. Merr cv. Zhongdou 40) seed germination and seedling growth were studied. Seeds were pre-treated with 0, 60, 80, 100 and 120?W of cold plasma for 15?s. Results showed that plasma treatments had positive effects on seed germination and seedling growth, and treatment of 80?W had the highest stimulatory effect. Germination and vigor indices significantly increased by 14.66% and 63.33%, respectively. Seed's water uptake improved by 14.03%, and apparent contact angle decreased by 26.19%. Characteristics of seedling growth, including shoot length, shoot dry weight, root length and root dry weight, significantly increased by 13.77%, 21.95%, 21.42% and 27.51%, respectively, compared with control. The seed reserve utilization, including weight of the mobilized seed reserve, seed reserve depletion percentage and seed reserve utilization efficiency significantly improved by cold plasma treatment. In addition, soluble sugar and protein contents were 16.51% and 25.08% higher than those of the control. Compared to a 21.95% increase in shoot weight, the root weight increased by 27.51% after treatment, indicating that plasma treatment had a greater stimulatory effect on plant roots. These results indicated that cold plasma treatment might promote the growth even yield of soybean. PMID:25080862
Ling, Li; Jiafeng, Jiang; Jiangang, Li; Minchong, Shen; Xin, He; Hanliang, Shao; Yuanhua, Dong
Effects of cold plasma treatment on soybean (Glycine max L. Merr cv. Zhongdou 40) seed germination and seedling growth were studied. Seeds were pre-treated with 0, 60, 80, 100 and 120 W of cold plasma for 15 s. Results showed that plasma treatments had positive effects on seed germination and seedling growth, and treatment of 80 W had the highest stimulatory effect. Germination and vigor indices significantly increased by 14.66% and 63.33%, respectively. Seed's water uptake improved by 14.03%, and apparent contact angle decreased by 26.19%. Characteristics of seedling growth, including shoot length, shoot dry weight, root length and root dry weight, significantly increased by 13.77%, 21.95%, 21.42% and 27.51%, respectively, compared with control. The seed reserve utilization, including weight of the mobilized seed reserve, seed reserve depletion percentage and seed reserve utilization efficiency significantly improved by cold plasma treatment. In addition, soluble sugar and protein contents were 16.51% and 25.08% higher than those of the control. Compared to a 21.95% increase in shoot weight, the root weight increased by 27.51% after treatment, indicating that plasma treatment had a greater stimulatory effect on plant roots. These results indicated that cold plasma treatment might promote the growth even yield of soybean.
Ling, Li; Jiafeng, Jiang; Jiangang, Li; Minchong, Shen; Xin, He; Hanliang, Shao; Yuanhua, Dong
Effects of cold plasma treatment on soybean (Glycine max L. Merr cv. Zhongdou 40) seed germination and seedling growth were studied. Seeds were pre-treated with 0, 60, 80, 100 and 120 W of cold plasma for 15 s. Results showed that plasma treatments had positive effects on seed germination and seedling growth, and treatment of 80 W had the highest stimulatory effect. Germination and vigor indices significantly increased by 14.66% and 63.33%, respectively. Seed's water uptake improved by 14.03%, and apparent contact angle decreased by 26.19%. Characteristics of seedling growth, including shoot length, shoot dry weight, root length and root dry weight, significantly increased by 13.77%, 21.95%, 21.42% and 27.51%, respectively, compared with control. The seed reserve utilization, including weight of the mobilized seed reserve, seed reserve depletion percentage and seed reserve utilization efficiency significantly improved by cold plasma treatment. In addition, soluble sugar and protein contents were 16.51% and 25.08% higher than those of the control. Compared to a 21.95% increase in shoot weight, the root weight increased by 27.51% after treatment, indicating that plasma treatment had a greater stimulatory effect on plant roots. These results indicated that cold plasma treatment might promote the growth even yield of soybean. PMID:25080862
Ling, Li; Jiafeng, Jiang; Jiangang, Li; Minchong, Shen; Xin, He; Hanliang, Shao; Yuanhua, Dong
As one of the most severe pollutants, cadmium has been reported to be harmful to plant cells, but the effects of cadmium on gymnosperm pollen germination and tube growth and the mechanism of this involvement are still unclear. Here, we report that cadmium not only strongly inhibited P. wilsonii pollen germination and tube growth, but also significantly altered tube morphology in a dose-dependent manner. Time-lapse images obtained with a laser scanning confocal microscope revealed that endocytosis was dramatically inhibited by cadmium stress. Further investigation with ER-Tracker dye indicated that cadmium stress reduced the number of the Golgi apparatus, and induced dilation of ER. Additionally, Lyso-Tracker staining showed that cadmium distinctly promoted the formation of acidic organelles in pollen tubes, likely derived from the dilated ER. Taken together, our studies indicated that P. wilsonii pollens were highly susceptible to cadmium stress, and that cadmium stress strongly inhibited pollen germination and tube growth by disrupting the endomembrane organelles, inhibiting endo/exocytosis, and forming acidic vacuoles, resulting in swollen tube tips and irregularly broadened tube diameters. These findings provide a new insight into the effects of cadmium toxicity on the tip growth of pollen tubes. PMID:24722362
Feng, Yu; Li, Xue; Wei, Qian; Sheng, Xianyong
\\u000a Numerous Bacillus strains have been investigated for their capacities to protect plants from pathogens and stimulate plant growth. Studying\\u000a the diversity of these bacteria provides clues to the distinctiveness of beneficial strains and raises questions regarding\\u000a the scale and evolutionary forces that led to the development of biocontrol activities. Soils harbor vast spore banks of Bacillus, subsets of which germinate,
Brian B. McSpadden Gardener
Describes the effect of "plant growth regulators" on plants, such as controlling the flowering, fruit development, plant size, and increasing crop yields. Provides a list of plant growth regulators which includes their chemical, common, and trade names, as well as their different use(s). (GA)
Nickell, Louis G.
, retention time, and germination for the seeds of 10 wetland plant species (Chenopodium album, Digitaria and fed each seed species in each trial, and included germination controls of non-consumed seeds. Overall, 19.0 6 1.8% (mean 6 SE) of seeds were recovered and of recovered seeds 7.6 6 1.2% germinated
In this study, we investigated the effect of light regimen (white light vs. darkness) on the germination of 12 species of the Echinopsis genus (tribe Trichocereeae, Cactaceae). This genus presents a variety of growth forms and relatively small and uniform seed size. These traits allowed us to test, within the same linage and removing seed mass effect, the hypothesis that the germination response to light (indifferent to light or positive photoblastic) is related to growth form. Our results reject this hypothesis since no seeds germinated in darkness, so all of the species can be classified as being positively photoblastic. The proportion of seed germination with white light was significantly different among cactus growth forms. Columnar cacti (arborescent, creeping and short) showed a greater proportion of seed germination than barrel and globose cacti. The germination rate differed among growth forms and species. At constant temperatures, creeping columnar cacti presented a significantly higher germination rate than the other growth forms. With alternating temperatures, columnar cacti showed higher germination rates than the other growth forms. The low proportion of seeds that germinated for some species indicates that they show seed dormancy. Our results suggest that germination responses to light in the cactus family could be related to seed mass and phylogenetic constraints.
Ortega-Baes, Pablo; Aparicio-González, Mónica; Galíndez, Guadalupe; del Fueyo, Patricia; Sühring, Silvia; Rojas-Aréchiga, Mariana
In order to study the adaptation ability of sweet sorghum (Sorghum bicolor L. Moench) in the Yellow River Delta, the sweet sorghum variety Mart was used in this study to determine the roles of different saline-alkaline ratio stress treatment during seed germination to seedling stage. The results showed that Na+ concentration had a significant impact on the seed germination, seedling growth, and plant survival of sweet sorghum. Increasing Na+ concentration led to a decline in germination rate, final germination percentage, survival percentage, plant height, and dry weight per plant, a prolonged mean time of germination, as well as loss of improvement effect of low-Na+ concentration. The interaction effect of Na+ concentration and pH on the mean time of germination and germination rate was not significant (p<0.05). However, under the condition of low-Na+ concentration (100 mM), high pH reduced the mean time of germination and increased the germination rate, without decline in final germination percentage and survival percentage. Therefore, at least in the duration of seed germination to the harvest period in the research, the sweet sorghum was resistant to the pH stress (?9.04) when the Na+ concentration was below 100 mM. When suffered from the saline-alkaline stress, the seedling of sweet sorghum was characterized by ecological adaptive features, such as decreased stem ratio and chlorophyll b content in leaves and increased root ratio and chlorophyll a content, in order to maintain the uptakes of water and nutrient, and carbon assimilation. When the stress intensified, the lipid oxidation products, e.g., malondialdehyde (MDA), increased in sweet sorghum seedlings. However, the increasing of soluble protein content and antioxidant enzyme activity (superoxide dismutase (SOD), guaiacol peroxidase (POD), and gatalase (CAT)) was only founded in neutral low-Na+ concentration treatment (A1), which indicated that high-salt concentration and pH all elicited harmful effects and limited the self-healing ability of sweet sorghum seedlings. In all, in order to grow sweet sorghum in the saline-alkaline soils of the Yellow River Delta, the salt concentration and pH value of the soil must be taken into consideration, and seeding density should be increased and supported by appropriate irrigation measures to reduce saline-alkaline stress so as to ensure the survival and growth of sweet sorghum seedlings. PMID:24840039
Zhao, Yanyun; Lu, Zhaohua; He, Lei
Taking normal corn, waxy corn, pop corn, and sweet corn as test materials, this paper studied their seed germination and seedling growth under effects of simulated acid rain (pH 6.0, 5.0, 4.0, 3.0, 2.0, and 1.0). Simulated acid rain at pH 2.0-5.0 had no significant effects on the seed germination and seedling growth, but at pH 1.0, the germination rate of normal corn, waxy corn, pop corn, and sweet corn was 91.3%, 68.7%, 27.5%, and 11.7%, respectively. As compared with those at pH 6.0 (CK), the germination rate, germination index, vigor index, germination velocity, shoot height, root length, shoot and root dry mass, and the transformation rate of stored substances at pH 1.0 had significant decrease, and the average germination time extended apparently. At pH 1.0, the effects of acid rain were greater at seedling growth stage than at germination stage, and greater on underground part than on aboveground part. Due to the differences in gene type, normal corn and waxy corn had the strongest capability against acid rain, followed by pop corn, and sweet corn. It was suggested that corn could be categorized as an acid rain-tolerant crop, the injury threshold value of acid rain was likely between pH 1.0 and pH 2.0, and normal corn and waxy corn would be prioritized for planting in acid rain-stricken area. PMID:24066549
The Differential Effect of Synthetic Plant Growth Substances and other Compounds upon Plant Species. I. Seed Germination and Early Growth Responses to alpha -Naphthylacetic Acid and Compounds of the General Formula arylOCH2COOR
Laboratory and small-scale experiments in soil are described in which alpha -naphthylacetic acid in solution, incorporated dry in fine sand and in ammonium sulphate, has been applied to oats (Avena sativa L.) and yellow charlock (Brassica Sinapis Visiani) at seed sowing and during early growth stages. Concentrations which kill the charlock leave the oats unharmed. Details are given of other
W. G. Templeman; W. A. Sexton
Spore germination and vegetative growth of Clostridium botulinum type E strain VH at 2 to 50 degrees C were studied. At all of these temperatures, germination began immediately after the addition of the spores to the germination medium. Microscopic observations during germination revealed three types of spores: phase bright (ungerminated), phase variable (partially germinated), and phase dark (fully germinated). At all temperatures except 50 degrees C, there was a pronounced lag between the initial appearance of phase-variable spores and their eventual conversion to phase-dark spores. The number of partially germinated spores increased steadily, reaching 40 to 60% by 18 to 21 h of incubation. During this time, phase-dark, fully germinated spores developed slowly and did not exceed 28% in any of the samples. At 18 to 26 h of incubation, the rate of full germination increased abruptly four-fold. There was extensive and relatively rapid germination at 2 degrees C, the lowest temperature tested, yielding about 60% phase-variable spores by 18 h, which became phase-dark by 26 h of incubation. The optimum temperature for partial and full germination was consistently 9 degrees C. Germination at 50 degrees C was exceptionally rapid and was completed within 1 to 2 h, although 40% remained phase bright. Vegetative cells showed detectable growth at 6 to 41 degrees C, with a distinct optimum at 32.5 degrees C. No growth occurred at 50 degrees C, and only marginal growth was observed at 6 to 14 degrees C. The psychrophilic nature of the germination process coupled with the cold tolerance of vegetative growth appears to give C. botulinum type E an advantage in cold climates as well as in cold-stored foods. PMID:7036898
Grecz, N; Arvay, L H
The allelopathic effects of aqueous extracts from sorghum stem and rice husks were examined on the germination and growth of maize. The extracts brought about considerable inhibitions in the germination of maize seeds and in the growth of radical and plumule. In both extracts, the degree of inhibition increased with the increase in the concentrations of the extracts thus suggesting
J. Kayode; J. M. Ayeni
The effect of salt and drought stress at the water potentials of-2, -4,-6and -8 bars induced by NaCl and PEG 6000 (Polyethylene glycol 6000) each, on germination and early seedling growth, were investigated for two varieties (PU-19 and Type-9). Electrical conductivity (EC) value of the NaCl solutions were 4.5, 8.8, 12.7 and 16.3 dS m(-1). Germination percentage, root and shoot length, and seedling fresh and dry weight were measured in the study. The objective was to determine genotypic differences among P. mungo varieties in terms of salt and drought stress and to determine factors (salt toxicity or osmotic stress due to PEG) inhibiting seed germination. The germination results revealed that the genotypes significantly differed for salt and drought stress. PU-19 appeared to be more tolerant to salt and drought stress comparable to var Type-9. Both NaCl and PEG inhibited germination and seedling growth in both the varieties, but the effects of NaCI compared to PEG was less on germination and seedling growth. All varieties were able to germinate at all NaCl levels without significant decrease in germination, while a drastic decrease in germination was recorded at -6 and -8 bars of PEG. It was concluded that inhibition in germination at equivalent water potential of NaCl and PEG was mainly due to an osmotic effect rather than salt toxicity. PMID:21046993
Summary. The effect of osmotic stress on germination, growth and soluble sugar content in Sorghum bicolor (L.) Moench cv. CSH 9 seeds and seedling components (endosperm and embryos) during early germination was inves- tigated. Under stress conditions germination decreased markedly, whereas the control at the same time reached its maximum germination (99%). A high percentage (67%) of ungerminated seeds from
Prabhjot Kaur Gill; Arun Dev Sharma; Prabhjeet Singh; Sukdev Singh Bhullar
The relative susceptibility of 30 cultivars of lettuce to inhibition by aflatoxin was studied. Seed germination was not inhibited by concentrations as high as 1,000 ?g/ml in cultivar Imperial 44 or by 100 ?g/ml in the remaining cultivars. Hypocotyl elongation was inhibited by 46 to 68% at a concentration of 100 ?g of aflatoxin per ml. Seedlings exposed to aflatoxin did not become chlorotic. The similarity between the morphological reaction of plants to coumarin and aflatoxin suggests a common mode of action, but further studies of the physiological basis for the inhibitory reactions induced by these compounds will be necessary before such conclusions will be valid. PMID:4698861
Crisan, Eli V.
Six plant species (Siberian and thickspike wheatgrass, cheatgrass, sand dropseed, Indian ricegrass, and Russian thistle) found on the Hanford Site were studied as part of an investigation into the revegetation of disturbed areas. Germination response to three environmental parameters (soil moisture, soil temperature, and planting depth) were measured. Results indicated that when a polyethylene glycol solution was used to control the osmotic potential of the imbibition media, no significant decrease in germination rate occurred down to -3.0 bars. However, below -7.0 bars all species experienced a decrease in germination. When germinated in soil, all species except Russian thistle exhibited a significant decrease in germination rate at -0.3 bars. Russian thistle was the only species tested that exhibited germination at a soil temperature of 1/sup 0/C. All species gave optimum germination at temperatures between 10 and 15/sup 0/C. Thickspike wheatgrass was the only species tested which was able to germinate and emerge from a planting depth of greater than 2 inches. If supplemental moisture is provided, a shallow planting would be advisable for those species tested. If not overcome by pretreatment prior to planting, seed dormancy may be a significant factor which will reduce the germination potential of some species tested.
Cox, G.R.; Kirkham, R.R.; Cline, J.F.
Nine Prunus accessions were evaluated for germination and plantlet growth in an in vitro osmotic screening test using mannitol\\u000a as an osmoticum. Embryos from diverse peaches, almonds and peach-almond hybrids were cultured in Woody Plant Medium, and in\\u000a this same medium modified with the inclusion of 350 mM mannitol. Embryos were stratified in vitro for 60 days, induced to\\u000a germinate
Craig A. Ledbetter; Debra E. Palmquist; Sharon J. Peterson
Distillery effluent or spent wash discharged as waste water contains various toxic chemicals that can contaminate water and soil and may affect the common crops if used for agricultural irrigation. Toxic nature of distillery effluent is due to the presence of high amounts of organic and inorganic chemical loads and its high-acidic pH. Experimental effects of untreated (Raw) distillery effluent, discharged from a distillery unit (based on fermentation of alcohol from sugarcane molasses), and the post-treatment effluent from the outlet of conventional anaerobic treatment plant (Treated effluent) of the distillery unit were studied in mung bean (Vigna radiata, L.R. Wilczek). Mung bean is a commonly used legume crop in India and its neighboring countries. Mung bean seeds were presoaked for 6h and 30 h, respectively, in different concentrations (5-20%, v/v) of each effluent and germination, growth characters, and seedling membrane enzymes and constituents were investigated. Results revealed that the leaching of carbohydrates and proteins (solute efflux) were much higher in case of untreated effluent and were also dependent to the presoaking time. Other germination characters including percentage of germination, speed of germination index, vigor index and length of root and embryonic axis revealed significant concentration-dependent decline in untreated effluent. Evaluation of seedlings membrane transport enzymes and structural constituents (hexose, sialic acid and phospholipids) following 6 h presoaking of seeds revealed concentration-dependent decline, which were much less in treated effluent as compared to the untreated effluent. Treated effluent up to 10% (v/v) concentration reflected low-observed adverse effect levels. PMID:17928137
Kannan, A; Upreti, Raj K
Most of the northeastern hardwood forests in North America are exposed repeatedly to acidic rainfall at pH values below 5.0. Pollen germination, tube growth and fertilization, important parts of the reproductive process, are sensitive to changes in their chemical environment. Accordingly, the authors investigated the effects of acidity on pollen germination and tube elongation of four northeastern tree species: flowering
D. M. Van Ryn; J. S. Jacobson
The COP9 signalosome (CSN) is an evolutionarily conserved multiprotein complex with an essential role in the development of higher eukaryotes. CSN deconjugates the ubiquitin-related modifier NEDD8 from the cullin subunit of cullin-RING type E3 ubiquitin ligases (CRLs), and CSN-mediated cullin deneddylation is required for full CRL activity. Although several plant E3 CRL functions have been shown to be compromised in Arabidopsis csn mutants, none of these functions have so far been shown to limit growth in these mutants. Here, we examine the role of CSN in the context of the E3 ubiquitin ligase SCF(SLEEPY1 (SLY1)), which promotes gibberellic acid (GA)-dependent responses in Arabidopsis thaliana. We show that csn mutants are impaired in GA- and SCF(SLY1)-dependent germination and elongation growth, and we show that these defects correlate with an accumulation and reduced turnover of an SCF(SLY1)-degradation target, the DELLA protein REPRESSOR-OF-ga1-3 (RGA). Genetic interaction studies between csn mutants and loss-of-function alleles of RGA and its functional homologue GIBBERELLIC ACID INSENSITIVE (GAI) further reveal that RGA and GAI repress defects of germination in strong csn mutants. In addition, we find that these two DELLA proteins are largely responsible for the elongation defects of a weak csn5 mutant allele. We thus conclude that an impairment of SCF(SLY1) is at least in part causative for the germination and elongation defects of csn mutants, and suggest that DELLA proteins are major growth repressors in these mutants. PMID:20083325
Dohmann, Esther Mirjam Natascha; Nill, Carola; Schwechheimer, Claus
Plant and animal cells release or secrete ATP by various mechanisms, and this activity allows extracellular ATP to serve as a signalling molecule. Recent reports suggest that extracellular ATP induces plant responses ranging from increased cytosolic calcium to changes in auxin transport, xenobiotic resistance, pollen germination, and growth. Although calcium has been identified as a secondary messenger for the extracellular ATP signal, other parts of this signal transduction chain remain unknown. Increasing the extracellular concentration of ATP?S, a poorly-hydrolysable ATP analogue, inhibited both pollen germination and pollen tube elongation, while the addition of AMPS had no effect. Because pollen tube elongation is also sensitive to nitric oxide, this raised the possibility that a connection exists between the two pathways. Four approaches were used to test whether the germination and growth effects of extracellular ATP?S were transduced via nitric oxide. The results showed that increases in extracellular ATP?S induced increases in cellular nitric oxide, chemical agonists of the nitric oxide signalling pathway lowered the threshold of extracellular ATP?S that inhibits pollen germination, an antagonist of guanylate cyclase, which can inhibit some nitric oxide signalling pathways, blocked the ATP?S-induced inhibition of both pollen germination and pollen tube elongation, and the effects of applied ATP?S were blocked in nia1nia2 mutants, which have diminished NO production. The concurrence of these four data sets support the conclusion that the suppression of pollen germination and pollen tube elongation by extracellular nucleotides is mediated in part via the nitric oxide signalling pathway. PMID:19363208
Reichler, Stuart A.; Torres, Jonathan; Rivera, Amy L.; Cintolesi, Viviana A.; Clark, Greg; Roux, Stanley J.
An investigation was made to see the salt tolerance of 10 weed species of rice. Properly dried and treated seeds of weed species were placed on 9 cm diameter petridishes lined with Whatman No. 1 filter paper under 6 salinity regimes, viz. 0 (control), 4, 8, 16, 24 and 32 dS m(-1). The petri dishes were then kept in germinator at 25 +/- 1.0 degrees C and 12 hr light. The number of germinated seeds were recorded daily. The final germination percentage, germination index (GI), seedling vigour index, mean germination time and time for 50% germination were estimated. Root and shoot lengths of the weed seedlings were measured at 20 days after salt application and relative growth values were calculated. Results revealed that salinity decreased final germination percentage, seed of germination as measured by GI, and shoot and root length in all the species. Germination of most of the weed seeds was completely arrested (0) at 32 dS m(-1) salinity except in E. colona (12%) and C. iria (13.9%). The species C. iria, E. colona, J. linifolia and E. crusgalli showed better germination (above 30%) upto 24 dS m(-1) salinity level and were regarded as salt-tolerant weed species. J. linifolia, F. miliacea, L. chinensis and O. sativa L. (weedy rice) were graded as moderately tolerant and S. zeylanica, S. grosus and C. difformis were regarded as least tolerant weed species. PMID:22319865
Hakim, M A; Juraimi, Abdul Shukor; Hanafi, M M; Selamat, A; Ismail, Mohd Razi; Karim, S M Rezaul
Background Some root-parasitic plants belonging to the Orobanche, Phelipanche or Striga genus represent one of the most destructive and intractable weed problems to agricultural production in both developed and developing countries. Compared with most of the other weeds, parasitic weeds are difficult to control by conventional methods because of their life style. The main difficulties that currently limit the development of successful control methods are the ability of the parasite to produce a tremendous number of tiny seeds that may remain viable in the soil for more than 15 years. Seed germination requires induction by stimulants present in root exudates of host plants. Researches performed on these minute seeds are until now tedious and time-consuming because germination rate is usually evaluated in Petri-dish by counting germinated seeds under a binocular microscope. Results We developed an easy and fast method for germination rate determination based on a standardized 96-well plate test coupled with spectrophotometric reading of tetrazolium salt (MTT) reduction. We adapted the Mosmann’s protocol for cell cultures to germinating seeds and determined the conditions of seed stimulation and germination, MTT staining and formazan salt solubilization required to obtain a linear relationship between absorbance and germination rate. Dose–response analyses were presented as applications of interest for assessing half maximal effective or inhibitory concentrations of germination stimulants (strigolactones) or inhibitors (ABA), respectively, using four parameter logistic curves. Conclusion The developed MTT system is simple and accurate. It yields reproducible results for germination bioassays of parasitic plant seeds. This method is adapted to high-throughput screenings of allelochemicals (stimulants, inhibitors) or biological extracts on parasitic plant seed germination, and strengthens the investigations of distinctive features of parasitic plant germination. PMID:23915294
Plant growth-promoting rhizobacteria (PGPR) constitute a wide range of root-colonizing bacteria that can enhance plant growth by increasing seed germination, plant weight, and crop yields. Some PGPR strains regulate plant growth by mimicking synthesis of plant hormones including indole-3-acetic acid...
With the advances in nanotechnology, silver nanoparticles (AgNPs) have been applied in many industries, increasing their potential exposure level in the environment, yet their environmental safety remains poorly evaluated. The possible effects of different sized AgNPs (20, 30-60, 70-120 and 150nm diameter) on jasmine rice, Oryza sativa L. cv. KDML 105, were investigated at different concentrations (0.1, 1, 10, 100 and 1000mg/L) upon seed germination and seedling growth. The results revealed that the level of seed germination and subsequent growth of those seedlings that germinated were both decreased with increasing sizes and concentrations of AgNPs. Based on the analysis of AgNPs accumulation in plant tissues, it implied that the higher uptake was found when the seeds were treated with the smaller AgNPs, 20nm diameter AgNPs, but it was trapped in the roots rather than transported to the leaves. These resulted in the less negative effects on seedling growth, when compared to the seed soaking with the larger AgNPs with 150nm diameter. The negative effects of AgNPs were supported by leaf cell deformation when rice seeds were treated with 150-nm-diameter AgNP at the concentration of 10 or 100mg/L during seed germination. These results further strengthen our understanding of environmental safety information with respect to nanomaterials. PMID:24726943
Thuesombat, Pakvirun; Hannongbua, Supot; Akasit, Sanong; Chadchawan, Supachitra
Two visitors watch a TV monitor showing plant growth inside a growth chamber designed for operation aboard the Space Shuttle as part of NASA's Space Product Development program. The exhibit, featuring work by the Wisconsin Center for Space Automation and Robotics, was at AirVenture 2000 sponsored by the Experimental Aircraft Association in Oshkosh, WI.
Seed dispersal is an important process for plants, but may be particularly important for plants occurring in spatially isolated\\u000a habitats like wetlands. Variation in the geographic distribution of wetland plant species may be strongly influenced by their\\u000a ability to use waterbirds, particularly waterfowl to enhance dispersal. We used controlled feeding and germination experiments\\u000a to investigate recovery, retention time, and germination
Chanpen Wongsriphuek; Bruce D. Dugger; Anne M. Bartuszevige
Velvetbean (Mucuna spp.) is a summer annual that has been used as a cover crop to reduce erosion, fix nitrogen and suppress weeds and plant-parasitic nematodes. Crude aqueous extracts (1:15 dry weight plant/volume water) were made from velvetbean plant parts, and various concentrations of the extracts were evaluated in vitro for toxicities to different stages of Meloidogyne incognita (Kofoid and White) Chitwood and for suppression of hypocotyl and root growth and inhibition of germination of tomato (Lycopersicon esculentum L.) and lettuce (Lactuca sativa L.). Germination was only affected by the full-strength extract from leaf blades. Lettuce root growth was the most sensitive indicator of allelopathic activity of the plant part extracts. Lettuce and tomato root growth was more sensitive to the extract from main roots than to extracts of other plant parts, with lethal concentration (LC50) values of 1.2 and 1.1% respectively. Meloidogyne incognita egg hatch was less sensitive to extracts from velvetbean than the juvenile (J2) stage. There was no difference among LC50 values of the extracts from different plant parts against the egg stage. Based on LC50 values, the extract from fine roots was the least toxic to J2 (LC50 39.9%), and the extract from vines the most toxic (LC50 7.8%). The effects of the extracts were nematicidal because LC50 values did not change when the extracts were removed and replaced with water. PMID:16953489
Zasada, Inga A; Klassen, Waldemar; Meyer, Susan L F; Codallo, Maharanie; Abdul-Baki, Aref A
Plants with limited resources adjust partitioning among growth, survival, and reproduction. We tested the effects of water and nutrient amendments on seed production, size, and quality in Sarcobatus vermiculatus (greasewood) to assess the magnitude and importance of changes in reproductive partitioning. In addition, we assessed interactions among the environment of seed-producing plants (adult plant scale), seed size, and seedling microenvironment (seedling scale) on successful seedling establishment. Interactions of these factors determine the scale of resource heterogeneity that affects seedling establishment in deserts. Both total number of seeds produced per plant and seed quality (weight and germination) increased significantly in the enriched treatment in a 3-year field experiment. Seedling length 3 days after germination and seed N concentration, other measures of seed quality, were higher for seed from both irrigated and enriched plants than for seed from control plants. Field S. vermiculatus seed production and quality can be substantially increased with irrigation and nutrient enrichment at the adult plant scale and this allows management of seed availability for restoration. However, based on a greenhouse study, seedling environment, not the environment of the seed-producing plant or seed size, was the most important factor affecting seedling germination, survival, and growth. Thus it appears that production of more seed may be more important than improved seed quality, because higher quality seed did not compensate for a low-resource seedling environment. For both natural establishment and restoration this suggests that heterogeneity at the scale of seedling microsites, perhaps combined with fertilization of adult shrubs (or multi-plant patches), would produce the greatest benefit for establishing seedlings in the field. PMID:18481096
Breen, A N; Richards, J H
The seed germination behaviour of a number of coastal species suggests that they can be separated into three categories, whose response to salinity shows some correlation with habitat. All but two germinated well in fresh water. After immersion for several days in 1\\/2, full, and 1 1\\/2 strength seawater all recover at least partly. Dune species are more adversely affected
S. R. J. Woodell
The dispersion and seedling establishment of pioneering plants can be favoured by the presence of frugivorous bats because the bats usually improve seed germination after ingestion. Although seed germinability is known to vary greatly after ingestion by different bats, the relative contribution of each bat species to seed germination within plant communities is poorly understood. In this study, we first determined the fauna of frugivorous bats in a semideciduous seasonal forest remnant in southern Brazil and subsequently identified the plant species of the seeds passed through their guts. Second, the germination performance (i.e., germination percentage and speed) of the seeds of three pioneering plants (Piper aduncum, Piper hispidinervum and Solanum granuloso-leprosum) ingested by the most abundant bats was compared with that of the non-ingested seeds (seeds collected from fruits). Additionally, the effects on seed germination of different bat species were compared. During one year, five species of frugivorous bats were caught, and the seeds of eleven identifiable plant species (not counting those of undetermined species) were found in their faeces. We found that the germination performance of the seeds of Piper species was significantly enhanced after ingestion by bats, whereas S. granuloso-leprosum seeds had neutral or reduced germinability when seeds in faeces were compared with pulp-removed seeds. Our results revealed that the bat species that were captured exerted different effects upon seed germination; such a disparity is expected to result in different rates of early establishment of these pioneer plants in tropical forests, most likely affecting forest composition and structure, particularly during the initial stages of succession.
de Carvalho-Ricardo, Maria C.; Uieda, Wilson; Fonseca, Renata Cristina B.; Rossi, Marcelo N.
Pseudobombax tomentosum and P. longiflorum are common trees in the Cerrado region, but the former species is more common in forest edges while the later is present in open cerrado areas. This work aimed to investigate differences in seed germination and seedling growth in these species, from seed collected from Cerrado areas in Central Brazil. For this, a seed germination experiment was designed and included four replicates with 25 seeds per species; seeds were randomly distributed in the germination chamber. To evaluate initial seedling growth, seedlings height was measured up to 67 days after seedling emergence; besides, some of these seedlings were grown for biomass evaluation during nine months. Results showed that seeds of the two species had the same germinability (near 100%) and mean germination time (ca. 12 days). However, P. longiflorum showed a more spread seed germination through time, with higher values of coefficient of variation in germination time and uncertainty index; and lower values of synchronization than P. tomentosum. The two species showed basically the same growth pattern, but lower values for height of apical meristem, diameter of underground structures (mostly roots), dry mass of shoots, underground structure and total mass of seedlings in P. tomentosum were obtained, compared to P. longiflorum. Both species allocated more dry mass to underground structures in detriment of shoot. This probably allows resprouting behavior which prevents hydric stress and detrimental fire action typical of the open Cerrado areas. PMID:22208102
Mendes-Rodrigues, Clesnan; Oliveira, Paulo Eugênio; Ranal, Marli Aparecida
Stimulatory effects of humic substances (HS) on plant growth have been observed and widely documented. Studies have often shown positive effects on seed germination, root initiation and total plant biomass. The consistency of these observations has been uncertain, predominantly due to the lack of understanding of the plant growth promotion mechanism. Often these effects have been attributed to a direct
Y. Chen; C. E. Clapp; H. Magen
Under shade environment in glasshouse, the effects of seed coat and sowing depth (0, 2, 5, 10 or 15 cm) on seed germination and early seedling growth of Quercus wutaishanica were studied. Seed coat had obvious inhibiting effects on the germination of Q. wutaishanica seeds. The germination percentage of uncoated seeds increased significantly, averagely by 19.4% at different sowing depths. The germination index and vigor index were increased significantly and the germination was speeded in the peeling treatment. The germination percentages of uncoated and coated seeds were the highest at the sowing depth of 2 cm with 78.9% and 62.2%, respectively. The germination index and vigor index were the highest at the sowing depth of 2 cm, while the coefficient of rate of germination were the highest at the sowing depth of 5 cm. Leaf area per seedling and dry mass of seedlings increased significantly in the peeling treatment compared with those in the unpeeling treatment, but specific root length decreased significantly. The shoot height in the peeling and unpeeling treatments were the highest at the sowing depth of 5 cm with 13.8 and 14.2 cm, respectively. With the increasing of sowing depth, the basal stem diameter of seedlings increased, but tap-root length, number of lateral root and maximum of lateral root all decreased. Sowing depth had little influence on dry mass of seedlings. PMID:24765842
Yan, Xing-Fui; Qiu, Zhi-Hu; Zhang, Qiang; Zhang, Kao-Wen; Zhou, Yun-Feng
In this study the effect of different concentrations of light crude oil (up to 10%) on the growth and germination of Festuca arundinacea (Tall fescue) was studied. Present results showed that the germination number and dry biomass of the plant decreased by increasing light crude oil concentration in the soil. The biomass was higher in 1% crude oil sample while it was lower in 10% crude oil sample. The length of leaves reduced in higher crude oil concentration in comparison with the control. Total and oil-degrading colony count of soil showed that the microbial population in 7 and 10% samples was higher than the control and low concentrations of crude oil (1 and 3% samples). The crude oil reduction in the vegetated and the non-vegetated samples was higher in 1% sample. All vegetated samples had higher crude oil reduction than non-vegetated samples. The higher reduction was occurred at 1% sample, while the lower reduction was seen at 10% sample.
Minai-Tehrani, Dariush; Shahriari, Malek-Hossein; Savaghebi-Firoozabadi, Gholamreza
In the past three decades, atmospheric pollution has caused substantial problems for the environment as well as for many biological processes. The objective of this study focuses on red spruce (Picea ruben Sarg.) regeneration potential and chemical change within the soil-water-plant continuum following simulated acid rain treatments. Inceptisols from three forests at 1735, 1920, and 2015 m at Mt. Mitchell, North Carolina had lower pH, bulk density, and higher organic matter, and base cations as altitude increased. Red spruce seeds were collected from two nearby standing trees at the 1735 m site. A strip-split-split plot experiment was constructed using soils from the two lower elevations, which support natural red spruce stands. Besides a control (pH 5.6, NO[sub 3]:SO[sub 4] ratio 0.10), eight treatments corresponding to two pHs (3.5 and 4.2) with four NO[sub 3]:SO[sub 4] ratios (0.20, 0.33, 0.40, and 0.67) each were used. Seedling emergence and growth, chemistry of soil. Soil leachate, and plant tissue were analyzed to test soil differences and treatment effects of acidity, nitrate, and sulfate. Temporal patterns of germination respond more to soil than to rain chemistry, but significant interactions were found. Besides higher survival, faster germinating seedlings in the 1735 m soil also produced more complex root system and more biomass. Lower root-to-shoot ratios at more acidic treatments suggest a negative effect of acidity on root growth. Canonical discriminant analysis revealed that factors controlling overall soil chemistry were dominated by soil origin, then by rain pH.
IN preliminary tests carried out during the last few years, it was observed that the application of potassium permanganate to various plants was followed by a marked growth response, and in this connexion a series of controlled pot experiments was carried out with the cactus Opuntia Leuchotricha in quartz sand.
M. E. Webster; Ian M. Robertson
Pollen germination and tube growth in the snow buttercup, Ranunculus adoneus, photographed under fluorescence microscopy. Snow buttercup flowers exhibit heliotropism, the capacity to track the sun's rays over the course of the day. The adaptive significance of solar tracking in snow buttercups is mediated through the impact of flower heliotropism on paternal and maternal floral environments. In controlled crosses, pollen from solar-tracking flowers has higher germination success than pollen from experimentally restrained flowers. Solar tracking in recipient flowers also enhances pollen germination and increases pollen tube to ovule ratios.
Candace Galen (University of Missouri; Division of Biological Sciences ADR; POSTAL)
Most of the northeastern hardwood forests in North America are exposed repeatedly to acidic rainfall at pH values below 5.0. Pollen germination, tube growth and fertilization, important parts of the reproductive process, are sensitive to changes in their chemical environment. Accordingly, the authors investigated the effects of acidity on pollen germination and tube elongation of four northeastern tree species: flowering dogwood, black birch, yellow birch, and sugar maple. Pollen was collected and germinated in a growth medium acidified to pH values ranging from 5.0 to 2.6. Pollen was found to be sensitive to acidification of the germination medium to below pH 4.2. These results suggest that acidic rain that now occurs in eastern North America may influence reproductive processes that are necessary for seed set and regeneration in northern hardwood forests.
Van Ryn, D.M.; Jacobson, J.S.
In bet hedging, organisms sacrifice short-term success to reduce the long-term variance in success. Delayed germination is the classic example of bet hedging, in which a fraction of seeds remain dormant as a hedge against the risk of complete reproductive failure. Here, we investigate the adaptive nature of delayed germination as a bet hedging strategy using long-term demographic data on Sonoran Desert winter annual plants. Using stochastic population models, we estimate fitness as a function of delayed germination and identify evolutionarily stable strategies for 12 abundant species in the community. Results indicate that delayed germination meets the criteria as a bet hedging strategy for all species. Density-dependent models, but not density-independent ones, predicted optimal germination strategies that correspond remarkably well with observed patterns. By incorporating naturally occurring variation in seed and seedling dynamics, our results present a rigorous test of bet hedging theory within the relevant environmental context. PMID:24393387
Gremer, Jennifer R; Venable, D Lawrence
The data support the hypothesis that there is a synergistic phytotoxic effect whenp-coumaric and ferulic acids are found together. Equimolar mixtures of both acids showed greater reduction in sorghum seed germination, shoot elongation, and total seedling growth than either phytotoxin caused when alone. Repeated experiments showed mixtures containing 5×10-3 Mp-coumaric and 5×10-3 M ferulic acids reduced germination to 34% of
James A. Rasmussen; Frank A. Einhellig
/ This study examined the possibility of growth, nodulation, and nitrogen accumulation of Sesbania rostrata in pure and amended Pb/Zn tailings. About 90% of seeds of S. rostrata germinated in pure Pb/Zn tailings, which contained high concentrations of Pb, Zn, Cu, and Cd. Although seedling growth suffered from the adverse environment of Pb/Zn tailings, they became established on tailings stands, in the greenhouse, as well as on the actual tailings dam, and completed their life cycle in 4 months. Dry matter production and nitrogen accumulation was 3200 kg/ha and 69.4 kg/ha, respectively in the actual tailings dam. Applying inorganic fertilizer to Pb/Zn tailings led to no obvious improvement in growth and nodulation of S. rostrata, while tailings amended by river sediment or domestic refuse rich in organic matter improved the growth and nodulation of the species. Azorhizobium caulinodans survived and formed N-fixing stem and root nodules in S. rostrata grown in pure Pb/Zn tailings with a nodule biomass exceeding 300 mg fresh matter per plant.KEY WORDS: Sesbania rostrata; Azorhizobium caulinodans; Pb/Zn mine tailings; Revegetation; Nitrogen fixation; Heavy metals; Tolerance PMID:9175548
Yang; Yuan; Xin; Chang; Wong
Exposure of dormant seed to cold smoke derived from burnt native vegetation had a positive influence on germination in one or more seed provenances in 45 out of 94 species of native Western Australian plants that are normally hard to germinate. When tested under controlled conditions some species showed earlier germination in smoke treatments than controls; in others smoke-treated seeds
Kingsley W. Dixon; Shauna Roche; John S. Pate
The response of lettuce (Lactuca sativa L. cv. Waldmann's Green) to low atmospheric pressure was examined during the initial 5 days of germination and emergence, and also during subsequent growth to vegetative maturity at 30 days. Growth took place inside a 66-l-volume low pressure chamber maintained at 70 kPa, and plant response was compared to that of plants in a second, matching chamber that was at ambient pressure (approximately 101 kPa) as a control. In other experiments, to determine short-term effects of low pressure transients, plants were grown at ambient pressure until maturity and then subjected to alternating periods of 24 h of low and ambient atmospheric pressures. In all treatments the partial pressure of O2 was maintained at 21 kPa (approximately the partial pressure in air at normal pressure), and the partial pressure of CO2 was in the range 66.5-73.5 Pa (about twice that in normal air) in both chambers, with the addition of CO2 during the light phase. With continuous exposure to low pressure, shoot and root growth was at least as rapid as at ambient pressure, with an overall trend towards slightly greater performance at the lower pressure. Dark respiration rates were greater at low pressure. Transient periods at low pressure decreased transpiration and increased dark respiration but only during the period of exposure to low pressure. We conclude that long-term or short-term exposure to subambient pressure (70 kPa) was without detectable detriment to vegetative growth and development.
Spanarkel, Robert; Drew, Malcolm C.
Plant Growth and Hormones 102 Plant Growth and Hormones Because plants have so many repeating parts, therefore, it helps to mark plants. Then you can monitor them over time and figure out (1) whether they are actively growing or dormant; and (2) if they are growing, how fast they are growing. You can measure "how
The accident at the Chernobyl Atomic Energy Station resulted in radiation contamination of large tracts of land and particularly the reactor building itself. Sustained exposure of microfungi to radiation appears to have resulted in formerly un- known adaptive features, such as directed growth of fungi to sources of ionizing radiation. We evaluate here spore germination and subsequent emergent hyphal growth
Tatyana Tugay; Nelli N. Zhdanova; Victor Zheltonozhsky; Leonid Sadovnikov; J. Dighton
We tested expectations that two desert shrubs would differ in germination and seedling relative growth rate (RGR) responses to Na and Cs stress. The study species, Chrysothamnus nauseosusssp. consimilis and Sarcobatus vermiculatus (hereafter referred to by genus), differ in their distribution along salinity gradients, with Chrysothamnusinhabiting only less saline areas. In growth chamber studies, declining Cs (20.82 to 22.71 MPa)
Geraldine L. Dodd; Lisa A. Donovan
The tomato seeds were flown in orbit aboard the Long Duration Exposure Facility (LDEF) for nearly six years. During this time, the tomato seeds received an abundant exposure to cosmic radiation and solar wind. Upon the return of the LDEF to earth, the seeds were distributed throughout the United States and 30 foreign countries for analysis. The purpose of the experiment was to determine the long term effect of cosmic rays on living tissue. Our university analysis included germination and growth rates as well as Scanning Electron Microscopy and X-ray analysis of the control as well as Space-exposed tomato seeds. In analyzing the seeds under the Electron Microscope, usual observations were performed on the nutritional and epidermis layer of the seed. These layers appeared to be more porous in the Space-exposed seeds than on the Earth-based control seeds. This unusual characteristic may explain the increases in the space seeds growth pattern. (Several test results show that the Space-exposed seeds germinate sooner than the Earth-Based seeds. Also, the Space-exposed seeds grew at a faster rate). The porous nutritional region may allow the seeds to receive necessary nutrients and liquids more readily, thus enabling the plant to grow at a faster rate. Roots, leaves and stems were cut into small sections and mounted. After sputter coating the specimens with Argon/Gold Palladium Plasma, they were ready to be viewed under the Electron Microscope. Many micrographs were taken. The X-ray analysis displayed possible identifications of calcium, potassium, chlorine, copper, aluminum, silicon, phosphate, carbon, and sometimes sulfur and iron. The highest concentrations were shown in potassium and calcium. The Space-exposed specimens displayed a high concentration of copper and calcium in the two specimens. There was a significantly high concentration of copper in the Earth-based specimens, whereas there was no copper in the Space-exposed specimens.
Hammond, E.C. Jr.; Bridgers, K.; Brown, C.W.
Background and Aims In arid environments many plant species are found associated with the canopies of woody perennials. Favourable conditions for establishment under canopies are likely to be associated with shade, but under canopies shade is distributed patchily and differs in quality. Diurnal temperature fluctuations and maximum temperatures could be reliable indicators of safe sites. Here, an examination is made as to whether canopy-associated species use temperature cues to germinate in shade patches, rather than matrix areas between trees. Methods The study was carried out in arid southern Kalahari savannah (Republic of South Africa). Perennial and annual species associated with Acacia erioloba trees and matrix species were germinated at temperature regimes resembling shaded and unshaded conditions. Soil temperature was measured in the field. Key Results Germination of all fleshy-fruited perennial acacia-associated species and two annual acacia-associated species was inhibited by the temperature regime resembling unshaded conditions compared with at least one of the regimes resembling shaded conditions. Inhibition in perennials decreased with seed mass, probably reflecting that smaller seedlings are more vulnerable to drought. Germination of matrix species was not inhibited by the unshaded temperature regime and in several cases it increased germination compared with shaded temperature regimes or constant temperature. Using phylogenetically independent contrasts a significant positive relationship was found between canopy association and the germination at shade temperatures relative to unshaded temperatures. Conclusions The data support the hypothesis that canopy species have developed mechanisms to prevent germination in open sun conditions. The results and data from the literature show that inhibition of germination at temperature regimes characteristic of open sun conditions can be found in fleshy-fruited species of widely divergent taxonomic groups. It is predicted that germination mechanisms to detect canopy shade based on temperature cues are widespread in species depending on nurse plants, especially bird-dispersed species. PMID:17259226
Kos, Martijn; Poschlod, Peter
The carry-over effect of sub-lethal herbicides was investigated on the germination of seeds collected from surviving Chenopodium album plants, which had received 1/8, 1/8 twice, 1/8 three times, 1/4, 1/2, 1/1 doses of either pre-emergence ioxynil or post-emergence bentazone in a previous onion (Allium cepa) crop. Seeds were also collected from surviving C. album plants, which had received 1/4, 1/2, 1/1 of either pre-emergence pendimethalin, propachlor and linuron, or 1/8, 1/8 twice, 1/8 three times, 1/4, 1/2, 1/1 of post-emergence ioxynil or linuron in a previous leek (Allium porrum) crop. Seeds of surviving plants were collected and tested for germination at temperature of 5, 10, 15, 20 and 25 degrees C. The effect of different temperatures on the total number of germinated seeds was significant. Germination was minimum at low temperatures (5 degrees C or 10 degrees C). Herbicides did not show any effect on germination of C. album and resulted in the same final germination percentage as seeds collected from the unsprayed control plots. PMID:19893909
Tanveer, Asif; Nadeem, Muhammad A; Ali, Asghar; Tahir, Muhammad; Zamir, Muhammad S I
Does Carpobrotus edulis have an impact on native plants? How do C. edulis’ soil residual effects affect the maintenance of native populations? What is the extent of interspecific competition in its invasion process? In order to answer those questions, we established pure and mixed cultures of native species and C. edulis on soil collected from invaded and native areas of Mediterranean coastal dunes in the Iberian Peninsula. We examined the impact of the invader on the germination, growth and survival of seeds and adult plants of two native plant species (Malcolmia littorea (L.) R.Br, and Scabiosa atropurpurea L.) growing with ramets or seeds of C. edulis. Residual effects of C. edulis on soils affected the germination process and early growth of native plants in different ways, depending on plant species and density. Interspecific competition significantly reduced the germination and early growth of native plants but this result was soil, density, timing and plant species dependent. Also, at any density of adult individuals of C. edulis, established native adult plants were not competitive. Moreover, ramets of C. edulis had a lethal effect on native plants, which died in a short period of time. Even the presence of C. edulis seedlings prevents the recruitment of native species. In conclusion, C. edulis have strong negative impacts on the germination, growth and survival of the native species M. littorea and S. atropurpurea. These impacts were highly depended on the development stages of native and invasive plants. Our findings are crucial for new strategies of biodiversity conservation in coastal habitats. PMID:25210924
Novoa, Ana; González, Luís
I tested predictions of the hypothesis that a longer seed passage time through the gut of the lizard Podarcis lilfordi enhances germination performance in the plant Withania frutescens. I compared germination success and germination time between seeds that were ingested by lizards and control seeds that were not. I also explored relationships between natural variation in seed passage time and germination performance. Germination success did not differ between ingested (63 %) and non-ingested seeds (56 %); there was no significant relationship between germinability and retention time. Germination time did not differ between ingested and non-ingested seeds, and was unrelated to retention time. Hence, I found no support for the hypothesis that prolonged retention times should improve germination performance. In addition, this is a pilot study stressing the importance of reptiles as seed dispersers, at least in certain habitats.
Castilla, Aurora M.
With regard to adaptation of green ash (Fraxinus pennsylvanica\\u000a Marshall) to ecological conditions in Croatia, pollen germination and pollen tube length after 2, 4 and 6 hours were examined in vitro at 10, 15, 20 and 25°C during two years 2001 and 2002. Narrow leaved ash (F. angustifolia\\u000a Vahl) pollen served as a control in 2002. The year, time and
Dario Kremer; Tomislav Jemri?
We report the complete sequence of the 5.7-Mbp genome of Pseudomonas putida BIRD-1, a metabolically versatile plant growth-promoting rhizobacterium that is highly tolerant to desiccation and capable of solubilizing inorganic phosphate and iron and of synthesizing phytohormones that stimulate seed germination and plant growth.
Matilla, M.A.; van der Lelie, D.; Pizarro-Tobias, P.; Roca, A.; Fernandez, M.; Duque, E.; Molina, L.; Wu, X.; Gomez, M. J.; Segura, A.; Ramos, J.-L.
Rare earth elements (REEs) enriched fertilizers have been commonly used in China since the 1980s, thus inducing a growing concern about their environmental impact in agriculture. In this work, the effect of some light REEs nitrate mixture and La(3+) nitrate on seed germination, seedling growth and antioxidant metabolism in Triticum durum was investigated with the aim of clarifying the potential benefits or damages of REEs on plants. Seed pre-soaking for 8 h with La(3+) and REEs nitrate inhibited seed germination at low concentrations (0.01 mM and 0.1 mM), while pre-soaking for 2 and 4 h already inhibited seed germination when higher concentrations (1 mM and 10 mM) of La(3+) and REEs nitrate were used. La(3+) and REEs nitrate treatment also affected seedling growth. Root growth was enhanced and inhibited at low and high concentrations, respectively. Shoot growth was inhibited by La(3+) and REEs nitrate at all tested concentrations after 12 d of treatments. Enzymatic and non enzymatic antioxidants were differently affected by La(3+) and REEs nitrate and their behaviour changed also depending on the plant organ. In roots La(3+) and REEs nitrate treatments induced an increase in ascorbate (ASC) and glutathione (GSH) contents. In shoots only La(3+) nitrate induced an increase in the ASC content whereas GSH decreased following both La(3+) and REEs nitrate treatments. An increase in ASC peroxidase activity was observed in shoots and roots, while catalase did not change in roots and slightly decreased in shoots. The possible role of the increase in some antioxidants as indicators of stress caused by lanthanide treatments is discussed. PMID:19215958
d'Aquino, Luigi; de Pinto, Maria Concetta; Nardi, Luca; Morgana, Massimo; Tommasi, Franca
The accident at the Chernobyl Atomic Energy Station resulted in radiation contamination of large tracts of land and particularly the reactor building itself. Sustained exposure of microfungi to radiation appears to have resulted in formerly unknown adaptive features, such as directed growth of fungi to sources of ionizing radiation. We evaluate here spore germination and subsequent emergent hyphal growth of microfungi in the presence of pure gamma or mixed beta and gamma radiation of fungi isolated from a range of long term background radiation levels. Conidiospore suspensions were exposed to collimated beams of radiation and percent spore germination and length of emergent hyphae were measured. All fungal species isolated from background radiation showed inhibition or no response in germination when irradiated. Isolates from sites with elevated radiation showed a stimulation in spore germination (69% mixed radiation and 46% for gamma irradiation). Most isolates from low background radiation sites showed a significant reduced or no response to exposure to either source of radiation, whereas the stimulatory effect of experimental exposure to radiation appeared to increase in magnitude as prior exposure to radiation increased. We propose that the enhanced spore germination and hyphal growth seen in the exposure trials is induced by prior long term exposure to radiation and these factors could be important in controlling the decomposition of radionuclide-bearing resources in the environment. PMID:17139845
Tugay, Tatyana; Zhdanova, Nelli N; Zheltonozhsky, Victor; Sadovnikov, Leonid; Dighton, John
Nod factors are lipochitooligosaccharide (LCO) produced by soil bacteria commonly known as rhizobia acting as signals for the legume plants to initiate symbiosis. Nod factors trigger early symbiotic responses in plant roots and initiate the development of specialized plant organs called nodules, where biological nitrogen fixation takes place. Here, the effect of specific LCO originating from flavonoid induced Rhizobium leguminosarum bv. viciae GR09 culture was studied on germination, plant growth and nodulation of pea and vetch. A crude preparation of GR09 LCO significantly enhanced symbiotic performance of pea and vetch grown under laboratory conditions and in the soil. Moreover, the effect of GR09 LCOs seed treatments on the genetic diversity of rhizobia recovered from vetch and pea nodules was presented. PMID:21723717
Kidaj, Dominika; Wielbo, Jerzy; Skorupska, Anna
Five gradient concentrations (0.02, 0.04, 0.06, 0.08, and 0.10 g/mL) of leaching liquors from the roots, stems, and leaves of the invasive plant Bidens frondosa were used as conditioning fluid to examine its influence on seed germination conditions of the native plant Geum japonicum var. chinense in Huangshan. All leaching liquors of organs suppressed the seed germination of Geum japonicum var. chinense and reduced the final germination percentage and rate, and increased the germination inhibition rate, with a bimodal dependence on concentration. The leaching liquor inhibited the seed germination significantly at the concentration of 0.02 g/mL respectively. The seed germination was also inhibited as the concentration reached to 0.04 g/mL and beyond. Hence the allelopathic effects of the organs were significantly enhanced respectively. This phenomenon represented the presence of allelopathy substances in the root, stem and leaf of Bidens frondosa. PMID:25511044
Wang, X F; Hassani, D; Cheng, Z W; Wang, C Y; Wu, J
To understand the molecular mechanisms underlying regulation of seed germination, we searched enriched cis elements in the upstream regions of Arabidopsis genes whose transcript levels increased during seed germination. Using available published microarray data, we found that two cis elements, Up1 or Up2, which regulate outgrowth of Arabidopsis axillary shoots, were significantly over-represented. Classification of Up1- and Up2-containing genes by gene ontology revealed that protein synthesis-related genes, especially ribosomal protein genes, were highly over-represented. Expression analysis using a reporter gene driven by a synthetic promoter regulated by these elements showed that the Up1 is necessary and sufficient for germination-associated gene induction, whereas Up2 acts as an enhancer of Up1. Up1-mediated gene expression was suppressed by treatments that blocked germination. Up1 is almost identical to the site II motif, which is the predicted target of TCP transcription factors. Of 24 AtTCP genes, AtTCP14, which showed the highest transcript level just prior to germination, was functionally characterized to test its involvement in the regulation of seed germination. Transposon-tagged lines for AtTCP14 showed delayed germination. In addition, germination of attcp14 mutants exhibited hypersensitivity to exogenously applied abscisic acid and paclobutrazol, an inhibitor of gibberellin biosynthesis. AtTCP14 was predominantly expressed in the vascular tissues of the embryo, and affected gene expression in radicles in a non-cell-autonomous manner. Taken together, these results indicate that AtTCP14 regulates the activation of embryonic growth potential in Arabidopsis seeds. PMID:17953649
Tatematsu, Kiyoshi; Nakabayashi, Kazumi; Kamiya, Yuji; Nambara, Eiji
A recent greenhouse study revealed a significant reduction of germination and growth of redroot pigweed (Amaranthus retroflexus) and common purslane (Portulaca oleracea) by rye mulch, whereas velvetleaf (Abutilon theophrasti) and common lambsquarters (Chenopodium album) were not suppressed. Since BOA detoxification by metabolic alteration may influence the relation between the benzoxazinoid content of the soil mulch and weed suppression, we tested the dynamics in BOA detoxification in different plant organs of three and 10-day-old seedlings of four warm season weeds incubated with five BOA concentrations (4, 20, 40, 80, and 200 ?mol g(-1) fresh weight). In addition, germination and length of 3-day-old seedlings were measured after exposure to 0, 0.3, 1.5, 3, 6, and 15 ?mol BOA. Finally, we tested the influence of the MDR translocator inhibitors verapamil, nifedipine, and the GST inhibitor ethycrynic acid on BOA accumulation and detoxification activity. Due to BOA-detoxification, all weeds were able to grow in environments with low BOA contents. At higher contents, Abutilon theophrasti and Chenopodium album had a better chance to survive because of highly active mechanisms that avoided the uptake of BOA (A. theophrasti) and of efficient detoxification activities in youngest seedlings (C. album). The interpretation of all of the data gave the following sequence of increasing sensitivity: A. theophrasti < C. album < P. oleracea ? A. retroflexus. The results were in agreement with recent findings of the suppression of these weeds by rye mulches and their benzoxazinoid contents. Our studies demonstrate for the first time that the detoxification of BOA influences the survival of certain weeds in environments enriched with this allelochemical. Therefore, detoxification processes affect the potential for weed suppression by soil allelochemicals in sustainable weed management. PMID:22614450
Schulz, Margot; Marocco, Adriano; Tabaglio, Vincenzo
Heavy metals have been widely recognized as highly toxic and dangerous. Plants, algae and bacteria respond to heavy metal toxicity by inducing different enzymes, creating ion influx/efflux for ionic balance and synthesizing small peptides. These peptides bind metal ions and reduce toxicity. Metals come from the natural weathering processes of the earth's crust, industrial discharge, pest or disease control agents applied to plants, urban run-off, mining, soil erosion, sewage effluents, air pollution fallout and other sources. Plants can be affected directly by air pollutants, as well as indirectly through the contamination of soil and water. At the same time, plant is a member of the food chain and may create a risk for man and animals through contamination of food supplies. In recent years a considerable progress has been made in the assay of trace elements in environmental plant samples. For higher plants, the accumulation of metals, especially cadmium, was tested when plants grew on sewage sludge-amended soils or in soils of cadmium residues from phosphate fertilizers. No reports were accessible to us on the direct effect of tested metals (Pb, Hg, Cr, As, Cd) on seed germination and root growth. The paucity of literature initiated our present work. In this study, an attempt has been made to investigate the acute toxicity of five metals (Cr[sup 6+], Cd[sup 2+], Hg[sup 2+], Pb[sup 2+], As[sup 5+]) which are widely spread in the environment and are widely recognized as highly toxic and dangerous. As the testing subject, mustard seeds (Sinapis alba) were used and their germination and root growth were observed. 12 refs., 1 tab.
Fargasova, A. (Slovak Technical Univ., Bratislava (Czech Republic))
Wheat (Triticum aestivum L.) is one of the most important cereals in Turkey. Besides many biotic and abiotic factors weeds compete for available nitrogen and light which ultimately affects grain yield, increase harvest, storage, transportation cost and grain quality. The objective of the research was to compare wheat and wheat competitive weeds for germination, emergence and seedling growth under saline
Gamze Kay; Mehmet Demir Kay; Yusuf Arslan
Mimosine and albizziine are two toxic, non-protein amino acids found in several legume species. Both compounds have been shown to inhibit seed germination and seedling growth, but no comparative study of the two compounds has been conducted. In the present study the 10-3 M concentration of both com...
According to the importance and diversity of Chenopodium album, Cynodon dactylon and Amaranthus retroflexus in safflower fields and significant role of safflower (Carthamus tinctorius L.) as an oil seed, an experiment was conducted using CRD based factorial design with three replications to study the allelopathic effects of root and shoot extracts of these weeds on germination and early growth stages
F. Rezaie; M. Yarnia
Because the National Science Education Standards (1996) outline specific things K-8 students should know about plants, and previous data indicated that elementary students had difficulty understanding some major ideas about plants and plant growth, the authors of this article thought it appropriate to initiate an investigation to determine the…
Barman, Charles R.; Stein, Mary; McNair, Shannan; Barman, Natalie S.
Though endopeptidases and carboxypeptidases are present in protein bodies of dry quiescent seeds the function of these proteases during germination is still a matter of debate. In some plants it was demonstrated that endopeptidases of dry protein bodies degrade storage proteins of these organelles. Other studies describe cases where this did not happen. The role that stored proteinases play in
K. Muntz; M. A. Belozersky; Y. E. Dunaevsky; A. Schlereth; J. Tiedemann
Podophyllum hexandrum Royle (=Sinopodophyllum hexandrum) is a high-altitude medicinal plant exploited for its etoposides which are potential anticancer compounds. An effective, conventional propagation method is by seed. However, seed germination is erratic, and seedling survival is low. A marginal increase in Podophyllum seed germination was attained with organic solvents. In the present study an attempt was made to decipher the physiological and biochemical barriers in terms of change in proteins during seed germination of Podophyllum. Comparative 2-DE analysis between un-germinated (dormant) and germinating seeds revealed nearly 113 differentially expressed proteins, whereas Peptide Mass Fingerprint (PMF) analysis of 97 protein spots revealed appearance of 27 proteins, up-accumulation of 11 proteins, down-accumulation of 19 proteins and disappearance of 40 proteins with germination. Identified 59 proteins in the homology search were involved in metabolism (carbohydrate and amino acid metabolism; 20 proteins), ABA/GA signaling (17 proteins) and stress (15 proteins) related proteins. Seven proteins were with unknown function. Two-DE, and MS/MS analysis in conjunction with semi-quantitative RT-PCR data of cell wall hydrolyzing genes, revealed that in Podophyllum the radicle protrusion occurs might be because of the up-accumulation of cell wall hydrolases i.e. ?-1, 3-glucanase and XET which weakens the thick walled micropylar endosperm. PMID:23153791
Dogra, Vivek; Ahuja, Paramvir Singh; Sreenivasulu, Yelam
Half-sib seed of several eastern white pine (Pinus strobus L.) families was used to examine seed mass effects on laboratory germination, and seedling emergence and growth under moderate\\u000a and low light (47 and 13% full sunlight) in a greenhouse. Percent germination and speed of germination under laboratory conditions\\u000a were not related to seed mass among half-sib families or multi-family seedlots
William C. Parker; Thomas L. Noland; Andrée E. Morneault
In prokaryotic and eukaryotic cells, the 3'-5'-exonucleolytic decay and processing of RNAs are essential for RNA metabolism. However, the understanding of the mechanism of 3'-5'-exonucleolytic decay in plants is very limited. Here, we report the characterization of an Arabidopsis (Arabidopsis thaliana) transfer DNA insertional mutant that shows severe growth defects in early seedling growth, including delayed germination and cotyledon expansion, thinner yellow/pale-green leaves, and a slower growth rate. High-efficiency thermal asymmetric interlaced polymerase chain reaction analysis showed that the insertional locus was in the sixth exon of AT4G27490, encoding a predicted 3'-5'-exonuclease, that contained a conserved RNase phosphorolytic domain with high similarity to RRP41, designated RRP41L. Interestingly, we detected highly accumulated messenger RNAs (mRNAs) that encode seed storage protein and abscisic acid (ABA) biosynthesis and signaling pathway-related protein during the early growth stage in rrp41l mutants. The mRNA decay kinetics analysis for seed storage proteins, 9-cis-epoxycarotenoid dioxygenases, and ABA INSENSITIVEs revealed that RRP41L catalyzed the decay of these mRNAs in the cytoplasm. Consistent with these results, the rrp41l mutant was more sensitive to ABA in germination and root growth than wild-type plants, whereas overexpression lines of RRP41L were more resistant to ABA in germination and root growth than wild-type plants. RRP41L was localized to both the cytoplasm and nucleus, and RRP41L was preferentially expressed in seedlings. Altogether, our results showed that RRP41L plays an important role in seed germination and early seedling growth by mediating specific cytoplasmic mRNA decay in Arabidopsis. PMID:23132787
Yang, Min; Zhang, Bangyue; Jia, Jianheng; Yan, Chunxia; Habaike, Ayijiang; Han, Yuzhen
Global warming is occurring more rapidly above the treeline than at lower elevations and alpine areas are predicted to experience above average warming in the future. Temperature is a primary factor in stimulating seed germination and regulating changes in seed dormancy status. Thus, plant regeneration from seed will be crucial to the persistence, migration and post disturbance recruitment of alpine plants in future climates. Here, we present the first assessment of the impact of soil warming on germination from the persistent alpine soil seed bank. Contrary to expectations, soil warming lead to reduced overall germination from the soil seed bank. However, germination response to soil temperature was species specific such that total species richness actually increased by nine with soil warming. We further explored the system by assessing the prevalence of seed dormancy and germination response to soil disturbance, the frequency of which is predicted to increase under climate change. Seeds of a significant proportion of species demonstrated physiological dormancy mechanisms and germination of several species appeared to be intrinsically linked to soil disturbance. In addition, we found no evidence of subalpine species and little evidence of exotic weed species in the soil, suggesting that the soil seed bank will not facilitate their invasion of the alpine zone. In conclusion, changes in recruitment via the alpine soil seed bank can be expected under climate change, as a result of altered dormancy alleviation and germination cues. Furthermore, the alpine soil seed bank, and the species richness therein, has the potential to help maintain local species diversity, support species range shift and moderate species dominance. Implications for alpine management and areas for further study are also discussed. PMID:23505066
Hoyle, Gemma L; Venn, Susanna E; Steadman, Kathryn J; Good, Roger B; McAuliffe, Edward J; Williams, Emlyn R; Nicotra, Adrienne B
Four higher plant species (Avena sativa L., oat; Lepidium sativum L., cress; Brassica rapa Metzg., turnip; and Phaseolus vulgaris L., bush bean) and 15 soils including five mineral oil-contaminated soils were tested to assess a soil-based continuous seed germination and early seedling growth bioassay. Seed germination was recorded and the shoot biomass of 14-day seedlings measured. An automatic self-watering system was compared with the daily hand watering. Results obtained from this study show that the self-watering system had minor effects on both seed germination and early seedling growth, and that soil nutrient status rather than soil texture significantly affected both seedling emergence and shoot biomass. Proportional dilution of suspicious samples from primary tests with an appropriate control soil is recommended for secondary tests. Shoot biomass is a more sensitive measurement endpoint than seed germination. Bush bean should not be recommended for use due to its low sensitivity to mineral oil and poor germination in soil. PMID:11459155
Gong, P; Wilke, B M; Strozzi, E; Fleischmann, S
Lysimachia minoricensis is one of the few Mediterranean endemic plants (Minorca, Balearic islands) that has gone extinct in the wild but which persists as extant germplasm or cultivated plants in several botanical gardens. Reproductive features (seed set, number of seeds per capsule, seed weight) and germination responses to constant temperatures, sea water and dry?heat pre?treatments were investigated to determine the extent to which they may have influenced the extinction of the species. Seed set in Lysimachia is not dependent on pollinators, suggesting a functional selfer breeding system. Most plants produced a large mean number of fruits (23·2) and seeds (46·6), and the mean production of seeds per individual was estimated to be almost 1100. Overall, no highly specific requirements were observed for seed germination. Seed germination was not inhibited in the dark, and a high germinability (over 87 % in all cases) was recorded in most experiments, with the exception of those performed at low temperatures (5 and 10 °C). These data suggest that fertility and seed viability were not the major causes of extinction. The high reproductive performance of L. minoricensis is in striking contrast to its status as a wild?extinct plant, suggesting that extrinsic factors were responsible for its extinction. PMID:12099529
ROSSELLÓ, JOSEP A.; MAYOL, MARIA
Hydrogen peroxide was studied as an alternative to conventional bleach and rinsing methods to disinfect hydroponic plant growth systems. A concentration of 0.5% hydrogen peroxide was found to be effective. Residual hydrogen peroxide can be removed from the system by repeated rinsing or by flowing the solution through a platinum on aluminum catalyst. Microbial populations were reduced to near zero immediately after treatment but returned to pre-disinfection levels 2 days after treatment. Treating nutrient solution with hydrogen peroxide and planting directly into trays being watered with the nutrient solution without replenishment, was found to be detrimental to lettuce germination and growth.
Barta, Daniel J.; Henderson, Keith
This paper studied the effects of different shading (55.4%, 18.9%, 5.5%, 2.2%, 0.5% , and 0.3% natural sunlight) on the seed germination and seedling growth of Quercus liaotungensis. The seed germination rate and germination index were the highest (72.5% and 0.22, respectively) at 55.4% natural sunlight, declined with decreasing light intensity, and were the lowest (42.5% and 0.11, respectively) at 0.3% natural sunlight. Strong light had definite delaying effect on the germination. The index of germination vigor increased with decreasing light intensity, being the maximum at 0.5% natural sunlight. The delay of seed germination under strong light could be the selective tradeoff on varied seed fates. Strong light benefited the basal stem diameter and root system growth and dry mass accumulation of Q. liaotunensis seedling, but resulted in the minimum seedlings height (6.06 cm). Greater morphological plasticity was observed for the seedlings under different shading, which lent support to the higher adaptability of the seedlings to light environment. For example, the specific leaf area, specific shoot length, specific root length, and chlorophyll b and total chlorophyll contents were the maximum at 0.5% natural sunlight, being 142.57 cm2 x g(-1), 156.86 cm x g(-1), 271.87 cm x g(-1), 0.07 g x cm(-2), and 0.24 g x cm(-2), respectively, and the minimum at 55.4% natural sunlight, being 44.89 cm2 x g(-1), 52.84 cm x g(-1), 101.98 cm x g(-1), 0.04 g x cm(-2), and 0.15 g x cm(-2), respectively. The variation of the root/shoot ratio of Q. liaotungensis seedlings under different shading could be the effects of the combination of light intensity and water availability. PMID:22007441
Yan, Xing-fu; Wang, Jian-li; Zhou, Li-biao
Germination, growth and survival of green Berberis thunbergii and its purple ornamental form, Berberis thunbergii var. atropurpurea, were compared in five natural environments (full sun meadow, edge of woods, moist woods, dry woods, pine woods) to determine\\u000a whether these two forms have a similar ability to naturalize. Berberis thunbergii and Berberis thunbergii var. atropurpurea had similar germination rates of about
Jessica D. LubellMark; Mark H. Brand
, Maximilian sunflower PMT 1564 and trailing wildbean PMT 1879. There was an increase germination in the NaC1 and CaC12 of all plants tested when compared to germination in NaC1 with the exception of alkali sacaton PMT 1733 and least snoutbeam PMT 1881... sacaton PMT 326, big sacaton PMT 889, alkali sacaton PMT 1733, big sacaton PMT 820, Maximilian sun'flower PMT 1564, bush sun- flower PMT 856, trailing wildbean PMT 1879 and Mason sandhill lovegrass PMT 338. Twelve undisturbed cores of Montell Clay were...
Neighbors, James Olen
We tested expectations that two desert shrubs would differ in germination and seedling relative growth rate (RGR) responses to Na and ?(s) stress. The study species, Chrysothamnus nauseosus ssp. consimilis and Sarcobatus vermiculatus (hereafter referred to by genus), differ in their distribution along salinity gradients, with Chrysothamnus inhabiting only less saline areas. In growth chamber studies, declining ?(s) (-0.82 to -2.71 MPa) inhibited germination of both species, and Chrysothamnus was less tolerant of ?(s) stress than Sarcobatus. Germination fell below 10% for Chrysothamnus at -1.64 MPa (NaCl and PEG), and for Sarcobatus at -2.4 MPa PEG. Neither species exhibited ion toxicity. There was substantial ion enhancement for Sarcobatus in lower ?(s), allowing for 40% germination in -2.71 MPa NaCl. For seedling RGR, species were not different at -0.29 or -0.82 MPa (0 and 100 mmol/L NaCl, respectively), but Chrysothamnus RGR declined substantially at -1.3 MPa (200 mmol/L NaCl). The greater stress tolerance of Sarcobatus was not associated with a lower RGR under nonsaline conditions. Species differences in seed and seedling ?(s) stress tolerance probably contribute to the restricted distribution of Chrysothamnus to less saline areas. The Na uptake of Sarcobatus seedlings enhances its ability to deal with declining ?(s) and establish in more saline areas. PMID:10449394
Dodd, G L; Donovan, L A
Nitric oxide (NO) plays essential roles in many biotic and abiotic stresses in plant development procedures, including pollen tube growth. Here, effects of NO on cold stress inhibited pollen germination and tube growth in Camellia sinensis were investigated in vitro. The NO production, NO synthase (NOS)-like activity, cGMP content and proline (Pro) accumulation upon treatment with NO scavenger cPTIO, NOS inhibitor L-NNA, NO donor DEA NONOate, guanylate cyclase (GC) inhibitor ODQ or phosphodiesterase (PDE) inhibitor Viagra at 25°C (control) or 4°C were analyzed. Exposure to 4°C for 2 h reduced pollen germination and tube growth along with increase of NOS-like activity, NO production and cGMP content in pollen tubes. DEA NONOate treatment inhibited pollen germination and tube growth in a dose-dependent manner under control and reinforced the inhibition under cold stress, during which NO production and cGMP content promoted in pollen tubes. L-NNA and cPTIO markedly reduced the generation of NO induced by cold or NO donor along with partly reverse of cold- or NO donor-inhibited pollen germination and tube growth. Furthermore, ODQ reduced the cGMP content under cold stress and NO donor treatment in pollen tubes. Meanwhile, ODQ disrupted the reinforcement of NO donor on the inhibition of pollen germination and tube growth under cold condition. Additionally, Pro accumulation of pollen tubes was reduced by ODQ compared with that receiving NO donor under cold or control condition. Effects of cPTIO and L-NNA in improving cold-treated pollen germination and pollen tube growth could be lowered by Viagra. Moreover, the inhibitory effects of cPTIO and L-NNA on Pro accumulation were partly reversed by Viagra. These data suggest that NO production from NOS-like enzyme reaction decreased the cold-responsive pollen germination, inhibited tube growth and reduced Pro accumulation, partly via cGMP signaling pathway in C. sinensis. PMID:23272244
Zhu-Ge, Qiang; Jiang, Xin; Wang, Wei-Dong; Fang, Wan-Ping; Chen, Xuan; Li, Xing-Hui
Attempts to use artificially lit cabinets to grow plants identical to those growing in sunlight have provided compelling evidence of the importance of light quality for plant growth. Changing the balance of red (R) to far-red (FR) radiation, but with a fixed photosynthetic input can shift the phytochrome photoequilibrium in a plant and generate large differences in plant growth. With FR enrichment the plants elongate, and may produce more leaf area and dry matter. Similar morphogenic responses are also obtained when light quality is altered only briefly (15-30 min) at the end-of-the-day. Conversely, for plants grown in natural conditions the response of plant form to selective spectral filtering has again shown that red and far-red wavebands are important as found by Kasperbauer and coworkers. Also, where photosynthetic photon flux densities (PPFD) of sunlight have been held constant, the removal of far-red alone alters plant growth. With FR depletion plants grown in sunlight are small, more branched and darker green. Here we examine the implications for plant growth and flowering when the far-red composition of incident radiation in plant growth chambers is manipulated.
King, R. W.; Bagnall, D. J.
Seed dispersal and germination were examined for 70 species from the cold Gurbantunggut Desert in northwest China. Mean and range (3 orders of magnitude) of seed mass were smaller and narrower than those in other floras (5–8 orders of magnitude), which implies that selection favors relatively smaller seeds in this desert. We identified five dispersal syndromes (anemochory, zoochory, autochory, barochory, and ombrohydrochory), and anemochorous species were most abundant. Seed mass (F = 3.50, P = 0.01), seed size (F = 8.31, P < 0.01), and seed shape (F = 2.62, P = 0.04) differed significantly among the five dispersal syndromes and barochorous species were significantly smaller and rounder than the others. There were no significant correlations between seed mass (seed weight) (P = 0.15), seed size (P = 0.38), or seed shape (variance) (P = 0.95) and germination percentage. However, germination percentages differed significantly among the dispersal syndromes (F = 3.64, P = 0.01) and seeds of ombrohydrochorous species had higher germination percentages than those of the other species. In the Gurbantunggut Desert, the percentage of species with seed dormancy was about 80%. In general, our studies suggest that adaptive strategies in seed dispersal and germination of plants in this area are closely related to the environment in which they live and that they are influenced by natural selection forces. PMID:25485296
Liu, Huiliang; Zhang, Daoyuan; Yang, Xuejun; Huang, Zhenying; Duan, Shimin; Wang, Xiyong
~rgence of three species during three weeks following planting in the greenhouse study ~ ~ ~ ~ SCOE EFFECTS GF DIFFERENT KINDS~ RATESx AND DEPTHS GF FERTILIZATION ON GERMINATION AND GRONTH GF FIVE SPECIES QF NATIVE GRASS IN THE FIELD AND GREENHOUSE... of placement, on the gexminstion snd growth of five important native gzass species under field conditions. In addition to the field study, s greenhouse study was made to detexmins the efi'sets of the various constituents of the 1'ertilisers used in the field...
Grumbles, Jim Bob
Background and Aims Despite the considerable number of studies on the impacts of climate change on alpine plants, there have been few attempts to investigate its effect on regeneration. Recruitment from seeds is a key event in the life-history of plants, affecting their spread and evolution and seasonal changes in climate will inevitably affect recruitment success. Here, an investigation was made of how climate change will affect the timing and the level of germination in eight alpine species of the glacier foreland. Methods Using a novel approach which considered the altitudinal variation of temperature as a surrogate for future climate scenarios, seeds were exposed to 12 different cycles of simulated seasonal temperatures in the laboratory, derived from measurements at the soil surface at the study site. Key Results Under present climatic conditions, germination occurred in spring, in all but one species, after seeds had experienced autumn and winter seasons. However, autumn warming resulted in a significant increase in germination in all but two species. In contrast, seed germination was less sensitive to changes in spring and/or winter temperatures, which affected only three species. Conclusions Climate warming will lead to a shift from spring to autumn emergence but the extent of this change across species will be driven by seed dormancy status. Ungerminated seeds at the end of autumn will be exposed to shorter winter seasons and lower spring temperatures in a future, warmer climate, but these changes will only have a minor impact on germination. The extent to which climate change will be detrimental to regeneration from seed is less likely to be due to a significant negative effect on germination per se, but rather to seedling emergence in seasons that the species are not adapted to experience. Emergence in autumn could have major implications for species currently adapted to emerge in spring. PMID:22596094
Mondoni, Andrea; Rossi, Graziano; Orsenigo, Simone; Probert, Robin J.
The effects of an aqueous plant-derived smoke extract, octanoic acid and ethylene on germination of light-sensitive Grand Rapids lettuce seeds were investigated. The smoke extract brought about a concentration dependent increase in germination and a complete inhibition of germination at high concentrations. Octanoic acid could not induce germination. Ethylene at concentrations over 5 µL L-1 increased lettuce seed germination, but
A. K. Jäger; A. Strydom; J. Staden
Little is known of maternal plant influence upon seed- ling characteristics of native shrubs. This study examined influence of maternal Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) stand position on emergence and growth of seed- lings. Seedlings from maternal plants in upslope, core, and downslope positions were grown in a common greenhouse setting. Percent germination, height, and canopy volume of
A. L. Hild; B. Christensen; A. Maier
The destruction of natural forest is increasing due to urbanization, industrialization, settlement and for the agricultural expansion over last few decades, and studies for their recovery need to be undertaken. With this aim, this comparative study was designed to see the effects of deforested soil on germination and growth performance of five different tree species. In the experiment, five species namely Gmelina arborea, Swietenia mahagoni, Dipterocarpus turbinatus, Acacia auriculiformis and Syzygium grande were germinated for six weeks on seedbeds and raised in pots (25cm diameter, 30cm height), that were filled with two soil and type of land use: deforested and adjacent natural forest of Dulhazara Safari Park. Growth performance of seedling was observed up to 15 months based on height, collar diameter and biomass production at the end. Our results showed that the germination rate was almost similar in both type of land uses. Height growth of D. turbinatus, G. arborea and S. mahagoni seedlings was almost similar and A. auriculi formis and S. grande lower in deforested soil compared to natural forest soil, while collar diameter ofA. auriculi formis, G. arborea, S. grande and S. mahagoni lower and D. turbinatus similar in deforested soil compared to natural forest soil. After uprooting at 19 months, S. mahagoni seedlings were showed significantly (p< or =0.05) higher oven dry biomass, D. turbinatus and A. auriculiformis higher, while G. arborea showed significantly (p< or =0.05) lower and S. grande almost similar oven dry biomass in deforested soil compared to natural forest soil. Oven dry biomass of D. turbinatus seedlings at 19 month age in deforested soil was 21.96g (n=5) and in natural forest soil 18.86g (n=5). However, differences in germination rate and growth performance for different tree species indicated that soil are not too much deteriorated through deforestation at Dulhazara and without any failure such deforested lands would be possible to bring under forest through plantation. PMID:23342503
Hossain, M Mohitul
In Arkansas, during seasonal drought periods, lake water levels drop leaving exposed mudflats which are primary sites for seedling establishment. Commonly, these exposed mudflats are partially covered with decomposing litter from previous stands of aquatic plants. In this study, aqueous leachates from the litter of four macrophytes, Eleocharis quadrangulata, Justicia americana, Polygonum lapathifolium, and Potamogeton nodosus, were used to test
JAMES B. GRACE
Seed germination is controlled by environmental signals, including light and endogenous phytohormones. Abscisic acid (ABA) inhibits, whereas gibberellin promotes, germination and early seedling development, respectively. Here, we report that ZFP3, a nuclear C2H2 zinc finger protein, acts as a negative regulator of ABA suppression of seed germination in Arabidopsis (Arabidopsis thaliana). Accordingly, regulated overexpression of ZFP3 and the closely related ZFP1, ZFP4, ZFP6, and ZFP7 zinc finger factors confers ABA insensitivity to seed germination, while the zfp3 zfp4 double mutant displays enhanced ABA susceptibility. Reduced expression of several ABA-induced genes, such as RESPONSIVE TO ABSCISIC ACID18 and transcription factor ABSCISIC ACID-INSENSITIVE4 (ABI4), in ZFP3 overexpression seedlings suggests that ZFP3 negatively regulates ABA signaling. Analysis of ZFP3 overexpression plants revealed multiple phenotypic alterations, such as semidwarf growth habit, defects in fertility, and enhanced sensitivity of hypocotyl elongation to red but not to far-red or blue light. Analysis of genetic interactions with phytochrome and abi mutants indicates that ZFP3 enhances red light signaling by photoreceptors other than phytochrome A and additively increases ABA insensitivity conferred by the abi2, abi4, and abi5 mutations. These data support the conclusion that ZFP3 and the related ZFP subfamily of zinc finger factors regulate light and ABA responses during germination and early seedling development. PMID:24808098
Joseph, Mary Prathiba; Papdi, Csaba; Kozma-Bognár, László; Nagy, István; López-Carbonell, Marta; Rigó, Gábor; Koncz, Csaba; Szabados, László
†Background and Aims Plant functional trait responses to processes such as grassland management have been analysed frequently; however, the scaling-up from individual traits to the outcomes of vegetation dynamics has seldom been tested. In this experiment, germination success was studied with respect to the relationships between grassland management (mowing and grazing), as well as abandonment, and two traits that are
S. Kahmen; P. Poschlod
In this chapter, the role of ions in growth and development in both the Eumycota and Oomycota is discussed. We have focused\\u000a this review on the role of exogenous ions and their effects on cells and have left a discussion of the role of Ca2+ ion in\\u000a signal transduction to other reviews. Cations play a pivotal role in determining the
B. D. Shaw; H. C. Hoch
KU ScholarWorks | The University of Kansas Pre-1923 Dissertations and Theses Collection The Annual Growth In Plants 1903 by J. E. Courtright This work was digitized by the Scholarly Communications program staff in the KU Libraries’ Center...
Courtright, J. E.
The effects of gamma radiation are investigated by studying plant germination, growth and development, and biochemical characteristics of maize. Maize dry seeds are exposed to a gamma source at doses ranging from 0.1 to 1 kGy. Our results show that the germination potential, expressed through the final germination percentage and the germination index, as well as the physiological parameters of maize seedlings (root and shoot lengths) decreased by increasing the irradiation dose. Moreover, plants derived from seeds exposed at higher doses (?0.5 kGy) did not survive more than 10 days. Biochemical differences based on photosynthetic pigment (chlorophyll a, chlorophyll b, carotenoids) content revealed an inversely proportional relationship to doses of exposure. Furthermore, the concentration of chlorophyll a was higher than chlorophyll b in both irradiated and non-irradiated seedlings. Electron spin resonance spectroscopy used to evaluate the amount of free radicals induced by gamma ray treatment demonstrates that the relative concentration of radiation-induced free radicals depends linearly on the absorbed doses. PMID:23996407
Marcu, Delia; Damian, Grigore; Cosma, Constantin; Cristea, Victoria
This analysis and discussion activity presents a structured sequence of questions to challenge students to explain why a plant that sprouts and grows in the light weighs more than the seed it came from, whereas a plant that sprouts and grows in the dark weighs less than the seed it came from.
We used a crossing experiment to investigate post-zygotic barriers that might limit introgression between a pair of closely-related, gynodioecious plant species--the widespread weed Silene vulgaris and the local Swedish endemic S. uniflora ssp. petraea. The study not only considered the effects of hybridization on conventionally-used (primary) fitness components such as seed set and progeny survival, but also provided a test for the effects of interspecific hybridization on characters with more subtle or habitat-specific effects on fitness. We detected highly significant paternal effects on seed germination properties, with the germination characteristics of hybrid seed resembling those of the species that served as the pollen donor. These paternal effects on germination represent a potentially strong barrier to interspecific introgression in the two species' natural habitats, where an inappropriate germination response in the habitat of the maternal parent may lead to the failure of seedling establishment. Interspecific crosses had weak or variable effects on progeny survival, flowering and sex ratio, but these effects could not be interpreted in terms of barriers to introgression. Our results indicate that nuclear restorers in S. vulgaris have the capacity to suppress cytoplasmic male-sterility genes in its endemic congener. PMID:18544070
Andersson, S; Månsby, E; Prentice, H C
Describes the analysis of dandelion peduncle growth based on peduncle length, epidermal cell dimensions, and fresh/dry mass. Methods are simple and require no special apparatus or materials. Suggests that limited practical work in this area may contribute to students' lack of knowledge on plant growth. (Author/DH)
• Ca(2+) -dependent protein kinase (CDPK) is believed to be involved in abscisic acid (ABA) signaling, and several members of the Arabidopsis CDPK superfamily have been identified as positive ABA signaling regulators, but it remains unknown if CDPK negatively regulates ABA signaling. • Here, we investigated the function of an Arabidopsis (Arabidopsis thaliana) CDPK, CPK12, in ABA signaling pathway. • We generated Arabidopsis CPK12-RNAi lines, and observed that downregulation of CPK12 resulted in ABA hypersensitivity in seed germination and post-germination growth, and altered expression of a set of ABA-responsive genes. Expression assay showed that CPK12 was ubiquitously expressed and localized to both cytosol and nucleus. Biochemical assays showed that CPK12 interacted with, phosphorylated and stimulated a type 2C protein phosphatase ABI2, and phosphorylated two ABA-responsive transcription factors (ABF1 and ABF4) in vitro. • Our findings show that the Arabidopsis CPK12 is a negative ABA-signaling regulator in seed germination and post-germination growth, suggesting that different members of the CDPK family may constitute a regulation loop by functioning positively and negatively in ABA signal transduction. PMID:21692804
Zhao, Rui; Sun, Hai-Li; Mei, Chao; Wang, Xiao-Jing; Yan, Lu; Liu, Rui; Zhang, Xiao-Feng; Wang, Xiao-Fang; Zhang, Da-Peng
In this paper the potential to use phospholipids and lysophospholipids as plant growth regulators is discussed. Recent evidence shows that phospholipids and phospholipases play an\\u000a important signalling role in the normal course of plant development and in the response of plants to abiotic and biotic stress.\\u000a It is apparent that phospholipase A (PLA), C (PLC) and D (PLD), lysophospholipids, and
A. Keith Cowan
Plant growth stages are identified as distinct morphological landmarks in a continuous developmental process. The terms describing these developmental stages record the morphological appearance of the plant at a specific point in its life cycle. The widely differing morphology of plant species consequently gave rise to heterogeneous vocabularies describing growth and development. Each species or family specific community developed distinct terminologies for describing whole-plant growth stages. This semantic heterogeneity made it impossible to use growth stage description contained within plant biology databases to make meaningful computational comparisons. The Plant Ontology Consortium (http://www.plantontology.org) was founded to develop standard ontologies describing plant anatomical as well as growth and developmental stages that can be used for annotation of gene expression patterns and phenotypes of all flowering plants. In this article, we describe the development of a generic whole-plant growth stage ontology that describes the spatiotemporal stages of plant growth as a set of landmark events that progress from germination to senescence. This ontology represents a synthesis and integration of terms and concepts from a variety of species-specific vocabularies previously used for describing phenotypes and genomic information. It provides a common platform for annotating gene function and gene expression in relation to the developmental trajectory of a plant described at the organismal level. As proof of concept the Plant Ontology Consortium used the plant ontology growth stage ontology to annotate genes and phenotypes in plants with initial emphasis on those represented in The Arabidopsis Information Resource, Gramene database, and MaizeGDB. PMID:16905665
Pujar, Anuradha; Jaiswal, Pankaj; Kellogg, Elizabeth A.; Ilic, Katica; Vincent, Leszek; Avraham, Shulamit; Stevens, Peter; Zapata, Felipe; Reiser, Leonore; Rhee, Seung Y.; Sachs, Martin M.; Schaeffer, Mary; Stein, Lincoln; Ware, Doreen; McCouch, Susan
Ten agronomic plant species were exposed to different concentrations of nano-TiO2 or CeO2 (0, 250, 500 and 1000 ug/l) and followed to examine effects on germination and early seedling development. For TiO2, cabbage showed increased and corn decreased percent germination, while ...
the mechanisms regulating recalcitrant seed germination aiming towards the development of a biochemical method to temporarily inhibit germination without re- frigeration. Treatment of fresh silver maple seeds seeds with paclobutrazol for 12 h followed by storage under ideal germination conditions
The exocyst, a complex of eight proteins, contributes to the morphogenesis of polarized cells in a broad range of eukaryotes. In these organisms, the exocyst appears to facilitate vesicle docking at the plasma membrane during exocytosis. Although we had identified orthologs for each of the eight exocyst components in Arabidopsis (Arabidopsis thaliana), no function has been demonstrated for any of them in plants. The gene encoding one exocyst component ortholog, AtSEC8, is expressed in pollen and vegetative tissues of Arabidopsis. Genetic studies utilizing an allelic series of six independent T-DNA mutations reveal a role for SEC8 in male gametophyte function. Three T-DNA insertions in SEC8 cause an absolute, male-specific transmission defect that can be complemented by expression of SEC8 from the LAT52 pollen promoter. Microscopic analysis shows no obvious abnormalities in the microgametogenesis of the SEC8 mutants, and the mutant pollen grains appear to respond to the signals that initiate germination. However, in vivo assays indicate that these mutant pollen grains are unable to germinate a pollen tube. The other three T-DNA insertions are associated with a partial transmission defect, such that the mutant allele is transmitted through the pollen at a reduced frequency. The partial transmission defect is only evident when mutant gametophytes must compete with wild-type gametophytes, and arises in part from a reduced pollen tube growth rate. These data support the hypothesis that one function of the putative plant exocyst is to facilitate the initiation and maintenance of the polarized growth of pollen tubes. PMID:16040664
Cole, Rex A; Synek, Lukás; Zarsky, Viktor; Fowler, John E
The role of nitric oxide (NO) in the ultraviolet-B radiation (UV-B)-induced reduction of in vitro pollen germination and tube growth of Paulownia tomentosa Steud. was studied. Results showed that exposure of the pollen to 0.4 and 0.8 W m(-2) UV-B radiation for 2 h resulted in not only the reduction of pollen germination and tube growth but also the enhancement of NO synthase (NOS, EC 220.127.116.11) activity and NO production in pollen grain and tube. Also, exogenous NO donors sodium nitroprusside and S-nitrosoglutathione inhibited both pollen germination and tube growth in a dose-dependence manner. NOS inhibitor N(G)-nitro-l-Arg-methyl eater (l-NAME) and NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO) not only largely prevented the NO generation but also partly reversed the UV-B-inhibited pollen germination and tube growth. These results indicate that UV-B radiation inhibits pollen germination and tube growth partly via promoting NO production in pollen grain and tube by a NOS-like enzyme. Additionally, a guanylyl cyclase inhibitor 6-anilino-5,8-quinolinequinone (LY-83583) prevented both the UV-B- and NO donors-inhibited pollen germination and tube growth, suggesting that the NO function is mediated by cyclic guanosine 5'-monophosphate. However, the effects of c-PTIO, l-NAME and LY-83583 on the UV-B-inhibited pollen germination and tube growth were only partial, suggesting that there are NO-independent pathways in UV-B signal networks. PMID:18251898
He, Jun-Min; Bai, Xiao-Ling; Wang, Rui-Bin; Cao, Bing; She, Xiao-Ping
The germination of korarima (Aframomum corrorima (Braun) P.C.M. Jansen) seeds faces certain problems. The study was carried out to explore the effects of different seed treatments on germination and seedling growth attributes of korarima. Seeds were subjected to seven pre-sowing treatments viz., control (no pretreatment) (T0), soaking in tap water for 24 h (T1), soaking in 50% sulfuric acid (H2SO4)
We report the possibility to modify the wetting properties of the surfaces of a diversity of seeds including: lentils (Lens culinaris), beans (Phaseolus vulgaris) and wheat (Triticum, species C9) by cold radiofrequency air plasma treatment. Air plasma treatment leads to the dramatic decrease in the apparent contact angle. Moreover, the speed of germination and yield (germination rate) of seeds can be modified by preliminary plasma treatment. The change in the wetting properties of seeds is at least partially due to oxidation of their surface under plasma treatment. Significant growth of the peaks corresponding to the nitrogen containing groups in the mass spectra of air plasma treated seeds was registered by TOF-SIMS spectroscopy. PMID:23077725
Bormashenko, Edward; Grynyov, Roman; Bormashenko, Yelena; Drori, Elyashiv
In order to investigation of allelopathic effects of some ornamental trees on seed germination of rye-grass (Lolium prenne) and tall fescue (Festuca arundinaceae), this experiment was conducted in a randomized complete block design with 3 replicates at the laboratory of Horticultural Sciences Department of Ferdowsi University of Mashhad, during 2008. In this research, we studied the effect of aqueous and hydro-alcoholic extracts of Afghanistan pine (Pinus eldarica), arizona cypress (Cupressus arizonica), black locust (Robinia psedue acacia) and box elder (Acer negundo) leaves that prepared in 1:5 ratio on seed germination percent and rate for two grasses. The results showed that all extracts decreased statistically seed germination in compared to control treatment. The highest germination percentage and germination rate of tested grass detected in control treatment. Hydro-alcoholic extracts of all woody plants (15, 30%) were completely inhibited seed germination of rye-grass and tall fescue. Also aqueous extract of arizona cypress was completely inhibited seed germination of tall fescue and had more inhibitory activity than other aqueous extracts on rye-grass. Between aqueous extracts, the highest and lowest seed germination of rye-grass was found in Afghanistan pine and arizona cypress, respectively. PMID:21313873
Arouiee, H; Nazdar, T; Mousavi, A
throughout plant growth and development. Seed germination, early seedling development, stomatal guard cell, AGB1, and GCR1 each negatively regulates ABA signaling in seed germination and early seedling network involving a number of different signals and effectors. For example, during seed germination
Jones, Alan M.
Pectin is a major component of the primary cell wall of higher plants. Some galacturonyl residues in the backbone of pectinaceous polysaccharides are often O-acetylated at the C-2 or C-3 position, and the resulting acetylesters change dynamically during the growth and development of plants. The processes involve both enzymatic acetylation and deacetylation. Through genomic sequence analysis, we identified a pectin acetylesterase (PAE1) from black cottonwood (Populus trichocarpa). Recombinant Pt PAE1 exhibited preferential activity in releasing the acetate moiety from sugar beet (Beta vulgaris) and potato (Solanum tuberosum) pectin in vitro. Overexpressing Pt PAE1 in tobacco (Nicotiana tabacum) decreased the level of acetyl esters of pectin but not of xylan. Deacetylation engendered differential changes in the composition and/or structure of cell wall polysaccharides that subsequently impaired the cellular elongation of floral styles and filaments, the germination of pollen grains, and the growth of pollen tubes. Consequently, plants overexpressing PAE1 exhibited severe male sterility. Furthermore, in contrast to the conventional view, PAE1-mediated deacetylation substantially lowered the digestibility of pectin. Our data suggest that pectin acetylesterase functions as an important structural regulator in planta by modulating the precise status of pectin acetylation to affect the remodeling and physiochemical properties of the cell wall's polysaccharides, thereby affecting cell extensibility. PMID:22247250
Gou, Jin-Ying; Miller, Lisa M.; Hou, Guichuan; Yu, Xiao-Hong; Chen, Xiao-Ya; Liu, Chang-Jun
. Inhibitors of type-2A protein phosphatase (PPase-2A), calyculin A (cal A) and okadaic acid (OA), inhibit pollen grain germination\\u000a and growth of pollen tubes of Lilium longiflorum Thunb. at nanomolar concentrations. Half-maximal inhibition of cytoplasmic PPase-2A activity was below 0.1?nM for cal A and\\u000a at 0.7?nM for OA. Other protein phosphatase inhibitors (tautomycin, cypermethrin, and dephostatin) were less effective. The
Gerhard Obermeyer; Hildegard Klaushofer; Marion Nagl; Margit Höftberger; Friedrich-Wilhelm Bentrup
Seed germination is an important character for plant growth and seed quality. We identified a rice mutant that was delayed\\u000a in its germination. There, T-DNA was inserted into Oryza sativa Delayed Seed Germination 1 (OsDSG1), causing a recessive null mutation. Overexpression of the gene enhanced seed germination. OsDSG1 is most similar to Arabidopsis AIP2, an E3 ligase targeting ABI3.Yeast two-hybrid
Gi-Gyeong Park; Jong-Jin Park; Jinmi Yoon; Sun-Nam Yu; Gynheung An
Background and Aims The small leafy succulent shrub Halocnemum strobilaceum occurs in saline habitats from northern Africa and Mediterranean Europe to western Asia, and it is a dominant species in salt deserts such as those of north-west China. The effects of temperature, light/darkness and NaCl salinity were tested on seed germination, and the effects of salinity were tested on seed germination recovery, radicle growth and radicle elongation recovery, using seeds from north-west China; the results were compared with those previously reported on this species from ‘salt steppes’ in the Mediterranean region of Spain. Methods Seed germination was tested over a range of temperatures in light and in darkness and over a range of salinities at 25 °C in the light. Seeds that did not germinate in the NaCl solutions were tested for germination in deionized water. Seeds from which radicles had barely emerged in deionized water were transferred to NaCl solutions for 10 d and then back to deionized water for 10 d to test for radicle growth and recovery. Key Results Seeds germinated to higher percentages in light than in darkness and at high than at low temperatures. Germination percentages decreased with an increase in salinity from 0·1 to 0·75 m NaCl. Seeds that did not germinate in NaCl solutions did so after transfer to deionized water. Radicle elongation was increased by low salinity, and then it decreased with an increase in salinity, being completely inhibited by ?2·0 m NaCl. Elongation of radicles from salt solutions <3·0 m resumed after seedlings were transferred to deionized water. Conclusions The seed and early seedling growth stages of the life cycle of H. strobilaceum are very salt tolerant, and their physiological responses differ somewhat between the Mediterranean ‘salt steppe’ of Spain and the inland cold salt desert of north-west China. PMID:17428834
Qu, Xiao-Xia; Huang, Zhen-Ying; Baskin, Jerry M.; Baskin, Carol C.
the germination percentage of interior-source seeds but hastened germination speed for seeds from both sources seed vigor, as reflected by germination speed and seedling length and dry weight, yet redried seeds with germination speed. Results suggest that it would be advantageous to redry seeds to a range of 25 to 35 p. 100
Paris-Sud XI, UniversitÃ© de
Fungal volatile organic compounds (VOCs) play important ecophysiological roles in mediating inter-kingdom signaling with arthropods but less is known about their interactions with plants. In this study, Arabidopsis thaliana was used as a model in order to test the physiological effects of 23 common vapor-phase fungal VOCs that included alcohols, aldehydes, ketones, and other chemical classes. After exposure to a shared atmosphere with the 23 individual VOCs for 72 hrs, seeds were assayed for rate of germination and seedling formation; vegetative plants were assayed for fresh weight and chlorophyll concentration. All but five of the VOCs tested (1-decene, 2-n-heptylfuran, nonanal, geosmin and -limonene) had a significant effect in inhibiting either germination, seedling formation or both. Seedling formation was entirely inhibited by exposure to 1-octen-3-one, 2-ethylhexanal, 3-methylbutanal, and butanal. As assayed by a combination of fresh weight and chlorophyll concentration, 2-ethylhexanal had a negative impact on two-week-old vegetative plants. Three other compounds (1-octen-3-ol, 2-ethylhexanal, and 2-heptylfuran) decreased fresh weight alone. Most of the VOCs tested did not change the fresh weight or chlorophyll concentration of vegetative plants. In summary, when tested as single compounds, fungal VOCs affected A. thaliana in positive, negative or neutral ways. PMID:25045602
Germination is a key process in plant recruitment and population dynamics, and seeds are expected to be under strong selection pressure to germinate under conditions that maximize subsequent plant survival. Increased rates of germination (i.e., accelerated germination) may occur in competitive environments. We examined the effects of conspecific density on the timing of germination of seeds of a bird-dispersed plant, Phytolacca americana (Phytolaccaceae, L.), in three different competitive environments. By comparing germination of seeds sown at the same time at different densities, we quantify the benefits of accelerated germination under conditions in which differences in performance among seedlings are attributable to germination timing only, and not to being sown at different times. We find that although the probability of germination is unchanged, the time to initiation of germination is significantly shorter when competition is greater. We also show that plants that germinate earlier are larger and have higher growth rates because they have more time to grow without competitors. Our work demonstrates that shifts in germination timing in response to competition can yield significant dividends for seeds that germinate earliest, but we caution that the magnitude and consequences of accelerated germination will likely depend on the competitive neighborhood. PMID:21622431
Orrock, John L; Christopher, Cory C
Capsaicin, a possible allelochemical, caused growth inhibition of roots and shoots of alfalfa (Medicago sativa), cress (Lepidium sativum), lettuce (Lactuca sativa), crabgrass (Digitaria sanguinalis), timothy (Phleum pratense) and ryegrass (Lolium multiflorum), and suppressed their germination. Increasing the dose of capsaicin increased the inhibition. The concentrations for 50\\u000a % inhibition of the root growth were 2.7, 0.32, 2.1, 0.27, 0.29 and
H. Kato-Noguchi; Y. Tanaka
A comparison is made of the growth of subterranean clover in two soils, ; Urrbrae red-brown earth and Mount Compass pcdzolized sand, sterilized by heat, ; propylene oxide, and irradiation. Plating of the soil at both planting and ; harvesting showed that heat and irradiation treated soils were sterile, whereas ; the soils treated with propylene oxide were not. In
G. D. Bowen; A. D. Rovira
A new model of one type of annual plant dynamics is proposed and discussed. The model is based on individual agents Monte Carlo simulations. We take into account, the plant requirements for external resources (sunshine, moisture etc.), competition among plants and the influence of accumulated dead biomass on the plant germination and seed production. We show that the density of plants could have oscillatory character, with periods depending on the rate of biomass reduction. Investigations on the temporal changes in the spatial distribution of plants show some clustering and moreover persistence of patterns during the oscillations. The average number of seeds produced by a plant in a year versus density of plants has a power-law type character. The obtained results are compared with field data and findings in other theoretical models. Agreement with experimental data is found, at least on a qualitative level. We have been also able to add new arguments in the long debate about the existence or not of oscillations in plant dynamics.
Kaçki, Zygmunt; P?kalski, Andrzej
This research was carried out to evaluate the allelopathic effect of leaves aqueous extract of Azadirachta indica on germination and seedling growth of Vigna radiata. Different methods were used to preparing leaves aqueous extract. Germination percentage and seedling growth of V. radiata significantly decreased gradually as the concentration of the aqueous leaves extracts of A. indica increased in comparison with water control. Severe toxicity was observed at high concentrations and moderate toxicity at low concentrations in comparison with water control. Aqueous leaves extract significantly inhibited root length more than shoot. These results indicated that some kind of inhibitor(s) was the responsible agent for the phytotoxic effect of A. indica on germination and seedling growth of V. radiata. PMID:19090247
Charchafchi, Fawzia Al; Al-Nabhani, Iman; Al-Kharousi, Hanan; Al-Quraini, Fatma; Al-Hanai, Amal
Chemical investigation of the rhizomes of Cyperus distans (Cyperaceae) led to the identification of ?-ciperone, cyperotundone and scabequinone, besides other common constituents. Complete assignment of the (13)C NMR data of scabequinone is being published for the first time. The inhibitory effects of C. distans extracts and scabequinone on the seed germination and seedling growth of Mimosa pudica, Senna obtusifolia and Pueraria phaseoloides were evaluated. Seed germination inhibition bioassay revealed that S. obtusifolia (52-53%) was more sensitive to the hexane and the methanol extracts at 1% than M. pudica (0-10%). Scabequinone at 250 mg L?¹ displayed seed germination inhibitions more than 50% and radicle growth reduction of more than 35% of the test species S. obtusifolia and P. phaseoloides, while the hypocotyl growth of M. pudica was significantly affected (>50%) by the quinone at the same concentration. These results demonstrate that scabequinone contributes to the overall inhibitory activities of C. distans. PMID:24941231
Vilhena, Karyme S S; Guilhon, Giselle Maria Skelding Pinheiro; Zoghbi, Maria das Graças B; Santos, Lourivaldo Silva; Souza Filho, Antonio Pedro Silva
Growth promotion of plants by other plants and microorganisms as well as microorganisms by plants and other microorganisms are discussed. Agrostemma Githago in mixed culture with wheat enhances growth and yield of wheat. Tricontanol and brassinolide stimulate growth of several crop plants. Chromosa...
ABSTRACT Resin obtained from Pinus radiata and five monoterpene components of resin (limonene, ?-pinene, ?-pinene, camphene, and myrcene) were tested to determine their effects on mycelial growth and germination and survival of spores of Fusarium circinatum, the cause of pitch canker in pine, and F. temperatum, which is interfertile with F. circinatum but not pathogenic to pine. Averaged across all treatments, F. temperatum sustained the greatest reduction in radial growth (16.9 ± 0.02% of control). The greatest reduction in dry weight also occurred in F. temperatum (11.7 ± 0.01% of control), and all isolates of F. circinatum were significantly less affected (P < 0.05). Spore germination rates in a saturated atmosphere of monoterpenes were relatively high for all tested isolates but, when placed in direct contact with resin, spore survival was significantly greater for F. circinatum than for F. temperatum. Our results are consistent with the hypothesis that greater tolerance of resin is one factor distinguishing F. circinatum from the nonpathogenic F. temperatum. However, differential tolerance of monoterpene components of resin is not sufficient to explain the observed variation in virulence to pine in F. circinatum. PMID:25163010
Slinski, S L; Zakharov, F; Gordon, T R
germination and plant establish- ment. In big sagebrush (Artemisia tridentata)/bunchgrass plant communities-induced changes occur- ring in the soil beneath the shrubs big sagebrush (Artemi- sia tridentata ssp. tridentata) and antelope bitterbrush (Purshia tridentata). Due to high fuel amounts, shrub subcanopies attain higher
Biologically processing rice and wheat straws into soil-like substrate (SLS) and then reusing them in plant cultivation system to achieve waste recycle is very crucially important in Bioregenerative life support system (BLSS). However, rice is a plant with strong allelopathic potential. It is not clear yet that what kinds of raw materials can be processed into proper SLS to grow rice in BLSS. Therefore, in this study, the aqueous extract of SLS made from three different materials including rice straw, wheat straw and rice-wheat straw mixture was utilized to investigate its effects on the seed germination and seedling growth of rice. The gradients of the extract concentrations (soil:water) were 1:3, 1:5, 1:9, and 1:15 with deionized water used as control. The effects of different types of SLS on seed germination and seedling vitality of rice were confirmed by analyzing the germination rate, seedling length, root length, the fresh weight and other indicants. In addition, based on the analysis towards pH, organic matter composition and other factors of the SLS as well as the chlorophyll, hormone content of rice, and the mechanism of the inhibition was speculated in order to explore the preventive methods of the phenomenon. Finally, the feasibility of cultivating rice on SLSs made from the raw materials mentioned above was evaluated and wheat raw was determined as the most appropriate material for growing rice.
Shao, Lingzhi; Fu, Yuming; Fu, Wenting; Yan, Min; Li, Leyuan; Liu, Hong
We report a microfluidic platform for the hydroponic growth of Arabidopsis plants with high-resolution visualization of root development and root-pathogen interactions. The platform comprises a set of parallel microchannels with individual input/output ports where 1-day old germinated seedlings are initially placed. Under optimum conditions, a root system grows in each microchannel and its images are recorded over a 198-h period. Different concentrations of plant growth media show different root growth characteristics. Later, the developed roots are inoculated with two plant pathogens (nematodes and zoospores) and their physicochemical interactions with the live root systems are observed.
Parashar, Archana; Pandey, Santosh
We developed a three-dimensional (3-D) clinostat to simulate a microgravity environment and studied the changes in plant growth\\u000a processes under this condition. The rate of germination of cress (Lepidium sativum), maize (Zea mays), rice (Oryza sativa), pea (Pisum sativum), or azuki bean (Vigna angularis) was not affected on the clinostat. The clinostat rotation did not influence the growth rate of
Takayuki Hoson; Seiichiro Kamisaka; Yoshio Masuda; Masamichi Yamashita
Younger students can learn about plant biology. Topics include characteristics of living things, germination and growth, the basic parts of plants, photosynthesis, reproduction, and ecological adaptations of plants. The information presented can also be ordered as a video.
Rare earth elements (REEs) enriched fertilizers have been commonly used in China since the 1980s, thus inducing a growing concern about their environmental impact in agriculture. In this work, the effect of some light REEs nitrate mixture and La3+ nitrate on seed germination, seedling growth and antioxidant metabolism in Triticum durum was investigated with the aim of clarifying the potential
Luigi d’Aquino; Maria Concetta de Pinto; Luca Nardi; Massimo Morgana; Franca Tommasi
A mathematical model is presented to estimate the effects of phytochemicals on seed germination. According to the model, phytochemicals tend to prevent germination at low seed densities. The model predicts that at high seed densities they may increase the probability of seed germination and the number of germinating seeds. Hence, the effects are reminiscent of the density-dependent effects of allelochemicals on plant growth, but the involved variables are germination probability and seedling number. The results imply that it should be possible to bypass inhibitory effects of allelopathy in certain agricultural practices and to increase the efficiency of nature conservation in several plant communities. PMID:18648596
A mathematical model is presented to estimate the effects of phytochemicals on seed germination. According to the model, phytochemicals tend to prevent germination at low seed densities. The model predicts that at high seed densities they may increase the probability of seed germination and the number of germinating seeds. Hence, the effects are reminiscent of the density-dependent effects of allelochemicals on plant growth, but the involved variables are germination probability and seedling number. The results imply that it should be possible to bypass inhibitory effects of allelopathy in certain agricultural practices and to increase the efficiency of nature conservation in several plant communities. PMID:19330163
Here, we report that SUGARS WILL EVENTUALLY BE EXPORTED TRANSPORTER (SWEET16) from Arabidopsis (Arabidopsis thaliana) is a vacuole-located carrier, transporting glucose (Glc), fructose (Fru), and sucrose (Suc) after heterologous expression in Xenopus laevis oocytes. The SWEET16 gene, similar to the homologs gene SWEET17, is mainly expressed in vascular parenchyma cells. Application of Glc, Fru, or Suc, as well as cold, osmotic stress, or low nitrogen, provoke the down-regulation of SWEET16 messenger RNA accumulation. SWEET16 overexpressors (35SPro:SWEET16) showed a number of peculiarities related to differences in sugar accumulation, such as less Glc, Fru, and Suc at the end of the night. Under cold stress, 35SPro:SWEET16 plants are unable to accumulate Fru, while under nitrogen starvation, both Glc and Fru, but not Suc, were less abundant. These changes of individual sugars indicate that the consequences of an increased SWEET16 activity are dependent upon the type of external stimulus. Remarkably, 35SPro:SWEET16 lines showed improved germination and increased freezing tolerance. The latter observation, in combination with the modified sugar levels, points to a superior function of Glc and Suc for frost tolerance. 35SPro:SWEET16 plants exhibited increased growth efficiency when cultivated on soil and showed improved nitrogen use efficiency when nitrate was sufficiently available, while under conditions of limiting nitrogen, wild-type biomasses were higher than those of 35SPro:SWEET16 plants. Our results identify SWEET16 as a vacuolar sugar facilitator, demonstrate the substantial impact of SWEET16 overexpression on various critical plant traits, and imply that SWEET16 activity must be tightly regulated to allow optimal Arabidopsis development under nonfavorable conditions. PMID:24028846
Klemens, Patrick A W; Patzke, Kathrin; Deitmer, Joachim; Spinner, Lara; Le Hir, Rozenn; Bellini, Catherine; Bedu, Magali; Chardon, Fabien; Krapp, Anne; Neuhaus, H Ekkehard
Resurrection plants are renowned for their vegetative desiccation tolerance (DT). While DT in vegetative tissues is rare in angiosperms, it is ubiquitous in mature orthodox seeds. During germination, seedlings gradually lose DT until they pass a point of no return, after which they can no longer survive dehydration. Here we investigate whether seedlings of the resurrection plant Xerophyta viscosa ever lose the capacity to establish DT. Seedlings from different stages of germination were dehydrated for 48 hours and assessed for their ability to recover upon rehydration. While a transient decline in the ability of X. viscosa seedlings to survive dehydration was observed, at no point during germination was the ability to re-establish DT completely lost in all seedlings. Pre-treatment of seedlings with PEG or sucrose reduced this transient decline, and improved the survival rate at all stages of germination. Additionally, we observed that the trait of poikilochlorophylly (or loss of chlorophyll) observed in adult X. viscosa leaves can be induced throughout seedling development. These results suggest that the window of DT seen in germinating orthodox seeds remains open in X. viscosa seedlings and that vegetative DT in Xerophyta species may have evolved from the ability to retain this program through to adulthood. PMID:24667896
Lyall, Rafe; Ingle, Robert A.; Illing, Nicola
Experiments to determine whether plant tissue cultures can be grown in the presence of simulated lunar soil (SLS) and the effect of simulated lunar soil on the growth and morphogenesis of such cultures, as well as the effect upon the germination of seeds and the development of seedlings were carried out . Preliminary results on seed germination and seedling growth of rice and calli growth of winged bean and soybean indicate that there is no toxicity or inhibition caused by SLS. SLS can be used as a support medium with supplements of certain major and micro elements.
In 2000 there was an oil spill at the Getúlio Vargas Refinery (REPAR) in Paraná. Nearly five years after contamination and the use of bioremediation, a study was carried out to identify the effects of the contaminated soil and the bioremediated soil on the germination and initial growth of C. xanthocarpa. The experiment was established with soil from REPAR, with three treatment groups: contaminated soil (C), bioremediated soil (B) and uncontaminated soil (U); with five repetitions of 50 seeds each. There was no significant difference in the percentage of germination and the speed of germination index. The production of total biomass (30 - 60 days) and shoot biomass (60 days) was greater in the bioremediated soil compared to the other treatments. The averages for the root biomass were lower in the contaminated soil than in the bioremediated soil. The shoot length and the total length of the seedling in the contaminated soil and uncontaminated soil were lower than in the bioremediated soil. PMID:21180902
Gogosz, A M; Bona, C; Santos, G O; Botosso, P C
We addressed the effects of growing-season rainfall of two consecutive years and of two microhabitats on seed density and floristic composition of the germinable seed bank of annual plants in a sandy desert. We hypothesised that seed composition and density is affected by the presence of vegetated patches, but that this effect varies according to rainfall. We predict an overall
L. Quevedo-Robledo; E. Pucheta; Y. Ribas-Fernández
To select appropriate native species in Northern Shaanxi for phytoremediation, the growth index of six kinds of leguminous plants planted in petroleum contaminated soils were investigated through pot culture. Petroleum concentrations were set at 0, 5 000, 10 000, 20 000, 40 000 mg x kg(-1) respectively with three replicates. Using different levels of seed germination rate, germination time, individual height, wilting rate, dry weight and chlorophyll content in leaves of tested plants as the ecological indicator. The results showed that tested plants have significantly different responses to petroleum pollution. Compared with those planted in clean soils, seed germination rate and individual height were promoted when petroleum concentration was lower than 5000 mg x kg(-1), but inhibition occurred when petroleum concentrations were higher than 10000 mg x kg(-1). Strong endurance of Medicago sativa was observed to petroleum polluted soil, especially at lower petroleum concentration. Leaf wilting of Robinia pseudoacacia was unobserved even when petroleum concentration was 40 000 mg x kg(-1), thus displaying the potential of remediating petroleum contaminated soils. The petroleum concentration was significantly and negatively correlated with seed germination rate, individual height and dry weight, but positively correlated with chlorophyll content in leaves. PMID:24881406
Shan, Bao-Qin; Zhang, Yong-Tao; Cao, Qiao-Ling; Kang, Zhen-Yan; Li, Shu-Yuan
To help develop technologies for growing edible biomass (food crops) in space, Kennedy Space Center partnered with Orbital Technologies Corporation (ORBITEC), of Madison, Wisconsin, through the Small Business Innovation Research (SBIR) program. One result of this research was the High Efficiency Lighting with Integrated Adaptive Control (HELIAC) system, components of which have been incorporated into a variety of agricultural greenhouse and consumer aquarium lighting features. The new lighting systems can be adapted to a specific plant species during a specific growth stage, allowing maximum efficiency in light absorption by all available photosynthetic tissues.
The work supported by DOE in the last year built on our earlier findings that stem growth in soybean subjected to limited water is inhibited first by a physical limitation followed in a few hours by metabolic changes that reduce the extensibility of the cell walls. With time, there is modest recovery in extensibility and a 28kD protein accumulates in the walls of the growth-affected cells. A 31kD protein that was 80% similar in amino acid sequence also was present but did not accumulate in the walls of the stem cells. Explorations of the mRNA for these proteins showed that the mRNA for the 28kD protein increased in the shoot in response to water deprivation but the mRNA for the 31kD protein did not accumulate. In contrast, the roots continued to grow and the mRNA for the 31kD protein accumulated but the mRNA for the 28kD protein was undetectable. We also explored how growth occurs in the absence of an external water supply. We found that, under these conditions, internal water is mobilized from surrounding nongrowing or slowly growing tissues and is used by rapidly growing cells. We showed that a low water potential is normally present in the enlarging tissues and is the likely force that extracts water from the surrounding tissues. We found that it involved a gradient in water potential that extended from the xylem to the outlying cells in the enlarging region and was not observed in the slowly growing basal tissue of the stems of the same plant. The gradient was measured directly with single cell determinations of turgor and osmotic potential in intact plants. The gradient may explain instances of growth inhibition with limited water when there is no change in the turgor of the enlarging cells. 17 refs.
Plant growth and development are regulated by interactions between the environment and endogenous developmental programs. Of the various environmental factors controlling plant development, light plays an especially important role, in photosynthesis, in seasonal and diurnal time sensing, and as a cue for altering developmental pattern. Recently, several laboratories have devised a variety of genetic screens using Arabidopsis thaliana to dissect
J. Chory; M. Chatterjee; R. K. Cook; T. Elich; C. Fankhauser; J. Li; P. Nagpal; M. Neff; A. Pepper; D. Poole; J. Reed; V. Vitart
Plant Growth Promoting Rhizobacteria (PGPR) are beneficial bacteria that colonize the plant root and enhance the plant growth. The use of PGPR is steadily increasing in agriculture and offers an attractive way to replace chemical fertilizers, pesticides and supplements. In the present study, PGPR were isolated from 18 different rhizosphere soil samples of coastal sand dune plants, belonging to the genus Ipomoea sp. collected from the Chennai coastal area. For isolation of bacteria from soil samples, pour plate technique was followed. The rhizobacterial population was ranged from 4.4 x 10(6)-7.5 x 10(7) CFU g(-1). From that, 46 morphologically different bacterial strains were isolated. Among 46, 18 strains exhibited the production of Indole Acetic Acid. (IAA). When screened for phosphate solubilzing activity, six strains showed maximum activity. All these selected six strains were screened for seed germination among which these two strains (AMET1136 and AMET 1148) showed remarkable increase in the seed germination of black gram and green gram. For plant growth promotion, three types of treatments namely, seed bacterization, soil drenching and mixed (seed+soil) were carried out to check the potential of these two strains. Among that one strain which was identified as Pseudomonas sp. AMET1148 showed remarkable and significant increase in shoot length and root length of the tested plants. The study concluded that PGPR from coastal sand dund plants can be developed as plant growth promoters in agricultural crops. PMID:24175421
Muthezhilan, R; Sindhuja, B S; Hussain, A Jaffar; Jayaprakashvel, M
Germination times and radial growth rates of cyclopiazonic acid producing strains of Aspergillus tamarii isolated from a smoked dried fish product were studied over water activities (a(w)) ranging from 0.99 to 0.79 at 25°C, 30°C, 35°C and 40°C on two laboratory media. The a(w) of the media was controlled by either NaCl or a mixture of glucose and fructose. The optimum germination and growth were observed at temperatures between 30°C and 35°C. Germination was favored at the highest a(w) of 0.99 under all conditions. Growth however was dependent on the media and temperature with a lower optimum a(w) of 0.95 for NaCl media and 0.95 to 0.92 a(w) on media containing glucose/fructose. The minimum a(w) for growth was often higher than for germination while both parameters were influenced by temperature and media type. Germination on NaCl media was prevented at a(w) values below 0.82 at 25°C and 30°C, 0.85 at 35°C and 40°C. However, growth did not occur at a(w) <0.85 at 25-35°C. At those temperatures on glucose/fructose media, growth was observed at the lowest a(w) tested (0.79). On both media, the restrictive effect of lowered water activity was more pronounced at 40°C than at 25-35°C. Delays in germination increased and growth rates decreased with marginal a(w) and temperature conditions. The fungi displayed better tolerance on glucose/fructose media than on NaCl media on which it was partly inhibited by the NaCl. The information obtained here could be used to develop strategies for the control of this xerophilic fungus on smoked dried fish and other tropical foods on which it predominates. PMID:23177051
Mohamed, Shazla; Mo, Li; Flint, Steve; Palmer, Jon; Fletcher, Graham C
Growth promotion of plants by other plants and microorganisms, as well as of microorganisms by plants and other microorganisms, is discussed. Agrostemma githago in mixed culture with wheat, enhances growth and yield of wheat. Allantoin, a purine derivative and the principal component of agrostem...
. Seed germination, greening of etiolated plants and inhibition of hypocotyl elongation are stimulated by light, which is sensed\\u000a by various types of photoreceptor. Nitric oxide (NO) has proven to be a bioactive molecule, especially in mammalian cells\\u000a and, most recently, in plants. Like some phytochrome-dependent processes, many NO-mediated ones are accomplished through increases\\u000a in cGMP levels. Given these similarities,
María Verónica Beligni; Lorenzo Lamattina
Electrolyzed oxidizing water (EOW) has been regarded as a potential environmentally friendly broad spectrum microbial decontaminant. EOW with a pH of 3.0 and oxidation reduction potential of 1,079.0 mV were generated by the electrolysis of a dilute NaCl solution (20 mM) in an electrochemical cell. The effects of EOW, 1% NaClO solution, and alkaline electrolyzed water on controlling microbial growth, germination ratio, and enrichment of gamma-aminobutyric acid in germinated brown rice (GBR) were evaluated in this study. Results show that EOW was the most effective at inhibiting microbial growth during germination. Rinsing the rice grains with EOW at 12-h intervals resulted in aerobic plate count reductions of 4.82 log CFU/g, while soaking resulted in bacterial count reductions of 5.38 log CFU/g after 72 h of germination. Moreover, EOW significantly enriched gamma-aminobutyric acid content in GBR (P < 0.05); content was increased 1.6 times in grain rinsed with EOW and 1.8 times in grain soaked in EOW. The findings indicate that EOW is a feasible disinfectant for industrial GBR production. PMID:20202333
Lu, Zhan-Hui; Zhang, Yan; Li, Li-Te; Curtis, Rempel B; Kong, Xiao-Lin; Fulcher, R Gary; Zhang, Gong; Cao, Wei
It may be assumed that the first plants in a lunar base will play a main role in forming a protosoil of acceptable fertility needed for purposively growing second generation plants like wheat, rice, tulips, etc. The residues of the first-generation plants could be composted and transformed by microorganisms into a soil-like substrate within a loop of regenerative life support system. The lunar regolith may be used as a substrate for plant growth at the very beginning of a mission to reduce its cost. The use of microbial communities for priming plants will allow one to facilitate adaption to stressful conditions and to support the plant development under growth limiting conditions. Well-defined plant-associated bacteria were used for growing three cultivars to colonize French marigold (Tagetes patula L.) in anorthosite, a substrate of low bioavailability, analogous to a lunar rock. The consortium was composed of plant growth promoting rhizobacteria and the bacterium Paenibacillus sp. IMBG156 which stimulated seed germination, better plant development, and finally, the flowering of inoculated tagetes. In contrast, control plants grew poorly in the anorthosite and practically did not survive until flowering. Analysis of bacterial community composition showed that all species colonized plant roots, however, the rate of colonization depended on the allelopatic characteristics of marigold varieties. Bacteria of consortium were able to liberate some elements (Ca, Fe, Mn, Si, Ni, Cu, Zn) from substrate anorthosite. Plant colonization by mixed culture of bacterial strains resulted in the increase of accumulation of K, Mg, Mn by the plant and in the lowering of the level of toxic metal accumulation. It was assumed that a rationally assembled consortium of bacterial strains promoted germination of marygold seeds and supported the plant development under growth limiting conditions by means of bioleaching plant essential nutritional elements and by protecting the plant against hyperaccumulation of some toxic metals.
Zaets, I.; Voznyuk, T.; Kovalchuk, M.; Rogutskyy, I.; Lukashov, D.; Mytrokhyn, O.; Mashkovska, S.; Foing, B.; Kozyrovska, N.
In this paper, the Betula platyphylla root-, branch-, and foliage aqueous extracts and Larix olgensis root-, branch-, foliage-, and bark aqueous extracts over a range of concentrations 5.0, 12.5, 25.0, 50.0, and 100.0 mg x mL(-1) were used to study their interspecific allelopathic effect on the seed germination and seedling growth of the two tree species. All the L. olgensis organs' extracts, except its root extracts at concentration 5.0 mg x mL(-1), had inhibition effect on B. platyphylla seed germination rate, which was 54%, 58%, 59%, and 66% under the effects of L. olgensis foliage-, branch-, bark-, and root extracts, respectively, as compared with the control. With increasing concentration, the inhibition effect of L. olgensis root- and branch extracts increased while that of L. olgensis foliage- and bark extracts decreased. The L. olgensis organs' extracts, especially the foliage extracts at concentration 100.0 mg x mL(-1), had strong inhibition effect on B. platyphylla seed radicle- and hypocotyl length growth, with a decrement of 38% and 55% (P < 0.05), respectively. L. olgensis branch- and foliage extracts promoted, but root- and bark extracts inhibited B. platyphylla seedling growth and biomass production. B. platyphylla organs' extracts promoted L. olgensis seed germination, root- and branch extracts promoted hypocotyl length growth, but foliage extracts at 50.0 and 100.0 mg x mL(-1) decreased the hypocotyl length growth by 27% and 28% (P < 0.05), respectively. B. platyphylla organs' extracts mainly promoted L. olgensis seedling growth, with the height- and collar diameter growth and biomass accumulation at B. platyphylla foliage extracts concentration 5.0 mg x mL(-1) increased by 54%, 60%, and 100% (P < 0.05), respectively. Our results suggested that there existed obvious allelopathic effect between B. platyphylla and L. olgensis, and thus, mixed planting B. platyphylla and L. olgensis could have promotion effects on the growth of the two tree species. PMID:22384579
Liu, Zhong-Ling; Wang, Qing-Cheng; Hao, Long-Fei
Background Germin-like superfamily members are ubiquitously expressed in various plant species and play important roles in plant development and defense. Although several GLPs have been identified in peanut (Arachis hypogaea L.), their roles in development and defense remain unknown. In this research, we study the spatiotemporal expression of AhGLPs in peanut and their functions in plant defense. Results We have identified three new AhGLP members (AhGLP3b, AhGLP5b and AhGLP7b) that have distinct but very closely related DNA sequences. The spatial and temporal expression profiles revealed that each peanut GLP gene has its distinct expression pattern in various tissues and developmental stages. This suggests that these genes all have their distinct roles in peanut development. Subcellular location analysis demonstrated that AhGLP2 and 5 undergo a protein transport process after synthesis. The expression of all AhGLPs increased in responding to Aspergillus flavus infection, suggesting AhGLPs' ubiquitous roles in defense to A. flavus. Each AhGLP gene had its unique response to various abiotic stresses (including salt, H2O2 stress and wound), biotic stresses (including leaf spot, mosaic and rust) and plant hormone stimulations (including SA and ABA treatments). These results indicate that AhGLPs have their distinct roles in plant defense. Moreover, in vivo study of AhGLP transgenic Arabidopsis showed that both AhGLP2 and 3 had salt tolerance, which made transgenic Arabidopsis grow well under 100 mM NaCl stress. Conclusions For the first time, our study analyzes the AhGLP gene expression profiles in peanut and reveals their roles under various stresses. These results provide an insight into the developmental and defensive roles of GLP gene family in peanut. PMID:23626720
Wang, Tong; Chen, Xiaoping; Zhu, Fanghe; Li, Haifen; Li, Ling; Yang, Qingli; Chi, Xiaoyuan; Yu, Shanlin; Liang, Xuanqiang
Poor seed germination and early seedling growth associated with urea-induced soil ammonia volatilization are major constraints in the adoption of dry direct-seeded rice. To directly examine soil ammonia volatilization and its damage to seed germination and early seedling growth of dry direct-seeded rice when urea is applied at seeding, two Petri-dish incubation experiments and a field experiment were conducted. Ammonia volatilization due to urea application significantly reduced seed germination and early seedling growth of dry direct-seedling rice. NBPT significantly reduced ammonia volatilization following urea application. The application of ammonium sulfate, instead of urea at seeding, may mitigate poor crop establishment of dry direct-seeded rice. Root growth of dry direct-seeded rice was more seriously inhibited by soil ammonia volatilization than that of shoot. Results suggest that roots are more sensitive to soil ammonia toxicity than shoots in dry direct-seeded rice system when N is applied as urea at seeding. PMID:22454611
Qi, Xiaoli; Wu, Wei; Shah, Farooq; Peng, Shaobing; Huang, Jianliang; Cui, Kehui; Liu, Hongyan; Nie, Lixiao
This document provides extensive background information about how Fast Plants grow and develop. The distinction between growth and development is explained. Also discussed is how genetics plus interactions with the environment produce variation during growth and development.
The Wisconsin Fast Plants Program
Background and Aims The framework provided by an emergence model was used: (1) for phenotyping germination and heterotrophic growth of Medicago truncatula in relation to two major environmental factors, temperature and water potential; and (2) to evaluate the extent of genetic differences in emergence-model parameters. Methods Eight cultivars and natural accessions of M. trunculata were studied. Germination was recorded from 5 to 30 °C and from 0 to ?0·75 MPa, and seedling growth from 10 to 20 °C. Key Results Thermal time to reach 50 % germination was very short (15 °Cd) and almost stable between genotypes, while base temperature (2–3 °C) and base water potential for germination (?0·7 to ?1·3 MPa) varied between genotypes. Only 35 °Cd after germination were required to reach 30 mm hypocotyl length with significant differences among genotypes. Base temperature for elongation varied from 5·5 to 7·5 °C. Low temperatures induced a general shortening of the seedling, with some genotypes more responsive than others. No relationship with initial seed mass or seed reserve distribution was observed, which might have explained differences between genotypes and the effects of low temperatures. Conclusions The study provides a set of reference values for M. trunculata users. The use of the ecophysiological model allows comparison of these values between such non-crop species and other crops. It has enabled phenotypic variability in response to environmental conditions related to the emergence process to be identified. The model will allow simulation of emergence differences between genotypes in a range of environments using these parameter values. Genomic tools available for the model species M. trunculata will make it possible to analyse the genetic and molecular determinants of these differences. PMID:19251713
Brunel, S.; Teulat-Merah, B.; Wagner, M.-H.; Huguet, T.; Prosperi, J. M.; Dürr, C.
Seed germination and early seedling growth are regulated by an intricate network of hormonal signaling pathways. The plant hormones gibberellic acid (GA) and brassinosteroids (BRs) are important positive regulators of these processes, whereas the hormone abscisic acid (ABA) is a potent negative regulator. In Arabidopsis, analysis of mutant plants has implicated heterotrimeric guanine nucleotide-binding protein (G protein) components in regulation of seed germination by all three of these hormones.
Sarah M. Assmann (Penn State University;Biology Department REV)
The vascular macrophyte Typha latifolia Linnaeus (common cattail) may be a sentinel for evaluating potential phytotoxicity to rooted aquatic macrophytes in aquatic\\u000a systems. To further evaluate the potential utility of this species, T. latifolia seed germination, shoot growth, and root elongation were measured in 7-day aqueous exposures using mean measured aqueous\\u000a copper concentrations of 10.0, 23, 41, 62, 174, and
S. L. Muller; D. B. Huggett
Glomus mosseae, a representative species of Endogonaceae (Phycomycetes) able to form vesicular-arbuscular mycorrhiza, was investigated for phytohormone production. Spores of G. mosseae were axenically germinated in water, and the resultant mycelial growth was assayed by standard procedures for extracting plant hormones from microbial cultures. Paper partition chromatography and specific bioassays were used to separate and identify plant growth-regulating substances. The microorganism synthesized at least two gibberellin-like substances, one with Rf corresponding in position to authentic gibberellic acid, and four substances with the properties of cytokinins. PMID:16345991
Barea, José M.; Azcón-Aguilar, Concepción
The present work aimed to evaluate the osmotic conditioning and shading on the germination and on the initial growth of aroeira seedlings. The seeds were pre-imbibed in solutions with different concentrations of PEG (polyethylene glycol) and KNO3 and incubated at 10°C and 20°C temperatures, during 0 (control), 12 and 24 hours. After these periods, the seeds were dried until they reached the initial levels of humidity. After that, they were put for germinating in BOD (Biochemical Oxygen Demand) chambers, at alternated 20-30°C. The control treatment and the pre-conditionings that presented the best results in BOD germination were selected, PEG (-1.0 MPa) + KNO3 (-1.0 MPa) and KNO3 (-1.0 MPa), with pre-imbibition for 12 h and incubated in BOD at 20°C. The seeds were sowed on trays and then they were transplanted, keeping under a net covered with 50% and 70% of shading and at sunlight. The osmotic conditioning did not change the seeds germination in BOD, but the highest aerial part size was observed in PEG -1.0 MPa + KNO3-1.0 MPa treatment. The shading levels at 50% and 70% and the osmotic conditioning with PEG -1.0 MPa + KNO3-1.0 MPa offered a higher emergence in a greenhouse condition; however, at sunlight the seeds presented a better index of quality on the 145th day. PMID:23828353
Scalon, Silvana P Q; Mota, Leandro H S; Mussury, Rosilda M
Previous studies have shown that UV-B could affect pollen germination and tube growth. However, the mechanism of response of pollen to UV-B has not been clear. The purpose of this study was to investigate the role of hydrogen peroxide (H2O2) in the UV-B-induced reduction of in vitro pollen germination and tube growth of Paeonia suffruticosa Andr. and Paulownia tomentosa Steud.
Jun-Min He; Zhi-Hui Liu; Han Xu; Xiao-Ping She; Chen Huang
Laboratory and greenhouse bioassays were used to test for inhibitory effects of senescent and decomposed leaves and aqueous extract from bilberry (Vaccinium myrtillus L.) against seed germination and seedling growth of aspen (Populus tremula L.), birch (Betula pendula Roth.), Scots pine (Pinus sylvestris L.), and Norway spruce [Picea abies (L.) Karst.]. Aqueous extracts from bilberry leaves were inhibitory to aspen seed germination and seedling growth and also induced root damage and growth abnormalities. Addition of activated carbon removed the inhibitory effects of extracts. Senescent leaves reduced pine and spruce seed germination, but rinsing of seeds reversed this inhibition. Senescent leaves were more inhibitory than decomposed leaf litter, suggesting that the inhibitory compounds in bilberry leaves are relatively soluble and released at early stages during decomposition. Spruce was generally less negatively affected by litter and aqueous extracts than the other tested species. This study indicates that chemical effects of bilberry litter have the potential to inhibit tree seedling recruitment, but these effects were not consistently strong. Phytotoxicity is unlikely to be of critical importance in determining success for spruce seedling establishment. PMID:24227618
Jäderlund, A; Zackrisson, O; Nilsson, M C
Germination responses of seeds of three native plant species - Nemophila menziesii H. and a. ssp. menziesii, Layia platyglossa (F. and M.) Gray ssp. platyglossa, and Clarkia rubicunda (Lindl.) Lewis and Lewis ssp. rubicunda - were investigated at atmospheric CO/sub 2/ levels of 0.03%, 0.07%, 0.14%, and 0.21% in controlled greenhouse experiments. Seeds were germinated in a 1:1 (vol/vol) mixture of vermiculite and sponge rock under natural conditions of daylengths and temperatures. Elevations in CO/sub 2/ concentrations did not significantly affect the germination responses of any of the three species, but their patterns of germination differed. The data suggest that increasing CO/sub 2/ concentrations such as those anticipated in the next century may not significantly affect germination of native plant species.
St. Omer, L.; Horvath, S.M.
Seed dormancy and germination are complex adaptive traits of higher plants that are influenced by a large number of genes and environmental factors. Studies of genetics and physiology have shown the important roles of the plant hormones abscisic acid and gibberellin in the regulation of dormancy and germination. More recently, the use of quantitative genetics and mutant approaches has allowed
Maarten Koornneef; Leónie Bentsink; Henk Hilhorst
In the conditions of stable existence of Static Magnetic Field (SMF) the growth processes of some plants' (chickpeas, beans and lentils) seeds have been investigated in different temperatures of microenvironment. It has been established that the rate of the plant growths is affected (speeded up) by SMF that is intimately related to environmental temperature, any other environmental parameters (humidity, illumination,
Akif A. Maharramov
The analysis and simulation of spiral growth in plants integrates algebra and trigonometry in a botanical setting. When the ideas presented here are used in a mathematics classroom/computer lab, students can better understand how basic assumptions about plant growth lead to the golden ratio and how the use of circular functions leads to accurate…
Allen, Bradford D.
This phase of this continuing project was completed in April, 1994, using Dahlgren No. 855 hybrid sunflower seeds and Park Seeds No. 0950 non-hybrid sunflower seeds in both the control groups and the tests groups. The control groups (1, 2, 3, 4, 5, and 6) were grown under normal, un-radiated, conditions. The tests groups (1a, 2a, 3a, 4a, 5a, and 6a) were grown onboard the Space Shuttle Discovery on the STS-60 flight in February 1994. All data from this experiment (both control and test groups) will be taken and recorded in a data log and compared against each other to determine the radiation effects of solar radiation on plant germination and growth.
), Camelina sativa (camelina) and Jatropha curcas (jatropha) applied to soil at varying application rates and incubation times affected seed germination and seedling survival of cotton [Gossypium hirsutum (L.)], sorghum [Sorghum bicolor (L.) Moench...
Rothlisberger, Katie Lynn
To better understand how to establishCarex species from seed in created and restored wetlands, a series of experimental studies was conducted onCarex seed and seedlings. These studies included (1) the effect of seed age (1 to 18 months after collection) on viability and\\u000a germination, (2) storage conditions (+4,-4 or +4\\/-4°C; wet or dry) on seed germination, (3) soil moisture on
Arnold G. van der Valk; Tony L. Bremholm; Elizabeth Gordon
Plant growth form diversity (GFD) is high in the vegetation of North American deserts, and increases from north (Great Basin Desert) to south (Sonoran Desert). While abiotic features (annual temperature, precipitation, and seasonality) appear to limit the range of desert plant GFD, biotic features associated with the coexisting plants at a site, and their GF distribution, add further constraints. Climate
M. L. Cody
BACKGROUND: Endophytic fungi are known plant symbionts. They produce a variety of beneficial metabolites for plant growth and survival, as well as defend their hosts from attack of certain pathogens. Coastal dunes are nutrient deficient and offer harsh, saline environment for the existing flora and fauna. Endophytic fungi may play an important role in plant survival by enhancing nutrient uptake
Sumera Afzal Khan; Muhammad Hamayun; Hyeokjun Yoon; Ho-Youn Kim; Seok-Jong Suh; Seon-Kap Hwang; Jong-Myeong Kim; In-Jung Lee; Yeon-Sik Choo; Ung-Han Yoon; Won-Sik Kong; Byung-Moo Lee; Jong-Guk Kim
as the maior food reserve in holly seeds and the stimulation of growth by dextrose (Ives, 1923), suggested the possible use of a lipase system for the breakdown of lipids to hasten germination. A new plant growth regulator, 2-chloroehanepho. phoic acid..., or castor bean lipase extract. All treatments were placed in a germinator maintained at 15. 5 C for the duration of the treatments. Specific treat-, ants were: l. Ethrel: Excised seed. were soaked for 8 hours in an aqueous solution of' 1, 0CO and 5, 000...
Fleming, Carl Michael
The ECERIFERUM9 (CER9) gene encodes a putative E3 ubiquitin ligase that functions in cuticle biosynthesis and the maintenance of plant water status. Here, we found that CER9 is also involved in abscisic acid (ABA) signaling in seeds and young seedlings of Arabidopsis (Arabidopsis thaliana). The germinated embryos of the mutants exhibited enhanced sensitivity to ABA during the transition from reversible dormancy to determinate seedling growth. Expression of the CER9 gene is closely related to ABA levels and displays a similar pattern to that of ABSCISIC ACID-INSENSITIVE5 (ABI5), which encodes a positive regulator of ABA responses in seeds. cer9 mutant seeds exhibited delayed germination that is independent of seed coat permeability. Quantitative proteomic analyses showed that cer9 seeds had a protein profile similar to that of the wild type treated with ABA. Transcriptomics analyses revealed that genes involved in ABA biosynthesis or signaling pathways were differentially regulated in cer9 seeds. Consistent with this, high levels of ABA were detected in dry seeds of cer9. Blocking ABA biosynthesis by fluridone treatment or by combining an ABA-deficient mutation with cer9 attenuated the phenotypes of cer9. Whereas introduction of the abi1-1, abi3-1, or abi4-103 mutation could completely eliminate the ABA hypersensitivity of cer9, introduction of abi5 resulted only in partial suppression. These results indicate that CER9 is a novel negative regulator of ABA biosynthesis and the ABA signaling pathway during seed germination. PMID:24812105
Zhao, Huayan; Zhang, Huoming; Cui, Peng; Ding, Feng; Wang, Guangchao; Li, Rongjun; Jenks, Matthew A.; Lü, Shiyou; Xiong, Liming
Germination vigor is driven by the ability of the plant embryo, embedded within the seed, to resume its metabolic activity in a coordinated and sequential manner. Studies using "-omics" approaches support the finding that a main contributor of seed germination success is the quality of the messenger RNAs stored during embryo maturation on the mother plant. In addition, proteostasis and DNA integrity play a major role in the germination phenotype. Because of its pivotal role in cell metabolism and its close relationships with hormone signaling pathways regulating seed germination, the sulfur amino acid metabolism pathway represents a key biochemical determinant of the commitment of the seed to initiate its development toward germination. This review highlights that germination vigor depends on multiple biochemical and molecular variables. Their characterization is expected to deliver new markers of seed quality that can be used in breeding programs and/or in biotechnological approaches to improve crop yields. PMID:22136565
Rajjou, Loïc; Duval, Manuel; Gallardo, Karine; Catusse, Julie; Bally, Julia; Job, Claudette; Job, Dominique
Superdispersive iron, cobalt and copper nanocrystalline powders were synthesized in a water–ethanol medium by the reduction method using sodium borohydride as a reducing agent and carboxymethyl cellulose as a stabilizer (for Fe and Co nanoparticles). Transmission electron microscopy micrographs and x-ray diffraction analyses of the freshly prepared nanocrystalline powders indicated that they were in a zerovalent state with particle sizes ranging from 20 to 60 nm. The soybean seeds were treated with an extra low nanocrystalline dose (not more than 300 mg of each metal per hectare) and then sowed on an experimental landfill plot consisting of a farming area of 180 m2. This pre-sowing treatment of soybean seeds, which does not exert any adverse effect on the soil environment, reliably changed the biological indices of the plant growth and development. In particular, in laboratory experiments, the germination rates of soybean seeds treated with zerovalent Cu, Co and Fe were 65, 80 and 80%, respectively, whereas 55% germination was observed in the control sample; in the field experiment, for all of the nanoscale metals studied, the chlorophyll index increased by 7–15% and the number of nodules by 20–49% compared to the control sample, and the soybean crop yield increased up to 16% in comparison with the control sample.
Buu Ngo, Quoc; Hien Dao, Trong; Chau Nguyen, Hoai; Tin Tran, Xuan; Van Nguyen, Tuong; Duong Khuu, Thuy; Huynh, Thi Ha
, including seed germination, seedling photo- morphogenesis, phototropism, gravitropism, chloroplast movement Phototropism Directional plant growth that is determined by the direction of the light source. Gravitropism
We used loss-of-function mutants to study three Arabidopsis thaliana sensor histidine kinases, AHK2, AHK3, and CRE1/AHK4, known to be cytokinin receptors. Mutant seeds had more rapid germination, reduced requirement for light, and decreased far-red light sensitivity, unraveling cytokinin functions in seed germination control. Triple mutant seeds were more than twice as large as wild-type seeds. Genetic analysis indicated a cytokinin-dependent endospermal and/or maternal control of embryo size. Unchanged red light sensitivity of mutant hypocotyl elongation suggests that previously reported modulation of red light signaling by A-type response regulators may not depend on cytokinin. Combined loss of AHK2 and AHK3 led to the most prominent changes during vegetative development. Leaves of ahk2 ahk3 mutants formed fewer cells, had reduced chlorophyll content, and lacked the cytokinin-dependent inhibition of dark-induced chlorophyll loss, indicating a prominent role of AHK2 and, particularly, AHK3 in the control of leaf development. ahk2 ahk3 double mutants developed a strongly enhanced root system through faster growth of the primary root and, more importantly, increased branching. This result supports a negative regulatory role for cytokinin in root growth regulation. Increased cytokinin content of receptor mutants indicates a homeostatic control of steady state cytokinin levels through signaling. Together, the analyses reveal partially redundant functions of the cytokinin receptors and prominent roles for the AHK2/AHK3 receptor combination in quantitative control of organ growth in plants, with opposite regulatory functions in roots and shoots. PMID:16361392
Riefler, Michael; Novak, Ondrej; Strnad, Miroslav; Schmülling, Thomas
For the future manned space exploration, the duration of the missions would significantly in-crease. Investigating plant growth and development under the space environmental conditions is of essential importance for the food supply projects for the astronauts. Hypogeomagnetic field (HGMF), namely, extremely low magnetic field, is one of the main characters of the space environment. Germination is the first vital step of plant growth and development, which determines the final yield of plants. The effect of HGMF on plant growth, especially early ger-mination, still remains open. In this study, we established a hypogeomagnetic field (HGMF) incubation system, the remnant magnetic field inside no more than 250 nT. Soybean seeds were incubated at 25 in HGMF, and the very beginning of soybean germination, from water ab-sorbance of cotyledon to radicle emergence, was examined within 24 h. Our results showed that the germination ratio and weight ratio of emerged soybean radicles were markedly increased during germination in HGMF. Furthermore, the tropism angle of emerged radicle with gravity in HGMF was statistically smaller than that in GMF when the radicle direction was placed opposite to gravity before germination. These results indicate that the germination and gravit-ropism of soybean is enhanced in a hypogeomagnetic environment, This is a new finding about the early seed germination in such a low environmental magnetic field which is comparable to the magnetic field of Lunar Swirls on the Moon (a few hundred nT), and it might provide new perspectives on the space science researches concerning plant growth and food supply.
Germination is basically a reversal of maturation involving rehydration and reactivation of metabolism and meristematic growth. During the early phase of germination, 0-24 hr after planting, many soil-borne pathogens can attack the seed and cause devastating diseases. Changes in metabolic activity...
The purpose of this plant biotechnology activity is to demonstrate the effect of changes in the environment on the growth and fertility of landscape grasses and crop grasses such as wheat and rice. Plants are placed in environments such as high salinity, cold, heat, or drought and learners observe the different reactions of the plants to these conditions. Learners compare the growth of treated plants to that of the control plants, which are grown under optimal conditions. Learners then discuss the desirability of breeding new types of plants that are better able to withstand these changes if they occur in the general environment. In the original description of the activity, the planting is prepared by the instructor as a demonstration, but learners could be involved in this process. This resource contains background information and questions for learners.
Objective To investigate effect of essential oils on Aspergillus spore germination, growth and mycotoxin production. Method In vitro antifungal and antiaflatoxigenic activity of essential oils was carried out using poisoned food techniques, spore germination assay, agar dilution assay, and aflatoxin arresting assay on toxigenic strains of Aspergillus species. Results Cymbopogon martinii, Foeniculum vulgare and Trachyspermum ammi (T. ammi) essential oils were tested against toxicogenic isolates of Aspergillus species. T. ammi oil showed highest antifungal activity. Absolute mycelial inhibition was recorded at 1 µl/mL by essential oils of T. ammi. The oil also showed, complete inhibition of spore germination at a concentration of 2 µl/mL. In addition, T. ammi oil showed significant antiaflatoxigenic potency by totally inhibiting aflatoxin production from Aspergillus niger and Aspergillus flavus at 0.5 and 0.75 µl/mL, respectively. Cymbopogon martinii, Foeniculum vulgare and T. ammi oils as antifungal were found superior over synthetic preservative. Moreover, a concentration of 5?336.297 µl/kg body weight was recorded for LC50 on mice indicating the low mammalian toxicity and strengthening its traditional reputations. Conclusions In conclusion, the essential oils from T. ammi can be a potential source of safe natural food preservative for food commodities contamination by storage fungi. PMID:25183114
Gemeda, Negero; Woldeamanuel, Yimtubezinash; Asrat, Daniel; Debella, Asfaw
The stimulation effect that some beneficial agronomic qualities have exhibited in present-generation plants have also been observed due to ion implantation on plants. However, there is relatively little knowledge regarding the molecular mechanism of the stimulation effects of ion-beam implantation. In order to extend our current knowledge about the functional genes related to this stimulation effect, we have reported a comprehensive microarray analysis of the transcriptome features of the promoted-growth rice seedlings germinating from seeds implanted by a low-energy N+ beam. The results showed that 351 up-regulated transcripts and 470 down-regulated transcripts, including signaling proteins, kinases, plant hormones, transposable elements, transcription factors, non-coding protein RNA (including miRNA), secondary metabolites, resistance proteins, peroxidase and chromatin modification, are all involved in the stimulating effects of ion-beam implantation. The divergences of the functional catalog between the vacuum and ion implantation suggest that ion implantation is the principle cause of the ion-beam implantation biological effects, and revealed the complex molecular networks required to adapt to ion-beam implantation stress in plants, including enhanced transposition of transposable elements, promoted ABA biosynthesis and changes in chromatin modification. Our data will extend the current understanding of the molecular mechanisms and gene regulation of stimulation effects. Further research on the candidates reported in this study should provide new insights into the molecular mechanisms of biological effects induced by ion-beam implantation. PMID:22843621
Ya, Huiyuan; Chen, Qiufang; Wang, Weidong; Chen, Wanguang; Qin, Guangyong; Jiao, Zhen
An important motivation for studying photomorphogenesis is to understand the relationships among plant photophysiology in canopies, canopy productivity, and agronomic yield. This understanding is essential to optimize lighting systems used for plant farming in controlled environments (CE) and for the design of genetically engineered crop strains with altered photoresponses. This article provides an overview of some basic principles of plant photomorphogenesis in canopies and discusses their implications for (1) scaling up information on plant photophysiology from individual plants in CE to whole canopies in the field, and (2) designing lighting conditions to increase plant productivity in CE used for agronomic purposes (e.g. space farming in CE Life Support Systems). We concentrate on the visible (lambda between 400 and 700 nm) and far-infrared (FR; lambda greater than 700 nm) spectral regions, since the ultraviolet (UV; 280 to 400 nm) is covered by other authors in this volume.
Ballare, Carlos L.; Scopel, Ana L.
Background and Aims Cell wall pectins and arabinogalactan proteins (AGPs) are important for pollen tube growth. The aim of this work was to study the temporal and spatial dynamics of these compounds in olive pollen during germination. Methods Immunoblot profiling analyses combined with confocal and transmission electron microscopy immunocytochemical detection techniques were carried out using four anti-pectin (JIM7, JIM5, LM5 and LM6) and two anti-AGP (JIM13 and JIM14) monoclonal antibodies. Key Results Pectin and AGP levels increased during olive pollen in vitro germination. (1 ? 4)-?-d-Galactans localized in the cytoplasm of the vegetative cell, the pollen wall and the apertural intine. After the pollen tube emerged, galactans localized in the pollen tube wall, particularly at the tip, and formed a collar-like structure around the germinative aperture. (1 ? 5)-?-l-Arabinans were mainly present in the pollen tube cell wall, forming characteristic ring-shaped deposits at regular intervals in the sub-apical zone. As expected, the pollen tube wall was rich in highly esterified pectic compounds at the apex, while the cell wall mainly contained de-esterified pectins in the shank. The wall of the generative cell was specifically labelled with arabinans, highly methyl-esterified homogalacturonans and JIM13 epitopes. In addition, the extracellular material that coated the outer exine layer was rich in arabinans, de-esterified pectins and JIM13 epitopes. Conclusions Pectins and AGPs are newly synthesized in the pollen tube during pollen germination. The synthesis and secretion of these compounds are temporally and spatially regulated. Galactans might provide mechanical stability to the pollen tube, reinforcing those regions that are particularly sensitive to tension stress (the pollen tube–pollen grain joint site) and mechanical damage (the tip). Arabinans and AGPs might be important in recognition and adhesion phenomena of the pollen tube and the stylar transmitting cells, as well as the egg and sperm cells. PMID:23712452
Castro, Antonio J.; Suárez, Cynthia; Zienkiewicz, Krzysztof; Alché, Juan de Dios; Zienkiewicz, Agnieszka; Rodríguez-García, María Isabel
In this activity, learners will be working with predictions with a time frame of one week, or longer. Start by planting seedlings. Once they begin to sprout, make predictions: How tall will the plants be in a week? in a month? Each week, learners measure and record the height of their plants. They explore change over time as they compare predictions and results, and as they analyze whether their plants grew about the same amount each week. Available as a web page and downloadable pdf.
We selected six tree species, Pinus massoniana Lamb., Cryptomeria fortunei Hooibr. ex Otto et Dietr., Cunninghamia lanceolata (Lamb.) Hook., Liquidambar formosana Hance, Pinus armandii Franch. and Castanopsis chinensis Hance, which are widely distributed as dominant species in the forest of southern China where acid deposition is becoming more and more serious in recent years. We investigated the effects and potential interactions between simulated acid rain (SiAR) and three calcium (Ca) levels on seed germination, radicle length, seedling growth, chlorophyll content, photosynthesis and Ca content in leaves of these six species. We found that the six species showed different responses to SiAR and different Ca levels. Pinus armandii and C. chinensis were very tolerant to SiAR, whereas the others were more sensitive. The results of significant SiAR?×?Ca interactions on different physiological parameters of the six species demonstrate that additional Ca had a dramatic rescue effect on the seed germination and seedling growth for the sensitive species under SiAR. Altogether, we conclude that the negative effects of SiAR on seed germination, seedling growth and photosynthesis of the four sensitive species could be ameliorated by Ca addition. In contrast, the physiological processes of the two tolerant species were much less affected by both SiAR and Ca treatments. This conclusion implies that the degree of forest decline caused by long-term acid deposition may be attributed not only to the sensitivity of tree species to acid deposition, but also to the Ca level in the soil. PMID:21470980
Liu, Ting-Wu; Wu, Fei-Hua; Wang, Wen-Hua; Chen, Juan; Li, Zhen-Ji; Dong, Xue-Jun; Patton, Janet; Pei, Zhen-Ming; Zheng, Hai-Lei
The effect of lettuce (Latuca sativa L.) germination and growth in nonsterilized potting compost of 0.1% and 1.0% w\\/w incorporation of fermenter biomass inocula of six strains of Trichoderma was investigated. Except for strains WT and T35 at 0.1 % w\\/w, all inocula inhibited germination. Biomass of strains WT, T35, 20, and 47 at 1.0% promoted shoot fresh weight, whereas
M. A. Ousley; J. M. Lynch; J. M. Whipps
During storage sprout growth was linearly related to the amount of available tuber substrate. Plants grown in nutrient solution were also highly dependent on the reserves of the parent tuber until a relatively late stage of development. Light intensity and daylength only slightly influenced sprout growth: temperature and variety were of considerable importance. Increase in sprout size at the time
D. W. R. Headford
Background Plant growth regulators (PGRs) are the most powerful tools for manipulating tree growth and yield in an existing orchard. A quick review of current commercial uses of PGRs in apple, citrus, stone fruit, nut, kiwi, and grape production provides insight into the physiological processes that can be influenced to the economic benefit of growers. PGRs are used successfully to
Carol J. Lovatt; Samuel Salazar-García
The hormone-mediated control of plant growth and development involves both synthesis and response. Previous studies have shown that gibberellin (GA) plays an essential role in Arabidopsis seed germination. To learn how GA stimulates seed germination, we performed comprehensive analyses of GA biosynthesis and response using gas chromatography-mass spectrometry and oligonucleotide-based DNA microarray analysis. In addition, spatial correlations between GA biosynthe-
Mikihiro Ogawa; Atsushi Hanada; Yukika Yamauchi; Ayuko Kuwahara; Yuji Kamiya; Shinjiro Yamaguchi
In many crops there is a positive correlation between seed size and the rate of germination and seedling establishment. Hairy vetch (Vicia villosa, Roth) is an annual cool-season legume used primarily for soil improvement or for forage. In the Southern Great Plains its growing season is limited to...
The inhibition of seed germination by an allelochemical is generally greater in small seeds than in large seeds. This response may have significant impact on weed control by allelopathic cover crops where the small-seeded weeds would be controlled more effectively than large-seeded species. In our...
Summary 1 The fruit-colour polymorphism of Myrtus communis , a common Mediterranean shrub, is examined. We investigate whether frugivores affect the maintenance of the poly- morphism, whether morphs differ in germination or seedling growth, and whether passage through frugivores' gut affects seed behaviour and seedling growth. 2 Blue berries are very similar in morphological traits and nutrient composition to the
Anna Traveset; Nuria Riera; Rafael E. Mas
The overall goal of this research is to determine the effect of microgravity proper on plant growth (metabolism and cell wall formation). In addressing this goal, the work conducted during this grant period was divided into three components: analyses of various plant tissues previously grown in space aboard MIR Space Station; analyses of wheat tissues grown on Shuttle flight STS-51; and Phenylpropanoid metabolism and plant cell wall synthesis (earth-based investigations).
Lewis, Norman G.
This investigation was undertaken to determine the relative effects of recommended land spraying while drilling (LWD) loading rate application for a source of water-based drilling waste material on selected soil properties and phytotoxicity. Drilling waste material was obtained from a well where a nitrate gypsum water based product was used to formulate the drilling fluid. The fluid and associated drill cuttings were used as the drilling waste source to conduct the experiment. The study was carried out in triplicate and involved five plant species, four drilling waste loading rates and a representative agricultural soil type in Alberta. Plant growth was monitored for a period of ten days. Drilling waste applied at 10 times above the recommended loading rate improved the growth and germination rate of all plants excluding radish. Loading rates in excess of 40 and 50 times had a deleterious effect on radish, corn and oat but not on alfalfa and barley. Germination rate decreased as waste loading rate increased. Effects on soil physical and chemical properties were more pronounced at the 40 and 50 times exceeding recommended loading rate. Significant changes in soil parameters occurred at the higher rates in terms of increase in soil porosity, pH, EC, hydraulic conductivity, SAR and textural classification. This study indicates that the applications of this type of water based drill cutting if executed at an optimal loading rate, may improve soil quality and results in better plant growth. PMID:24117079
Saint-Fort, Roger; Ashtani, Sahar
Three wetland macrophytes, Sesbania herbacea, Bidens frondosa, and Eclipta prostrata, were exposed (0.4-1,000-ppb nominal concentrations) to the antimicrobial triclosan for 28 d in a flow-through system. Sesbania herbacea had decreased seed germination at the 100-ppb exposure level at days 7, 14, and 21, and B. frondosa germination was reduced at the 1,000-ppb exposure level at day 7. Eclipta prostrata germination was unaffected. Seedling effects monitored were total fresh weight, shoot and root fresh weights, root length, and root surface area. Root metrics were most affected by exposure. Total root length was diminished at all exposure levels in S. herbacea and B. frondosa and at the 10-ppb and higher concentrations for E. prostrata. Root surface area decreased at all exposure levels in B. frondosa and at the 10-ppb level and above in S. herbacea and E. prostrata. Root and shoot bioconcentration factors (BCFs) were estimated for S. herbacea and B. frondosa. While BCFs were low in shoots of both species and roots of S. herbacea (<10), they were elevated in B. frondosa roots (53-101). Methyl-triclosan was formed in the system and accumulated in shoot and root tissues of S. herbacea to concentrations that exceeded those of the parent compound. However, methyl-triclosan was nontoxic in an Arabidopsis thaliana enoyl-acyl carrier protein reductase (the putative enzymatic target of triclosan) assay and did not appear to contribute to the effects of exposure. Two of the three plant species assessed exhibited reduced root systems at environmentally relevant concentrations, raising the concern that wetland plant performance could be compromised in constructed wetlands receiving wastewater treatment plant discharges. PMID:19653736
Stevens, Kevin J; Kim, Seon-Young; Adhikari, Sajag; Vadapalli, Vatsala; Venables, Barney J
Dried mosses (five moss species) were progressively extracted and subjected to a four-step Craig distribution. Seven pure flavonoids were isolated and identified. The flavonoids were the flavones apigenin, apigenin-7-O-triglycoside, lucenin-2, luteolin-7-O-neohesperidoside, saponarine and vitexin; and the biflavonoid bartramiaflavone and they were submitted to biological tests. The tests were performed in vitro on spore germination and protonemal growth of the moss Tortula muralis and on seed germination and root growth of Raphanus sativus. Flavonoids caused a decrease in the percentage of spore germination, protonemal development and root growth. In addition they caused morphological alterations, such as forked tips, swollen apices, rounded cells and early formation of brood cells in the protonemata. Data were discussed in relation to the presence of allelochemicals in mosses. PMID:12591270
Basile, Adriana; Sorbo, Sergio; López-Sáez, José Antonio; Castaldo Cobianchi, Rosa
Synthetic detergents constitute one of the most important water pollutants by contaminating the lakes and rivers through domestic and industrial use. Considerable information is now available for the adverse effects of detergents an aquatic fauna including fish, algae, and higher aquatic plants. Marked inhibition of germination in orchids and brinjals and of seedlings growth in raddish suggest that rapidly growing systems could be sensitive to detergent polluted water. The present study of the effect of linear alkyl benzene sulphonate on germination of the spores of a fern, Diplazium esculentum aims at the understanding of the effects of water pollution on pteridophytes and the development of spore germination assay for phytoxicity evaluation.
Devi, Y.; Devi, S.
Vermicompost has been promoted as a viable alternative container media component for the horticulture industry. The purpose of this research was to investigate the use of vermicompost at different points in the production cycle of tomato, marigold, pepper, and cornflower. The incorporation of vermicompost of pig manure origin into germination media up to 20% v/v enhanced shoot and root weight, leaf area, and shoot:root ratios of both tomato and French marigold seedlings; however amendment with vermicompost had little influence on pepper and cornflower seedling growth. Moreover there was no effect on the germination of seed of any species. When seedlings of tomato, French marigold, and cornflower were transplanted into 6-cell packs there was greater plant growth in media amended with vermicompost compared to the control media, and the greatest growth when vermicompost was amended into both the germination and transplant media. This effect was increased when seedlings in the transplant media were irrigated with water containing fertilizer. PMID:17689243
Bachman, G R; Metzger, J D
The yellow hornpoppy, Glaucium flavum Cr. (Fam. Papaveraceae) is a perennial herb, distributed in the Mediterranean region, including Egypt. The plant contains many benzyl isoquinoline alkaloids from the aporphine type such as glaucine, isoboldine, 1-chelidonine, 1-norchelidonine and 3-O-methylarterenol, making it to display various medicinal activities including antitussive, anticancer, antioxidant, antimicrobial, antiviral, hypoglycemic, analgesic, antipyretic, bronchodilator and anti-inflammatory effects. The plant is now rare and endangered in the Egyptian flora due to urban sprawl. The present study looks into Glaucium flavum seeds' in vitro germination as well as the ability of the explants taken from the growing seedlings to form stable callus lines in order to enable micropropagation as a way to save the rare plant. The study also scans the production of different medicinally valuable alkaloids, particularly glaucine, in produced callus. PMID:25272947
Mohamed, M E; Arafa, A M; Soliman, S S; Eldahmy, S I
Background and Aims The role of fire as a germination cue for Mediterranean Basin (MB) plants is still unclear. The current idea is that heat stimulates germination mainly in Cistaceae and Fabaceae and that smoke has a limited role as a post-fire germination cue, in comparison with other Mediterranean-type ecosystems (MTEs), suggesting that fire-stimulated germination is less relevant in the MB than in other MTEs. However, recent studies showed that the assembly of Mediterranean plant communities is strongly driven by post-fire germination, suggesting an important role for fire as a germination cue. We hypothesize that both heat and smoke have important effects on the different post-fire recruitment processes of MB species (e.g. level and rate of germination and initial seedling growth). Methods To ascertain the role of heat and smoke in the post-fire germination response of MB woody plants, a germination experiment was performed with seven heat and two smoke treatments on 30 MB woody species from seven different families, including species with water-permeable seeds and species with water-impermeable seeds. Key Results Heat stimulated the germination (probability and rate) of 21 species and smoke in eight species, out of the 30 species studied. In addition, six species showed enhanced initial seedling growth after the smoke treatments. Conclusions The results suggest that both heat and smoke are important germination cues in a wide range of MB woody species and that fire-cued germination in woody plants of the MB may be as important as in other MTEs. PMID:20181568
Moreira, B.; Tormo, J.; Estrelles, E.; Pausas, J. G.
Sand bluestem (Andropogon hallii Hack.) populations AB-medium Syn-1 and Syn-2, and CD-tall Syn-1 and Syn-2 were developed from populations AB-medium Syn-0 and CD-tall Syn-0 by recurrent selection for increased seed germination in low water potentials. The objective of this research was to verify if...
Two urban composts, one very coarse, low in organic matter but mature, and the other particulated, high in organic matter but not well stabilized, were tested. Germination ‘in vitro’ and in soil of cress, ryegrass and sunflower seeds, seedling performance (root, shoot and sheath lengths) and seedling composition (in soil) of ryegrass were evaluated. Other organic composts, including a vermi-compost,
J. M. Murillo; F. Cabrera; R. López; P. Martín-Olmedo
Potential allelopathic compounds of Juniperus ashei Buchh. (Ashe juniper) and their effect on a native grass were determined in laboratory and field studies. Solid-phase microextraction and gas chromatography/mass spectrometry were used to determine if monoterpenes found in the essential oils of J. ashei are released in leaf and litter leachate, as well as volatilized from leaf tissue. Camphor, bornyl acetate, and limonene were found in leaf and fresh litter leachates; however, degraded litter did not contain any of these compounds. Camphor was the most common potentially allelopathic compound found in J. ashei leaf and litter leachate and in volatiles from leaf tissue. The effects of leaf and litter tissue on the germination of Bouteloua curtipendula (Michx.) Torr. (side-oats grama) was tested by using the "sandwich agar method". The highest germination of B. curtipendula (29.6%) occurred in the control, which was significantly higher than fresh litter (13.2%) and degraded litter (16.2%). The lowest germination (6.2%) occurred with J. ashei leaves. In the field experiment, aboveground dry mass of B. curtipendula was evaluated in relation to position within the canopy and intercanopy of J. ashei adult trees when light and water were held constant across locations. Aboveground dry mass of B. curtipendula was significantly greater in the intercanopies of J. ashei (163.7 g m(2)) compared to the dry mass in the understory (44.8 g m(2)) and dripline (44.5 g m(2)), suggesting some negative influence by J. ashei. Chemical analyses indicate that monoterpenes are released through leaching and volatilization from J. ashei, and germination and field studies suggest that these compounds inhibit B. curtipendula. PMID:19153797
Young, G P; Bush, J K
Here you will find basic information on the reproduction and growth of plants; from a seed that develops into a full grown plant and then, when sexually mature, produces its own seeds. Plant development and reproduction Standard 3, objective 3 (4 th grade). Observe plant growth and relate it to soil conditions. Objectives : List the resources needed for the healthy growth of plants. Explain how a seed germinates and plants grow. Describe the ...
The effects of the growth retardants tetcyclacis, a norbornenodiazetine, and LAB 150 978, a dioxanylalkenyl triazole, on seedling growth and endogenous levels of phytohormone-like substances in Glycine max L. cv Maple Arrow were studied. The levels of phytohormone-like substances in the root and in the various shoot tissues were analyzed by immunoassay. After seed treatment with both compounds, shoot growth was reduced more intensively than root growth. Both compounds decreased, on a fresh weight basis, the amount of various immunoreactive gibberellins when compared with the levels in control plants, especially in the shoot tip. Likewise, the growth retardants lowered the levels of abscisic acid-like material, particularly in the primary leaf, the epicotyl and the root. In contrast, the levels of trans-zeatin-riboside and dihydrozeatin-riboside-type cytokinins were considerably elevated by the growth retardants, mainly in the primary leaf, epicotyl, and hypocotyl. On the other hand the level of isopentenyladenosine-like material was less influenced. In general, the immunoreactive 3-indoleacetic acid content in the different plant parts was changed only slightly. It is assumed that besides their effect on gibberellin content both compounds interfere directly or indirectly with the regulation of the endogenous levels of abscisic acid and cytokinins. This might be seen as an additional mode of action of growth retardants explaining some side effects on developmental processes of treated plants, e.g. delayed senescence and enhanced chlorophyll concentration in the leaves. PMID:16665554
Grossmann, Klaus; Kwiatkowski, Jacek; Siebecker, Heinrich; Jung, Johannes
Plant growth and development are regulated by interactions between the environment and endogenous developmental programs. Of the various environmental factors controlling plant development, light plays an especially important role, in photosynthesis, in seasonal and diurnal time sensing, and as a cue for altering developmental pattern. Recently, several laboratories have devised a variety of genetic screens using Arabidopsis thaliana to dissect the signal transduction pathways of the various photoreceptor systems. Genetic analysis demonstrates that light responses are not simply endpoints of linear signal transduction pathways but are the result of the integration of information from a variety of photoreceptors through a complex network of interacting signaling components. These signaling components include the red/far-red light receptors, phytochromes, at least one blue light receptor, and negative regulatory genes (DET, COP, and FUS) that act downstream from the photoreceptors in the nucleus. In addition, a steroid hormone, brassinolide, also plays a role in light-regulated development and gene expression in Arabidopsis. These molecular and genetic data are allowing us to construct models of the mechanisms by which light controls development and gene expression in Arabidopsis. In the future, this knowledge can be used as a framework for understanding how all land plants respond to changes in their environment. PMID:8901532
Chory, J; Chatterjee, M; Cook, R K; Elich, T; Fankhauser, C; Li, J; Nagpal, P; Neff, M; Pepper, A; Poole, D; Reed, J; Vitart, V
Plant growth and development are regulated by interactions between the environment and endogenous developmental programs. Of the various environmental factors controlling plant development, light plays an especially important role, in photosynthesis, in seasonal and diurnal time sensing, and as a cue for altering developmental pattern. Recently, several laboratories have devised a variety of genetic screens using Arabidopsis thaliana to dissect the signal transduction pathways of the various photoreceptor systems. Genetic analysis demonstrates that light responses are not simply endpoints of linear signal transduction pathways but are the result of the integration of information from a variety of photoreceptors through a complex network of interacting signaling components. These signaling components include the red/far-red light receptors, phytochromes, at least one blue light receptor, and negative regulatory genes (DET, COP, and FUS) that act downstream from the photoreceptors in the nucleus. In addition, a steroid hormone, brassinolide, also plays a role in light-regulated development and gene expression in Arabidopsis. These molecular and genetic data are allowing us to construct models of the mechanisms by which light controls development and gene expression in Arabidopsis. In the future, this knowledge can be used as a framework for understanding how all land plants respond to changes in their environment. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8901532
Chory, J; Chatterjee, M; Cook, R K; Elich, T; Fankhauser, C; Li, J; Nagpal, P; Neff, M; Pepper, A; Poole, D; Reed, J; Vitart, V
An antibiotic-producing and hydrogen-cyanide-producing rhizobacteria strain Bacillus BS2 showed a wide range of antifungal activity against many Fusarium sp. and brinjal wilt disease pathogen Rhizoctonia solani. Seed bacterization with the strain BS2 promoted seed germination and plant growth in leguminous plants Phaseolus vulgaris and non-leguminous plants Solanum melongena L, Brassica oleracea var. capitata, B. oleraceae var. gongylodes and Lycopersicon esculentum Mill in terms of relative growth rate, shoot height, root length, total biomass production and total chlorophyll content of leaves. Yield of bacterized plants were increased by 10 to 49% compared to uninoculated control plants. Brinjal sapling raised through seed bacterization by the strain BS2 showed a significantly reduced wilt syndrome of brinjal caused by Rhizoctonia solani. Control of wilt disease by the bacterium was clue to the production of antibiotic-like substances, whereas plant growth-promotion was due to the activity of hydrogen cyanide. Root colonization study confirmed that the introduced bacteria colonized the roots and occupied 23-25% of total aerobic bacteria, which was confirmed using dual antibiotic (nalidixic acid and streptomycin sulphate) resistant mutant strain. The results obtained through this investigation suggested the potentiality of the strain BS2 to be used as a plant growth promoter and suppressor of wilt pathogen. PMID:15266911
Boruah, H P Deka; Kumar, B S Dileep
This work provides information on research and experimentation concerning various aspects of food production in space and particularly on the moon. Options for human settlement of the moon and Mars and strategies for a lunar base are discussed. The lunar environment, including the mineralogical and chemical properties of lunar regolith are investigated and chemical and physical considerations for a lunar-derived soil are considered. It is noted that biological considerations for such a soil include controlled-environment crop production, both hydroponic and lunar regolith-based; microorganisms and the growth of higher plants in lunar-derived soils; and the role of microbes to condition lunar regolith for plant cultivation. Current research in the controlled ecological life support system (CELSS) project is presented in detail and future research areas, such as the growth of higher research plants in CELSS are considered. Optimum plant and microbiological considerations for lunar derived soils are examined.
Ming, Douglas W. (editor); Henninger, Donald L. (editor)
We present experimental results for the dynamical scaling properties of the development of plant calli. We have assayed two different species of plant calli, Brassica oleracea and Brassica rapa, under different growth conditions, and show that their dynamical scalings share a universality class. From a theoretical point of view, we introduce a scaling hypothesis for systems whose size evolves in time. We expect our work to be relevant for the understanding and characterization of other systems that undergo growth due to cell division and differentiation, such as, for example, tumor development.
Galeano, J.; Buceta, J.; Juarez, K.; Pumariño, B.; de la Torre, J.; Iriondo, J. M.
\\u000a Plant growth promoting rhizobacteria (PGPR) have gained worldwide importance and acceptance for agricultural benefits. This\\u000a is due to the emerging demand for dependence diminishing of synthetic chemical products, to the growing necessity of sustainable\\u000a agriculture within a holistic vision of development and to focalize environmental protection. Scientific researches involve\\u000a multidisciplinary approaches to understand adaptation of PGPR, effects on plant physiology
Márcia Figueiredo; Lucy Seldin; Fabio Fernando de Araujo; Rosa Mariano
Sedimentation of the Illinois River in central Illinois has greatly diminished the utility and ecological value of the Peoria Lakes reach of the river. Consequently, a large dredging project has been proposed to improve its wildlife habitat and recreation potential, but disposal of the dredged sediment presents a challenge. Land placement is an attractive option. Previous work in Illinois has demonstrated that sediments are potentially capable of supporting agronomic crops due to their high natural fertility and water holding capacity. However, Illinois River sediments have elevated levels of heavy metals, which may be important if they are used as garden or agricultural soil. A greenhouse experiment was conducted to determine if these sediments could serve as a plant growth medium. A secondary objective was to determine if plants grown on sediments accumulated significant heavy metal concentrations. Our results indicated that lettuce (Lactuca sativa L.), barley (Hordeum vulgare L.), radish (Raphanus sativus L.), tomato (Lycopersicon lycopersicum L.), and snap bean (Phaseolus vulagaris L. var. humillis) grown in sediment and a reference topsoil did not show significant or consistent differences in germination or yields. In addition, there was not a consistent statistically significant difference in metal content among tomatoes grown in sediments, topsoil, or grown locally in gardens. In the other plants grown on sediments, while Cd and Cu in all cases and As in lettuce and snap bean were elevated, levels were below those considered excessive. Results indicate that properly managed, these relatively uncontaminated calcareous sediments can make productive soils and that metal uptake of plants grown in these sediments is generally not a concern.
Darmody, R.G.; Marlin, J.C.; Talbott, J.; Green, R.A.; Brewer, E.F.; Stohr, C.
Myrigalone A (MyA) is a rare flavonoid in fruit leachates of Myrica gale, a deciduous shrub adapted to flood-prone habitats. As a putative allelochemical it inhibits seed germination and seedling growth. Using Lepidium sativum as a model target species, experiments were conducted to investigate how environmental cues modulate MyA’s interference with key processes of seed germination. Time course analyses of L. sativum testa and endosperm rupture under different light conditions and water potentials were combined with quantifying testa permeability, endosperm weakening, tissue-specific gibberellin (GA) and abscisic acid (ABA) contents, as well as embryo growth and apoplastic superoxide production important for cell expansion growth. Lepidium sativum testa permeability and early water uptake by imbibition is enhanced by MyA. During late germination, MyA inhibits endosperm weakening and embryo growth, both processes required for endosperm rupture. Inhibition of embryo cell expansion by MyA depends on environmental cues, which is evident from the light-modulated severity of the MyA-mediated inhibition of apoplastic superoxide accumulation. Several important key weakening and growth processes during early and late germination are targets for MyA. These effects are modulated by light conditions and ambient water potential. It is speculated that MyA is a soil seed bank-destroying allelochemical that secures the persistence of M. gale in its flood-prone environment. PMID:22821938
Food security depends on enhancing production and reducing loss to pests and pathogens. A promising alternative to agrochemicals is the use of plant growth-promoting rhizobacteria (PGPR), which are commonly associated with many, if not all, plant species. However, exploiting the benefits of PGPRs requires knowledge of bacterial function and an in-depth understanding of plant-bacteria associations. Motility is important for colonization efficiency and microbial fitness in the plant environment, but the mechanisms employed by bacteria on and around plants are not well understood. We describe and investigate an atypical mode of motility in Pseudomonas fluorescens SBW25 that was revealed only after flagellum production was eliminated by deletion of the master regulator fleQ. Our results suggest that this 'spidery spreading' is a type of surface motility. Transposon mutagenesis of SBW25?fleQ (SBW25Q) produced mutants, defective in viscosin production, and surface spreading was also abolished. Genetic analysis indicated growth-dependency, production of viscosin, and several potential regulatory and secretory systems involved in the spidery spreading phenotype. Moreover, viscosin both increases efficiency of surface spreading over the plant root and protects germinating seedlings in soil infected with the plant pathogen Pythium. Thus, viscosin could be a useful target for biotechnological development of plant growth promotion agents. PMID:24684210
Alsohim, Abdullah S; Taylor, Tiffany B; Barrett, Glyn A; Gallie, Jenna; Zhang, Xue-Xian; Altamirano-Junqueira, Astrid E; Johnson, Louise J; Rainey, Paul B; Jackson, Robert W
Glucose and phytohormones such as abscisic acid (ABA), ethylene, and gibberellin (GA) coordinately regulate germination and seedling development. However, there is still inadequate evidence to link their molecular roles in affecting plant responses. Calcium acts as a second messenger in a diverse range of signal transduction pathways. As calcium sensors unique to plants, calcineurin B-like (CBL) proteins are well known to modulate abiotic stress responses. In this study, it was found that CBL1 was induced by glucose in Arabidopsis. Loss-of-function mutant cbl1 exhibited hypersensitivity to glucose and paclobutrazol, a GA biosynthetic inhibitor. Several sugar-responsive and GA biosynthetic gene expressions were altered in the cbl1 mutant. CBL1 protein physically interacted with AKIN?1, the regulatory ? subunit of the SnRK1 complex which has a central role in sugar signaling. Our results indicate a novel role for CBL1 in modulating responses to glucose and GA signals. PMID:23437128
Li, Zhi-Yong; Xu, Zhao-Shi; Chen, Yang; He, Guang-Yuan; Yang, Guang-Xiao; Chen, Ming; Li, Lian-Cheng; Ma, You-Zhi
Glucose and phytohormones such as abscisic acid (ABA), ethylene, and gibberellin (GA) coordinately regulate germination and seedling development. However, there is still inadequate evidence to link their molecular roles in affecting plant responses. Calcium acts as a second messenger in a diverse range of signal transduction pathways. As calcium sensors unique to plants, calcineurin B-like (CBL) proteins are well known to modulate abiotic stress responses. In this study, it was found that CBL1 was induced by glucose in Arabidopsis. Loss-of-function mutant cbl1 exhibited hypersensitivity to glucose and paclobutrazol, a GA biosynthetic inhibitor. Several sugar-responsive and GA biosynthetic gene expressions were altered in the cbl1 mutant. CBL1 protein physically interacted with AKIN?1, the regulatory ? subunit of the SnRK1 complex which has a central role in sugar signaling. Our results indicate a novel role for CBL1 in modulating responses to glucose and GA signals. PMID:23437128
Li, Zhi-Yong; Xu, Zhao-Shi; Chen, Yang; He, Guang-Yuan; Yang, Guang-Xiao; Chen, Ming; Li, Lian-Cheng; Ma, You-Zhi
Acacia dealbata Link is a widespread invader in Mediterranean type ecosystems, and traits promoting its invasiveness are currently under investigation. Due to the dense atmosphere below its canopy, we hypothesized that volatile organic compounds (VOCs) released from flowers, leaves, litter, or a mixture of treatments exert inhibitory effects on the natives Trifolium subterraneum, Lolium multiflorum, Medicago sativa, and also on its own seeds. We reported that VOCs from flowers significantly reduced germination in L. multiflorum and A. dealbata; moreover, root length, stem length, aboveground and belowground biomass were also reduced in all species studied. Volatile organic compounds from flowers and the mixture also increased significantly malondialdehyde content in T. subterraneum and L. multiflorum. The effects of VOCs on antioxidant enzymatic activities were species dependent. Flowers enhanced peroxidase but decreased superoxide dismutase activity in T. subterraneum. In contrast, VOCs released from leaves increased the activity of superoxide dismutase in L. multiflorum. GC/MS analyses revealed 27 VOCs in the volatile fraction from flowers, 12 of which were exclusive to this fraction. Within them, heptadecadiene, n-nonadecane, n-tricosane, and octadecene represent 62% of the fraction. We present evidence that the VOCs released from A. dealbata flowers strongly inhibited germination and seedling growth of selected species, and mainly on its own seedlings. As far as we know, this is the first evidence of phytotoxicity induced by VOCs in invasive species belonging to the Acacia genus. PMID:25260655
Souza-Alonso, Pablo; González, Luís; Cavaleiro, Carlos
Previous research has demonstrated the low tolerance of Posidonia oceanica mature shoots to salinity variability but there is no information about the response of its seeds and seedlings to this impact. In the present study, two independent experiments were conducted to investigate the effects of salinity variation on germination, development and survival of P. oceanica seeds and seedlings under laboratory-controlled conditions. Maximum P. oceanica seed germination occurred at the control salinity (37), while mortality was lowest for this treatment. However, no significant differences were detected with other salinity levels (39-49). In contrast, salinity appears to play an important role in seedling development. The number of blades, the length of the primary root and the maximum length of leaves of seedlings were significantly reduced with increased salinities. The results observed in the present study are consistent with those obtained for mature P. oceanica shoots, and suggest that hypersalinities, such as those associated with brine discharge of a desalination plant, may limit P. oceanica seedling recruitment, affecting the expansion and recovery of Posidonia meadows.
Fernández-Torquemada, Yolanda; Sánchez-Lizaso, José Luis
and severity of Cephalosporium stripe at low soil pH (4.5 to 5.5) is also well documented, but not definitively explained (2,5,13). Increased Cephalosporium stripe at low soil pH may result from the increased survival of soil pH and matric poten- tial on germination of conidia in soil. Pre- liminary results have been
Murray, Timothy D.
Germination of Silphium terebinthenaceum was enhanced by a post-stratification most-heat treatment at 80°C. Tested seeds of four other perennial herbs common to midwestern prairies (Andropogon scoparius, Sorghastrum nutans, Eryngium yuccifolium, and Solidago rigida) showed little adverse or beneficial effects of the heat treatment. Heat treatments alone had little effect on the seeds; the length of stratification periods necessary to effect
John E. Stuurwold
The technical book "Plant Growth and climate Change" (2006. James I.L. Morison and M.D. Morecroft, Eds. Blackwell Publishing. 213 pp.) was reviewed for the scientific readership of the peer-reviewed journal HortScience. The text is well organized into nine independently-authored chapters each of whi...
Plant pathology Growth inhibition of Agaricus bisporus and associated thermophilic species Agaricus bisporus and 3 isolates of thermophilic fungi active in mushroom composting. At concentrations compost I fungicide residue I Agaricus bisporus I Torula thermophila I Humicola grisea var ther- moidea
Paris-Sud XI, UniversitÃ© de
The influence of bio-fillers incorporated into polypropylene (PP) on the growth of plants was evaluated. Biocontainers were created by injection molding of PP with 25-40% by weight of Osage orange tree, Paulownia tree, coffee tree wood or dried distillers grain and 5% by weight of maleated polypropy...
In order to maximize efficiency of plant propagation via direct organogenesis, the influence of plant growth regulators on the growth and development of Stevia rebaudiana grown in vitro was studied. Results indicated that benzyl adenine increased multiplication rate, vitrification and somaclonal variation.\\u000a However, the best results were recorded with MS nutrient medium without plant growth regulators during in vitro growth
Ibrahim A. Ibrahim; Mahmoud I. Nasr; Berlanti R. Mohammed; Mohammed M. El-Zefzafi
- 1 - Faster plant growth in a safe, economical way April 3, 2012 Good science and good business: synthesizing plant metabolite creates an economical growth treatment Biagro Western Sales, Inc., was founded plant metabolite that, when applied to plants, speeds crop emergence, increases growth rates and yields
The influence of seedbed (undisturbed forest floor, burned forest floor, and mineral soil), light (closed forest, open forest, and clearcut), and competing vegetation (present, not present) on germination and initial seedling survival and growth of subalpine fir (Abies lasiocarpa) and Engelmann spruce (Picea engelmannii) was investigated after applying seeds to small (1 m2) plots established in each of the two
M. C Feller
relationship to seed germination and seedling growth Diana Soriano1, Alma Orozco-Segovia1, Judith MaSeed reserve composition in 19 tree species of a tropical deciduous forest in Mexico and its for revision: 20 December 2010 Accepted: 21 January 2011 Background and Aims The size and composition of seed
To date, there has been only limited commercial use of plant growth-promoting bacteria in agriculture, horticulture, and silviculture. However, with recent progress toward understanding the mechanisms that these organisms utilize to facilitate plant growth, the use of plant growth-promoting bacteria is expected to continue to increase worldwide. One of the key mechanisms employed by plant growth-promoting bacteria to facilitate plant
Bernard R. Glick; Biljana Todorovic; Jennifer Czarny; Zhenyu Cheng; Jin Duan; Brendan McConkey
Plants with limited resources adjust partitioning among growth, survival, and reproduction. We tested the effects of water\\u000a and nutrient amendments on seed production, size, and quality in Sarcobatus vermiculatus (greasewood) to assess the magnitude and importance of changes in reproductive partitioning. In addition, we assessed interactions\\u000a among the environment of seed-producing plants (adult plant scale), seed size, and seedling microenvironment
A. N. Breen; J. H. Richards
or base temperatures for seed germination were determined, and germina- tion capacity of the cultivars was evaluated under a range of tempera- ture conditions in a germinator and in sand plantings. The ger'mination performances were correlated among... in rate of germination among cultivars were observed only at 12. 8 C, Cultivar differences in percent and rate of germination were observed in ambient temperature conditions and no cultivar differences occurred for percent and rate of emergence at 15. 6...
Wickramasinghe, Palitha Jagath
Background Endophytic fungi are known plant symbionts. They produce a variety of beneficial metabolites for plant growth and survival, as well as defend their hosts from attack of certain pathogens. Coastal dunes are nutrient deficient and offer harsh, saline environment for the existing flora and fauna. Endophytic fungi may play an important role in plant survival by enhancing nutrient uptake and producing growth-promoting metabolites such as gibberellins and auxins. We screened roots of Ixeris repenes (L.) A. Gray, a common dune plant, for the isolation of gibberellin secreting endophytic fungi. Results We isolated 15 endophytic fungi from the roots of Ixeris repenes and screened them for growth promoting secondary metabolites. The fungal isolate IR-3-3 gave maximum plant growth when applied to waito-c rice and Atriplex gemelinii seedlings. Analysis of the culture filtrate of IR-3-3 showed the presence of physiologically active gibberellins, GA1, GA3, GA4 and GA7 (1.95 ng/ml, 3.83 ng/ml, 6.03 ng/ml and 2.35 ng/ml, respectively) along with other physiologically inactive GA5, GA9, GA12, GA15, GA19, GA20 and, GA24. The plant growth promotion and gibberellin producing capacity of IR-3-3 was much higher than the wild type Gibberella fujikuroi, which was taken as control during present study. GA5, a precursor of bioactive GA3 was reported for the first time in fungi. The fungal isolate IR-3-3 was identified as a new strain of Penicillium citrinum (named as P. citrinum KACC43900) through phylogenetic analysis of 18S rDNA sequence. Conclusion Isolation of new strain of Penicillium citrinum from the sand dune flora is interesting as information on the presence of Pencillium species in coastal sand dunes is limited. The plant growth promoting ability of this fungal strain may help in conservation and revegetation of the rapidly eroding sand dune flora. Penicillium citrinum is already known for producing mycotoxin citrinin and cellulose digesting enzymes like cellulase and endoglucanase, as well as xylulase. Gibberellins producing ability of this fungus and the discovery about the presence of GA5 will open new aspects of research and investigations. PMID:19099608
Khan, Sumera Afzal; Hamayun, Muhammad; Yoon, Hyeokjun; Kim, Ho-Youn; Suh, Seok-Jong; Hwang, Seon-Kap; Kim, Jong-Myeong; Lee, In-Jung; Choo, Yeon-Sik; Yoon, Ung-Han; Kong, Won-Sik; Lee, Byung-Moo; Kim, Jong-Guk
The rice blast fungus Magnaporthe oryzae is a model for studying fungal–plant interactions. Although it produces two types of spores (microconidia and macroconidia), previous infection studies have exclusively dealt with macroconidia. Germination of microconidia has not been reported, and their role in plant infection is not defined. Here we show that approximately 10% of microconidia germinate on plant surfaces, and that colonies derived from germinated microconidia are normal in growth and pathogenesis. In infection assays with rice and barley seedlings, microconidia fail to infect intact plants, but they can colonize and develop necrotic lesions on wounded leaves and stems. Microconidia also cause disease symptoms on inoculated spikelets in infection assays with barley and Brachypodium heads. Furthermore, microconidia are detected inside rice plants that developed blast lesions under laboratory or field conditions. Therefore, microconidia can germinate and are infectious, and may be an important factor in the rice blast cycle. PMID:25082370
Zhang, Huili; Wu, Zhongshou; Wang, Chenfang; Li, Yang; Xu, Jin-Rong
Soybean and eggplant grown and shaken in a greenhouse exhibited decreased internode length, internode diameter, leaf area, and fresh and dry weight of roots and shoots in much the same way as outdoor-exposed plants. Perhaps more important than decreased dimensions of plant parts resulting from periodic seismic treatment is the inhibition of photosynthetic productivity that accompanies this stress. Soybeam plants briefly shaken or rubbed twice daily experienced a decrease in relative as well as absolute growth rate compared to that of undisturbed controls. Growth dynamics analysis revealed that virtually all of the decline in relative growth rate (RGR) was due to a decline in net assimilation rate (NAR), but not in leaf area ratio (LAR). Lower NAR suggests that the stress-induced decrease in dry weight gain is due to a decline in photosynthetic efficiency. Possible effects on stomatal aperture was investigated by measuring rates of whole plant transpiration as a function of seismo-stress, and a transitory decrease followed by a gradual, partial recovery was detected.
Mitchell, C. A.
Respiratory oxidative phosphorylation is a cornerstone of cellular metabolism in aerobic multicellular organisms. The efficiency of this process is generally assumed to be maximized, but the presence of dynamically regulated nonphosphorylating bypasses implies that plants can alter phosphorylation efficiency and can benefit from lowered energy generation during respiration under certain conditions. We characterized an Arabidopsis (Arabidopsis thaliana) mutant, ndufs4 (for NADH dehydrogenase [ubiquinone] fragment S subunit 4), lacking complex I of the respiratory chain, which has constitutively lowered phosphorylation efficiency. Through analysis of the changes to mitochondrial function as well as whole cell transcripts and metabolites, we provide insights into how cellular metabolism flexibly adapts to reduced phosphorylation efficiency and why this state may benefit the plant by providing moderate stress tolerance. We show that removal of the single protein subunit NDUFS4 prevents assembly of complex I and removes its function from mitochondria without pleiotropic effects on other respiratory components. However, the lack of complex I promotes broad changes in the nuclear transcriptome governing growth and photosynthetic function. We observed increases in organic acid and amino acid pools in the mutant, especially at night, concomitant with alteration of the adenylate content. While germination is delayed, this can be rescued by application of gibberellic acid, and root growth assays of seedlings show enhanced tolerance to cold, mild salt, and osmotic stress. We discuss these observations in the light of recent data on the knockout of nonphosphorylating respiratory bypass enzymes that show opposite changes in metabolites and stress sensitivity. Our data suggest that the absence of complex I alters the adenylate control of cellular metabolism. PMID:19675153
Meyer, Etienne H; Tomaz, Tiago; Carroll, Adam J; Estavillo, Gonzalo; Delannoy, Etienne; Tanz, Sandra K; Small, Ian D; Pogson, Barry J; Millar, A Harvey
Three plant growth-promoting bacteria (PGPB; Bacillus pumilus ES4, B. pumilus RIZO1, and Azospirillum brasilense Cd) were tested for their ability to enhance plant growth and development of the native Sonoran Desert shrub quailbush (Atriplex lentiformis) and for their effect on the native bacterial community in moderately acidic, high-metal content (AHMT) and in neutral, low metal content natural tailings (NLMT) in controlled greenhouse experiments. Inoculation of quailbush with all three PGPB significantly enhanced plant growth parameters, such as germination, root length, dry weight of shoots and roots, and root/shoot ratio in both types of tailings. The effect of inoculation on the indigenous bacterial community by the most successful PGPB Bacillus pumilus ES4 was evaluated by denaturating gradient gel electrophoresis (PCR-DGGE) fingerprinting and root colonization was followed by specific fluorescent in situ hybridization (FISH). Inoculation with this strain significantly changed the bacterial community over a period of 60 days. FISH analysis showed that the preferred site of colonization was the root tips and root elongation area. This study shows that inoculation of native perennial plants with PGPB can be used for developing technologies for phytostabilizing mine tailings. PMID:25009362
de-Bashan, Luz E.; Hernandez, Juan-Pablo; Bashan, Yoav; Maier, Raina
A low lipid, high starch containing tissue, namely cotyledons of germinating pea seedlings was examined for its capacity to synthesize fatty acid. Intact tissue slices readily incorporate acetate-14C into fatty acids from C16 to C24. Although crude homogenates synthesize primarily 16:0 and 18:0 from malonyl CoA, subsequent fractionation into a 10,000g pellet, a 105g pellet and supernatant (soluble synthetase) revealed that the 105g pellet readily synthesizes C16 to C28 fatty acids whereas the 10,000g and the supernatant synthesize primarily C16 and C18. All systems require acyl carrier protein (ACP), TPNH, DPNH if malonyl CoA is the substrate and ACP, Mg2+, CO2, ATP, TPNH, and DPNH if acetyl CoA is the substrate. The cotyledons of germinating pea seedlings appear to have a soluble synthetase and 10,000g particles for the synthesis of C16 and C18 fatty acid, and 105g particles which specifically synthesize the very long chain fatty acid from malonyl CoA, presumably via malonyl ACP. PMID:16656949
Macey, Michael J. K.; Stumpf, P. K.
A biological inoculant for enhancing the growth of plants is disclosed. The inoculant includes the bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101, Pantoea agglomerans P102, Klebsiella pneumoniae 342, Klebsiella pneumoniae zmvsy, Herbaspirillum seropedicae Z152, Gluconacetobacter diazotrophicus PA15, with or without a carrier. The inoculant also includes strains of the bacterium Pantoea agglomerans and K. pneumoniae which are able to enhance the growth of cereal grasses. Also disclosed are the novel bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101 and P102, and Klebsiella pneumoniae 342 and zmvsy.
Triplett, Eric W. (Middleton, WI); Kaeppler, Shawn M. (Oregon, WI); Chelius, Marisa K. (Greeley, CO)
I. II. III. IV. V. References SUMMARY: Anoxia tolerance in plants is distinguished by direction of the sparse supply of energy to processes crucial to cell maintenance and sometimes to growth, as in rice seedlings. In anoxic rice coleoptiles energy is used to synthesise proteins, take up K(+) , synthesise cell walls and lipids, and in cell maintenance. Maintenance of electrochemical H(+) gradients across the tonoplast and plasma membrane is crucial for solute compartmentation and thus survival. These gradients sustain some H(+) -solute cotransport and regulate cytoplasmic pH. Pyrophosphate (PPi ), the alternative energy donor to ATP, allows direction of energy to the vacuolar H(+) -PPi ase, sustaining H(+) gradients across the tonoplast. When energy production is critically low, operation of a biochemical pHstat allows H(+) -solute cotransport across plasma membranes to continue for at least for 18 h. In active (e.g. growing) cells, PPi produced during substantial polymer synthesis allows conversion of PPi to ATP by PPi -phosphofructokinase (PFK). In quiescent cells with little polymer synthesis and associated PPi formation, the PPi required by the vacuolar H(+) -PPi ase and UDPG pyrophosphorylase involved in sucrose mobilisation via sucrose synthase might be produced by conversion of ATP to PPi through reversible glycolytic enzymes, presumably pyruvate orthophosphate dikinase. These hypotheses need testing with species characterised by contrasting anoxia tolerance. PMID:25472708
Atwell, Brian J; Greenway, Hank; Colmer, Timothy D
Background and Aims The size and composition of seed reserves may reflect the ecological strategy and evolutionary history of a species and also temporal variation in resource availability. The seed mass and composition of seed reserves of 19 co-existing tree species were studied, and we examined how they varied among species in relation to germination and seedling growth rates, as well as between two years with contrasting precipitation (652 and 384 mm). Methods Seeds were collected from a tropical deciduous forest in the northwest of Mexico (Chamela Biological Station). The seed dry mass, with and without the seed coat, and the concentrations of lipids, nitrogen and non-structural carbohydrates for the seed minus seed coat were determined. The anatomical localization of these reserves was examined using histochemical analysis. The germination capacity, rate and lag time were determined. The correlations among these variables, and their relationship to previously reported seedling relative growth rates, were evaluated with and without phylogenetic consideration. Key Results There were interannual differences in seed mass and reserve composition. Seed was significantly heavier after the drier year in five species. Nitrogen concentration was positively correlated with seed coat fraction, and was significantly higher after the drier year in 12 species. The rate and lag time of germination were negatively correlated with each other. These trait correlations were also supported for phylogenetic independent contrasts. Principal component analysis supported these correlations, and indicated a negative association of seedling relative growth rate with seed size, and a positive association of germination rate with nitrogen and lipid concentrations. Conclusions Nitrogen concentration tended to be higher after the drier year and, while interannual variations in seed size and reserve composition were not sufficient to affect interspecific correlations among seed and seedling traits, some of the reserves were related to germination variables and seedling relative growth rate. PMID:21385781
Soriano, Diana; Orozco-Segovia, Alma; Márquez-Guzmán, Judith; Kitajima, Kaoru; Gamboa-de Buen, Alicia; Huante, Pilar
ORIGINAL PAPER Growth of planted black spruce seedlings following mechanical site preparation to improve growth conditions of planted black spruce seedlings in boreal forested peatlands where closed thick organic layers. Keywords Black spruce . Forest floor disturbance . Mechanical site preparation
Fungus-subsidized growth through the seedling stage is the most critical feature of the life history for the thousands of mycorrhizal plant species that propagate by means of 'dust seeds.' We investigated the extent of specificity towards fungi shown by orchids in the genera Cephalanthera and Epipactis at three stages of their life cycle: (i) initiation of germination, (ii) during seedling
MARTIN I. BIDARTONDO; DAVID J. READ
The presence of biological soil crusts can affect the germination and survival of vascular plants, but the reasons are not\\u000a well investigated. We have conducted a field investigation and greenhouse experiments to test the effect of crusts on two\\u000a desert annual plants, which occur on the stabilized dunes of the Tengger Desert in N China. The results showed that biological
Xin-Rong Li; Xiao-Hong Jia; Li-Qun Long; Stefan Zerbe
Plant growth retardants are widely used in cultivation of medicinal plant, but there is still lack of scientific guidance. In order to guide the use of plant growth retardants in medicinal plant cultivation efficiently and reasonably, this paper reviewed the mechanism, function characteristic, plant and soil residue of plant growth retardants, such as chlorocholine chloride, mepiquat chloride, paclobutrazol, unicnazle and succinic acid, and summarized the application of plant growth retardants in medicinal plants cultivation in recent years, with focus on the effect of growth and yield of the officinal organs and secondary metabolites. PMID:24380290
Zhai, Yu-Yao; Guo, Bao-Lin; Cheng, Ming
,N- Dimethylsuccinamic acid (SA), in contrast, breaks down via a hydrolytic mechanism. Introduction The plant growthTransformation of the Plant Growth Regulator Daminozide (Alar) and Structurally Related Compounds heavily used plant growth regulators in the U.S. (5). In addition to daminozide, the hydrazide moiety
Microcystins (MCs) are produced by cyanobacteria in aquatic environments and adversely affect macrophytes at very high concentrations. However, the effects of MC on macrophytes at concentrations of environmental relevance are largely unknown. The main objective of this study was to analyze the allelopathic effects of MC-LR at natural concentrations (1, 8 and 16 ?g MC-LR/L) on five charophyte species (Chara aspera, C. baltica, C. hispida, C. vulgaris and Nitella hyalina) and the angiosperm Myriophyllum spicatum. Macrophyte specimens were obtained from a restored area located in Albufera de València Natural Park, a protected coastal Mediterranean wetland. Two different experiments were conducted involving (i) the addition of MC-LR to natural sediment to evaluate its effects on seed germination and (ii) the addition of MC-LR to water cultures of macrophytes to evaluate its effects on growth and metabolic functions. In water, the MC-LR concentration decreased by 84% in two weeks; the loss was not significant in sediment. The first seedlings (all C. hispida) emerged from the wetland sediment following a delay of a few days in the presence of MC-LR. The germination rates in 8 and 16 ?g MC-LR/L treatments were 44% and 11% of that occurring in the absence of MC, but these differences disappeared over time. The final density was 6-7 germlings/dm(3). Final germling length was unaffected by MC-LR. Rotifers (Lecane spp.) emerging from the natural sediment during the experiment were favored by MC-LR; the opposite pattern was observed in the cladoceran Daphnia magna. The growth rates of C. vulgaris, C. baltica and N. hyalina were unaffected by MC exposure, whereas those of C. hispida and C. aspera were reduced in the MC treatments relative to the control treatment. The concentration of chlorophyll-a and the in vivo net photosynthetic rate were lower in the presence of MC-LR, even at the lowest concentration, for all of the characeans tested. M. spicatum was sensitive to the presence of MC-LR in the culture medium; the growth and chlorophyll-a concentrations were reduced. Therefore, environmentally relevant concentrations of MC might induce important changes in macrophyte meadows and the structure of the associated plankton community. Synchrony or delay in the processes evaluated here in response to environmentally relevant concentrations of cyanobacteria MC exudates can enhance understanding of the turning point to alternative states and the point of no return in eutrophicated shallow lakes. PMID:24121158
Rojo, Carmen; Segura, Matilde; Cortés, Francisco; Rodrigo, María A
Spinach seeds (Spinacia oleracea L.) given massive doses of gamma-irradiation (500 krad) germinate and form a seedling with two green cotyledons and a radicle, but develop no further. Irradiated cotyledons show no increase in cell number or total DNA over a 7-day period in the light, while in control cotyledons there is a small increase in cell number and large increases in total DNA and chloroplast number. The chloroplasts of irradiated cotyledons are delayed in their division, become greatly enlarged and contain large amounts of starch. The whole population of chloroplasts subsequently undergoes a wave of division. The daughter chloroplasts show normal thylakoid development, but have some abnormal structural features caused by the radiation stress. Information on the effect of X-irradiation, ultraviolet irradiation, and 5-fluorodeoxyuridine on chloroplast replication and on chloroplast and nuclear DNA synthesis was obtained from cultured spinach leaf discs. It appears that chloroplast replication is more resistant to ionizing radiation than cell division and can proceed in the absence of nuclear DNA synthesis and greatly reduced chloroplast DNA synthesis. PMID:16659421
Rose, R; Possingham, J
This study is a follow-up of a similar study done by Loehle (1990). The objectives of the original study were to: (1) measure the toxicity of groundwater contaminated by the F-Area seepage basins where this water surfaces in a seepline along Fourmile Branch and (2) to evaluate the effectiveness of rainwater for washing contaminants from the soil. Results of seed germination tests show no significant difference between water extracted from one extraction of F-Area seepline soil, soil from a control area, the sixth consecutive extraction from F-Area soil, and a deionized water control. A root-growth assay on the same seeds shows a significant effect with the order of growth, first extraction of F-Area soil Eaton, D.; Murphy, C.E. 1993-09-01
Eaton, D.; Murphy, C.E.
Siderophores scavenges Fe(+3) from the vicinity of the roots of plants, and thus limit the amount of iron required for the growth of pathogens such as Fusarium oxysporum, Pythium ultimum, and Fusarium udum, which cause wilt and root rot disease in crops. The ability of Pseudomonas to grow and to produce siderophore depends upon the iron content, pH, and temperature. Maximum yield of siderophore of 130 ?M was observed at pH 7.0 ± 0.2 and temperature of 30 °C at 30 h. The threshold level of iron was 50 ?M, which increases up to 150 ?M, favoring growth but drastically affecting the production of siderophore by Pseudomonas aeruginosa JAS-25. The seeds of agricultural crops like Cicer arietinum (chick pea), Cajanus cajan (pigeon pea), and Arachis hypogaea (ground nut) were treated with P. aeruginosa JAS-25, which enhanced the seed germination, root length, shoot length, and dry weight of chick pea, pigeon pea, and ground nut plants under pot studies. The efficient growth of the plants was not only due to the biocontrol activity of the siderophore produced by P. aeruginosa JAS-25 but also may be by the production of indole acetic acid (IAA), which influences the growth of the plants as phytohormones. PMID:25062779
Sulochana, M B; Jayachandra, S Y; Kumar, S Anil; Parameshwar, A B; Reddy, K Mohan; Dayanand, A
We examined the effects of cold stratification and salinity on seed flotation of eight salt marsh species. Four of the eight species were tested for germination success under different stratification, salinity, and flooding conditions. Species were separated into two groups, four species received wet stratification and four dry stratification and fresh seeds of all species were tested for flotation and germination. Fresh seeds of seven out of eight species had flotation times independent of salinity, six of which had average flotation times of at least 50 d. Seeds of Spartina alterniflora and Spartina patens had the shortest flotation times, averaging 24 and 26 d, respectively. Following wet stratification, the flotation time of S. alterniflora seeds in higher salinity water (15 and 36 ppt) was reduced by over 75% and germination declined by more than 90%. Wet stratification reduced the flotation time of Distichlis spicata seeds in fresh water but increased seed germination from 2 to 16% in a fluctuating inundation regime. Fresh seeds of Iva frutescens and S. alternflora were capable of germination and therefore are non-dormant during dispersal. Fresh seeds of I. frutescens had similar germination to dry stratified seeds ranging 25-30%. Salinity reduced seed germination for all species except for S. alterniflora. A fluctuating inundation regime was important for seed germination of the low marsh species and for germination following cold stratification. The conditions that resulted in seeds sinking faster were similar to the conditions that resulted in higher germination for two of four species. ?? 2009 Elsevier B.V.
Elsey-Quirk, T.; Middleton, B.A.; Proffitt, C.E.
Germination is a key process in plants' phenological cycles. Accelerating this process could lead to improvment of the seedling growth as well as the cultivation efficiency. To achieve this, the effect of microwave frequency on the germination of rice seeds was examined. The physiological feedbacks of the MR 219 rice variety in terms of seed germination rate (GR), germination percentage (GP), and mean germination time (MGT) were analyzed by exposing its seeds to 2450?MHz of microwave frequency for one, four, seven, and ten hours. It was revealed that exposing the seeds to the microwave frequency for 10 hours resulted in the highest GP. This treatment led to 100% of germination after three days with a mean germination time of 2.1 days. Although the other exposure times of microwave frequency caused the moderate effects on germination with a GPa3 ranged from 93% to 98%, they failed to reduce the MGTa3. The results showed that ten-hour exposure times of microwave frequency for six days significantly facilitated and improved the germination indices (primary shoot and root length). Therefore, the technique is expected to benefit the improvement of rice seed germination considering its simplicity and efficacy in increasing the germination percentage and rate as well as the primary shoot and root length without causing any environmental toxicity. PMID:24307869
Valdiani, Alireza; Maziah, Mahmood; Mohsenkhah, Mohammad
Background WD40 domains have been found in a plethora of eukaryotic proteins, acting as scaffolding molecules assisting proper activity of other proteins, and are involved in multi-cellular processes. They comprise several stretches of 44-60 amino acid residues often terminating with a WD di-peptide. They act as a site of protein-protein interactions or multi-interacting platforms, driving the assembly of protein complexes or as mediators of transient interplay among other proteins. In Arabidopsis, members of WD40 protein superfamily are known as key regulators of plant-specific events, biologically playing important roles in development and also during stress signaling. Results Using reverse genetic and protein modeling approaches, we characterize GIGANTUS1 (GTS1), a new member of WD40 repeat protein in Arabidopsis thaliana and provide evidence of its role in controlling plant growth development. GTS1 is highly expressed during embryo development and negatively regulates seed germination, biomass yield and growth improvement in plants. Structural modeling analysis suggests that GTS1 folds into a ?-propeller with seven pseudo symmetrically arranged blades around a central axis. Molecular docking analysis shows that GTS1 physically interacts with two ribosomal protein partners, a component of ribosome Nop16, and a ribosome-biogenesis factor L19e through ?-propeller blade 4 to regulate cell growth development. Conclusions Our results indicate that GTS1 might function in plant developmental processes by regulating ribosomal structural features, activities and biogenesis in plant cells. Our results suggest that GIGANTUS1 might be a promising target to engineer transgenic plants with higher biomass and improved growth development for plant-based bioenergy production. PMID:24467952
Nineteen plants belonging to 11 species of the cruciferae were studied to determine the effects of aflatoxin B1 on seed germination and seedling development. Germination was not inhibited in any test organism at a concentration of 100 ?g of aflatoxin per ml of agar substrate. Inhibition of elongation of the hypocotyls and roots in the species studied varied from 29 to 93% and from 22 to 91% in the respective tissues. Lepidium sativum was the most susceptible plant studied and exhibited the maximal inhibitory response noted above at concentrations of 8 ?g of aflatoxin per ml. The ultrastructure of Lepidium root cells treated with crystalline aflatoxin B1 exhibited morphological changes characteristic of those found in aflatoxin-treated animal cells. In addition to changes in the cytoplasmic organelles, numerous ring-shaped nucleoli with prominent nucleolar caps were produced. The effect of aflatoxin on plant cells is compared with similar effects induced by actinomycin D. Seed germination and seedling development is discussed in relation to the effects of both compounds on deoxyribonucleic acid-dependent ribonucleic acid biosynthesis. Images PMID:4767301
Crisan, Eli V.
Investigation of the metabolome and the transcriptome of pollen of lily (Lilium longiflorum) gave a comprehensive overview of metabolic pathways active during pollen germination and tube growth. More than 100 different metabolites were determined simultaneously by gas chromatography coupled to mass spectrometry, and expressed genes of selected metabolic pathways were identified by next-generation sequencing of lily pollen transcripts. The time-dependent changes in metabolite abundances, as well as the changes after inhibition of the mitochondrial electron transport chain, revealed a fast and dynamic adaption of the metabolic pathways in the range of minutes. The metabolic state prior to pollen germination differed clearly from the metabolic state during pollen tube growth, as indicated by principal component analysis of all detected metabolites and by detailed observation of individual metabolites. For instance, the amount of sucrose increased during the first 60 minutes of pollen culture but decreased during tube growth, while glucose and fructose showed the opposite behavior. Glycolysis, tricarbonic acid cycle, glyoxylate cycle, starch, and fatty acid degradation were activated, providing energy during pollen germination and tube growth. Inhibition of the mitochondrial electron transport chain by antimycin A resulted in an immediate production of ethanol and a fast rearrangement of metabolic pathways, which correlated with changes in the amounts of the majority of identified metabolites, e.g. a rapid increase in ?-aminobutyric acid indicated the activation of a ?-aminobutyric acid shunt in the tricarbonic acid cycle, while ethanol fermentation compensated the reduced ATP production after inhibition of the oxidative phosphorylation. PMID:23660836
Obermeyer, Gerhard; Fragner, Lena; Lang, Veronika; Weckwerth, Wolfram
Mungbean (Phaseolus aureus Roxb.) seedlings were grown hypobarically to assess the effects of low pressure (21-24 kilopascals) on growth and mitochondrial respiration. Control seedlings grown at ambient pressure (101 kilopascals) were provided amounts of O2 equivalent to those provided experimental seedlings at reduced pressure to factor out responses to O2 concentration and to total pressure. Respiration was assayed using washed mitochondria, and was found to respond only to O2 concentration. Regardless of total pressure, seedlings grown at 2 millimoles O2 per liter had higher state 3 respiration rates and decreased percentages of alternative respiration compared to ambient (8.4 millimoles O2 per liter) controls. In contrast, seedling growth responded to total pressure but not to O2 concentration. Seedlings were significantly larger when grown under low pressure. While low O2 (2 millimoles O2 per liter) diminished growth at ambient pressure, growth at low pressure in the same oxygen concentration was enhanced. Respiratory development and growth of mungbean seedlings under low pressure is unimpaired whether oxygen or air is used as the chamber gas, and further, low pressure can improve growth under conditions of poor aeration.
Musgrave, M. E.; Gerth, W. A.; Scheld, H. W.; Strain, B. R.
One of the central the mechanisms used by many soil bacteria to directly promote plant growth is the production of the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase. This enzyme facilitates plant growth as a consequence of the fact that it sequesters and cleaves plant- produced ACC (the immediate precursor of ethylene in plants), thereby lowering the level of ethylene in the plant.
Bernard R. Glick
Examination of the substrate specifity of the carboxypeptidase activity of ungerminated and germinated mung beans (Vigna radiata (L.) Wilczek) reveals the presence of two distinct enzymes. The first of these, carboxypeptidase I, is maximally active against carbobenzyloxy-Ala-Phe. It is present in large amounts in the cotyledons of ungerminated seeds, and declines rapidly during germination. The second, carboxypeptidase II, is most
Karl A. Wilson; Berit R. Rightmire; Anna L. Tan-Wilson
The effect of lettuce (Latuca sativa L.) germination and growth in nonsterilized potting compost of 0.1% and 1.0% w/w incorporation of fermenter biomass inocula of six strains of Trichoderma was investigated. Except for strains WT and T35 at 0.1 % w/w, all inocula inhibited germination. Biomass of strains WT, T35, 20, and 47 at 1.0% promoted shoot fresh weight, whereas strains TH1 and 8MF2 were inhibitory. In contrast, when biomass of strains WT, TH1, and 8MF2 was autoclaved and incorporated at 1%, shoot fresh weight was promoted, but the biomass of T35 was inhibitory. None of the strains incorporated at 0.1 % w/w increased shoot fresh weight, and autoclaved biomass of TH1, T35, and 20 incorporated at 0.1% w/w resulted in lower shoot fresh weights in comparison with uninoculated controls. The shoot dry weight of lettuce seedlings could be enhanced by germinating seeds in uninoculated compost and after five days' growth transferring them into WT-inoculated compost. Inoculum of strain TH1 when applied using this method was very inhibitory. With WT the degree of increase in shoot fresh weight and germination rate declined as the fermentation time to produce inocula was increased. PMID:24190096
Ousley, M A; Lynch, J M; Whipps, J M
??Endophytic microorganisms that colonize the internal tissues of plants enhance agricultural production through plant growth promoting mechanisms. Considering the enormous potential of the endophytic newlinebacteria… (more)
Anu Rajan S
In order to select potential Plant Growth Promoting Rhizobacteria (PGPRs), a selection of strains from the predominant genera in the rhizosphere of four lupine species, based on genetic divergence criteria, carried out in a previous study, yielded 11 Aureobacterium (Aur), four Cellulomonas (Cell), two Arthrobacter (Arth), two Pseudomonas (Ps), and six Bacillus (Bc) strains. Cell?free culture filtrates of each bacterium
Francisco J. Gutiérrez Mañero; Agustin Probanza; Beatriz Ramos; Juan J. Colón Flores; Jose A. Lucas García
Abscisic acid (ABA) is a phytohormone that positively regulates seed dormancy and stress tolerance. PYL/RCARs were identified an intracellular ABA receptors regulating ABA-dependent gene expression in Arabidopsis thaliana. However, their function in monocot species has not been characterized yet. Herein, it is demonstrated that PYL/RCAR orthologues in Oryza sativa function as a positive regulator of the ABA signal transduction pathway. Transgenic rice plants expressing OsPYL/RCAR5, a PYL/RCAR orthologue of rice, were found to be hypersensitive to ABA during seed germination and early seedling growth. A rice ABA signalling unit composed of OsPYL/RCAR5, OsPP2C30, SAPK2, and OREB1 for ABA-dependent gene regulation was further identified, via interaction assays and a transient gene expression assay. Thus, a core signalling unit for ABA-responsive gene expression modulating seed germination and early seedling growth in rice has been unravelled. This study provides substantial contributions toward understanding the ABA signal transduction pathway in rice. PMID:22071266
Kim, Hyunmi; Hwang, Hyunsik; Hong, Jung-Woo; Lee, Young-Na; Ahn, Il Pyung; Yoon, In Sun; Yoo, Sang-Dong; Lee, Sukchan; Lee, Sung Chul; Kim, Beom-Gi
In this study, among a collection of Ni-resistant bacterial strains isolated from the rhizosphere of Alyssum serpyllifolium and Phleum phleoides grown on serpentine soil, five plant growth-promoting bacteria (PGPB) were selected based on their ability to utilize 1-aminocyclopropane-1-carboxylate (ACC) as the sole N source and promote seedling growth. All of the strains tested positive for indole-3-acetic acid (IAA) production and
Ying Ma; Mani Rajkumar; Helena Freitas
Dolk's (1936) finding that more growth hormone diffuses from the lower side of a gravity-stimulated plant shoot than from the upper side is presently confirmed by means of both an isotope dilution assay and selected ion monitoring-gas chromatography-mass spectrometry, and it is established that the asymmetrically distributed hormone is indole-3-acetic acid (IAA). This is the first physicochemical demonstration that there is more IAA on the lower sides of a geostimulated plant shoot. It is also found that free IAA primarily occurs in the conductive vascular tissues of the shoot, while IAA esters predominate in the growing cortical cells. A highly sensitive gas chromatographic isotope dilution assay shows that the hormone asymmetry also occurs in the nonvascular tissue.
Bandurski, R. S.; Schulze, A.
Dried mosses (five moss species) were progressively extracted and subjected to a four-step Craig distribution. Seven pure flavonoids were isolated and identified. The flavonoids were the flavones apigenin, apigenin-7-O-triglycoside, lucenin-2, luteolin-7-O-neohesperidoside, saponarine and vitexin; and the biflavonoid bartramiaflavone and they were submitted to biological tests. The tests were performed in vitro on spore germination and protonemal growth of the moss
Adriana Basile; Sergio Sorbo; José Antonio López-Sáez; Rosa Castaldo Cobianchi
Seeds and seedlings of five hardwood species were subjected to a simulated acid rain adjusted to pH values of 2.0, 3.5, 5.0, 6.0, and to distilled water (the control). Seed germination was remarkably inhibited by pH 2.0 treatment for three species. Significant foliar damage, decline in chlorophyll contents, and retardation of growth for the seedlings of all the species, were
Hou Bac Fan; Yi Hong Wang
The thermal resistance of Bacillus licheniformis spores was increased from a D70-value of 590 min to one of 900 min by the addition of 4% NaCl to the heating medium [tryptone-yeast extract-glucose (TYG) broth, pH 6.8], but was decreased to 470 min in TYG broth acidified to pH 4.4. Sodium nitrite (0.02%) enhanced spore destruction at 80 degrees C but not at 70 degrees C; addition of 4% NaCl eliminated this effect. Less than half the number of spores surviving heat comparable to commercial cooking were heat-damaged to the extent of being unable to grow aerobically in the presence of 4% NaCl. No growth occurred during anaerobic incubation even when the media contained no added NaCl. Oxygen was not required to trigger spore germination, but trace amounts were needed for the successful outgrowth of germinated spores. Spore germination was accelerated and enhanced by the presence of at least 2% NaCl. Therefore under anaerobic conditions NaCl promotes microbiological stability because the germinated spores cannot develop further and become moribund. It is concluded that the plastic casing of luncheon-meat chubs is not sufficiently oxygen-impermeable to allow the product a long shelf-life other than at chill temperatures unless the chubs are stored in an oxygen-free atmosphere. PMID:6530382
Bell, R G; De Lacy, K M
Germination and seedling establishment are vulnerable stages in the plant life cycle. We investigated how seed mass and family (progeny origin) affect germination and juvenile performance in the grassland herb Knautia arvensis. Seeds were produced by cross-pollination by hand. The fate of 15 individually weighed seeds from each of 15 plants was followed during a 3-month growth chamber experiment. Progeny origin affected
Vibekke Vange; Ivar Heuch; Vigdis Vandvik
Experiments were conducted to evaluate the efficacy of calliterpenone, a natural plant growth promoter from a shrub Callicarpa macrophylla Vahl., in enhancing the growth and yield promoting effects of plant growth promoting rhizobacteria (PGPRs), in menthol mint (Mentha arvensis L).This study is based on our previous results indicating the microbial growth promotion by calliterpenone and assumption that application of calliterpenone along with PGPRs will improve the population of PGPRs resulting in higher impacts on plant growth and yield. Of the 15 PGPRs (identified as potent ones in our laboratory), 25 ?l of 0.01 mM calliterpenone (8.0 ?g/100 ml) was found to be useful in improving the population of nine PGPRs in culture media. The five selected strains of PGPRs exhibiting synergy with calliterpenone in enhancing growth of maize compared to PGPR or calliterpenone alone were selected and tested on two cultivars (cvs. Kosi and Kushal) of M. arvensis. Of the five strains, Bacillus subtilis P-20 (16S rDNA sequence homologous to Accession No NR027552) and B. subtilis Daz-26 (16SrDNA sequence homologuos to Accession No GU998816) were found to be highly effective in improving the herb and essential oil yield in the cultivars Kushal and Kosi respectively when co-treated with calliterpenone. The results open up the possibilities of using a natural growth promoter along with PGPRs as a bio-agri input for sustainable and organic agriculture. PMID:23271460
Maji, Deepamala; Barnawal, Deepti; Gupta, Aakansha; King, Shikha; Singh, A K; Kalra, A
Repression of AUXIN RESPONSE FACTOR10 by microRNA160 is critical for seed germination and post-germination important roles in seed germination and post-germination. Transgenic plants expressing an miR160-resistant sensu stricto germination and post-germination, mARF10 mutant seeds and plants were hypersensitive
The growth of the filamentous fungus Aspergillus niger, a common food spoilage organism, is inhibited by the weak acid preservative sorbic acid (trans-trans-2,4-hexadienoic acid). Conidia inoculated at 105/ml of medium showed a sorbic acid MIC of 4.5 mM at pH 4.0, whereas the MIC for the amount of mycelia at 24 h developed from the same spore inoculum was threefold lower. The MIC for conidia and, to a lesser extent, mycelia was shown to be dependent on the inoculum size. A. niger is capable of degrading sorbic acid, and this ability has consequences for food preservation strategies. The mechanism of action of sorbic acid was investigated using 31P nuclear magnetic resonance (NMR) spectroscopy. We show that a rapid decline in cytosolic pH (pHcyt) by more than 1 pH unit and a depression of vacuolar pH (pHvac) in A. niger occurs in the presence of sorbic acid. The pH gradient over the vacuole completely collapsed as a result of the decline in pHcyt. NMR spectra also revealed that sorbic acid (3.0 mM at pH 4.0) caused intracellular ATP pools and levels of sugar-phosphomonoesters and -phosphodiesters of A. niger mycelia to decrease dramatically, and they did not recover. The disruption of pH homeostasis by sorbic acid at concentrations below the MIC could account for the delay in spore germination and retardation of the onset of subsequent mycelial growth. PMID:15184150
Plumridge, Andrew; Hesse, Stephan J. A.; Watson, Adrian J.; Lowe, Kenneth C.; Stratford, Malcolm; Archer, David B.
Differentially expressed myo-inositol monophosphatase gene (CaIMP) in chickpea (Cicer arietinum L.) encodes a lithium-sensitive phosphatase enzyme with broad substrate specificity and improves seed germination and seedling growth under abiotic stresses
myo-Inositol monophosphatase (IMP) is an essential enzyme in the myo-inositol metabolic pathway where it primarily dephosphorylates myo-inositol 1-phosphate to maintain the cellular inositol pool which is important for many metabolic and signalling pathways in plants. The stress-induced increased accumulation of inositol has been reported in a few plants including chickpea; however, the role and regulation of IMP is not well defined in response to stress. In this work, it has been shown that IMP activity is distributed in all organs in chickpea and was noticeably enhanced during environmental stresses. Subsequently, using degenerate oligonucleotides and RACE strategy, a full-length IMP cDNA (CaIMP) was cloned and sequenced. Biochemical study revealed that CaIMP encodes a lithium-sensitive phosphatase enzyme with broad substrate specificity, although maximum activity was observed with the myo-inositol 1-phosphate and l-galactose 1-phosphate substrates. Transcript analysis revealed that CaIMP is differentially expressed and regulated in different organs, stresses and phytohormones. Complementation analysis in Arabidopsis further confirmed the role of CaIMP in l-galactose 1-phosphate and myo-inositol 1-phosphate hydrolysis and its participation in myo-inositol and ascorbate biosynthesis. Moreover, Arabidopsis transgenic plants over-expressing CaIMP exhibited improved tolerance to stress during seed germination and seedling growth, while the VTC4/IMP loss-of-function mutants exhibited sensitivity to stress. Collectively, CaIMP links various metabolic pathways and plays an important role in improving seed germination and seedling growth, particularly under stressful environments. PMID:24123252
Laboratory experiments were conducted to determine juglone sensitivity of 16 species (Trifolium incarnatum, Coronilla varia, Vicia villosa, Lespedeza stipulacea, L. cuneata, Acer ginnala, Caragana arbor-escens, Elaegnus angustifolia, E. umbellata, Lonicera maackii, Quercus alba, Fraxinus americana, Liriodendron tulipifera, Alnus glutinosa, Pinus strobus, andP. sylvestris) being considered for mixed plantings withJugions nigra (black walnut). All species were sensitive to juglone, but seed
W. J. Rietveld
Plants require minimal amounts of certain metals (Zn,Fe,Cu,etc) for optimal growth and productivity, but excess of these metals leads to cell death. When growth is limited by metal excess or metal deficiency plants respond by synthesizing nonproteinogenic chelating substances. Phytosiderophores are secreted by roots of iron deficient grasses and are important in providing sufficient Fe for normal growth. In response
A. M. Kinnersley
Fiber-optic sensors developed for use in measuring concentrations of ammonia and ethylene near plants during experiments on growth of plants in enclosed environments. Developmental fiber-optic sensors satisfy need to measure concentrations as low as few parts per billion (ppb) and expected to contribute to research on roles of ethylene and ammonia in growth of plants.
Zhou, Quan; Tabacco, Mary Beth
From our experiences, awl-fruit sedge (Carex stipata Muhl. ex Willd. [Cyperaceae]) is an easily propagated wetland plant in Washington State. Because seeds can be collected from the same growth year, germinated without stratification, and grown into plants, C. stipata can be quickly propagated during summer for fall and winter outplanting. We believed, however, that perigynium removal could improve success. We
Derrick D. Cooper; Nate Hough-Snee
:From our experiences, awl-fruit sedge (Carex stipata Muhl. ex Willd. [Cyperaceae]) is an easily propagated wetland plant in Washington State. Because seeds can be collected from the same growth year, germinated without stratification, and grown into plants, C. stipata can be quickly propagated during summer for fall and winter outplanting. We believed, however, that perigynium removal could improve success. We
Derrick D. Cooper; Nate Hough-Snee
P-solubilizing bacterial isolate CB7 isolated from apple rhizosphere soil of Himachal Pradesh, India was identified as Bacillus circulans on the basis of phenotypic characteristics, biochemical tests, fatty acid methyl esters analysis, and 16S rRNA gene sequence. The isolate exhibited plant growth-promoting traits of P-solubilization, auxin, 1-aminocyclopropane-1-carboxylate deaminase activity, siderophore, nitrogenase activity, and antagonistic activity against Dematophora necatrix. In vitro studies revealed that P-solubilization and other plant growth-promoting traits were dependent on the presence of glucose in PVK medium and removal of yeast extract had no significant effect on plant growth-promoting traits. Plant growth-promoting traits of isolate CB7 were repressed in the presence of KH2 PO4 . P-solubilization activity was associated with the release of organic acids and a drop in the pH of the Pikovskaya's medium. HPLC analysis detected gluconic and citric acid as major organic acids in the course of P-solubilization. Remarkable increase was observed in seed germination (22.32%), shoot length (15.91%), root length (25.10%), shoot dry weight (52.92%) and root dry weight (31.4%), nitrogen (18.75%), potassium (57.69%), and phosphorus (22.22%) content of shoot biomass over control. These results demonstrate that isolate CB7 has the promising PGPR attributes to be developed as a biofertilizer to enhance soil fertility and promote plant growth. PMID:24464353
Mehta, Preeti; Walia, Abhishek; Kulshrestha, Saurabh; Chauhan, Anjali; Shirkot, Chand Karan
As part of an approach to select potential mycoinsecticides for aphid biocontrol, we investigated the effects of temperature on the growth, germination and pathogenicity of some hyphomycete fungi. Commercially available mycoinsecticides (based on Beauveria bassiana (Balsamo) Vuillemin and Verticillium lecanii (Zimmermann) Viegas) and other isolates of B bassiana, V lecanii, Metarhizium anisopliae (Metschnikoff) Sorokin and Paecilomyces fumosoroseus (Wize) Brown & Smith were evaluated. The rate of in vitro conidial germination of all isolates was slower at 10 and 15 degrees C than at 20 and 25 degrees C. Similarly, in vitro growth of most isolates was adversely affected at 10 and 15 degrees C. The greatest reduction at 10 degrees C in rates of conidial germination and colony growth, compared with other temperatures, was for M anisopliae isolates. Germination of V lecanii (isolate HRI 1.72) was fastest at 10 degrees C compared with the other fungi. It was also the most pathogenic of three isolates tested against Aphis fabae Scopoli and Myzus persicae Sulzer at 10, 18 and 23 degrees C. Generally, A fabae was more susceptible than M persicae to infection by the fungal isolates tested. A significant interaction between aphid species and temperature indicated that the pathogenic nature of an isolate was dependent not only on the target aphid species but also the temperature conditions of the bioassay. The series of studies, detailed above, allowed a temperature profile to be formed for the different isolates. Verticillium lecanii isolate HRI 1.72 (commercialised as Vertalec) was the most promising isolate selected from results of the series of experiments. Temperature profiles in conjunction with infectivity assays can be useful in selecting appropriate isolates for a particular thermal environment. PMID:12587869
Yeo, Helen; Pell, Judith K; Alderson, Peter G; Clark, Suzanne J; Pye, Barry J
Plant cells perceive forces that arise from the environment and from the biophysics of plant growth. These forces provide meaningful cues that can affect the development of the plant. Seedlings of Arabidopsis thaliana were used to examine the cytoplasmic tensile character of cells that have been implicated in the gravitropic response. Laser-trapping technology revealed that the starch-containing statoliths of the central columella cells in root caps are held loosely within the cytoplasm. In contrast, the peripheral cells have starch granules that are relatively resistant to movement. The role of the actin cytoskeleton in affecting the tensile character of these cells is discussed. To explore the role that biophysical forces might play in generating developmental cues, we have developed an experimental model system in which protoplasts, embedded in a synthetic agarose matrix, are subjected to stretching or compression. We have found that protoplasts subjected to these forces from five minutes to two hours will subsequently elongate either at right angles or parallel to the tensive or compressive force vector. Moreover, the cortical microtubules are found to be organized either at right angles or parallel to the tensive or compressive force vector. We discuss these results in terms of an interplay of information between the extracellular matrix and the underlying cytoskeleton.
Fisher, D. D.; Cyr, R. J.
Comprehensive spectroscopic monitoring of plant health and growth in bioregenerative life support system environments is possible using a variety of spectrometric technologies. Absorption spectrometry and atomic emission spectrometry in combination allow for direct, on-line, reagentless monitoring of plant nutrients from nitrate and potassium to micronutrients such as copper and zinc. Fluorometric spectrometry is ideal for the on-line detection, identification and quantification of bacteria and fungi. Liquid Atomic Emission Spectrometry (LAES) is a new form of spectrometry that allows for direct measurement of atomic emission spectra in liquids. An electric arc is generated by a pair of electrodes in the liquid to provide the energy necessary to break molecular bonds and reduce the substance to atomic form. With a fiber probe attached to the electrodes, spectral light can be transmitted to a photodiode array spectrometer for light dispersion and analysis. Ultraviolet (UV) absorption spectrometry is a long-established technology, but applications typically have required specific reagents to produce an analyte-specific absorption. Nitrate and iron nutrients have native UV absorption spectra that have been used to accurately determine nutrient concentrations at the +/- 5% level. Fluorescence detection and characterization of microbes is based upon the native fluorescent signatures of most microbiological species. Spectral and time-resolved fluorometers operating with remote fiber-optic probes will be used for on-line microbial monitoring in plant nutrient streams. PMID:11540187
Schlager, K J
sensitive indicators of the vigor or well being of the plant and of environmental conditions. They become deciduous under certain conditions and reduced in number and length under other conditions. S. ~o1 rhiza produces p to 16 fh t m e o ly 12 o less... of these layers forms a rather distinct sub- epidermal tissue. Its cells bear the anthocyanin pigment that gives the deep red color to the underside of the leaf. The cells of the upper mesophyll region are not oriented in a typical palisade pattern...
Shelton, Donald Ross
Plant Physiology: Manipulating Plant Growth with Solar Radiation Dennis Decoteau, Ph.D. Department The importance of light in the growth of plants is a well-established phenomenon. A common observation is that plants grown in the dark are yellow (chlorotic), taller (etiolated), have thinner stems, and in general
Decoteau, Dennis R.
We used loss-of-function mutants to study three Arabidopsis thaliana sensor histidine kinases, AHK2, AHK3, and CRE1\\/ AHK4, known to be cytokinin receptors. Mutant seeds had more rapid germination, reduced requirement for light, and decreased far-red light sensitivity, unraveling cytokinin functions in seed germination control. Triple mutant seeds were more than twice as large as wild-type seeds. Genetic analysis indicated a
Michael Riefler; Ondrej Novak; Miroslav Strnad; Thomas Schmullinga
In 2009 a greenhouse experiment was conducted to determine the effects of boron (B) and plant growth-promoting rhizobacteria (PGPR) treatments, applied either alone or in combination, on yield, plant growth, leaf total chlorophyll content, stomatal conductance, membrane leakage, and leaf relative water content of wheat (Triticum aestivum L. cv. Bezostiya) and barley (Hordeum vulgare L. cv. Tokak) plants. Results showed
Metin Turan; Medine Gulluce; Fikrettin ?ahin
Plant growth is enhanced by the presence of symbiotic soil microbes. In order to better understand how plants might prosper on Mars, we set up an experiment to test whether symbiotic microbes function to enhance plant growth in a Martian soil simulant.
Kliman, D. M.; Cooper, J. B.; Anderson, R. C.
The pollens of apple flowers have been treated with simulated acid rain solutions in range of pHs 2.9 to 5.0 in order to determine the threshold proportion values that lead the observed symptoms of detriments of acid rain. Compared to controls (pH 6.5), pollen germination decreased by 41.75% at pH 3.3 and pollen tube elongation decreased by 24.3% at pH 3.4. Acid rain threshold proportion value was around pH 3.3 and 3.4 for apple pollen germination and pollen tube elongation, respectively. Furthermore, pollen tube elongation was determined to be more sensitive to acid rain than pollen germination. The pH values below 3.1 resulted in complete destruction of pollen tubes. Pollen germination entirely stopped at around pH 3.0. Finally, it has been shown that the acid rain has a blocking effect on pollen germination and pollen tube elongation in apple. The conclusion is that not only pH value but also the quantity of acid rain is important factor in germination. The results were found statistically significant through the LSD test at levels of p < 0.05 and p < 0.01. PMID:12705325
Munzuroglu, O; Obek, E; Geckil, H
Germination and seedling establishment are vulnerable stages in the plant life cycle. We investigated how seed mass and family (progeny origin) affect germination and juvenile performance in the grassland herb Knautia arvensis. Seeds were produced by cross-pollination by hand. The fate of 15 individually weighed seeds from each of 15 plants was followed during a 3-month growth chamber experiment. Progeny origin affected germination, both through seed mass and as an independent factor. Two groups of progenies could be distinguished by having rapid or delayed germination. The two groups had similar mean seed masses, but a positive relationship between seed mass and germination rate could be established only among the rapidly germinating progenies. These biologically relevant patterns were revealed because timing of germination was taken into account in the analyses, not only frequencies. Time-to-event data were analysed with failure-time methods, which gave more stable estimates for the relation between germination and seed mass than the commonly applied logistic regression. Progeny origin and seed mass exerted less impact on later characters like juvenile survival, juvenile biomass, and rosette number. These characters were not affected by the timing of germination under the competition-free study conditions. The decrease in the effect of progeny origin from the seed and germination to the juvenile stages suggests that parental effects other than those contributing to the offspring genotype strongly influenced the offspring phenotype at the earliest life stages. Further, the division of progeny germination patterns into two fairly distinct groups indicates that there was a genetic basis for the variation in stratification requirements among parental plants. Field studies are needed to elucidate effects of different timing of germination in the seasonal grasslands that K. arvensis inhabits.
Vange, Vibekke; Heuch, Ivar; Vandvik, Vigdis
Laboratory experiments were performed to determine phytotoxic potentials of white top (Lepidium draba) methanol extracts (root, stem and leaf) on germination and early growth of corn (Zea mays) and redroot pigweed (Amaranthus retroflexus). Furthermore, the effects of different methanol extracts of L. draba on the phytohormone (indole-3-acetic acid (IAA), gibberellic acid (GA), abscisic acid (ABA) and zeatin) levels of corn and redroot pigweed were investigated. It was observed that all concentrations of methanol extracts of root, stem and leaf of L. draba inhibited germination, radicle and plumule elongation when compared with the respective controls. Besides this, the degree of inhibition was increased in concert with increasing concentrations of extracts used. On the other hand, phytohormone levels changed with the application of different extract concentrations. Comparing with the control, the GA levels significantly decreased while the ABA levels increased in all the application groups. Zeatin and IAA levels showed changes depending upon the applied extracts and concentrations. PMID:23293131
Kaya, Yusuf; Aksakal, Ozkan; Sunar, Serap; Erturk, Filiz Aygun; Bozari, Sedat; Agar, Guleray; Erez, Mehmet Emre; Battal, Peyami
This system was developed to measure the effects of low-atmospheric pressure on the growth and function of plants for applications in Advanced Life Support systems research. The system is composed of six independent growth vessels...
Purswell, Joseph Lawrence
This peer-reviewed article from the November 2007 issue of BioScience takes a close look at the physiology of plant reproduction. Although most people think of pollen merely as an allergen, its true biological function is to facilitate sexual reproduction in flowering plants. The angiosperm pollen grain, upon arriving at a receptive stigma, germinates, producing a tube that extends through the style to deliver its cargo to the ovule, thereby fertilizing the egg, and completing the life cycle of the plant. The pollen tube grows rapidly, exclusively at its tip, and produces a cell that is highly polarized both in its outward shape and its internal cytoplasmic organization. Recent studies reveal that the growth oscillates in rate. Many underlying physiological processes, including ionic fluxes and energy levels, also oscillate with the same periodicity as the growth rate, but usually not with the same phase. Current research focuses on these phase relationships in an attempt to decipher their hierarchical sequence and to provide a physiological explanation for the factors that govern pollen tube growth.
Kathleen Wilsen (University of Northern Colorado, Greeley; School of Biological Sciences)
Germination of Arabidopsis seeds is light dependent and under phytochrome control. Previously, phytochromes A and B and at least one additional, unspecified phytochrome were shown to be involved in this process. Here, we used a set of photoreceptor mutants to test whether phytochrome D and/or phytochrome E can control germination of Arabidopsis. The results show that only phytochromes B and E, but not phytochrome D, participate directly in red/far-red light (FR)-reversible germination. Unlike phytochromes B and D, phytochrome E did not inhibit phytochrome A-mediated germination. Surprisingly, phytochrome E was required for germination of Arabidopsis seeds in continuous FR. However, inhibition of hypocotyl elongation by FR, induction of cotyledon unfolding, and induction of agravitropic growth were not affected by loss of phytochrome E. Therefore, phytochrome E is not required per se for phytochrome A-mediated very low fluence responses and the high irradiance response. Immunoblotting revealed that the need of phytochrome E for germination in FR was not caused by altered phytochrome A levels. These results uncover a novel role of phytochrome E in plant development and demonstrate the considerable functional diversification of the closely related phytochromes B, D, and E. PMID:11788765
Hennig, Lars; Stoddart, Wendy M; Dieterle, Monika; Whitelam, Garry C; Schäfer, Eberhard
This study shows the direct effect of atmospheric particulate matter on plant growth. Tomato (Solanum lycopersicum L.) plants were grown for 18d directly on PM10 collected on quartz fiber filters. Organic and elemental carbon and polycyclic aromatic hydrocarbons (PAHs) contents were analyzed on all the tested filters. The toxicity indicators (i.e., seed germination, root elongation, shoot and/or fresh root weight, chlorophyll and carotenoids content) were quantified to study the negative and/or positive effects in the plants via root uptake. Substantial differences were found in the growth of the root apparatus with respect to that of the control plants. A 17-58% decrease of primary root elongation, a large amount of secondary roots and a decrease in shoot (32%) and root (53-70%) weights were found. Quantitative analysis of the reactive oxygen species (ROS) indicated that an oxidative burst in response to abiotic stress occurred in roots directly grown on PM10, and this detrimental effect was also confirmed by the findings on the chlorophyll content and chlorophyll-to-carotenoid ratio. PMID:24955951
Daresta, Barbara Elisabetta; Italiano, Francesca; de Gennaro, Gianluigi; Trotta, Massimo; Tutino, Maria; Veronico, Pasqua
Background and Aims Suaeda aralocaspica is a C4 summer annual halophyte without Kranz anatomy that is restricted to the deserts of central Asia. It produces two distinct types of seeds that differ in colour, shape and size. The primary aims of the present study were to compare the dormancy and germination characteristics of dimorphic seeds of S. aralocaspica and to develop a conceptual model of their dynamics. Methods Temperatures simulating those in the natural habitat of S. aralocaspica were used to test for primary dormancy and germination behaviour of fresh brown and black seeds. The effects of cold stratification, gibberellic acid, seed coat scarification, seed coat removal and dry storage on dormancy breaking were tested in black seeds. Germination percentage and recovery responses of brown seeds, non-treated black seeds and 8-week cold-stratified black seeds to salt stress were tested. Key Results Brown seeds were non-dormant, whereas black seeds had non-deep Type 2 physiological dormancy (PD). Germination percentage and rate of germination of brown seeds and of variously pretreated black seeds were significantly higher than those of non-pretreated black seeds. Exposure of seeds to various salinities had significant effects on germination, germination recovery and induction into secondary dormancy. A conceptual model is presented that ties these results together and puts them into an ecological context. Conclusions The two seed morphs of S. aralocaspica exhibit distinct differences in dormancy and germination characteristics. Suaeda aralocaspica is the first cold desert halophyte for which non-deep Type 2 PD has been documented. PMID:18772148
Wang, Lei; Huang, Zhenying; Baskin, Carol C.; Baskin, Jerry M.; Dong, Ming
Ras1 and Ras2 are two distinct Ras GTPases in Beauveria bassiana, an entomopathogenic fungus whose biocontrol potential against insect pests depends largely on virulence and multi-stress tolerance. The functions of both proteins were characterized for the first time by constructing dominant-active (GTP-bound) Ras1(G19V) and dominant-negative (GDP-bound) Ras1(D126A) and integrating them and normal Ras1 into wild type and ?Ras2 for a series of phenotypic and transcriptional analyses. The resultant mutants showed gradient changes of multiple phenotypes but little difference in conidial thermotolerance. Expression of Ras1(D126A) caused vigorous hyphal growth, severely defective conidiation, and increased tolerances to oxidation, cell wall disturbance, fungicide and UV-A/UV-B irradiations, but affected slightly germination, osmosensitivity and virulence. These phenotypes were antagonistically altered by mRas1(G19V) expressed in either wild type or ?Ras2, which was severely defective in conidial germination and hyphal growth and displayed intermediate changes in other mentioned phenotypes between paired mutants expressing Ras1(G19V) or Ras1(D126A) in wild type and ?Ras2. Their growth, UV tolerance or virulence was significantly correlated with cellular response to oxidation or cell wall disturbance. Transcriptional changes of 35 downstream effector genes involved in conidiation and multi-stress responses also related to most of the phenotypic changes among the mutants. Our findings highlight that Ras1 and Ras2 regulate differentially or antagonistically the germination, growth, conidiation, multi-stress tolerance and virulence of B.?bassiana, thereby exerting profound effects on the fungal biocontrol potential. PMID:22958161
Xie, Xue-Qin; Guan, Yi; Ying, Sheng-Hua; Feng, Ming-Guang
During sexual reproduction, pollen performance is greatly influenced by the female tissues. The stigma exudate, i.e., the extracellular secretion that covers the stigma outermost surface, has been usually regarded as a reservoir of water, secondary metabolites, cell wall precursors and compounds that serve as energy supply for rapid pollen tube growth. In an attempt to identify the proteins present in the stigma secretome, we performed a large-scale analysis in two species (Lilium longiflorum and Olea europaea) following a proteomic-based approach. The resulting data strongly suggest that the stigma exudate is not a mere storage site but also a biochemically active environment with a markedly catabolic nature. Thus, this secretion may modulate early pollen tube growth and contribute to the senescence of stigma after pollination. In addition, a putative cross-talk between genetic programs that regulate stress/defense and pollination responses in the stigma is also suggested. The stigma exudate might also functionally diverge between species on the basis on their ecology and the biochemical, morphological and anatomical features of their stigmas. Unexpectedly, we identified in both exudates some intracellular proteins, suggesting that a mechanism other than the canonical ER-Golgi exocytic pathway may exist in the stigma and contribute to exudate secretion. PMID:24589550
Rejón, Juan David; Delalande, François; Schaeffer-Reiss, Christine; Carapito, Christine; Zienkiewicz, Krzysztof; de Dios Alché, Juan; Isabel Rodríguez-García, María; Van Dorsselaer, Alain; Castro, Antonio J
PLANT-ANIMAL INTERACTIONS - ORIGINAL RESEARCH Plant defense, herbivory, and the growth of Cordia defense, tolerance, and herbivore pressure. In symbiotic antÂplant mutualisms, plants provide nesting in defense or tolerance may occur at life stages when a plant has more resources for defense allocation
Tip growth is employed throughout the plant kingdom. Our understanding of tip growth has benefited from modern tools in molecular genetics, which have enabled the functional characterization of proteins mediating tip growth. Here we first discuss the evolutionary role of tip growth in land plants and then describe the prominent model tip-growth systems, elaborating on some advantages and disadvantages of each. Next we review the organization of tip-growing cells, the role of the cytoskeleton, and recent developments concerning the physiological basis of tip growth. Finally, we review advances in the understanding of the extracellular signals that are known to guide tip-growing cells. PMID:23451782
Rounds, Caleb M; Bezanilla, Magdalena
Plant growth-promoting rhizobacteria (PGPR) are beneficial bacteria that colonize plant roots and enhance plant growth by a wide variety of mechanisms. The use of PGPR is steadily increasing in agriculture and offers an attractive way to replace chemical fertilizers, pesticides, and supplements. Here, we have isolated and characterized the PGPR from the rhizosphere soil of rice field for the enhancement
M. Ashrafuzzaman; Farid Akhtar Hossen; M. Razi Ismail; M. Zahurul Islam; S. M. Shahidullah; Sariah Meon
B12D belongs to a function unknown subgroup of the Balem (Barley aleurone and embryo) proteins. In our previous work on rice seed germination, we identified a B12D-like protein encoded by LOC_Os7g41350 (named OsB12D1). OsB12D1 pertains to an ancient protein family with an amino acid sequence highly conserved from moss to angiosperms. Among the six OsB12Ds, OsB12D1 is one of the major transcripts and is primarily expressed in germinating seed and root. Bioinformatics analyses indicated that OsB12D1 is an anoxic or submergence resistance-related gene. RT-PCR results showed OsB12D1 is induced remarkably in the coleoptiles or roots by flooding during seed germination and early seedling growth. The OsB12D1-overexpressed rice seeds could protrude radicles in 8 cm deep water, further exhibiting significant flooding tolerance compared to the wild type. Moreover, this tolerance was not affected by the gibberellin biosynthesis inhibitor paclobutrazol. OsB12D1 was identified in the mitochondrion by subcellular localization analysis and possibly enhances electron transport through mediating Fe and oxygen availability under flooded conditions. This work indicated that OsB12D1 is a promising gene that can help to enhance rice seedling establishment in farming practices, especially for direct seeding. PMID:25089878
He, Dongli; Zhang, Hui; Yang, Pingfang
B12D belongs to a function unknown subgroup of the Balem (Barley aleurone and embryo) proteins. In our previous work on rice seed germination, we identified a B12D-like protein encoded by LOC_Os7g41350 (named OsB12D1). OsB12D1 pertains to an ancient protein family with an amino acid sequence highly conserved from moss to angiosperms. Among the six OsB12Ds, OsB12D1 is one of the major transcripts and is primarily expressed in germinating seed and root. Bioinformatics analyses indicated that OsB12D1 is an anoxic or submergence resistance-related gene. RT-PCR results showed OsB12D1 is induced remarkably in the coleoptiles or roots by flooding during seed germination and early seedling growth. The OsB12D1-overexpressed rice seeds could protrude radicles in 8 cm deep water, further exhibiting significant flooding tolerance compared to the wild type. Moreover, this tolerance was not affected by the gibberellin biosynthesis inhibitor paclobutrazol. OsB12D1 was identified in the mitochondrion by subcellular localization analysis and possibly enhances electron transport through mediating Fe and oxygen availability under flooded conditions. This work indicated that OsB12D1 is a promising gene that can help to enhance rice seedling establishment in farming practices, especially for direct seeding. PMID:25089878
He, Dongli; Zhang, Hui; Yang, Pingfang
We studied the suitability of Panchgavya (five products of cow), new organic amendment, application on seed germination, plant growth, and soil health. After characterization, Panchgavya was mixed with water to form different concentration and was tested for seed germination, germination index, and root and shoot growth of different seedlings. Four percent solution of Panchgavya was applied to different plants to test its efficacy. Panchgavya and other two organic amendments were incorporated in soil to test the change of soil chemical and microbiological parameters. Panchgavya contained higher nutrients as compared to farm yard manure (FYM) and vermicompost. Its application on different seeds has positively influenced germination percentage, germination index, root and shoot length, and fresh and dry weight of the seedling. Water-soluble macronutrients including pH and metal were positively and negatively correlated with the growth parameters, respectively. Four percent solution of Panchgavya application on some plants showed superiority in terms of plant height and chlorophyll content. Panchgavya-applied soil had higher values of macro and micronutrients (zinc, copper, and manganese), microbial activity as compared to FYM, and vermicompost applied soils. Application of Panchgavya can be gainfully used as an alternative organic supplement in agriculture. PMID:24234225
Jain, Paras; Sharma, Ravi Chandra; Bhattacharyya, Pradip; Banik, Pabitra
Free-living plant growth-promoting rhizobacteria (PGPR) can be used in a variety of ways when plant growth enhancements are required. The most intensively researched use of PGPR has been in agriculture and horticulture. Several PGPR formulations are currently available as commercial products for agricultural production. Recently developing areas of PGPR usage include forest regeneration and phytoremediation of contaminated soils. As the
M. Lucy; E. Reed; Bernard R. Glick
Virus infection can severely inhibit plant growth and distort development. This article reviews changes in plant growth regulator metabolism caused by infection. In general, virus infection decreases auxin and gibberellin concentrations and increases abscisic acid concentration. Ethylene production is stimulated in necrotic or chlorotic reactions to infection, but not where the virus spreads systemically without necrosis. While these broad trends
R. S. S. Fraser; R. J. Whenham
influenced by plant horizontal growth Effect and response to environmental variability is strongly linkedModeling clonal plant growth: from ecological concepts to mathematics Workshop MODECOL 7-8 June, rhizomes in the shoot basis Resource storage Clonal properties #12;Intraclonal plasticity Clonal
Evolution of the germination rate (the proportion of newly produced and dormant seeds that germinates every year) of annual plants is investigated, when the environment is temporally stochastic and spatially heterogeneous. The environment consists of two habitats with synchronous stochastic variation in the annual yield and permanent difference in constant seed survival rates. Density dependence operates within the habitats, which are connected via restricted seed dispersal. We find that instead of a single common evolutionarily stable strategy the coexistence of several germination strategies is possible and that in an initially monomorphic population evolutionary branching may occur. During evolutionary branching the population undergoes disruptive selection and splits into two branches of different lineages that converge to the evolutionarily stable coalition of different germination strategies. It is shown that spatial heterogeneity and restricted dispersal are essential for evolutionary branching. Disruptive selection on the germination rate presents yet another possibility for parapatric speciation. PMID:11798430
Mathias, Andrea; Kisdi, Eva
Phytoremediation can be a viable alternative to traditional, more costly remediation techniques. Three greenhouse studies were conducted to evaluate plant growth with different soil amendments in crude oil-contaminated soil. Growth of alfalfa (Medicago sativa L., cultivar: Riley), bermudagrass (Cynodon dactylon L., cultivar: Common), crabgrass (Digitaria sanguinalis, cultivar: Large), fescue (Lolium arundinaceum Schreb., cultivar: Kentucky 31), and ryegrass (Lolium multiflorum Lam., cultivar: Marshall) was determined in crude oil-contaminated soil amended with either inorganic fertilizer, hardwood sawdust, papermill sludge, broiler litter or unamended (control). In the first study, the addition of broiler litter reduced seed germination for ryegrass, fescue, and alfalfa. In the second study, bermudagrass grown in broiler litter-amended soil produced the most shoot biomass, bermudagrass produced the most root biomass, and crabgrass and bermudagrass produced the most root length. In the third study, soil amended with broiler litter resulted in the greatest reduction in gravimetric total petroleum hydrocarbon (TPH) levels across the six plant treatments following the 14-wk study. Ryegrass produced more root biomass than any other species when grown in inorganic fertilizer- or hardwood sawdust + inorganic fertilizer-amended soil. The studies demonstrated that soil amendments and plant species selection were important considerations for phytoremediation of crude oil-contaminated soil. PMID:14750564
White, P M; Wolf, D C; Thoma, G J; Reynolds, C M
In the process of remediation of mine sites, the establishment of a vegetation cover is one of the most important tasks. This study tests two different approaches to manipulate soil properties in order to facilitate plant growth. Mine waste from Ingurtosu, Sardinia, Italy rich in silt, clay, and heavy metals like Cd, Cu, and Zn was used in a series of greenhouse experiments. Bacteria with putative beneficial properties for plant growth were isolated from this substrate, propagated and consortia of ten strains were used to inoculate the substrate. Alternatively, sand and volcanic clay were added. On these treated and untreated soils, seeds of Helianthus annuus, of the native Euphorbia pithyusa, and of the grasses Agrostis capillaris, Deschampsia flexuosa and Festuca rubra were germinated, and the growth of the seedlings was monitored. The added bacteria established well under all experimental conditions and reduced the extractability of most metals. In association with H. annuus, E. pithyusa and D. flexuosa bacteria improved microbial activity and functional diversity of the original soil. Their effect on plant growth, however, was ambiguous and usually negative. The addition of sand and volcanic clay, on the other hand, had a positive effect on all plant species except E. pithyusa. Especially the grasses experienced a significant benefit. The effects of a double treatment with both bacteria and sand and volcanic clay were rather negative. It is concluded that the addition of mechanical support has great potential to boost revegetation of mining sites though it is comparatively expensive. The possibilities offered by the inoculation of bacteria, on the other hand, appear rather limited. PMID:23990253
Wernitznig, S; Adlassnig, W; Sprocati, A R; Turnau, K; Neagoe, A; Alisi, C; Sassmann, S; Nicoara, A; Pinto, V; Cremisini, C; Lichtscheidl, I
Evaluation of Strains of Metarhizium anisopliae and Beauveria bassiana against Spodoptera litura on the Basis of Their Virulence, Germination Rate, Conidia Production, Radial Growth and Enzyme Activity
Ten strains of the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were evaluated to find the most effective strain for optimization studies. The first criterion tested for strain selection was the mortality (> 50%) of Spodoptera litura larvae after inoculation of the fungus for 4 days. Results on several bioassays revealed that B. bassiana BNBCRC showed the most virulence on mortality S. litura larvae (80% mortality). B. bassiana BNBCRC also showed the highest germination rate (72.22%). However, its conidia yield (7.2 × 108 conidia/mL) was lower than those of B. bassiana B 14841 (8.3 × 108 conidia/mL) and M. anisopliae M6 (8.2 × 108 conidia/mL). The highest accumulative radial growth was obtained from the strain B14841 (37.10 mm/day) while the strain BNBCRC showed moderate radial growth (24.40 mm/day). M. anisopliae M6 possessed the highest protease activity (145.00 mU/mL) while M. anisopliae M8 possessed the highest chitinase activity (20.00 mU/mL) during 96~144 hr cultivation. Amongst these criteria, selection based on virulence and germination rate lead to the selection of B. bassiana BNBCRC. B. bassiana B14841 would be selected if based on growth rate while M. anisopliae M6 and M8 possessed the highest enzyme activities. PMID:22870053
Watermelon Seed Germination Purdue University Cooperative Extension Service BP-62 Seed Germination of the necessary genetic material or chromosomes. These seed, known as triploid, have special germination requirements. This bulletin addresses triploid watermelon seed germination and transplant production. First
Plant pathology Growth enhancement of maize (Zea mays L) through Azospirillum lipoferum inoculation : effect of plant genotype and bacterial concentration JF Arsac C Lamothe D Mulard, J Fages' Pioneer France exhibited, and the in- fluence of the plant genotype was clearly demonstrated. The optimal level
Paris-Sud XI, UniversitÃ© de
Plant growth-promoting rhizobacteria (PGPR) are free-living bacteria which actively colonize plant roots, exerting beneficial effects on plant development. The PGPR may (i) promote the plant growth either by using their own metabolism (solubilizing phosphates, producing hormones or fixing nitrogen) or directly affecting the plant metabolism (increasing the uptake of water and minerals), enhancing root development, increasing the enzymatic activity of the plant or "helping" other beneficial microorganisms to enhance their action on the plants; (ii) or may promote the plant growth by suppressing plant pathogens. These abilities are of great agriculture importance in terms of improving soil fertility and crop yield, thus reducing the negative impact of chemical fertilizers on the environment. The progress in the last decade in using PGPR in a variety of plants (maize, rice, wheat, soybean and bean) along with their mechanism of action are summarized and discussed here. PMID:24144612
Pérez-Montaño, F; Alías-Villegas, C; Bellogín, R A; del Cerro, P; Espuny, M R; Jiménez-Guerrero, I; López-Baena, F J; Ollero, F J; Cubo, T
Summary Weed control is essential for successful new woodland creation by direct seeding, particularly in the first year after germination. Currently, herbicides probably offer the most practical way of achieving this in UK conditions, although successful direct seeding offers the potential for reductions in total overall herbicide use compared with conventional establishment using transplants. There is a need to identify
IAN WILLOUGHBY; DAVID CLAY; FIONA DIXON
Protein expression patterns in imbibed seeds of three cultivars of chickpea (Cicer arietinum L.) with different rates of germination under limiting water supply in soil (>10% water holding capacity) were compared. A large number of soluble proteins expressed earlier and at higher levels in cv Rupali seeds compared to two other genotypes that germinated less rapidly (KH850) or not at all (KJ850). Among the proteins identified were those with chaperone-like functions, including LEA and HSP proteins and proteins involved in metabolism of reactive oxygen species (ROS). Only NAD-malate dehydrogenase was identified as an early, differentially abundant enzyme of the TCA cycle, but in cv Rupali, expression of phospho-enol-pyruvate carboxykinase rose very rapidly to a high level, indicating that an anaplerotic C input to the TCA cycle may have been important. Proteinase inhibitors were more highly expressed in the genotype that did not germinate compared to cv Rupali. Clustering analysis of proteomic data indicated a link between groups of proteins, implying a common regulatory mechanism possibly at the transcriptional level. The chaperone-like proteins and enzymes of ROS homeostasis provide a useful starting point for molecular genetic analysis that may well identify other important genes for the early germination trait. PMID:22765518
Vessal, Saeedreza; Siddique, Kadambot H M; Atkins, Craig A
The objective of this paper is to demonstrate whether air plasma can change the seed germination characteristics, seedling emergence, as well as biochemical reactivity, in Andrographis paniculata (A. paniculata) seedlings by modifying the seed coat and finding a beneficial treatment dose. Eight treatment doses and one control were used to conduct electrical conductivity determination, a germination test, a seedling emergence test and a biochemical assay. The results showed that after being treated with air plasma excited at 5950 V for 10 s, the permeability of the seeds was improved significantly, resulting in the acceleration of seed germination and seedling emergence. In the meantime, the catalase activity and catalase isoenzyme expression were also improved, while the malondialdehyde content in the seedlings was decreased (which means greater counteraction with environmental stress). After being treated with 4250 V for 10 s and 5950 V for 20 s, the seed germination was enhanced, but without an obvious change in seedling emergence. However, after treatment with 3400 V for 20 s and 5100 V for 10 s, the permeability of the seeds was decreased, resulting in a delay in seedling emergence. These results indicate that air plasma can change the physiological and biochemical characteristics of Andrographis paniculata seeds by modifying the seed coat, combined with the effects of the active plasma species, and that different treating doses have different effects.
Tong, Jiayun; He, Rui; Zhang, Xiaoli; Zhan, Ruoting; Chen, Weiwen; Yang, Size
Summary T cell-dependent humoral immune responses are initiated by the activation of naive B cells in the T cell areas of the secondary lymphoid tissues. This primary B cell activation leads to mi- gration of germinal center (GC) cell precursors into B cell follicles where they engage follicular dendritic cells (FDC) and T cells, and differentiate into memory B cells
Robbert van der Voort; Taher E. I. Taher; Robert M. J. Keehnen; Lia Smit; Martijn Groenink; Steven T. Pals
In vertebrates, the endocannabinoid signaling pathway is an important lipid regulatory pathway that modulates a variety of physiological and behavioral processes. N-Acylethanolamines (NAEs) comprise a group of fatty acid derivatives that function within this pathway, and their signaling activity is terminated by an enzyme called fatty acid amide hydrolase (FAAH), which hydrolyzes NAEs to ethanolamine and their corresponding free fatty acids. Bioinformatic approaches led to the identification of plant homologues of FAAH that are capable of hydrolyzing NAEs in vitro. To better understand the role of NAEs in plants, we identified T-DNA knockouts to Arabidopsis FAAH (AtFAAH; At5g64440) and generated plants overexpressing AtFAAH. Here we show that seeds of AtFAAH knockouts had elevated levels of endogenous NAEs, and seedling growth was hypersensitive to exogenously applied NAE. On the other hand, seeds and seedlings of AtFAAH overexpressors had lower endogenous NAE content, and seedlings were less sensitive to exogenous NAE. Moreover, AtFAAH overexpressors displayed enhanced seedling growth and increased cell size. AtFAAH expression and FAAH catalytic activity increased during seed germination and seedling growth, consistent with the timing of NAE depletion during seedling establishment. Collectively, our results show that AtFAAH is one, but not the only, modulator of endogenous NAE levels in plants, and that NAE depletion likely participates in the regulation of plant growth. PMID:16880402
Wang, Yuh-Shuh; Shrestha, Rhidaya; Kilaru, Aruna; Wiant, William; Venables, Barney J.; Chapman, Kent D.; Blancaflor, Elison B.
Due to their widespread distribution and toxic nature, herbicides may have a serious impact on the environment and exert adverse effects on associated organisms. The present study was conducted to determine the acute toxicological effects of some plant growth hormones used as herbicides on four biological subjects and compare the subjects' sensitivity to individual testing substances. The herbicides 4-(indol-3-yl)acetic acid C10H9O2N (IAA), N6-(beta 2-isopentenyl)adenosine (pi-indolylpropionic acid) C11H11O2N (IPA), 2,4-dichlorophenoxyacetic acid C8H6O3Cl2 (2,4-D), 4-chloro-2-methylphenoxyacetic acid C9H9O3Cl (MCPA), and 1,napthylacetic acid C12H10O2 (NAA) were tested and the following biological subjects were used: Daphnia magna, Tubifex tubifex, Scenedesmus quadricauda, and seeds of Sinapis alba. For S. alba, the influence of herbicides on seed germination (G) and root growth inhibition (I) was observed. For T. tubifex, the tests lasted 96 hr, for D. magna 48 hr, for S. quadricauda 20 days, and for S. alba 72 hr. The rank order of toxicity of herbicides used for T. tubifex was NAA > IAA > IPA > 2,4-D > MCPA; for D. magna. NAA > IAA > IPA > MCPA > 2,4-D; for S. quadricauda, IAA > IPA > NAA > MCPA > 2,4-D; for S. alba seed germination, NAA > IPA > 2,4-D > MCPA > IAA; and for root growth inhibition. NAA > 2,4-D > MCPA > IAA > IPA.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7534692
Spores of foodborne pathogens can survive traditional thermal processing schedules used in the manufacturing of processed meat products. Heat-activated spores can germinate and grow to hazardous levels when these products are improperly chilled. Germination and outgrowth of Clostridium perfringens spores in roast beef during chilling was studied following simulated cooling schedules normally used in the processed-meat industry. Inhibitory effects of organic acid salts on germination and outgrowth of C. perfringens spores during chilling and the survival of vegetative cells and spores under abusive refrigerated storage was also evaluated. Beef top rounds were formulated to contain a marinade (finished product concentrations: 1% salt, 0.2% potassium tetrapyrophosphate, and 0.2% starch) and then ground and mixed with antimicrobials (sodium lactate and sodium lactate plus 2.5% sodium diacetate and buffered sodium citrate and buffered sodium citrate plus 1.3% sodium diacetate). The ground product was inoculated with a three-strain cocktail of C. perfringens spores (NCTC 8238, NCTC 8239, and ATCC 10388), mixed, vacuum packaged, heat shocked for 20 min at 75 degrees C, and chilled exponentially from 54.5 to 7.2 degrees C in 9, 12, 15, 18, or 21 h. C. perfringens populations (total and spore) were enumerated after heat shock, during chilling, and during storage for up to 60 days at 10 degrees C using tryptose-sulfite-cycloserine agar. C. perfringens spores were able to germinate and grow in roast beef (control, without any antimicrobials) from an initial population of ca. 3.1 log CFU/g by 2.00, 3.44, 4.04, 4.86, and 5.72 log CFU/g after 9, 12, 15, 18, and 21 h of exponential chilling. A predictive model was developed to describe sigmoidal C. perfringens growth curves during cooling of roast beef from 54.5 to 7.2 degrees C within 9, 12, 15, 18, and 21 h. Addition of antimicrobials prevented germination and outgrowth of C. perfringens regardless of the chill times. C. perfringens spores could be recovered from samples containing organic acid salts that were stored up to 60 days at 10 degrees C. Extension of chilling time to > or =9 h resulted in >1 log CFU/g growth of C. perfringens under anaerobic conditions in roast beef. Organic acid salts inhibited outgrowth of C. perfringens spores during chilling of roast beef when extended chill rates were followed. Although C. perfringens spore germination is inhibited by the antimicrobials, this inhibition may represent a hazard when such products are incorporated into new products, such as soups and chili, that do not contain these antimicrobials, thus allowing spore germination and outgrowth under conditions of temperature abuse. PMID:16355831
Sánchez-Plata, Marcos X; Amézquita, Alejandro; Blankenship, Erin; Burson, Dennis E; Juneja, Vijay; Thippareddi, Harshavardhan
The phytohormone abscisic acid (ABA) and the lipoxygenases (LOXs) pathway play important roles in seed germination and seedling growth and development. Here, we reported on the functional characterization of Arabidopsis CPR5 in the ABA signaling and LOX pathways. The cpr5 mutant was hypersensitive to ABA in the seed germination, cotyledon greening and root growth, whereas transgenic plants overexpressing CPR5 were insensitive. Genetic analysis demonstrated that CPR5 gene may be located downstream of the ABI1 in the ABA signaling pathway. However, the cpr5 mutant showed an ABA independent drought-resistant phenotype. It was also found that the cpr5 mutant was hypersensitive to NDGA and NDGA treatment aggravated the ABA-induced delay in the seed germination and cotyledon greening. Taken together, these results suggest that the CPR5 plays a regulatory role in the regulation of seed germination and early seedling growth through ABA and LOX pathways independently. PMID:21556325
Yang, Xiang; Wang, Yaqin; Su, Xiaojun; Du, Jinju; Yang, Chengwei
Germin and germin-like proteins (GLPs) are encoded by a family of genes found in all plants. They are part of the cupin superfamily of biochemically diverse proteins, a superfamily that has a conserved tertiary structure, though with limited similarity in primary sequence. The subgroups of GLPs have different enzyme functions that include the two hydrogen peroxide–generating enzymes, oxalate oxidase (OxO)
Jim M. Dunwell; J. George Gibbings; Tariq Mahmood; S. M. Saqlan Naqvi
Background and Aims Plant growth regulators play an important role in seed germination. However, much of the current knowledge about their function during seed germination was obtained using orthodox seeds as model systems, and there is a paucity of information about the role of plant growth regulators during germination of recalcitrant seeds. In the present work, two endangered woody species with recalcitrant seeds, Araucaria angustifolia (Gymnosperm) and Ocotea odorifera (Angiosperm), native to the Atlantic Rain Forest, Brazil, were used to study the mobilization of polyamines (PAs), indole-acetic acid (IAA) and abscisic acid (ABA) during seed germination. Methods Data were sampled from embryos of O. odorifera and embryos and megagametophytes of A. angustifolia throughout the germination process. Biochemical analyses were carried out in HPLC. Key Results During seed germination, an increase in the (Spd + Spm) : Put ratio was recorded in embryos in both species. An increase in IAA and PA levels was also observed during seed germination in both embryos, while ABA levels showed a decrease in O. odorifera and an increase in A. angustifolia embryos throughout the period studied. Conclusions The (Spd + Spm) : Put ratio could be used as a marker for germination completion. The increase in IAA levels, prior to germination, could be associated with variations in PA content. The ABA mobilization observed in the embryos could represent a greater resistance to this hormone in recalcitrant seeds, in comparison to orthodox seeds, opening a new perspective for studies on the effects of this regulator in recalcitrant seeds. The gymnosperm seed, though without a connective tissue between megagametophyte and embryo, seems to be able to maintain communication between the tissues, based on the likely transport of plant growth regulators. PMID:21685432
Pieruzzi, Fernanda P.; Dias, Leonardo L. C.; Balbuena, Tiago S.; Santa-Catarina, Claudete; dos Santos, André L. W.; Floh, Eny I. S.
Plant growth is mediated by three fundamental processes: cell growth, division, and expansion. The\\u000a mechanistic analysis of their contributions are complicated by the observation that the balance of their\\u000a contributions to organ growth are not hard-wired. Reduced cell proliferation, irrespective of whether this\\u000a is caused by decreased cell growth or diminished cell division, can be, at least partially, compensated\\u000a for
Some of the factors interfering with the specific response of young common bean plants to two rhizosphere fluorescent pseudomonads\\u000a were studied. These two bacterial strains produced symptoms in foliar plant parts and reduced yield in beans and several other\\u000a plant species when inoculated on roots. Sensitivity in the plants subjected to bacterial application was highest at early\\u000a growth stages (up
To enhance a seventh-grade life science unit, the author had students grow bean plants in the classroom. Students were then able to observe roots, stems, leaves, flowers, and fruit up close as they learned about them. Students who held misconceptions prior to the activity had them corrected, learned about plant parts and growth during the plant unit, and observed firsthand how plants change as they grow.
This review includes novel natural products of microbial and plant origin reported to exert plant growth-regulating activities.\\u000a The well-known “classic” plant hormones are excluded. The substances described with their biological activities are restricted\\u000a to those that have been isolated from microbial or plant sources later than 1990 or that have been intensively investigated\\u000a during the last few years, such as
Dieter Gross; Benno Parthier
This activity is a classroom investigation where students gather descriptive data on two different plants with a partner, and on other plants during a classroom discussion.They will then interpret their findings, and classify the plants, if applicable, into monocots or dicots.
Carole DuRand Melrose High School Melrose, Minnesota
The germin protein family is comprised of two main subgroups in plants, oxalate oxidases (OXOs) and germin-like proteins (GLPs). These proteins are implicated in a variety of plant processes including germination, development, pollen formation, and response to abiotic and biotic stress. Here, we exa...
Plant-growth promoting rhizobacteria (PGPR) play an important role in plant health and soil fertility. The experiment was conducted as factorial experiment with two factors of Azospirillum and Azotobacter. The bacterial strains were Azospirillum lipoferum s-21, A. brasilense DSM 1690, A. lipoferum DSM 1691, Azotobacter chroococcum s-5, and A. chroococcum DSM 2286. The results indicated that growth promotion by PGPR appears
Ahmad Gholami; Atena Biyari; Manoochehr Gholipoor; Hadi Asadi Rahmani
Experiments with germinating seeds of Wayne soybean (Glycine max Merr.) show that between the 4th and the 8th hour of germination, respiration experiences a transition from predominantly “alternate” respiration, which is sensitive to salicylhydroxamic acid, to a cyanide-sensitive respiration. The dependence of early germination stages on alternate respiration is reflected in several types of seed functions, including subsequent root growth rate, chlorophyll synthesis, and germination itself. The early period of germination is shown to require a normal O2 tension, which is no longer a requirement at later stages. The changing sensitivity to cyanide and to salicylhydroxamic acid is found to be common to seven different types of germinating seeds. It is proposed that the alternate pathway of respiration provides something essential for the completion of the earliest stages of seed germination. PMID:16659465
Yentur, Semahat; Leopold, A. Carl
Method Taking advantage of the current rapid development in imaging systems and computer vision algorithms, we present HPGA, a high-throughput phenotyping platform for plant growth modeling and functional analysis, which produces better understanding of energy distribution in regards of the balance between growth and defense. HPGA has two components, PAE (Plant Area Estimation) and GMA (Growth Modeling and Analysis). In PAE, by taking the complex leaf overlap problem into consideration, the area of every plant is measured from top-view images in four steps. Given the abundant measurements obtained with PAE, in the second module GMA, a nonlinear growth model is applied to generate growth curves, followed by functional data analysis. Results Experimental results on model plant Arabidopsis thaliana show that, compared to an existing approach, HPGA reduces the error rate of measuring plant area by half. The application of HPGA on the cfq mutant plants under fluctuating light reveals the correlation between low photosynthetic rates and small plant area (compared to wild type), which raises a hypothesis that knocking out cfq changes the sensitivity of the energy distribution under fluctuating light conditions to repress leaf growth. Availability HPGA is available at http://www.msu.edu/~jinchen/HPGA. PMID:24565437
The effects of nano-TiO2 (rutile) and non-nano-TiO2 on the germination and growth of naturally aged spinach seeds were studied by measuring the germination rate and the germination\\u000a and vigor indexes of aged spinach seeds. An increase of these factors was observed at 0.25–4‰ nano-TiO2 treatment. During the growth stage, the plant dry weight was increased, as was the chlorophyll formation,
Lei Zheng; Fashui Hong; Shipeng Lu; Chao Liu
3 Abstract: An efficient protocol for plant regeneration has been developed for crop improvement programs. The present study was designed to assess the regeneration response of cotyledonary node explant taken from the germinating seeds of peanut (Arachis hypogaea L.). Complete plants were regenerated from in vitr o cultured sectioned cotyledonary nodes. Multiple shoots arose on 6-benzylaminopurine (BAP) supplemented Murashige and
Aman Verma; C. P. Malik; V. K. Gupta; Y. K. Sinsinwar
Numerous species of soil bacteria which flourish in the rhizosphere of plants or around plant tissues stimulate plant growth and reduce nematode population by antagonistic behavior. These bacteria are collectively known as PGPR (plant growth promoting rhizobacteria). The effects of six isolates of PGPR Pseudomonas putida, Pseudomonas fluorescens, Serratia marcescens, Bacillus amyloliquefaciens, Bacillus subtilis and Bacillus cereus, were studied on tomato plant growth and root knot nematode reproduction after 45 days from nematode infection. The highest number of shoot dry weight/g (43.00 g) was detected in the plant treated with S. marcescens; then P. putida (34.33 g), B. amyloliquefaciens (31.66 g), P. fluorescens (30.0 g), B. subtilis (29.0 g), B. cereus (27.0 g) and nematode alone (untreated) 20 g/plant. While the highest number of plant height was observed when plant was treated with S. marcescens, P. fluorescens, P. putida, B. amyloliquefaciens and P. putida 52.66, 50.66, 48 and 48 cm respectively. No significant differences were seen between previous treatments but only had significant differences compared with untreated plant. The highest number of fruit/plant was observed when plants were treated with S. marcescens (10.66), then B. amyloliquefaciens (8.66), P. putida (8), P. fluorescens (8) and B. cereus (7.66). No significant differences between the last 4 treatments, but all had significant differences compared with untreated plants. The highest weight of plant yield (g) was observed with S. marcescens (319.6 g/plant) and the lowest weight of plant yield was observed in plants treated with nematode alone (untreated). On the other hand, the lowest numbers of J2/10 g of soil (78), galls/root, (24.33) galls/root, egg masses/root (12.66) and egg/egg masses were observed in the plants treated with S. marcescens. PMID:23961220
Almaghrabi, Omar A.; Massoud, Samia I.; Abdelmoneim, Tamer S.
The lectin from stinging nettle rhizomes, Urtica dioica agglutinin (UDA), did not affect the evolution of wet and dry weight, protein, nucleic acid, ATP, cAMP and glycerol content during early germination of Phycomyces blakesleeanus spores. However, earlier investigations established a strongly reduced mycelial growth of several phytopathogenic fungi by this small plant lectin. Total uptake and incorporation of radioactive precursors
Jan Van Parijs; Hilde M. Joosen; Willy J. Peumans; Jan M. Geuns; André J. Laere
Coumarin is a compound that inhibits seed germination and seedling growth. This inhibitory effect may confer a competitive advantage for the plants that secrete coumarin into the environment. This study was conducted to evaluate the effect of hydration-dehydration of radish seed in the presence of...
Plant-associated microorganisms fulfill important functions for plant growth and health. Direct plant growth promotion by\\u000a microbes is based on improved nutrient acquisition and hormonal stimulation. Diverse mechanisms are involved in the suppression\\u000a of plant pathogens, which is often indirectly connected with plant growth. Whereas members of the bacterial genera Azospirillum and Rhizobium are well-studied examples for plant growth promotion, Bacillus,
Myrica gale L. (sweet gale) fruit leachate contains myrigalone A (MyA), a rare C-methylated dihydrochalcone and putative allelochemical, which is known to be a phytotoxin impeding seedling growth. We found that MyA inhibited Lepidium sativum L. seed germination in a dose-dependent manner. MyA did not affect testa rupture, but inhibited endosperm rupture and the transition to subsequent seedling growth. MyA inhibited micropylar endosperm cap (CAP) weakening and the increase in the growth potential of the radical/hypocotyl region (RAD) of the embryo, both being key processes required for endosperm rupture. We compared the contents of abscisic acid (ABA) and gibberellins in the tissues and found that the major bioactive forms of gibberellin in L. sativum seed tissues were GA(4) and GA(6), while GA(8) and GA(13) were abundant inactive metabolites. MyA did not appreciably affect the ABA contents, but severely interfered with gibberellin metabolism and signaling by inhibiting important steps catalyzed by GA3 oxidase, as well as by interfering with the GID1-type gibberellin signaling pathway. The hormonally and developmentally regulated formation of apoplastic superoxide radicals is important for embryo growth. Specific zones within the RAD were associated with accumulation of apoplastic superoxide radicals and endoreduplication indicative of embryo cell extension. MyA negatively affected both of these processes and acted as a scavenger of apoplastic reactive oxygen species. We propose that MyA is an allelochemical with a novel mode of action on seed germination. PMID:21908442
Oracz, Krystyna; Voegele, Antje; Tarkowská, Danuse; Jacquemoud, Dominique; Turecková, Veronika; Urbanová, Terezie; Strnad, Miroslav; Sliwinska, Elwira; Leubner-Metzger, Gerhard
Explores using corn seeds to demonstrate plant growth and development. This experiment allows students to formulate hypotheses, observe and record information, and practice mathematics. Presents background information, materials, procedures, and observations. (SAH)
Haldeman, Janice H.; Gray, Margarit S.
Overburden materials from surface coal mines in southwestern Indiana were analyzed for physical and chemical properties. Plant growth potential of selected materials, with and without sewage sludge and fertilizer amendments, was evaluated in greenhouse pot culture and outdoor con...
Clinostat rotates coaxial pair of plant-growth cabinets about horizontal axis while supplying cabinets with electric power for built-in computers, lamps, fans, and auxiliary equipment, such as nutrient pumps. Each cabinet self-contained unit for growing plants in controlled environment. By rotating cabinets and contents about horizontal axis, scientists simulate and study some of effects of microgravity on growth of plants. Clinostat includes vertical aluminum mounting bracket on horizontal aluminum base. Bearings on bracket hold shaft with V-belt pulley. At each end of shaft, circular plate holds frame mount for cabinet. Mounting plates also used to hold transparent sealed growth chambers described in article, "Sealed Plant-Growth Chamber For Clinostat" (KSC-11538).
Bushong, Wilton E.; Fox, Ronald C.; Brown, Christopher S.; Biro, Ronald R.; Dreshel, Thomas W.
The rhizosphere supports the development and activity of a huge and diversified microbial community, including microorganisms capable to promote plant growth. Among the latter, plant growth-promoting rhizobacteria (PGPR) colonize roots of monocots and dicots, and enhance plant growth by direct and indirect mechanisms. Modification of root system architecture by PGPR implicates the production of phytohormones and other signals that lead, mostly, to enhanced lateral root branching and development of root hairs. PGPR also modify root functioning, improve plant nutrition and influence the physiology of the whole plant. Recent results provided first clues as to how PGPR signals could trigger these plant responses. Whether local and/or systemic, the plant molecular pathways involved remain often unknown. From an ecological point of view, it emerged that PGPR form coherent functional groups, whose rhizosphere ecology is influenced by a myriad of abiotic and biotic factors in natural and agricultural soils, and these factors can in turn modulate PGPR effects on roots. In this paper, we address novel knowledge and gaps on PGPR modes of action and signals, and highlight recent progress on the links between plant morphological and physiological effects induced by PGPR. We also show the importance of taking into account the size, diversity, and gene expression patterns of PGPR assemblages in the rhizosphere to better understand their impact on plant growth and functioning. Integrating mechanistic and ecological knowledge on PGPR populations in soil will be a prerequisite to develop novel management strategies for sustainable agriculture. PMID:24062756
Vacheron, Jordan; Desbrosses, Guilhem; Bouffaud, Marie-Lara; Touraine, Bruno; Moënne-Loccoz, Yvan; Muller, Daniel; Legendre, Laurent; Wisniewski-Dyé, Florence; Prigent-Combaret, Claire
It is difficult to grow potato from seeds, because their germinating capacity is low. To increase the germinating capacity and germinating force of potato seeds, it is reasonable to treat them with RPGs. In this work, we studied the effects of Vital-1 and Vital-2 on potato selection material. At the initial stage of the study, an optimum concentration of the
M. G. Voronkov; T. N. Martynova
Brassicaceae plants are nonmycorrhizal. They were found to inhibit VA mycorrhizal infection in their host plants. We tested if they can influence growth of ectomycorrhizal (ECM) fungi. When roots and leaves of Brassicaceae plants and ECM fungi were cultured together in the same petri dishes, the root exudates of turnip (Brassica rapa), swede (B. napobrassica), cabbage (B. oleracea, var. capitata), broccoli (B. oleracea, var. italica Plenck), kohlrobi (B. caulorapa Pasq.), mustard (B. juncea), radish (Raphanus sativus), and choy (B. napus) significantly stimulated hyphal growth of the ectomycorrhizal fungus Paxillus involutus. Root exudates of turnip and cabbage stimulated hyphal growth of Pisolithus tinctorius and two isolates of P. involutus. Colony area of P. involutus was increased by 452 and 414%, respectively, in the presence of turnip and cabbage germinants. Root exudates of turnip increased the biomass of P. involutus and P. tinctorius by 256 and 122% and cabbage by 220 and 82%, respectively. The stimulatory effect was not affected by autoclaving the root exudates. Root exudates had chemical reactions with glutathione and lysine, which resulted in a reduction of the growth stimulation of ECM fungi. Myrosinase enhanced further the stimulatory effects of turnip on the ECM colony diameter growth by 23%. Autoclaved roots and leaves of turnip did not stimulate fungal growth, but mechanically ground roots and leaves of turnip stimulated growth of P. involutus by 147 and 135%, respectively. After desulfuration with aryl sulphatuse, the glucosinolates (GLSs) in turnip roots and leaves were identified by HPLC. The major ones were indole GLSs. Prominent compounds identified were 1-methoxy-3-indolymethyl GLS and4-methoxy-3-indolymethyl GLS. The finding provides an opportunity to field test the use of Brassicaceae plants in enhancing ectomycorrhizal formation in conifers by interplanting conifers with Brassicaceae plants in forest tree nursery and agroforestry systems. PMID:12918920
Zeng, Ren Sen; Mallik, Azim U; Setliff, Ed
\\u000a Among the diverse soil microflora, plant growth promoting rhizobacteria (PGPR) mark an important role in enhancing plant growth\\u000a through a range of beneficial effects. This is often achieved by forming biofilms in the rhizosphere, which has advantages\\u000a over planktonic mode of bacterial existence. However, the biofilm formation of PGPR has been overlooked in past research.\\u000a This chapter focuses on new
Gamini Seneviratne; M. Weerasekara; K. Seneviratne; J. Zavahir; M. Kecskés; I. Kennedy
Although the epidermal cell-layer is of undisputed physiological importance to all angiosperms, its\\u000a potential role in controlling the growth of plant organs has remained a subject of research and contention\\u000a for more than a century. Recent advances in our understanding of the molecular control of plant cell\\u000a proliferation, growth and specification, in combination with novel biotechnological techniques, have provided\\u000a new tools for
Gwyneth C. Ingram
Increased air pollution in a number of developing African countries, together with the reports of vegetation damage typically associated with acid precipitation in commercial forests in South Africa, has raised concerns over the potential impacts of acid rain on natural vegetation in these countries. Recalcitrant (i.e. desiccation sensitive) seeds of many indigenous African species, e.g. must germinate shortly after shedding and hence, may not be able to avoid exposure to acid rain in polluted areas. This study investigated the effects of simulated acid rain (rainwater with pH adjusted to pH 3.0 and 4.5 with 70:30, H2 SO4 :HNO3 ) on germination, seedling growth and oxidative metabolism in a recalcitrant-seeded African tree species Trichilia dregeana Sond., growing in its natural seed bank. The results suggest that acid rain did not compromise T. dregeana seed germination and seedling establishment significantly, relative to the control (non-acidified rainwater). However, pH 3.0 treated seedlings exhibited signs of stress typically associated with acid rain: leaf tip necrosis, abnormal bilobed leaf tips, leaf necrotic spots and chlorosis, reduced leaf chlorophyll concentration, increased stomatal density and indications of oxidative stress. This may explain why total and root biomass of pH 3.0 treated seedlings were significantly lower than the control. Acid rain also induced changes in the species composition and relative abundance of the different life forms emerging from T. dregeana's natural seed bank and in this way could indirectly impact on T. dregeana seedling establishment success. PMID:24835442
Ramlall, Chandika; Varghese, Boby; Ramdhani, Syd; Pammenter, Norman W; Bhatt, Arvind; Berjak, Patricia; Sershen
Phthalic acid esters (PAEs) pollution in agricultural soils caused by widely employed plastic products is becoming more and more widespread in China. PAEs polluted soil can lead to phytotoxicity in higher plants and potential health risks to human being. We evaluated the individual toxicity of di-n-butyl phthalate (DnBP) and bis(2-ethylhexyl) phthalate (DEHP), two representative PAEs, to sown rape (Brassica chinensis L.) seeds within 72 h (as germination stage) and seedlings after germination for 14 days by monitoring responses and trends of different biological parameters. No significant effects of six concentrations of PAE ranging from 0 (not treated/NT) to 500 mg?kg(-1) on germination rate in soil were observed. However, root length, shoot length, and biomass (fresh weight) were inhibited by both pollutants (except root length and biomass under DEHP). Stimulatory effects of both target pollutants on malondialdehyde (MDA) content, superoxide dismutase (SODase) activity, ascorbate peroxidase (APXase) content, and polyphenoloxidase (PPOase) activity in shoots and roots (SODase activity in shoots excluded) were in the same trend with the promotion of proline (Pro) but differed with acetylcholinesterase activity (except in shoots under DnBP) for analyzed samples treated for 72 h and 14 days. Responses of representative storage compounds free amino acids (FAA) and total soluble sugar (TSS) under both PAEs were raised. Sensitivity of APXase and Pro in roots demonstrates their possibility in estimation of PAE phytotoxicity and the higher toxicity of DnBP, which has also been approved by the morphological photos of seedlings at day 14. Higher sensitivity of the roots was also observed. The recommended soil allowable concentration is 5 mg DnBP?kg(-1) soil for the development of rape. We still need to know the phytotoxicity of DEHP at whole seedling stage for both the growing and development; on the other hand, soil criteria for PAE compounds are urgently required in China. PMID:23389857
Ma, Tingting; Christie, Peter; Teng, Ying; Luo, Yongming
resulting in more efficient water extraction from the deeper soil layers and thereby higher grain yield. How- Plant growth regulators (PGR) shorten the straw of cereals, but ever, Bragg et al. (1984) and Steen and Wunsche (1990) their effects on other traits of plant stand structure have been inconsis- tent. To arrive at an assessment of whole-plant response, experiments did
A. Rajala; P. Peltonen-Sainio
The fifth workshop on seedling physiology and growth problems in oak plantings was held at the Holiday Inn Gateway Center in Ames, Iowa on March 4 and 5, 1992 with more than 45 participants. The workshop continues to serve as an informal forum for researchers to exchange ideas and research results. Papers were divided into four general subject areas: (1) field performance of planted oaks, (2) seedling propagation and production, (3) oak physiology and genetics, and (4) natural and acorn germination regeneration. All abstracts prepared for the workshop are included in the technical report.
Thompson, J.R.; Schultz, R.C.; Van Sambeek, J.W.
The exocyst, an octameric tethering complex and effector of Rho and Rab GTPases, facilitates polarized secretion in yeast and animals. Recent evidence implicates three plant homologs of exocyst subunits (SEC3, SEC8, and EXO70A1) in plant cell morphogenesis. Here, we provide genetic, cell biological, and biochemical evidence that these and other predicted subunits function together in vivo in Arabidopsis thaliana. Double mutants in exocyst subunits (sec5 exo70A1 and sec8 exo70A1) show a synergistic defect in etiolated hypocotyl elongation. Mutants in exocyst subunits SEC5, SEC6, SEC8, and SEC15a show defective pollen germination and pollen tube growth phenotypes. Using antibodies directed against SEC6, SEC8, and EXO70A1, we demonstrate colocalization of these proteins at the apex of growing tobacco pollen tubes. The SEC3, SEC5, SEC6, SEC8, SEC10, SEC15a, and EXO70 subunits copurify in a high molecular mass fraction of 900 kD after chromatographic fractionation of an Arabidopsis cell suspension extract. Blue native electrophoresis confirmed the presence of SEC3, SEC6, SEC8, and EXO70 in high molecular mass complexes. Finally, use of the yeast two-hybrid system revealed interaction of Arabidopsis SEC3a with EXO70A1, SEC10 with SEC15b, and SEC6 with SEC8. We conclude that the exocyst functions as a complex in plant cells, where it plays important roles in morphogenesis. PMID:18492870
Hála, Michal; Cole, Rex; Synek, Lukás; Drdová, Edita; Pecenková, Tamara; Nordheim, Alfred; Lamkemeyer, Tobias; Madlung, Johannes; Hochholdinger, Frank; Fowler, John E; Zárský, Viktor
Past medicinal plant research primarily focused on bioactive phytochemicals, however, the focus is currently shifting due to the recognition that a significant number of phytotherapeutic compounds are actually produced by associated microbes or through interaction with their host. Medicinal plants provide an enormous bioresource of potential use in modern medicine and agriculture, yet their microbiome is largely unknown. The objective of this review is (i) to introduce novel insights into the plant microbiome with a focus on medicinal plants, (ii) to provide details about plant- and microbe-derived ingredients of medicinal plants, and (iii) to discuss possibilities for plant growth promotion and plant protection for commercial cultivation of medicinal plants. In addition, we also present a case study performed both to analyse the microbiome of three medicinal plants (Matricaria chamomilla L., Calendula officinalis L., and Solanum distichum Schumach. and Thonn.) cultivated on organically managed Egyptian desert farm and to develop biological control strategies. The soil microbiome of the desert ecosystem was comprised of a high abundance of Gram-positive bacteria of prime importance for pathogen suppression under arid soil conditions. For all three plants, we observed a clearly plant-specific selection of the microbes as well as highly specific diazotrophic communities that overall identify plant species as important drivers in structural and functional diversity. Lastly, native Bacillus spec. div. strains were able to promote plant growth and elevate the plants’ flavonoid production. These results underline the numerous links between the plant-associated microbiome and the plant metabolome. PMID:24391634
Köberl, Martina; Schmidt, Ruth; Ramadan, Elshahat M.; Bauer, Rudolf; Berg, Gabriele
The biological effects of extremely low frequency magnetic fields (ELF MFs) on living organisms have been explored in many studies, but few of them investigate how different waveform MFs act upon their growth. In this study, the biological effects of both a 60Hz sinusoidal MF and a 60Hz pulsed MF on the early growth of plants are presented using mung
Hsin-Hsiung Huang; Show-Ran Wang
Plant improvement Genetic variation for heterotrophic growth in maize in relation to temperature C was conducted in the frame of early maize (Zea mays L) adaptation to northern Eu- rope climatic conditions, and for optimum temperature between 27 and 30 Â°C). maize / temperature / heterotrophic growth / radicle / non
Selective removal of near ultraviolet and green wavelengths from white light permitted enhanced growth of marigold, tomato, corn, and Impatiens plants, Chlamydomonas cells and the mycelium of Sordaria. Additions of near ultraviolet and green radiations caused repressions in the growth of marigold and Sordaria. These wavelengths do not alter the oxidative mechanisms of mitochondria, intact algal cells or marigold leaf
R. M. Klein; P. C. Edsall; A. C. Gentile
Clean chip residual (CCR) is a potential replacement for pine bark (PB) in nursery crop substrates. It is a by-product of in-field forestry harvesting practices and has been shown to produce annual plants and perennials similar in size to plants grown in PB. This study evaluated growth of woody orna...
In today's atmosphere fossil fuel emissions and land use change since the industrial revolution have increased atmospheric CO2 concentration from 280 ppm to nearly 400 ppm, a value not experienced by plants for over 10 million years. In contrast, over the same period atmospheric CO2 levels have been much lower than preindustrial levels. Plants' recent evolutionary history has thus been under carbon starvation while over the next 90 years atmospheric CO2 is expected to rise to a bountiful ~800 ppm. Plants' response to this rapid increase is likely influenced by their long evolution in low CO2, but this has been hardly studied at all. Very little is known about how plant traits drove carbon cycling in the past and how these relationships may shift going from past to future CO2.In a climate chamber experiment we germinated and grew seedlings of 30 species (C3, C4, woody, herbaceous) at past low CO2 (150ppm), ambient CO2, and future high CO2(750ppm). Our aim was to understand how plant traits are affected by CO2 and if and why winners and losers in terms of growth performance shift going from past to future CO2 concentrations. Results show a great effect of low and high CO2 on specific leaf area, biomass and allocation shifts above and belowground but mixed results in patterns between species and plant types. Ongoing work focuses on leaf level chemistry and photosynthesis and the interaction between CO2 and drought stress with promising initial results.
Temme, Andries; Cornwell, Will; Cornelissen, Hans; Aerts, Rien
Dormancy is a common strategy adopted by bacterial cells as a means of surviving adverse environmental conditions. For Streptomyces bacteria, this involves developing chains of dormant exospores that extend away from the colony surface. Both spore formation and subsequent spore germination are tightly controlled processes, and while significant progress has been made in understanding the underlying regulatory and enzymatic bases for these, there are still significant gaps in our understanding. One class of proteins with a potential role in spore-associated processes are the so-called resuscitation-promoting factors, or Rpfs, which in other actinobacteria are needed to restore active growth to dormant cell populations. The model species Streptomyces coelicolor encodes five Rpf proteins (RpfA to RfpE), and here we show that these proteins have overlapping functions during growth. Collectively, the S. coelicolor Rpfs promote spore germination and are critical for growth under nutrient-limiting conditions. Previous studies have revealed structural similarities between the Rpf domain and lysozyme, and our in vitro biochemical assays revealed various levels of peptidoglycan cleavage capabilities for each of these five Streptomyces enzymes. Peptidoglycan remodeling by enzymes such as these must be stringently governed so as to retain the structural integrity of the cell wall. Our results suggest that one of the Rpfs, RpfB, is subject to a unique mode of enzymatic autoregulation, mediated by a domain of previously unknown function (DUF348) located within the N terminus of the protein; removal of this domain led to significantly enhanced peptidoglycan cleavage. PMID:25512314
Sexton, Danielle L; St-Onge, Renée J; Haiser, Henry J; Yousef, Mary R; Brady, Lauren; Gao, Chan; Leonard, Jacqueline; Elliot, Marie A
The inhibitory activities of nisin or/and potassium sorbate on spores and vegetative cells of Bacillus sporothermodurans LTIS27, which are known to be a contaminant of dairy products and to be extremely heat-resistant, were investigated. First, the tested concentrations of nisin or potassium sorbate inhibited vegetative cell growth; with the minimum inhibitory concentrations were 5 × 10(3) IU/ml and 2% (w/v), respectively. Then, the behaviour of vegetative cells and spores in presence of sub-lethal concentrations of nisin (50 UI/ml) or/and potassium sorbate (0.2%), in milk at 37 °C for 5 days, were evaluated. In the absence of inhibitors, strain grew and sporulated at the end of the exponential phase. Nisin (50 UI/ml) was able to inhibit spore outgrowth but didn't affect their germination. It induced an immediate and transitory reduction (1.6log(10) after 1 h and 2.8log(10) after 6 h of incubation) of vegetative cell growth which reappeared between 10 h and 24 h. Potassium sorbate (0.2%) had a durable bacteriostatic effect (1.1log(10) after 6 h), on vegetative cells, followed by a slower regrowth. It was able to inhibit both germination and outgrowth of spores. Association of nisin and potassium sorbate, at sub-lethal concentrations, showed a synergistic effect and resulted in a total inhibition of cells growth after 5 days. The results illustrate the efficacy of nisin and potassium sorbate in combination, and the commercial potential of applying such treatment to decontaminate any product that has a problem with persistence of bacterial spores. PMID:25475264
Aouadhi, Chedia; Mejri, Slah; Maaroufi, Abderrazak
Polymers of L-lactic acid are shown to promote plant growth. Dry weight of duckweed (Lemna minor L.) and corn (Zea mays L) was more than doubled when plants were grown in media containing the dimer of L-lactic acid, L-lactoyllactic acid. Higher polymers were equally effective at increasing plant biomass. Monomeric lactic acid and polymers of D-lactic acid showed no biological
Alan M. Kinnersley; Taylor C. Scott; John H. Yopp; George H. Whitten
Spiraea thunbergii Sieb. contains 1-O-cis-cinnamoyl-beta-D-glucopyranose (CG) and 6-O-(4'-hydroxy-2'-methylene-butyroyl)-1-O-cis-cinnamoyl-beta-D-glucopyranose (BCG) as major plant growth inhibiting constituents. In the present study, we determined the inhibitory activity of CG and BCG on root elongation of germinated seedlings of lettuce (Lactuca sativa), pigweed (Amaranthus retroflexus), red clover (Trifolium pratense), timothy (Phleum pratense), and bok choy (Brassica rapa var chinensis) in comparison with that of two well-known growth inhibitors, 2,4-dichlorophenoxyacetic acid (2,4-D) and (+)-2-cis-4-trans-abscisic acid (cis-ABA), as well as two related chemicals of CG and BCG, cis-cinnamic acid (cis-CA) and trans-cinnamic acid (trans-CA). The EC50 values for CG and BCG on lettuce were roughly one-half to one-quarter of the value for cis-ABA. cis-Cinnamic acid, which is a component of CG and BCG, possessed almost the same inhibitory activity of CG and BCG, suggesting that the essential chemical structure responsible for the inhibitory activity of CG and BCG is cis-CA. The cis-stereochemistry of the methylene moiety is apparently needed for high inhibitory activity, as trans-CA had an EC50 value roughly 100 times that of CG, BCG, and cis-CA. Growth inhibition by CG, BCG, and cis-CA was influenced by the nature of the soil in the growing medium: alluvial soil preserved the bioactivity, whereas volcanic ash and calcareous soils inhibited bioactivity. These findings indicate a potential role of cis-CA and its glucosides as allelochemicals for use as plant growth regulators in agricultural fields. PMID:15898503
Hiradate, Syuntaro; Morita, Sayaka; Furubayashi, Akihiro; Fujii, Yoshiharu; Harada, Jiro
The natural occurrence of jasmonic acid and its methyl ester in plants has been studied using different methods such as GC,\\u000a GC-MS, HPLC, radioimmunoassay, and bioassay. Jasmonic acid was detected in several Legumin