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Plant Survival (plant + survival)

Distribution by Scientific Domains

Life Sciences	70%
Earth and Environmental Science	20%

Selected Abstracts

Plant survival after freezing in wheat ,Cappelle Desprez' (,Bezostaya 1') intervarietal chromosome substitution lines

PLANT BREEDING, Issue 2 2008
G. Ganeva
Abstract The effect of individual chromosomes of the wheat variety ,Bezostaya 1' on plant resistance to low temperatures was studied using the available set of intervarietal ,Cappelle Desprez' (,Bezostaya 1') chromosome substitution lines. The number of plants surviving after freezing at ,12, ,15 and ,17°C was determined for both parents and lines in trials in 2004/2005 and 2005/2006. Significant differences between the three temperature treatments and between lines were found, implying that two factors, the level of temperature stress and chromosome substitutions, were influencing plant survival. Improved frost resistance in both trials was associated with genes located on five chromosomes: 5A, 2D, 4A, 5D and 6A. An increase in the plant frost resistance because of the effects of 7A and 1A chromosomes was also observed in the 2005/2006 trial, when the overall autumn and winter (January) temperatures were lower than in 2004/2005. [source]

Species richness and susceptibility to heat and drought extremes in synthesized grassland ecosystems: compositional vs physiological effects

FUNCTIONAL ECOLOGY, Issue 6 2004
L. VAN PEER
Summary 1We investigated effects of declining plant species richness (S) on resistance to extremes in grassland communities. 2Synthesized model ecosystems of different S, grown outdoors in containers, were exposed to a stress peak combining heat and drought. The heat wave was induced experimentally by infrared irradiation in free air conditions. 3Before the heat wave, the more species-rich communities produced more biomass as a result of a large and positive complementarity effect that outweighed a small negative selection effect. 4Water use during the heat wave was likewise enhanced by S, which could not be attributed to dominance of ,water-wasting' species. Instead, water consumption at high S exceeded that expected from changes in community biomass and biomass composition. The observed enhancement of resource (water) acquisition under stress with increasing S therefore probably originated from complementarity. 5Despite enhanced water use in the more diverse communities, plant survival was significantly less, affecting all species alike. Physiological stress, recorded as photochemical efficiency of photosystem II electron transport, was significantly greater. Before the heat wave, the changes in biomass composition that coincided with increasing S did not favour species that would later prove intrinsically sensitive or insensitive. 6Complementarity in resource use for biomass production had a cost in terms of reduced survival under stress, despite the likelihood of complementarity in water acquisition during exposure. The greater loss of individuals from the more diverse grasslands suggests enhanced risk of local extinction. [source]

Assessment of vegetation effects on hydraulics and of feedbacks on plant survival and zonation in ephemeral channels

HYDROLOGICAL PROCESSES, Issue 6 2010
P. J. Sandercock
Abstract The interaction of vegetation and flow in channels is important for understanding the influences of forces in channels and effects on erosion, sediment flux and deposition; it has implications for channel habitats, channel instability and restoration schemes. Methods are needed for calculating forces on plants and data are required on thresholds for plant destruction and survival. A simple method of calculating the effect of hydraulics on vegetation and its zonation within ephemeral channels is described. Detailed cross section surveys of channel morphology, vegetation and estimates of Manning's n are input into the software program WinXSPRO to calculate the hydraulics of flows across the channel for a given event or flow level, incorporating subdivision into zones of differing morphology and vegetation across the section. This was applied to a number of cross sections on ephemeral channels in SE Spain and typical roughness values for Mediterranean vegetation types in channels were assessed. The method is demonstrated with reference to two well-documented floods in SE Spain, in September 1997 on the Torrealvilla and in October 2003 along the Salada. These flows led to the mortality of herbs, reed and smaller shrub species. Some damage to larger shrubs and trees occurred, but trees such as Tamarisk (Tamarix canariensis) were shown to withstand high forces. Some grasses were highly resistant to removal and induced sedimentation. Significant erosion was limited to areas with little vegetation covering the channel floor. Further quantification of resistance of vegetation to flows and upper threshold values for removal is continuing by relating calculated hydraulic conditions using the methods outlined to measurements of vegetation responses in events at monitoring sites. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Underground Vetch (Vicia sativa ssp. amphicarpa): A Potential Pasture and Forage Legume for Dry Areas in West Asia

JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 3 2003
A. M. Abd El Moneim
Abstract Subterranean vetch [Vicia sativa ssp. amphicarpa (Dorth.) Aschers & Graebn.] is native to disturbed grasslands of the Mediterranean basin where heavy grazing, seasonal drought and erosion act as strong selection forces. It produces two pod types, above-ground and 5 cm below the soil surface. Unlike subterranean clover (Trifolium subterranean L.), which buries its seeds after flowering above-ground, subterranean vetch flowers and forms pods beneath the soil surface on underground stems. The aerial pods are produced after vegetative development ceases, while the underground pods are produced in ontogeny. The ability of this unusual vetch to survive in marginal areas with low rainfall (about 250 mm year,1) and to produce nutritious herbage and pods is an important characteristic which helps address rehabilitation of degraded rangelands and increase feed production for small ruminants. Research at the International Center for Agricultural Research in the Dry Areas (ICARDA) during the 1988,93 growing seasons has assessed the herbage and seed productivity of underground vetch, its ability to grow in rotation with barley in marginal low-rainfall areas, and its capacity to regenerate after heavy grazing. Drier conditions in 1989 favoured earlier underground flowering; the number of underground pods was higher than that of aerial pods. Grain yield of barley (var. Atlas) was around 2.0 t ha,1 after underground vetch and only 1.2 t ha,1 after barley. Grazing underground vetch had no effect on the productivity of the succeeding barley crop. The aerial and underground pods serve two distinct functions; aerial pods increase dissemination within suitable habitats, while underground pods increase the probability of plant survival under adverse conditions such as drought and heavy grazing. Underground vetch has two potential uses, namely the rehabilitation of marginal areas and production in rotation with barley. [source]

Plant responses to drought and phosphorus deficiency: contribution of phytohormones in root-related processes

JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 4 2005
Lutz Wittenmayer
Abstract Environmental stresses are one of the most limiting factors in agricultural productivity. A large portion of the annual crop yield is lost to pathogens (biotic stress) or the detrimental effects of abiotic-stress conditions. There are numerous reports about chemical characterization of quantitatively significant substrate fluxes in plant responses to stress factors in the root-rhizosphere system, e.g., nutrient mobilization, heavy-metal and aluminum immobilization, or establishment of plant-growth-promoting rhizobacteria (PGPR) by exudation of organic anions, phytosiderophores, or carbohydrates into the soil, respectively. The hormonal regulation of these responses is not well understood. This paper highlights this complex process, stressing the involvement of phytohormones in plant responses to drought and phosphorus deficiency as examples. Beside ethylene, abscisic acid (ABA) plays an important role in drought-stress adaptation of plants. This hormone causes morphological and chemical changes in plants, ensuring plant survival under water-limited conditions. For example, ABA induces stomata closure, reduction in leaf surface, and increase in root : shoot ratio and, thus, reduction in transpiration and increase in soil volume for water uptake. Furthermore, it supports water uptake in soil with decreasing water potential by osmotic adjustment. Suitability of hormonal parameters in the selection for improving stress resistance is discussed. Auxins, ethylene, and cytokinins are involved in morphological adaption processes to phosphorus (P) deficiency (increase in root surface, e.g., by the formation of more dense root hairs or cluster roots). Furthermore, indole-3-acetic acid increases root exudation for direct and indirect phosphorus mobilization in soil. Nevertheless, the direct use of the trait "hormone content" of a particular plant organ or tissue, for example the use of the drought-stress-induced ABA content of detached leaves in plant breeding for drought-stress-resistant crops, seems to be questionable, because this procedure does not consider the systemic principle of hormonal regulation in plants. Reaktionen von Pflanzen auf Trockenstress und Phosphormangel: Die Rolle von Phytohormonen in wurzelbezogenen Prozessen Umweltstress stellt den wesentlichsten Limitierungsfaktor für die landwirtschaftliche Produktion dar. Ein erheblicher Teil der jährlichen Ernten geht durch pathogene Organismen (biotischer Stress) oder durch die verheerende Wirkung abiotischer Stressoren verloren (v. a. Trockenstress und Nährstoffmangel). Es gibt zahlreiche Untersuchungen zur stofflichen Charakterisierung der pflanzlichen Stressreaktion an der Wurzel, z.,B. Nährstoffmobilisierung, Schadstoffimmobilisierung oder Etablierung von wachstumsfördernden Rhizobakterien durch Wurzelabscheidungen. Die hormonelle Steuerung dieser Prozesse ist bisher weniger erforscht. Der Artikel geht dieser Problematik am Beispiel von Trockenstress und Phosphormangel unter besonderer Berücksichtigung von Phytohormonen nach. Bei der Anpassung von Pflanzen an Wassermangelbedingungen spielt neben Ethylen das Phytohormon Abscisinsäure (ABA) eine wichtige Rolle. Es induziert morphologische und chemische Veränderungen in der Pflanze, die ein Überleben unter Wassermangelbedingungen ermöglichen. Beispielsweise induziert die ABA den Stomataschluss, eine Verringerung der Blattoberfläche sowie eine Erhöhung des Wurzel:Spross-Verhältnisses und bewirkt dadurch eine verringerte Transpiration und Vergrößerung des Bodenvolumens zur Erschließung von Wasservorräten. Darüber hinaus kann eine ABA-induzierte Anreicherung von osmotisch wirksamen Verbindungen zur Wasseraufnahme bei sinkendem Wasserpotential im Boden beitragen. Bei Phosphat (P)-Mangel sind vor allem Auxine, Cytokine und Ethylen an der morphologischen Anpassung der Wurzeln (Vergrößerung der Wurzeloberfläche durch verstärkte Bildung von Wurzelhaaren oder Proteoidwurzeln) beteiligt. Darüber hinaus bewirkt Indolyl-3-Essigäure eine Intensivierung der Abgabe von Wurzelabscheidungen zur direkten oder indirekten P-Mobilisierung in der Rhizosphäre. Trotzdem wird die unmittelbare Verwendung des Indikators "Hormongehalt" eines bestimmten Pflanzenorganes, beispielsweise der trockenstressinduzierte ABA-Gehalt von abgeschnittenen Blättern, für die Züchtung auf Stressresistenz als problematisch angesehen, da sie das systemische Prinzip der Hormonregulation nicht berücksichtigt. [source]

Plant survival after freezing in wheat ,Cappelle Desprez' (,Bezostaya 1') intervarietal chromosome substitution lines

Revegetation Methods for High-Elevation Roadsides at Bryce Canyon National Park, Utah

RESTORATION ECOLOGY, Issue 2 2004
S. L. Petersen
Abstract Establishment of native plant populations on disturbed roadsides was investigated at Bryce Canyon National Park (BCNP) in relation to several revegetation and seedbed preparation techniques. In 1994, the BCNP Rim Road (2,683,2,770 m elevation) was reconstructed resulting in a 23.8-ha roadside disturbance. Revegetation comparisons included the influence of fertilizer on plant establishment and development, the success of indigenous versus commercial seed, seedling response to microsites, methods of erosion control, and shrub transplant growth and survival. Plant density, cover, and biomass were measured 1, 2, and 4 years after revegetation implementation (1995,1998). Seeded native grass cover and density were the highest on plots fertilized with nitrogen and phosphorus, but by the fourth growing season, differences between fertilized and unfertilized plots were minimal. Fertilizers may facilitate more rapid establishment of seeded grasses following disturbance, increasing soil cover and soil stability on steep and unstable slopes. However the benefit of increased soil nutrients favored few of the desired species resulting in lower species richness over time compared to unfertilized sites. Elymus trachycaulus (slender wheatgrass) plants raised from indigenous seed had higher density and cover than those from a commercial seed source 2 and 4 years after sowing. Indigenous materials may exhibit slow establishment immediately following seeding, but they will likely persist during extreme climatic conditions such as cold temperatures and relatively short growing seasons. Seeded grasses established better near stones and logs than on adjacent open microsites, suggesting that a roughened seedbed created before seeding can significantly enhance plant establishment. After two growing seasons, total grass cover between various erosion-control treatments was similar indicating that a variety of erosion reduction techniques can be utilized to reduce erosion. Finally shrub transplants showed minimal differential response to fertilizers, water-absorbing gels, and soil type. Simply planting and watering transplants was sufficient for the greatest plant survival and growth. [source]

Mounding as a Technique for Restoration of Prairie on a Capped Landfill in the Puget Sound Lowlands

RESTORATION ECOLOGY, Issue 2 2002
Kern Ewing
Abstract Closed landfills create large open spaces that are often proposed as sites for restored or created ecosystems. Grasslands are probably prescribed most often because of the presumption that grass root systems will not breach the landfill cap. Capped landfills have a number of soil degradation problems, including compaction, decreased permeability, lack of organic material, diminished soil fauna, inappropriate texture, and lack of structure. In this study in the Puget Sound lowlands, Washington, U.S.A., mounding (low sandy-loam mounds, about 20 cm high and 2 m in diameter), addition of fertilizer, and mulching with yard-waste compost were applied to landfill sites as treatments in a factorial-design experiment. Prairie plants (1,344 individuals, 7 species) were planted into 4-m2 plots (n = 48), and plant growth and survival and the increase in weed biomass were monitored for 3 years. Mulching had no effect on plant survival or growth. Fertilization had a negative effect on Lupinus lepidus, a nitrogen-fixing species. Mounding had a positive effect on growth and survival of Eriophyllum lanatum, Festuca idahoensis, and Aster curtus. Potentilla pacifica was indifferent to mounding, and Carex inops responded negatively. Mounds should probably be used as one element of a complex of habitats on restored landfills. [source]

Hormonal regulation of temperature-induced growth in Arabidopsis

THE PLANT JOURNAL, Issue 4 2009
Jon A. Stavang
Summary Successful plant survival depends upon the proper integration of information from the environment with endogenous cues to regulate growth and development. We have investigated the interplay between ambient temperature and hormone action during the regulation of hypocotyl elongation, and we have found that gibberellins (GAs) and auxin are quickly and independently recruited by temperature to modulate growth rate, whereas activity of brassinosteroids (BRs) seems to be required later on. Impairment of GA biosynthesis blocked the increased elongation caused at higher temperatures, but hypocotyls of pentuple DELLA knockout mutants still reduced their response to higher temperatures when BR synthesis or auxin polar transport were blocked. The expression of several key genes involved in the biosynthesis of GAs and auxin was regulated by temperature, which indirectly resulted in coherent variations in the levels of accumulation of nuclear GFP,RGA (repressor of GA1) and in the activity of the DR5 reporter. DNA microarray and genetic analyses allowed the identification of the transcription factor PIF4 (phytochrome-interacting factor 4) as a major target in the promotion of growth at higher temperature. These results suggest that temperature regulates hypocotyl growth by individually impinging on several elements of a pre-existing network of signaling pathways involving auxin, BRs, GAs, and PIF4. [source]

A role for protein kinase CK2 in plant development: evidence obtained using a dominant-negative mutant

THE PLANT JOURNAL, Issue 1 2008
Jordi Moreno-Romero
Summary Protein kinase CK2 is an evolutionary conserved Ser/Thr phosphotransferase composed of two distinct subunits, , (catalytic) and , (regulatory), that combine to form a tetrameric complex. Plant genomes contain multiple genes for each subunit, the expression of which gives rise to different active holoenzymes. In order to study the effects of loss of function of CK2 on plant development, we have undertaken a dominant-negative mutant approach. We generated an inactive catalytic subunit by site-directed mutagenesis of an essential lysine residue. The mutated open reading frame was cloned downstream of an inducible promoter, and stably transformed Arabidopsis thaliana plants and tobacco BY2 cells were isolated. Continuous expression of the CK2 kinase-inactive subunit did not prevent seed germination, but seedlings exhibited a strong phenotype, affecting chloroplast development, cotyledon expansion, and root and shoot growth. Prolonged induction of the transgene was lethal. Moreover, dark-germinated seedlings exhibited an apparent de-etiolated phenotype that was not caused by disruption of the light-signalling pathways. Short-term induction of the CK2 kinase-inactive subunit allowed plant survival, but root growth and lateral root formation were significantly affected. The expression pattern of CYCB1;1::GFP in the root meristems of mutant plants demonstrated an important decrease of mitotic activity, and expression of the CK2 kinase-inactive subunit in stably transformed BY2 cells provoked perturbation of the G1/S and G2 phases of the cell cycle. Our results are consistent with a model in which CK2 plays a key role in cell division and cell expansion, with compelling effects on Arabidopsis development. [source]