The Experts below are selected from a list of 41508 Experts worldwide ranked by ideXlab platform
Jian-kang Zhu - One of the best experts on this subject based on the ideXlab platform.
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Understanding and improving Salt Tolerance in plants
Crop Science, 2005Co-Authors: Viswanathan Chinnusamy, Andret Jagendorf, Jian-kang ZhuAbstract:One-fifth of irrigated agriculture is adversely affected by soil salinity. Hence, developing Salt-tolerant crops is essential for sustaining food production. Progress in breeding for Salt-tolerant crops has been hampered by the lack of understanding of the molecular basis of Salt Tolerance and lack of availability of genes that confer Salt Tolerance. Genetic evidence suggests that perception of Salt stress leads to a cytosolic calcium-signal that activates the calcium sensor protein SOS3. SOS3 binds to and activates a ser/thr protein kinase SOS2. The activated SOS2 kinase regulates activities of SOS1, a plasma membrane Na+/H+ antiporter, and NHX1, a tonoplast Na+/H+ antiporter. This results in Na+ efflux and vacuolar compartmentation. A putative osmosensory histidine kinase (AtHK1)-MAPK cascade probably regulates osmotic homeostasis and ROS scavenging. Osmotic stress and ABA (abscisic acid)-mediated regulation of LEA (late-embryogenesis-abundant)-type proteins also play important roles in plant Salt Tolerance. Genetic engineering of ion transporters and their regulators, and of the CBF (C-repeat-binding factor) regulons, holds promise for future development of Salt-tolerant crops.
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Salt Tolerance.
The arabidopsis book, 2002Co-Authors: Liming Xiong, Jian-kang ZhuAbstract:Studying Salt stress is an important means to the understanding of plant ion homeostasis and osmo-balance. Salt stress research also benefits agriculture because soil salinity significantly limits plant productivity on agricultural lands. Decades of physiological and molecular studies have generated a large body of literature regarding potential Salt Tolerance determinants. Recent advances in applying molecular genetic analysis and genomics tools in the model plant Arabidopsis thaliana are shading light on the molecular nature of Salt Tolerance effectors and regulatory pathways.
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Plant Salt Tolerance
Trends in Plant Science, 2001Co-Authors: Jian-kang ZhuAbstract:Soil salinity is a major abiotic stress in plant agriculture worldwide. This has led to research into Salt Tolerance with the aim of improving crop plants. However, Salt Tolerance might have much wider implications because transgenic Salt-tolerant plants often also tolerate other stresses including chilling, freezing, heat and drought. Unfortunately, suitable genetic model systems have been hard to find. A recently discovered halophytic plant species, Thellungiella halophila, now promises to help in the detection of new Tolerance determinants and operating pathways in a model system that is not limited to Arabidopsis traits or ecotype variations.
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genetic analysis of plant Salt Tolerance using arabidopsis
Plant Physiology, 2000Co-Authors: Jian-kang ZhuAbstract:Soil salinity is one of the most significant abiotic stresses for plant agriculture. Apart from the practical goal of genetically improving the Salt Tolerance of crop plants, Salt Tolerance research represents an important part of basic plant biology, contributing to our understanding of subjects
Timothy J. Flowers - One of the best experts on this subject based on the ideXlab platform.
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Plant Salt Tolerance: Adaptations in halophytes
Annals of Botany, 2015Co-Authors: Timothy J. Flowers, Timothy D ColmerAbstract:Background Most of the water on Earth is seawater, each kilogram of which contains about 35 g of Salts, and yet most plants cannot grow in this solution; less than 0·2 % of species can develop and reproduce with repeated exposure to seawater. These ‘extremophiles’ are called halophytes.Scope Improved knowledge of halophytes is of importance to understanding our natural world and to enable the use of some of these fascinating plants in land re-vegetation, as forages for livestock, and to develop Salt-tolerant crops. In this Preface to a Special Issue on halophytes and saline adaptations, the evolution of Salt Tolerance in halophytes, their life-history traits and progress in understanding the molecular, biochemical and physiological mechanisms contributing to Salt Tolerance are summarized. In particular, cellular processes that underpin the ability of halophytes to tolerate high tissue concentrations of Na+ and Cl−, including regulation of membrane transport, their ability to synthesize compatible solutes and to deal with reactive oxygen species, are highlighted. Interacting stress factors in addition to salinity, such as heavy metals and flooding, are also topics gaining increased attention in the search to understand the biology of halophytes.Conclusions Halophytes will play increasingly important roles as models for understanding plant Salt Tolerance, as genetic resources contributing towards the goal of improvement of Salt Tolerance in some crops, for re-vegetation of saline lands, and as ‘niche crops’ in their own right for landscapes with saline soils.
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Repeated evolution of Salt-Tolerance in grasses
Biology letters, 2013Co-Authors: Thomas H Bennett, Timothy J. Flowers, Lindell BromhamAbstract:The amount of Salt-affected agricultural land is increasing globally, so new crop varieties are needed that can grow in Salt-affected soils. Despite concerted effort to develop Salt-tolerant cereal crops, few commercially viable Salt-tolerant crops have been released. This is puzzling, given the number of naturally Salt-tolerant grass species. To better understand why Salt-Tolerance occurs naturally but is difficult to breed into crop species, we take a novel, biodiversity-based approach to its study, examining the evolutionary lability of Salt-Tolerance across the grass family. We analyse the phylogenetic distribution of naturally Salt-tolerant species on a phylogeny of 2684 grasses, and find that Salt-Tolerance has evolved over 70 times, in a wide range of grass lineages. These results are confirmed by repeating the analysis at genus level on a phylogeny of over 800 grass genera. While Salt-Tolerance evolves surprisingly often, we find that its evolution does not often give rise to a large clade of Salt-tolerant species. These results suggest that Salt-Tolerance is an evolutionarily labile trait in grasses.
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Improving Salt Tolerance of wheat and barley: future prospects
Australian Journal of Experimental Agriculture, 2005Co-Authors: Timothy D Colmer, Rana Munns, Timothy J. FlowersAbstract:Cropping on saline land is restricted by the low Tolerance of crops to salinity and waterlogging. Prospects for improving Salt Tolerance in wheat and barley include the use of: (i) intra-specific variation, (ii) variation for Salt Tolerance in the progenitors of these cereals, (iii) wide-hybridisation with halophytic ‘wild’ relatives (an option for wheat, but not barley), and (iv) transgenic techniques. In this review, key traits contributing to Salt Tolerance, and sources of variation for these within the Triticeae, are identified and recommendations for use of these traits in screening for Salt Tolerance are summarised. The potential of the approaches to deliver substantial improvements in Salt Tolerance is discussed, and the importance of adverse interactions between waterlogging and salinity are emphasised. The potential to develop new crops from the diverse halophytic flora is also considered.
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Improving crop Salt Tolerance
Journal of Experimental Botany, 2004Co-Authors: Timothy J. FlowersAbstract:Salinity is an ever‐present threat to crop yields, especially in countries where irrigation is an essential aid to agriculture. Although the Tolerance of saline conditions by plants is variable, crop species are generally intolerant of one‐third of the concentration of Salts found in seawater. Attempts to improve the Salt Tolerance of crops through conventional breeding programmes have met with very limited success, due to the complexity of the trait: Salt Tolerance is complex genetically and physiologically. Tolerance often shows the characteristics of a multigenic trait, with quantitative trait loci (QTLs) associated with Tolerance identified in barley, citrus, rice, and tomato and with ion transport under saline conditions in barley, citrus and rice. Physiologically Salt Tolerance is also complex, with halophytes and less tolerant plants showing a wide range of adaptations. Attempts to enhance Tolerance have involved conventional breeding programmes, the use of in vitro selection, pooling physiological traits, interspecific hybridization, using halophytes as alternative crops, the use of marker‐aided selection, and the use of transgenic plants. It is surprising that, in spite of the complexity of Salt Tolerance, there are commonly claims in the literature that the transfer of a single or a few genes can increase the Tolerance of plants to saline conditions. Evaluation of such claims reveals that, of the 68 papers produced between 1993 and early 2003, only 19 report quantitative estimates of plant growth. Of these, four papers contain quantitative data on the response of transformants and wild‐type of six species without and with salinity applied in an appropriate manner. About half of all the papers report data on experiments conducted under conditions where there is little or no transpiration: such experiments may provide insights into components of Tolerance, but are not grounds for claims of enhanced Tolerance at the whole plant level. Whether enhanced Tolerance, where properly established, is due to the chance alteration of a factor that is limiting in a complex chain or an effect on signalling remains to be elucidated. After ten years of research using transgenic plants to alter Salt Tolerance, the value of this approach has yet to be established in the field.
Timothy D Colmer - One of the best experts on this subject based on the ideXlab platform.
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Plant Salt Tolerance: Adaptations in halophytes
Annals of Botany, 2015Co-Authors: Timothy J. Flowers, Timothy D ColmerAbstract:Background Most of the water on Earth is seawater, each kilogram of which contains about 35 g of Salts, and yet most plants cannot grow in this solution; less than 0·2 % of species can develop and reproduce with repeated exposure to seawater. These ‘extremophiles’ are called halophytes.Scope Improved knowledge of halophytes is of importance to understanding our natural world and to enable the use of some of these fascinating plants in land re-vegetation, as forages for livestock, and to develop Salt-tolerant crops. In this Preface to a Special Issue on halophytes and saline adaptations, the evolution of Salt Tolerance in halophytes, their life-history traits and progress in understanding the molecular, biochemical and physiological mechanisms contributing to Salt Tolerance are summarized. In particular, cellular processes that underpin the ability of halophytes to tolerate high tissue concentrations of Na+ and Cl−, including regulation of membrane transport, their ability to synthesize compatible solutes and to deal with reactive oxygen species, are highlighted. Interacting stress factors in addition to salinity, such as heavy metals and flooding, are also topics gaining increased attention in the search to understand the biology of halophytes.Conclusions Halophytes will play increasingly important roles as models for understanding plant Salt Tolerance, as genetic resources contributing towards the goal of improvement of Salt Tolerance in some crops, for re-vegetation of saline lands, and as ‘niche crops’ in their own right for landscapes with saline soils.
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use of wild relatives to improve Salt Tolerance in wheat
Journal of Experimental Botany, 2006Co-Authors: Timothy D Colmer, T J Flowers, Rana MunnsAbstract:There is considerable variability in Salt Tolerance amongst members of the Triticeae, with the tribe even containing a number of halophytes. This is a review of what is known of the differences in Salt Tolerance of selected species in this tribe of grasses, and the potential to use wild species to improve Salt Tolerance in wheat. Most investigators have concentrated on differences in ion accumulation in leaves, describing a desirable phenotype with low leaf Na + concentration and a high K + /Na + ratio. Little information is available on other traits (such as 'tissue Tolerance' of accumulated Na + and Cl - ) that might also contribute to Salt Tolerance. The sources of Na + 'exclusion' amongst the various genomes that make up tetraploid (AABB) durum wheat (Triticum turgidum L. ssp. durum), hexaploid (AABBDD) bread wheat (Triticum aestivum L. ssp. aestivum), and wild relatives (e.g. Aegilops spp., Thinopyrum spp., Elytrigia elongata syn. Lophopyrum elongatum, Hordeum spp.) are described. The halophytes display a capacity for Na + 'exclusion', and in some cases Cl - 'exclusion', even at relatively high salinity. Significantly, it is possible to hybridize several wild species in the Triticeae with durum and bread wheat. Progenitors have been used to make synthetic hexaploids. Halophytic relatives, such as tall wheat-grass spp., have been used to produce amphiploids, disomic chromosome addition and substitution lines, and recombinant lines in wheat. Examples of improved Na + 'exclusion' and enhanced Salt Tolerance in various derivatives from these various hybridization programmes are given. As several sources of improved Na + 'exclusion' are now known to reside on different chromosomes in various genomes of species in the Triticeae, further work to identify the underlying mechanisms and then to pyramid the controlling genes for the various traits, that could act additively or even synergistically, might enable substantial gains in Salt Tolerance to be achieved.
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Improving Salt Tolerance of wheat and barley: future prospects
Australian Journal of Experimental Agriculture, 2005Co-Authors: Timothy D Colmer, Rana Munns, Timothy J. FlowersAbstract:Cropping on saline land is restricted by the low Tolerance of crops to salinity and waterlogging. Prospects for improving Salt Tolerance in wheat and barley include the use of: (i) intra-specific variation, (ii) variation for Salt Tolerance in the progenitors of these cereals, (iii) wide-hybridisation with halophytic ‘wild’ relatives (an option for wheat, but not barley), and (iv) transgenic techniques. In this review, key traits contributing to Salt Tolerance, and sources of variation for these within the Triticeae, are identified and recommendations for use of these traits in screening for Salt Tolerance are summarised. The potential of the approaches to deliver substantial improvements in Salt Tolerance is discussed, and the importance of adverse interactions between waterlogging and salinity are emphasised. The potential to develop new crops from the diverse halophytic flora is also considered.
Tracey A. Cuin - One of the best experts on this subject based on the ideXlab platform.
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Plant Salt Tolerance
2012Co-Authors: Sergey Shabala, Tracey A. CuinAbstract:Soil salinity is destroying several hectares of arable land every minute. Because remedial land management cannot completely solve the problem, Salt tolerant crops or plant species able to remove excessive Salt from the soil could contribute significantly to managing the salinity problem. The key to engineering crops for Salt Tolerance lies in a thorough understanding of the physiological mechanisms underlying the adaptive responses of plants to salinity. Plant Salt Tolerance: Methods and Protocols describes recent advances and techniques employed by researchers to understand the molecular and ionic basis of salinity Tolerance and to investigate the mechanisms of Salt stress perception and signalling in plants. With chapters written by leading international scientists, this book covers nearly 30 different methods, such as microelectrode and molecular methods, imaging techniques, as well as various biochemical assays. Written in the highly successful Methods in Molecular BiologyTM series format, chapters contain introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and notes on troubleshooting and avoiding known pitfalls. Authoritative and easily accessible, Plant Salt Tolerance: Methods and Protocols serves as an essential read for every student or researcher tackling various aspects of the salinity problem.
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Plant Salt Tolerance - Plant Salt Tolerance
Methods in Molecular Biology, 2012Co-Authors: Sergey Shabala, Tracey A. CuinAbstract:Soil salinity is destroying several hectares of arable land every minute. Because remedial land management cannot completely solve the problem, Salt tolerant crops or plant species able to remove excessive Salt from the soil could contribute significantly to managing the salinity problem. The key to engineering crops for Salt Tolerance lies in a thorough understanding of the physiological mechanisms underlying the adaptive responses of plants to salinity. Plant Salt Tolerance: Methods and Protocols describes recent advances and techniques employed by researchers to understand the molecular and ionic basis of salinity Tolerance and to investigate the mechanisms of Salt stress perception and signalling in plants. With chapters written by leading international scientists, this book covers nearly 30 different methods, such as microelectrode and molecular methods, imaging techniques, as well as various biochemical assays. Written in the highly successful Methods in Molecular BiologyTM series format, chapters contain introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and notes on troubleshooting and avoiding known pitfalls. Authoritative and easily accessible, Plant Salt Tolerance: Methods and Protocols serves as an essential read for every student or researcher tackling various aspects of the salinity problem.
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Potassium transport and plant Salt Tolerance
Physiologia Plantarum, 2008Co-Authors: Sergey Shabala, Tracey A. CuinAbstract:Salinity is a major abiotic stress affecting approximately 7% of the world's total land area resulting in billion dollar losses in crop production around the globe. Recent progress in molecular genetics and plant electrophysiology suggests that the ability of a plant to maintain a high cytosolic K+/Na+ ratio appears to be critical to plant Salt Tolerance. So far, the major efforts of plant breeders have been aimed at improving this ratio by minimizing Na+ uptake and transport to shoot. In this paper, we discuss an alternative approach, reviewing the molecular and ionic mechanisms contributing to potassium homeostasis in salinized plant tissues and discussing prospects for breeding for Salt Tolerance by targeting this trait. Major K+ transporters and their functional expression under saline conditions are reviewed and the multiple modes of their control are evaluated, including ameliorative effects of compatible solutes, polyamines and supplemental calcium. Subsequently, the genetic aspects of inheritance of K+ transport 'markers' are discussed in the general context of Salt Tolerance as a polygenic trait. The molecular identity of 'Salt Tolerance' genes is analysed, and prospects for future research and breeding are examined.
Stephen D. Tyerman - One of the best experts on this subject based on the ideXlab platform.
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mechanisms of cl transport contributing to Salt Tolerance
Plant Cell and Environment, 2010Co-Authors: Natasha L. Teakle, Stephen D. TyermanAbstract:Mechanisms of Cl(-) transport in plants are poorly understood, despite the importance of minimizing Cl(-) toxicity for Salt Tolerance. This review summarizes Cl(-) transport processes in plants that contribute to genotypic differences in Salt Tolerance, identifying key traits from the cellular to whole-plant level. Key aspects of Cl(-) transport that contribute to Salt Tolerance in some species include reduced net xylem loading, intracellular compartmentation and greater efflux of Cl(-) from roots. We also provide an update on the biophysics of anion transport in plant cells and address issues of charge balance, selectivity and energy expenditure relevant to Cl(-) transport mechanisms. Examples are given of anion transport systems where electrophysiology has revealed possible interactions with salinity. Finally, candidate genes for anion transporters are identified that may be contributing to Cl(-) movement within plants during salinity. This review integrates current knowledge of Cl(-) transport mechanisms to identify future pathways for improving Salt Tolerance.
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Mechanisms of Cl‐ transport contributing to Salt Tolerance
Plant cell & environment, 2009Co-Authors: Natasha L. Teakle, Stephen D. TyermanAbstract:Mechanisms of Cl(-) transport in plants are poorly understood, despite the importance of minimizing Cl(-) toxicity for Salt Tolerance. This review summarizes Cl(-) transport processes in plants that contribute to genotypic differences in Salt Tolerance, identifying key traits from the cellular to whole-plant level. Key aspects of Cl(-) transport that contribute to Salt Tolerance in some species include reduced net xylem loading, intracellular compartmentation and greater efflux of Cl(-) from roots. We also provide an update on the biophysics of anion transport in plant cells and address issues of charge balance, selectivity and energy expenditure relevant to Cl(-) transport mechanisms. Examples are given of anion transport systems where electrophysiology has revealed possible interactions with salinity. Finally, candidate genes for anion transporters are identified that may be contributing to Cl(-) movement within plants during salinity. This review integrates current knowledge of Cl(-) transport mechanisms to identify future pathways for improving Salt Tolerance.
