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ABSTRACT: Heavy metal pollution of soil is a significant environmental problem and has its negative potential impact on human health
and agriculture. Phytoremediation strategies with appropriate heavy metal-adapted rhizobacteria (for example, mycorrhizae)
have received more and more attention. Some plants possess a range of potential mechanisms that may be involved in the detoxification
of heavy metals, and they manage to survive under metal stresses. High tolerance to heavy metal toxicity could rely either
on reduced uptake or increased plant internal sequestration, which is manifested by an interaction between a genotype and
its environment. A coordinated network of molecular processes provides plants with multiple metal-detoxifying mechanisms and
repair capabilities, which allow plants to survive under metal-containing soil environments. The growing application of molecular
genetic technologies has led to an increased understanding of mechanisms of heavy metal tolerance/accumulation in plants and,
subsequently, many transgenic plants with increased heavy metal resistance, as well as increased uptake of heavy metals, have
been developed for the purpose of phytoremediation. This article reviews advantages, disadvantages, possible mechanisms, current
status and future directions of phytoremediation for heavy metal contaminated soils and environments.
KeywordsPhytoremediation-Heavy metals-Soil-Mechanisms-Signal transduction-Phytohormones-Transcription factors-Biotechnology-Hyperaccumulator-Gene expression
12/2009: pages 227-244;
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ABSTRACT: Water is vital for plant growth, development and productivity. Permanent or temporary water deficit stress limits the growth and distribution of natural and artificial vegetation and the performance of cultivated plants (crops) more than any other environmental factor. Productive and sustainable agriculture necessitates growing plants (crops) in arid and semiarid regions with less input of precious resources such as fresh water. For a better understanding and rapid improvement of soil-water stress tolerance in these regions, especially in the water-wind eroded crossing region, it is very important to link physiological and biochemical studies to molecular work in genetically tractable model plants and important native plants, and further extending them to practical ecological restoration and efficient crop production. Although basic studies and practices aimed at improving soil water stress resistance and plant water use efficiency have been carried out for many years, the mechanisms involved at different scales are still not clear. Further understanding and manipulating soil-plant water relationships and soil-water stress tolerance at the scales of ecology, physiology and molecular biology can significantly improve plant productivity and environmental quality. Currently, post-genomics and metabolomics are very important in exploring anti-drought gene resources in various life forms, but modern agriculturally sustainable development must be combined with plant physiological measures in the field, on the basis of which post-genomics and metabolomics have further practical prospects. In this review, we discuss physiological and molecular insights and effects in basic plant metabolism, drought tolerance strategies under drought conditions in higher plants for sustainable agriculture and ecoenvironments in arid and semiarid areas of the world. We conclude that biological measures are the bases for the solutions to the issues relating to the different types of sustainable development.
Critical Reviews in Biotechnology 06/2009; 29(2):131-51. · 6.47 Impact Factor
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ABSTRACT: Higher plants not only provide human beings renewable food, building materials and energy, but also play the most important role in keeping a stable environment on earth. Plants differ from animals in many aspects, but the important is that plants are more easily influenced by environment than animals. Plants have a series of fine mechanisms for responding to environmental changes, which has been established during their long-period evolution and artificial domestication. The machinery related to molecular biology is the most important basis. The elucidation of it will extremely and purposefully promote the sustainable utilization of plant resources and make the best use of its current potential under different scales. This molecular mechanism at least includes drought signal recognition (input), signal transduction (many cascade biochemical reactions are involved in this process), signal output, signal responses and phenotype realization, which is a multi-dimension network system and contains many levels of gene expression and regulation. We will focus on the physiological and molecular adaptive machinery of plants under soil water stress and draw a possible blueprint for it. Meanwhile, the issues and perspectives are also discussed. We conclude that biological measures is the basic solution to solving various types of issues in relation to sustainable development and the plant measures is the eventual way.
Current Genomics 06/2009; 10(4):269-80. · 2.41 Impact Factor
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[show abstract]
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ABSTRACT: Higher plants play a major role in keeping a stable environment on the globe. They regulate global climate and surroundings
in many ways at different levels such as molecular, cellular, organ, individual, community, regional, ecosystem and global
ecosystem levels. This article will focus on the abiotic aspect of the environment. Readers interested in the biotic aspect
can read recent publications by Garcia-Brugger et al. [Early signalling events induced by eliators of plant defenses. Mol.
Plant Microbe In. 19 (2006) 711–724], Lecourieux et al. [Calcium in plant defence-signalling pathways, New Phytol. 171 (2006)
249–269], and Conrath et al. [Priming: Getting ready for battle, Mol. Plant Microbe In. 19 (2006) 1062–1071], for related
progress. Plant behavior and character expression are controlled at the molecular level by gene expression and environmental
cues. In a persistently changing environment there are many abiotic adverse stress conditions such as cold, drought, salinity
and UV-B, which influence plant growth and crop production. Unlike animals, higher plants, which are sessile, cannot escape
from their surroundings, but adapt themselves to changing environments by inducing a series of molecular responses to cope
with these problems. The physiological processing basis for these molecular responses is the integration of many transduced
events into a comprehensive network of signaling pathways. Here, higher plant hormones occupy a central place in this transduction
network, frequently acting in conjunction with other signals, to regulate cellular processes such as division, elongation
and differentiation, which are the fundamental basis for higher plant development and related character expression. Stress
factors are also major ecological factors influencing the environment, which are general environmental stimuli and cues to
higher plants. Molecular responses to environmental stresses have been studied intensively over the last few years. The findings
show an intricate network of signaling pathways controlling perception of environmental signals, the generation of second
messengers and signal transduction. In this review, up-to-date progresses are introduced in terms of functional analysis of
signaling components and issues with respect to the agricultural environment and sustainable development. These advances mainly
include identification of the abiotic stress-responsive genes, extensive realization of the mutual concerted relationship
between plants and the environment on different scales, molecular mechanisms of stress signal transduction and pathways, and
so on. Here, a general network of stress-responsive gene expression-control model is proposed, with an emphasis on the integration
between stress signal transduction pathways and the agricultural environment.
KeywordsAgricultural sustainable development–Biological measures–Eco-environment–Environmental stresses–Global climate change–Higher plants–Network of signaling transduction – Plant biology
12/2008: pages 297-308;
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ABSTRACT: Considerable progresses have taken place, both in the methodology available to study changes in intracellular cytosolic calcium and in our understanding of calcium signaling cascades, but how calcium signals function in plant drought resistance is questionable. In plant cells, calcium plays roles as a second messenger coupling a wide range of extracellular stimuli with intracellular responses. Different extracellular stimuli trigger specific calcium signatures: dynamics, amplitude and duration of calcium transients specify the nature, implication and intensity of stimuli. Calcium-binding proteins (sensors) play a critical role in decoding calcium signatures and transducing signals by activating specific targets and corresponding metabolic pathways. Calmodulin is a calcium sensor known to regulate the activity of many mammalian proteins, whose targets in plants are now being identified. Higher plants possess a rapidly growing list of calmodulin targets with a variety of cellular functions. Nevertheless, many targets appear to be unique to higher plants and remain characterized, calling for a concerted effort to elucidate their functions. To date, three major classes of plant calcium signals, including calcium permeable ion channels, Ca(2+)/H(+) antiporters and Ca(2+)-ATPases, have been responsible for drought-stress signal transduction. This review summarizes the current knowledge of calcium signals involved in plant anti-drought and plant water use efficiency (WUE) and presents suggestions for future focus of study.
Comptes Rendus Biologies 09/2008; 331(8):587-96. · 1.53 Impact Factor
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ABSTRACT: Main antioxidants in higher plants include glutathione, ascorbate, tocopherol, proline, betaine, and others, which are also information-rich redox buffers and important redox signaling components that interact with biomembrane-related compartments. As an evolutionary consequence of aerobic life for higher plants, reactive oxygen species (ROS) are formed by partial reduction of molecular oxygen. The above enzymatic and non-enzymatic antioxidants in higher plants can protect their cells from oxidative damage by scavenging ROS. In addition to crucial roles in defense system and as enzyme cofactors, antioxidants influence higher plant growth and development by modifying processes from mitosis and cell elongation to senescence and death. Most importantly, they provide essential information on cellular redox state, and regulate gene expression associated with biotic and abiotic stress responses to optimize defense and survival. An overview of the literature is presented in terms of main antioxidants and redox signaling in plant cells. Special attention is given to ROS and ROS-antioxidant interaction as a metabolic interface for different types of signals derived from metabolism and from the changing environment, which regulates the appropriate induction of acclimation processes or, execution of cell death programs, which are the two essential directions for higher plants.
Comptes Rendus Biologies 07/2008; 331(6):433-41. · 1.53 Impact Factor
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ABSTRACT: Plant aquaporins play an important role in water uptake and movement-an aquaporin that opens and closes a gate that regulates water movement in and out of cells. Some plant aquaporins also play an important role in response to water stress. Since their discovery, advancing knowledge of their structures and properties led to an understanding of the basic features of the water transport mechanism and increased illumination to water relations. Meanwhile, molecular and functional characterization of aquaporins has revealed the significance of their regulation in response to the adverse environments such as salinity and drought. This paper reviews the structure, species diversity, physiology function, regulation of plant aquaporins, and the relations between environmental factors and plant aquaporins. Complete understanding of aquaporin function and regulation is to integrate those mechanisms in time and space and to well regulate the permeation of water across biological membranes under changing environmental and developmental conditions.
Colloids and Surfaces B Biointerfaces 05/2008; 62(2):163-72. · 3.46 Impact Factor
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ABSTRACT: Aquaporins are important molecules that control the moisture level of cells and water flow in plants. Plant aquaporins are present in various tissues, and play roles in water transport, cell differentiation and cell enlargement involved in plant growth and water relations. The insights into aquaporins' diversity, structure, expression, post-translational modification, permeability properties, subcellular location, etc., from considerable studies, can lead to an understanding of basic features of the water transport mechanism and increased illumination into plant water relations. Recent important advances in determining the structure and activity of different aquaporins give further details on the mechanism of functional regulation. Therefore, the current paper mainly focuses on aquaporin structure-function relationships, in order to understand the function and regulation of aquaporins at the cellular level and in the whole plant subjected to various environmental conditions. As a result, the straightforward view is that most aquaporins in plants are to regulate water flow mainly at cellular scale, which is the most widespread general interpretation of the physiological and functional assays in plants.
Molecular Membrane Biology 05/2008; 25(3):179-91. · 2.86 Impact Factor
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ABSTRACT: Water is vital for plant growth and development. Water-deficit stress, permanent or temporary, limits the growth and the distribution of natural vegetation and the performance of cultivated plants more than any other environmental factors do. Although research and practices aimed at improving water-stress resistance and water-use efficiency have been carried out for many years, the mechanism involved is still not clear. Further understanding and manipulating plant-water relations and water-stress tolerance at the scale of physiology and molecular biology can significantly improve plant productivity and environmental quality. Currently, post-genomics and metabolomics are very important to explore anti-drought gene resource in different life forms, but modern agricultural sustainable development must be combined with plant physiological measures in the field, on the basis of which post-genomics and metabolomics will have further a practical prospect. In this review, we discussed the anatomical changes and drought-tolerance strategies under drought condition in higher plants.
Comptes Rendus Biologies 04/2008; 331(3):215-25. · 1.53 Impact Factor
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[show abstract]
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ABSTRACT: Antioxidants in plant cells mainly include glutathione, ascorbate, tocopherol, proline, betaine and others, which are also information-rich redox buffers and important redox signaling components that interact with cellular compartments. As an unfortunate consequence of aerobic life for higher plants, reactive oxygen species (ROS) are formed by partial reduction of molecular oxygen. The above enzymatic and non-enzymatic antioxidants in higher plant cells can protect their cells from oxidative damage by scavenging ROS. In addition to crucial roles in defense system and as enzyme cofactors, antioxidants influence higher plant growth and development by modifying processes from miotosis and cell elongation to senescence and death. Most importantly, they provide essential information on cellular redox state, and regulate gene expression associated with biotic and abiotic stress responses to optimize defense and survival. An overview of the literature is presented in terms of primary antioxidant free radical scavenging and redox signaling in plant cells. Special attention is given to ROS and ROS-anioxidant interaction as a metabolic interface for different types of signals derived from metabolisms and from the changing environment. This interaction regulates the appropriate induction of acclimation processes or execution of cell death programs, which are the two essential directions for higher plant cells.
International journal of biological sciences 02/2008; 4(1):8-14. · 2.70 Impact Factor
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Journal of Plant Interactions 09/2007; 2(3):135-147. · 0.64 Impact Factor
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ABSTRACT: Water deficiency and lower fertilizer utilization efficiency are major constraints of productivity and yield stability. Improvements of crop water use efficiency (WUE) and nutrient use efficiency (NUE) is becoming an important objective in crop breeding. With the introduction of new physiological and biological approaches, we can better understand the mutual genetics mechanism of high use efficiency of water and nutrient. Much work has been done in past decades mainly including the interactions between different fertilizers and water influences on root characteristics and crop growth. Fertilizer quantity and form were regulated in order to improve crop WUE. The crop WUE and NUE shared the same increment tendency during evolution process; some genes associated with WUE and NUE have been precisely located and marked on the same chromosomes, some genes related to WUE and NUE have been cloned and transferred into wheat and rice and other plants, they can enhance water and nutrient use efficiency. The proteins transporting nutrient and water were identified such as some water channel proteins. The advance on the mechanism of higher water and nutrient use efficiency in crop was reviewed in this article, and it could provide some useful information for further research on WUE and NUE in crop.
Colloids and Surfaces B Biointerfaces 06/2007; 57(1):1-7. · 3.46 Impact Factor
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ABSTRACT: As shortage in water resources is a fact, bio-watersaving becomes one hot topic at present. The concept of bio-watersaving has been developed from agronomic watersaving to physiological watersaving then to gene watersaving. The definition of bio-watersaving is yielding more agricultural productions under the same water condition by exploiting the physiological and genetic potential of organisms themselves. There are two aspects in bio-watersaving: one is managing crop system and watersaving irrigation according to the drought characteristics and physiological water need of plants; the second is breeding new varieties with good drought resistance and high water use efficiency (WUE) and high yield and good quality traits, through exploiting new drought resistance genes and high WUE genes with the aid of biotechnology. Gene watersaving is the base for physiological watersaving, so gene watersaving has the biggest potential to be exploited in future, and will play an important role in high use efficiency of water and soil resources, and agricultural sustainable development in China and the globe.
Colloids and Surfaces B Biointerfaces 04/2007; 55(1):1-9. · 3.46 Impact Factor
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ABSTRACT: Drought is one of the major ecological factors limiting crop production and food quality globally, especially in the arid and semi-arid areas of the world. Wheat is the staple food for more than 35% of world population and wheat cultivation is mainly restricted to such zones with scarcity of water, so wheat anti-drought physiology study is of importance to wheat production, food safety and quality and biotechnological breeding for the sake of coping with abiotic and biotic conditions. The current study is to investigate changes of anti-oxidative physiological indices of 10 wheat genotypes at tillering stage. The main results and conclusion of tillering stage in terms of activities of POD, SOD, CAT and MDA content as followed: (1) 10 wheat genotypes can be generally grouped into three kinds (A-C, respectively) according to their changing trend of the measured indices; (2) A group performed better drought resistance under the condition of treatment level 1 (appropriate level), whose activities of anti-oxidative enzymes (POD, SOD, CAT) were higher and MDA lower; (3) B group exhibited stronger anti-drought under treatment level 2 (light-stress level), whose activities of anti-oxidative enzymes were higher and MDA lower; (4) C group expressed anti-drought to some extent under treatment level 3 (serious-stress), whose activities of anti-oxidative enzymes were stronger, MDA lower; (5) these results demonstrated that different wheat genotypes have different physiological mechanisms to adapt themselves to changing drought stress, whose molecular basis is discrete gene expression profiling (transcriptom). The study in this respect is the key to wheat anti-drought and biological-saving water in worldwide arid and semi-arid areas; (6) POD, SOD, and CAT activities and MDA content of different wheat genotypes had quite different changing trend at different stages and under different soil water stress conditions, which was linked with their origin of cultivation and individual soil water threshold, which will provide better reference to selecting proper plant species for eco-environmental construction and crops for sustainable agriculture in arid and semi-arid areas.
Colloids and Surfaces B Biointerfaces 03/2007; 54(2):143-9. · 3.46 Impact Factor
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ABSTRACT: Higher plants play the most important role in keeping a stable environment on the earth, which regulate global circumstances in many ways in terms of different levels (molecular, individual, community, and so on), but the nature of the mechanism is gene expression and control temporally and spatially at the molecular level. In persistently changing environment, there are many adverse stress conditions such as cold, drought, salinity and UV-B (280-320 mm), which influence plant growth and crop production greatly. Plants differ from animals in many aspects, but the important may be that plants are more easily influenced by environment than animals. Plants have a series of fine mechanisms for responding to environmental changes, which has been established during their long-period evolution and artificial domestication. These mechanisms are involved in many aspects of anatomy, physiology, biochemistry, genetics, development, evolution and molecular biology, in which the adaptive machinery related to molecular biology is the most important. The elucidation of it will extremely and purposefully promote the sustainable utilization of plant resources and make the best use of its current potential under different scales. This molecular mechanism at least include environmental signal recognition (input), signal transduction (many cascade biochemical reactions are involved in this process), signal output, signal responses and phenotype realization, which is a multi-dimensional network system and contain many levels of gene expression and regulation. We will focus on the molecular adaptive machinery of higher plant plasticity under abiotic stresses.
Colloids and Surfaces B Biointerfaces 02/2007; 54(1):37-45. · 3.46 Impact Factor
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ABSTRACT: The study for biointerfaces at different scales in the past years has pricked up the march of biological sciences, in which biomembrane concept and its characteristics, receptor proteins, ion channel proteins, LEA proteins, calcium and newly recognized second messengers, ROS, MAPKs and their related sensors and new genes in osmoregulation, signal transduction, and other aspects have been understood fully, widening area of understanding the extensive interactions from biosystem and biointerfaces. The related discipline, plant stress physiology, especially, crop stress physiology has gained much attention world widely, the important reason of which is from the reducing quality of global ecoenvironment and decreasing food supply. This short review will place a stress on the recent progresses in plant stress physiology, combined with the new results from our State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau.
Colloids and Surfaces B Biointerfaces 02/2007; 54(1):33-6. · 3.46 Impact Factor
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ABSTRACT: Through 2-year field experiments, 7 wheat genotypes were better in their field yield. These 7 wheat genotypes and other 3 wheat species, which are being popularized on a large scale in different locations of China, were selected as experimental materials for the sake of measuring their difference in WUE and production and comparing their relationship at soil water deficits, future more, providing better drought resistance lines and theoretical guide for wheat production and practices and exploring anti-drought physiological mechanisms of different wheat genotypes. Under the condition of 3 soil-water-stress treatments (75% field capacity (FC), 55% FC, 45% FC, named level 1, level 2 and level 3, respectively), pot experiments for them were conducted and the related data were collected from their life circle. The main results were as followed: (1) according to the selected soil stress levels, water use efficiency (WUE) of 10 different wheat genotypes was divided into two groups (A and B); group A included genotypes 2, 3, 4, 5, 6, 7, 8, whose WUE decreased basically from level 1 to level 3 and reached individual peak of WUE at level 1; Group 2 included genotypes 1, 9, 10, whose WUE reached their individual peak at level 2; (2) based on total water consumption through all life circle, genotypes 1, 4, 8, 9 had lower water consumption (TWC) at level 1, genotypes 2, 3, 5, 6, 7 lower TWC at level 2, genotype 10 lower TWC at level 3; (3) at level 1, genotypes 2, 3, 4, 5, 6, 7, 8 had higher grain weight of single spike (GWSS), genotypes 1, 9, 10 better GWSS at level 2, which was in good line with individual WUE of different wheat genotypes; (4) by analyzing the indexes related to examining cultivars, it was found that genotypes 1, 2, 3, 4, 5, 6, 9, 10 had longer plant length (PL), spike length (SL), bigger grain number (GN) except genotypes 7 and 8 at level 1, RL was in better line with genotypes 1, 2, 3, 8, 9, 10, but not in the other genotypes at level 1.
Colloids and Surfaces B Biointerfaces 01/2007; 53(2):271-7. · 3.46 Impact Factor
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ABSTRACT: Phytochromes in higher plants play a great role in development, responses to environmental stresses and signal transduction, which are the fundamental principles for higher plants to be adapted to changing environment. Deep and systematic understanding of the phytochrome in higher plants is of crucial importance to molecular biology, purposeful improvement of environment in practice, especially molecular mechanism by which higher plants perceive UV-B stress. The last more than 10 years have seen rapid progress in this field with the aid of a combination of molecular, genetic and cell biological approaches. No doubt, what is the most important, is the application of Arabidopsis experimental system and the generation of various mutants regarding phytochromes (phy A-E). Increasing evidence demonstrates that phytochrome signaling transduction constitutes a highly ordered multidimensional network of events. Some phytochromes and signaling intermediates show light-dependent nuclear-cytoplasmic partitioning, which implies that early signaling events take place in the nucleus and that subcellular localization patterns most probably represent an important signaling control point. The main subcellular localization includes nucleus, cytosol and chloroplasts, respectively. Additionally, proteasome-mediated degradation of signaling intermediates most possibly function in concert with subcellular partitioning events as an integrated checkpoint. What higher plants do in this way is to execute accurate responses to the changes in the light environment on the basis of interconnected subcellular organelles. By integrating the available data, at the molecular level and from the angle of eco-environment, we should be able to construct a solid foundation for further dissection of phytochrome signaling transduction in higher plants.
Colloids and Surfaces B Biointerfaces 12/2005; 45(3-4):154-61. · 3.46 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Higher plants play a major role in keeping a stable environment on the globe. They regulate global climate and surroundings in many ways at different levels such as molecular, cellular, organ, individual, community, regional, ecosystem and global ecosystem levels. This article will focus on the abiotic aspect of the environment. Readers interested in the biotic aspect can read recent publications by Garcia-Brugger et al. [Early signalling events induced by eliators of plant defenses, Mol. Plant Microbe In. 19 (2006) 711–724], Lecourieux et al. [Calcium in plant defence-signalling pathways, New Phytol. 171 (2006) 249–269], and Conrath et al. [Priming: Getting ready for battle, Mol. Plant Microbe In. 19 (2006) 1062–1071], for related progress. Plant behavior and character expression are controlled at the molecular level by gene expression and environmental cues. In a persistently changing environment there are many abiotic adverse stress conditions such as cold, drought, salinity and UV-B, which influence plant growth and crop production. Unlike animals, higher plants, which are sessile, cannot escape from their surroundings, but adapt themselves to changing environments by inducing a series of molecular responses to cope with these problems. The physiological processing basis for these molecular responses is the integration of many transduced events into a comprehensive network of signaling pathways. Here, higher plant hormones occupy a central place in this transduction network, frequently acting in conjunction with other signals, to regulate cellular processes such as division, elongation and differentiation, which are the fundamental basis for higher plant development and related character expression. Stress factors are also major ecological factors influencing the environment, which are general environmental stimuli and cues to higher plants. Molecular responses to environmental stresses have been studied intensively over the last few years. The findings show an intricate network of signaling pathways controlling perception of environmental signals, the generation of second messengers and signal transduction. In this review, up-to-date progresses are introduced in terms of functional analysis of signaling components and issues with respect to the agricultural environment and sustainable development. These advances mainly include identification of the abiotic stress-responsive genes, extensive realization of the mutual concerted relationship between plants and the environment on different scales, molecular mechanisms of stress signal transduction and pathways, and so on. Here, a general network of stress-responsive gene expression-control model is proposed, with an emphasis on the integration between stress signal transduction pathways and the agricultural environment.
http://dx.doi.org/10.1051/agro:2006031.
