ReviewDrought-induced responses of photosynthesis and antioxidant metabolism in higher plants
Introduction
Plants are subjected to several harsh environmental stresses that adversely affect growth, metabolism, and yield. Drought, salinity, low and high temperatures, flood, pollutants, and radiation are the important stress factors limiting the productivity of crops (Lawlor, 2002). Several biotic (insects, bacteria, fungi, and viruses) and abiotic (light, temperature, water availability, nutrients, and soil structure) factors affect the growth in higher plants (as reviewed by [44], [46]). Among these, drought is a major abiotic factor that limits agricultural crop production. Plants experience drought stress either when the water supply to roots becomes difficult or when the transpiration rate becomes very high. These two conditions often coincide under arid and semi-arid climates. Water stress tolerance is seen in almost all plant species but its extent varies from species to species. Although the general effects of drought on plant growth are fairly well known, the primary effects of water deficit at the biochemical and the molecular levels are not well understood (Zhu, 2002; Chaitanya et al., 2003; Chaves et al., 2003). In order to improve the agricultural productivity within the limited land resources, it is imperative to ensure higher crop yields against unfavorable environmental stresses. Understanding plant responses to the external environment is of greater importance and also a fundamental part for making the crops stress tolerant. In this article we provide an overview of the current understanding of photosynthetic carbon metabolism under drought. In addition, we will describe the cellular antioxidative defense strategies used to circumvent the deleterious effects of drought in the leaves of higher plants.
Section snippets
Photosynthesis under drought
The foliar photosynthetic rate, A, of higher plants is known to decrease as the relative water content (RWC) and leaf water potential decrease (Lawlor and Cornic, 2002). However, the debate continues as to whether drought mainly limits photosynthesis through stomatal closure or through metabolic impairment (Tezara et al., 1999; Lawson et al., 2003). Stomatal limitation was generally accepted to be the main determinant of reduced photosynthesis under drought stress (Cornic, 2000). This has been
Drought-induced oxidative stress in plants
Acclimation of plants to changing environmental conditions such as drought stress is essential for survival and growth. Plant responses to drought stress, especially in reference to chloroplast metabolism, are complex. Drought stress is known to inhibit photosynthetic activity in tissues due to an imbalance between light capture and its utilization (Foyer and Noctor, 2000). Down regulation of photosystem II (PSII) activity results in an imbalance between the generation and utilization of
Plant responses to drought stress
The responses of plants to drought stress are highly complex, involving deleterious and/or adaptive changes. In particular, if the drought stress is under field conditions, the plant responses can be modified synergistically or antagonistically. Early responses of plants to drought stress usually help the plant to survive for some time, while the acclimation of the plant subjected to drought is indicated by the accumulation of certain new metabolites associated with the structural capabilities
Abscisic acid (ABA) responsiveness to water deficit in plants
The plant hormone ABA is produced de novo under water deficit conditions and plays a major role in response and tolerance to dehydration (Shinozaki and Yamaguchi-Shinozaki, 1999). ABA is synthesized from xanthophylls via violaxanthin, xanthoxin and ABA-aldehyde (C-40 pathway). The conversion of violaxanthin to xanthoxin is the rate-limiting step in ABA biosynthesis under drought stress. The involvement of drought-induced ABA and ethylene in shoot and root growth is still a controversial subject
Deciphering the molecular events in plants under drought
Plants respond to water deficit and adapt to semi-arid drought conditions by various physiological, biochemical, anatomical, and morphological changes, including transitions in gene expression. Plants also adapt different types of life strategies to cope and resist drought stress. Two such strategies are drought avoidance and drought tolerance. Drought avoidance is the ability of the plant to maintain high tissue water potential under drought conditions, while drought tolerance is a plant's
Perspectives of future research
Plant productivity is greatly affected by environmental stresses, and drought stress is among the worst scourges of agriculture. Water deficit occurs, not only during drought, but also during cold conditions and causes turgor stress at the cellular level. Thus, a change in the osmotic potential across the plasma membrane should be one of the triggers of the stress response at the molecular level, thus resulting in an oxidative burst under drought stress conditions. An understanding of the
References (93)
- et al.
Genetic analysis of ABA signal transduction pathways
Trends Plant Sci
(1998) - et al.
Accumulation of LEA proteins in salt (NaCl) stressed young seedlings of rice (Oryza sativa L.) cultivar Bura Rata and their degradation during recovery from salinity stress
J Plant Physiol
(2003) Drought stress inhibits photosynthesis by decreasing stomatal aperture—not by affecting ATP synthesis
Trends Plant Sci
(2000)- et al.
Plant's defence and its benefits for animals and medicinerole of phenolics and terpenoids in avoiding oxygen stress
Plant Physiol Biochem
(2002) - et al.
Exogenous silicon (Si) increases antioxidant enzyme activity and reduces lipid peroxidation in roots of salt-stressed barley (Hordeum vulgare L.)
J Plant Physiol
(2003) Vegetation stressan introduction to the stress concept in plants
J. Plant Physiol
(1996)Fluorescence imaging as a diagnostic tool for plant stress
Trends Plant Sci
(1997)- et al.
Temperature dependencies of antioxidative enzymes in two contrasting species
Plant Physiol Biochem
(2002) Fructose-2, 6 bisphosphate modulated photosynthesis in sorghum leaves grown under low water regimes
Phytochemistry
(1996)- et al.
Metabolic engineering of osmoprotectant accumulation in plants
Metab Eng
(2002)
Characterization of a novel caroteniod cleavage dioxygenase from plants
J Biol Chem
A specific role for tocopherol and of chemical singlet oxygen quenchers in the maintenance of photosystem II structure and function in Chlamydomonas reinhardtii
FEBS Lett
CO2 enrichment delays a rapid, drought induced decrease in Rubisco small subunit transcript abundance
J Plant Physiol
Comparision of proline accumulation in two Mediterranean shrubs subjected to natural and experimental water deficit
Plant Soil
Interactive effects of ozone and drought stress on pigments and activities of antioxidative enzymes in Pinis halpensis
Plant Cell Environ
Overexpression of superoxide dismutase in transformed modifies the regulation of photosynthesis at low CO2 partial pressures or following exposure to prooxidant herbicide methyl viologen
Plant Physiol
The water-water cycle in chloroplastsscavenging of active oxygens and dissipation of excess photons
Ann Rev Plant Physiol Plant Mol Biol
Plant stress adaptations—making metabolism move
Trends Biotech
CO2 and water vapor exchange across leaf cuticle (epidermis) at various water potentials
Plant Physiol
Classification of genes differentially expressed during water deficit stress in Arabidopsis thalianaan analysis using micro array and differential expression data
Ann Bot
Variation in photosynthetic rates and biomass productivity among four mulberry cultivars
Photosynthetica
Variation in heat stress-induced antioxidant enzyme activities among three mulberry cultivars
Plant Gowth Regul
Water stress effects on photosynthesis in different mulberry cultivars
Plant Growth Regul
How plants cope with water stress in the field. Photosynthesis and growth
Ann Bot
Understanding plant responses to drought —from genes to the whole plant
Funct Plant Biol
Dehydrins. Emergence of a biochemical role of a family of plant dehydrin proteins
Physiol Plant
Recent advances in the role and biosynthesis of ascorbic acid in plants
Plant Cell Environ
The role of xanthophylls cycle carotenoids in the protection of photosynthesis
Trends Plant Sci
Differential localization of antioxidants in maize leaves
Plant Physiol
Models of photosynthesis
Plant Physiol
Prospects for enhancement the soluble antioxidants ascorbate and glutathione
Biol Fac
Oxygen processing in photosynthesisregulation and signaling
New Phytol
Drought induced effects on nitrate reductase activity and mRNA and on the coordination of nitrogen and carbon metabolism in maize leaves
Plant Physiol
Oxygen exchange in relation to carbon assimilation in water-stressed leaves during photosynthesis
Ann Bot
Loss of chloropyll with limited reduction of photosynthesis as an adaptive response of Syrian barley landraces to high-light and heat stress
Aust J Plant Physiol
Transformation of Arabidopsis with codA gene for choline oxidaseaccumulation of glycine betaine and enhanced tolerance to salt and cold stress
Plant J
Stomatal conductance and photosynthesis vary linearly with plant hydraulic conductance in Ponderosa pine
Plant Cell Environ
Inhibition of endogenous ascorbate synthesis in potato leaves supplied with exogenous ascorbate
Free Rad Res
A stress inducible gene for 9-cis-epoxy carotenoid dioxygenase involved in abscisic acid biosynthesis under water stress in drought tolerant cowpea
Plant Physiol
Biphasic superoxide generation in potato tubers. A self amplifying response to stress
Plant Physiol
Genetic engineering of glycine betaine production towards enhancing stress tolerance in plants
Plant Physiol
Bundle sheath proteins are more sensitive to oxidative damage than those of the mesophyll in maize leaves exposed to paraquat or low temperature
J Exp Bot
Overexpression of Δ-pyrroline-5-carboxylase synthetase increases proline production and confers osmotolerance in transgenic plants
Plant Physiol
Effects of ozone and mild drought stress on gas exchange, antioxidants and chloroplast pigments in current-year needles of young Norway spruce (Picea abies L Karst)
Trees
Effects of drought preconditioning on thermo tolerance of photosystem II and susceptibility of photosynthesis to heat stress in cedar seedlings
Tree Physiol
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