Plant Drought Stress: Effects, Mechanisms and Management
Plant Drought Stress: Effects, Mechanisms and Management
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DOI：
10.1051/agro:2008021
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发表时间：
2009-01-01
期刊：
影响因子：
--
通讯作者：
Basra, S. M. A.
中科院分区：
文献类型：
--
作者：
Farooq, M.;Wahid, A.;Basra, S. M. A.
水的缺乏是植物生产力的一个严重的环境制约因素。干旱造成的作物产量损失可能超过所有其他原因造成的损失，因为干旱的严重程度和持续时间都很关键。本文综述了干旱胁迫对植物生长、物候、水分与养分关系、光合作用、同化物分配和呼吸作用的影响。本文还从形态学、生理学和分子生物学等方面阐述了植物抗旱机理。已经提出了各种管理策略来科普干旱压力。干旱胁迫降低了叶片大小、茎的伸长和根的增殖，扰乱了植物的水分关系，降低了水分利用效率。植物对干旱胁迫表现出细胞水平和整体水平的多种生理生化反应，是一个复杂的现象。叶片CO2同化的减少主要是由于气孔关闭、膜损伤和各种酶活性的干扰，特别是CO2固定和腺苷三磷酸合成酶的活性。通过光呼吸途径的代谢物通量增强增加了组织上的氧化负荷，因为这两个过程都会产生活性氧。干旱胁迫下活性氧对生物大分子的伤害是植物生长的主要障碍之一。植物表现出一系列的机制来抵御干旱胁迫。主要机制包括通过增加扩散阻力减少水分损失，通过多产和深根系统增强水分吸收及其有效利用，以及较小和多汁的叶片减少蒸腾损失。在营养物质中，钾离子有助于渗透调节;硅增加根内皮层硅化并改善细胞水分平衡。低分子量的渗透调节物质，包括甜菜碱、脯氨酸和其他氨基酸、有机酸和多元醇，对干旱下维持细胞功能至关重要。植物生长物质如水杨酸、生长素、赤霉素、细胞分裂素和脱落酸调节植物对干旱的反应。多胺、瓜氨酸和几种酶可作为抗氧化剂，减少缺水的不良影响。在分子水平上，已经鉴定了几个干旱响应基因和转录因子，如脱水响应元件结合基因、水通道蛋白、胚胎发育后期丰富蛋白和干旱胁迫蛋白。植物耐旱性的管理可以通过采用诸如大规模筛选和育种、标记辅助选择、向种子或生长中的植物外源施用激素和植物保护剂以及抗旱工程等策略来实现。干旱造成的作物产量损失可能超过所有其他原因造成的损失，因为干旱的严重程度和持续时间都很关键。本文综述了干旱胁迫对植物生长、物候、水分与养分关系、光合作用、同化物分配和呼吸作用的影响。本文还从形态学、生理学和分子生物学等方面阐述了植物抗旱机理。已经提出了各种管理策略来科普干旱压力。干旱胁迫降低了叶片大小、茎的伸长和根的增殖，扰乱了植物的水分关系，降低了水分利用效率。植物对干旱胁迫表现出细胞水平和整体水平的多种生理生化反应，是一个复杂的现象。叶片对CO2的同化作用主要受到气孔关闭、膜损伤和各种酶活性的干扰，尤其是CO的活性。固定和三磷酸腺苷合成。通过光呼吸途径的代谢物通量增强增加了组织上的氧化负荷，因为这两个过程都会产生活性氧。干旱胁迫下活性氧对生物大分子的伤害是植物生长的主要障碍之一。植物表现出一系列的机制来抵御干旱胁迫。主要机制包括通过增加扩散阻力减少水分损失，通过多产和深根系统增强水分吸收及其有效利用，以及较小和多汁的叶片减少蒸腾损失。在营养物质中，钾离子有助于渗透调节;硅增加根内皮层硅化并改善细胞水分平衡。低分子量的渗透调节物质，包括甜菜碱、脯氨酸和其他氨基酸、有机酸和多元醇，对干旱下维持细胞功能至关重要。植物生长物质如水杨酸、生长素、赤霉素、细胞分裂素和脱落酸调节植物对干旱的反应。多胺、瓜氨酸和几种酶可作为抗氧化剂，减少缺水的不良影响。在分子水平上，已经鉴定了几个干旱响应基因和转录因子，如脱水响应元件结合基因、水通道蛋白、胚胎发育后期丰富蛋白和干旱胁迫蛋白。植物耐旱性的管理可以通过采用诸如大规模筛选和育种、标记辅助选择、向种子或生长植物外源施用激素和植物保护剂以及抗旱工程等策略来实现。
Scarcity of water is a severe environmental constraint to plant productivity. Drought-induced loss in crop yield probably exceeds losses from all other causes, since both the severity and duration of the stress are critical. Here, we have reviewed the effects of drought stress on the growth, phenology, water and nutrient relations, photosynthesis, assimilate partitioning, and respiration in plants. This article also describes the mechanism of drought resistance in plants on a morphological, physiological and molecular basis. Various management strategies have been proposed to cope with drought stress. Drought stress reduces leaf size, stem extension and root proliferation, disturbs plant water relations and reduces water-use efficiency. Plants display a variety of physiological and biochemical responses at cellular and whole-organism levels towards prevailing drought stress, thus making it a complex phenomenon. CO2 assimilation by leaves is reduced mainly by stomatal closure, membrane damage and disturbed activity of various enzymes, especially those of CO2 fixation and adenosine triphosphate synthesis. Enhanced metabolite flux through the photorespiratory pathway increases the oxidative load on the tissues as both processes generate reactive oxygen species. Injury caused by reactive oxygen species to biological macromolecules under drought stress is among the major deterrents to growth. Plants display a range of mechanisms to withstand drought stress. The major mechanisms include curtailed water loss by increased diffusive resistance, enhanced water uptake with prolific and deep root systems and its efficient use, and smaller and succulent leaves to reduce the transpirational loss. Among the nutrients, potassium ions help in osmotic adjustment; silicon increases root endodermal silicification and improves the cell water balance. Low-molecular-weight osmolytes, including glycinebetaine, proline and other amino acids, organic acids, and polyols, are crucial to sustain cellular functions under drought. Plant growth substances such as salicylic acid, auxins, gibberrellins, cytokinin and abscisic acid modulate the plant responses towards drought. Polyamines, citrulline and several enzymes act as antioxidants and reduce the adverse effects of water deficit. At molecular levels several drought-responsive genes and transcription factors have been identified, such as the dehydration-responsive element-binding gene, aquaporin, late embryogenesis abundant proteins and dehydrins. Plant drought tolerance can be managed by adopting strategies such as mass screening and breeding, marker-assisted selection and exogenous application of hormones and osmoprotectants to seed or growing plants, as well as engineering for drought resistance.Scarcity of water is a severe environmental constraint to plant productivity. Drought-induced loss in crop yield probably exceeds losses from all other causes, since both the severity and duration of the stress are critical. Here, we have reviewed the effects of drought stress on the growth, phenology, water and nutrient relations, photosynthesis, assimilate partitioning, and respiration in plants. This article also describes the mechanism of drought resistance in plants on a morphological, physiological and molecular basis. Various management strategies have been proposed to cope with drought stress. Drought stress reduces leaf size, stem extension and root proliferation, disturbs plant water relations and reduces water-use efficiency. Plants display a variety of physiological and biochemical responses at cellular and whole-organism levels towards prevailing drought stress, thus making it a complex phenomenon. CO2 assimilation by leaves is reduced mainly by stomatal closure, membrane damage and disturbed activity of various enzymes, especially those of CO.) fixation and adenosine triphosphate synthesis. Enhanced metabolite flux through the photorespiratory pathway increases the oxidative load on the tissues as both processes generate reactive oxygen species. Injury caused by reactive oxygen species to biological macromolecules under drought stress is among the major deterrents to growth. Plants display a range of mechanisms to withstand drought stress. The major mechanisms include curtailed water loss by increased diffusive resistance, enhanced water uptake with prolific and deep root systems and its efficient use, and smaller and succulent leaves to reduce the transpirational loss. Among the nutrients, potassium ions help in osmotic adjustment; silicon increases root endodermal silicification and improves the cell water balance. Low-molecular-weight osmolytes, including glycinebetaine, proline and other amino acids, organic acids, and polyols, are crucial to sustain cellular functions under drought. Plant growth substances such as salicylic acid, auxins, gibberrellins, cytokinin and abscisic acid modulate the plant responses towards drought. Polyamines, citrulline and several enzymes act as antioxidants and reduce the adverse effects of water deficit. At molecular levels several drought-responsive genes and transcription factors have been identified, such as the dehydration-responsive element-binding gene, aquaporin, late embryogenesis abundant proteins and dehydrins. Plant drought tolerance can be managed by adopting strategies such as mass screening and breeding, marker-assisted selection and exogenous application of hormones and osmoprotectants to seed or growing plants, as well as engineering for drought resistance.