Ramachandra Reddy Attipalli, Chaitanya Kolluru Viswanatha, Vivekanandan Munusamy
School of Life Sciences, Pondicherry University, Pondicherry 605 014, India.
J Plant Physiol. 2004 Nov;161(11):1189-202. doi: 10.1016/j.jplph.2004.01.013.
Environmental stresses trigger a wide variety of plant responses, ranging from altered gene expression and cellular metabolism to changes in growth rates and crop yields. A plethora of plant reactions exist to circumvent the potentially harmful effects caused by a wide range of both abiotic and biotic stresses, including light, drought, salinity, high temperatures, and pathogen infections. Among the environmental stresses, drought stress is one of the most adverse factors of plant growth and productivity. Understanding the biochemical and molecular responses to drought is essential for a holistic perception of plant resistance mechanisms to water-limited conditions. Drought stress progressively decreases CO2 assimilation rates due to reduced stomatal conductance. Drought stress also induces reduction in the contents and activities of photosynthetic carbon reduction cycle enzymes, including the key enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase. The critical roles of proline and glycine-betaine, as well as the role of abscisic acid (ABA), under drought stress conditions have been actively researched to understand the tolerance of plants to dehydration. In addition, drought stress-induced generation of active oxygen species is well recognized at the cellular level and is tightly controlled at both the production and consumption levels in vivo, through increased antioxidative systems. Knowledge of sensing and signaling pathways, including ABA-mediated changes in response to drought stress, is essential to improve crop management. This review focuses on the ability and strategies of higher plants to respond and adapt to drought stress.
环境胁迫会引发植物的多种反应，从基因表达和细胞代谢的改变到生长速率和作物产量的变化。植物存在大量反应以规避由多种非生物和生物胁迫（包括光照、干旱、盐度、高温和病原体感染）所造成的潜在有害影响。在环境胁迫中，干旱胁迫是植物生长和生产力最不利的因素之一。了解植物对干旱的生化和分子反应对于全面认识植物在水分受限条件下的抗性机制至关重要。由于气孔导度降低，干旱胁迫会逐渐降低二氧化碳同化率。干旱胁迫还会导致光合碳还原循环酶的含量和活性降低，包括关键酶核酮糖-1,5-二磷酸羧化酶/加氧酶。脯氨酸和甘氨酸甜菜碱的关键作用以及脱落酸（ABA）在干旱胁迫条件下的作用已得到积极研究，以了解植物对脱水的耐受性。此外，干旱胁迫诱导的活性氧生成在细胞水平上已得到充分认识，并且通过增强抗氧化系统在体内的产生和消耗水平上受到严格控制。了解包括ABA介导的对干旱胁迫反应变化在内的感知和信号传导途径对于改善作物管理至关重要。本综述重点关注高等植物对干旱胁迫做出反应和适应的能力及策略。
