Mechanisms underlying plant resilience to water deficits: prospects for water-saving agriculture
Mechanisms underlying plant resilience to water deficits: prospects for water-saving agriculture
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DOI：
10.1093/jxb/erh269
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发表时间：
2004-11-01
影响因子：
6.9
通讯作者：
Oliveira, MM
中科院分区：
文献类型：
--
作者：
Chaves, MM;Oliveira, MM
干旱是当今农业地区以外作物扩张的最大限制之一。在地球仪的一些区域，由于全球气候的公认变化，这一问题在过去可以忽略不计，但在这些区域，这一问题将变得越来越重要。今天，人们关注的是改善干旱易发地区的耕作方法和作物基因型;因此，了解植物抗旱和有效利用水的机制是实现这些目标的基础。在本文中，主要限制碳同化和代谢调节，发挥作用，在植物响应水分亏缺，单独或与其他压力，进行了审查。对碳同化的影响包括增加气孔和叶肉对扩散的阻力，以及生物化学和光化学调节。氧化应激对经历干旱的作物至关重要。解毒系统的作用，防止不可逆的损害光合机械和氧化还原分子作为本地或系统的信号进行了修订。植物在脱水和再水化过程中避免或修复膜损伤的能力对于维持膜完整性至关重要，特别是对于那些嵌入功能蛋白的膜。在这些蛋白质中有水转运蛋白，其在调节植物水分状况和运输其他代谢物中的作用是深入研究的主题。远距离化学信号作为对干旱的早期反应，早在十多年前就开始被解开。这些信号对碳同化和同化物在生殖和非生殖结构之间的分配的影响进行了修订和讨论的背景下，新的管理技术。这些应用旨在将提高作物用水效率与持续产量和提高产品质量结合起来。通过了解导致成功适应脱水和复水的机制，已经有可能确定能够改变新陈代谢和提高植物耐旱性的关键基因。本文概述了关于这一主题的最重要的数据，包括渗透调节或保护工程，水转运蛋白和C-4性状。重点是最成功的或有前途的情况下，在作物基因工程，使用功能或调节基因。以及有前途的技术，如转录因子的转移。
Drought is one of the greatest limitations to crop expansion outside the present-day agricultural areas. It will become increasingly important in regions of the globe where, in the past, the problem was negligible, due to the recognized changes in global climate. Today the concern is with improving cultural practices and crop genotypes for drought-prone areas; therefore, understanding the mechanisms behind drought resistance and the efficient use of water by the plants is fundamental for the achievement of those goals. In this paper, the major constraints to carbon assimilation and the metabolic regulations that play a role in plant responses to water deficits, acting in isolation or in conjunction with other stresses, is reviewed. The effects on carbon assimilation include increased resistance to diffusion by stomata and the mesophyll, as well as biochemical and photochemical adjustments. Oxidative stress is critical for crops that experience drought episodes. The role of detoxifying systems in preventing irreversible damage to photosynthetic machinery and of redox molecules as local or systemic signals is revised. Plant capacity to avoid or repair membrane damage during dehydration and rehydration processes is pivotal for the maintenance of membrane integrity, especially for those that embed functional proteins. Among such proteins are water transporters, whose role in the regulation of plant water status and transport of other metabolites is the subject of intense investigation. Long-distance chemical signalling, as an early response to drought, started to be unravelled more than a decade ago. The effects of those signals on carbon assimilation and partitioning of assimilates between reproductive and non-reproductive structures are revised and discussed in the context of novel management techniques. These applications are designed to combine increased crop water-use efficiency with sustained yield and improved quality of the products. Through an understanding of the mechanisms leading to successful adaptation to dehydration and rehydration, it has already been possible to identify key genes able to alter metabolism and increase plant tolerance to drought. An overview of the most important data on this topic, including engineering for osmotic adjustment or protection, water transporters, and C-4 traits is presented in this paper. Emphasis is given to the most successful or promising cases of genetic engineering in crops, using functional or regulatory genes. as well as to promising technologies, such as the transfer of transcription factors.