Verslues Paul E
Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.
Philos Trans R Soc Lond B Biol Sci. 2025 May 29;380(1927):20240232. doi: 10.1098/rstb.2024.0232.
The concept of a 'growth versus defence' antagonism is sometimes applied as a framework to explain plant responses to drought and other abiotic stress. However, for drought stress, reduced growth to conserve water is a major part of the defence against further drying. This intertwined nature of growth and defence during drought makes it both conceptually and practically problematic to analyse them as two competing processes. Furthermore, physiological analysis of plants experiencing moderate severity water limitation, where turgor is maintained but growth is reduced, finds that the reduced growth is generally not due to resource limitation, as is sometimes assumed in the 'growth versus defence' model. For studies of more severe water limitation, where plants fall below the point of turgor loss, growth is not possible and therefore there can be no trade-off with defence. It is proposed that the concept of 'growth versus risk mitigation' provides a more useful framework for understanding the relationship between drought stress and growth. The 'growth versus risk mitigation' concept clarifies both the reasons why growth is actively suppressed during moderate severity water limitation and the conditions under which it may be useful to remove such growth restraints.This article is part of the theme issue 'Crops under stress: can we mitigate the impacts of climate change on agriculture and launch the 'Resilience Revolution'?'.
“生长与防御”拮抗的概念有时被用作一个框架来解释植物对干旱和其他非生物胁迫的反应。然而，对于干旱胁迫而言，减少生长以保存水分是抵御进一步干燥的主要部分。干旱期间生长与防御的这种相互交织的性质，使得将它们作为两个相互竞争的过程进行分析在概念上和实践中都存在问题。此外，对经历中度水分限制（此时膨压得以维持但生长减缓）的植物进行生理分析发现，生长减缓通常并非如“生长与防御”模型中有时所假设的那样是由于资源限制。对于更严重水分限制的研究，即植物低于膨压丧失点时，生长是不可能的，因此也就不存在与防御的权衡。有人提出，“生长与风险缓解”的概念为理解干旱胁迫与生长之间的关系提供了一个更有用的框架。“生长与风险缓解”的概念既阐明了在中度水分限制期间生长被主动抑制的原因，也阐明了去除这种生长限制可能有用的条件。本文是主题为“受胁迫的作物：我们能否减轻气候变化对农业的影响并发起‘复原力革命’？”的一部分。
