Tardieu François, Parent Boris, Caldeira Cecilio F, Welcker Claude
INRA, Unité Mixte de Recherche 759 Laboratoire d'Ecophysiologie des Plantes sous Stress Environnementaux, F-34060 Montpellier, France.
Plant Physiol. 2014 Apr;164(4):1628-35. doi: 10.1104/pp.113.233353. Epub 2014 Feb 25.
The sensitivity of expansive growth to water deficit has a large genetic variability, which is higher than that of photosynthesis. It is observed in several species, with some genotypes stopping growth in a relatively wet soil, whereas others continue growing until the lower limit of soil-available water. The responses of growth to soil water deficit and evaporative demand share an appreciable part of their genetic control through the colocation of quantitative trait loci as do the responses of the growth of different organs to water deficit. This result may be caused by common mechanisms of action discussed in this paper (particularly, plant hydraulic properties). We propose that expansive growth, putatively linked to hydraulic processes, determines the sink strength under water deficit, whereas photosynthesis determines source strength. These findings have large consequences for plant modeling under water deficit and for the design of breeding programs.
生长扩展性对水分亏缺的敏感性具有很大的遗传变异性，这一遗传变异性高于光合作用的遗传变异性。在多个物种中都观察到了这种情况，一些基因型在相对湿润的土壤中就停止生长，而其他基因型则会持续生长直至土壤有效水的下限。生长对土壤水分亏缺和蒸发需求的响应，与不同器官生长对水分亏缺的响应一样，通过数量性状位点的共定位在很大程度上共享其遗传控制。这一结果可能是由本文所讨论的共同作用机制（特别是植物水力特性）导致的。我们提出，推测与水力过程相关的扩展性生长决定了水分亏缺条件下的库强，而光合作用决定源强。这些发现对水分亏缺条件下的植物建模以及育种计划的设计具有重大影响。
