School of Agriculture and Food, The University of Melbourne, Melbourne, VIC, Australia.
School of Biological Sciences, University of Western Australia, Crawley, Perth, Australia.
J Exp Bot. 2020 Jul 25;71(15):4452-4468. doi: 10.1093/jxb/eraa049.
Water and nitrogen availability limit crop productivity globally more than most other environmental factors. Plant availability of macronutrients such as nitrate is, to a large extent, regulated by the amount of water available in the soil, and, during drought episodes, crops can become simultaneously water and nitrogen limited. In this review, we explore the intricate relationship between water and nitrogen transport in plants, from transpiration-driven mass flow in the soil to uptake by roots via membrane transporters and channels and transport to aerial organs. We discuss the roles of root architecture and of suberized hydrophobic root barriers governing apoplastic water and nitrogen movement into the vascular system. We also highlight the need to identify the signalling cascades regulating water and nitrogen transport, as well as the need for targeted physiological analyses of plant traits influencing water and nitrogen uptake. We further advocate for incorporation of new phenotyping technologies, breeding strategies, and agronomic practices to improve crop yield in water- and nitrogen-limited production systems.
水和氮的可利用性比大多数其他环境因素更能限制全球作物的生产力。例如硝酸盐等大量营养素在植物中的可用性在很大程度上受到土壤中可用水量的调节，而且在干旱时期，作物可能会同时受到水和氮的限制。在这篇综述中，我们探讨了植物中水和氮运输之间的复杂关系，从土壤中蒸腾驱动的质量流到通过膜转运体和通道被根系吸收，再到向气生器官的运输。我们讨论了根结构的作用和木质素化疏水性根屏障在控制质外体水和氮向维管束系统移动中的作用。我们还强调了需要确定调节水和氮运输的信号级联，以及需要对影响水和氮吸收的植物性状进行有针对性的生理学分析。我们还主张采用新的表型技术、育种策略和农业实践来改善在水和氮限制生产系统中的作物产量。
