Arid Land Research Center, Tottori University, Tottori, Japan.
NARO Institute of Crop Science, Tsukuba, Japan.
Nat Plants. 2019 Feb;5(2):153-159. doi: 10.1038/s41477-019-0361-8. Epub 2019 Feb 8.
Water availability is a key determinant of terrestrial plant productivity. Many climate models predict that water stress will increasingly challenge agricultural yields and exacerbate projected food deficits. To ensure food security and increase agricultural efficiency, crop water productivity must be increased. Research over past decades has established that the phytohormone abscisic acid (ABA) is a central regulator of water use and directly regulates stomatal opening and transpiration. In this study, we investigated whether the water productivity of wheat could be improved by increasing its ABA sensitivity. We show that overexpression of a wheat ABA receptor increases wheat ABA sensitivity, which significantly lowers a plant's lifetime water consumption. Physiological analyses demonstrated that this water-saving trait is a consequence of reduced transpiration and a concomitant increase in photosynthetic activity, which together boost grain production per litre of water and protect productivity during water deficit. Our findings provide a general strategy for increasing water productivity that should be applicable to other crops because of the high conservation of the ABA signalling pathway.
水资源的可获得性是陆地植物生产力的关键决定因素。许多气候模型预测，水分胁迫将日益挑战农业产量，并加剧预计的粮食短缺。为了确保粮食安全和提高农业效率，必须提高作物水分生产率。过去几十年的研究已经确立，植物激素脱落酸（ABA）是水分利用的中央调节剂，并直接调节气孔开度和蒸腾作用。在这项研究中，我们研究了通过增加小麦的 ABA 敏感性是否可以提高其水分生产率。我们发现，过表达小麦 ABA 受体增加了小麦对 ABA 的敏感性，这显著降低了植物的终生耗水量。生理分析表明，这种节水特性是蒸腾作用减少和光合作用活性相应增加的结果，这共同提高了每升水的谷物产量，并在水分亏缺时保护了生产力。我们的研究结果为提高水分生产率提供了一种通用策略，由于 ABA 信号通路的高度保守性，该策略应该适用于其他作物。
