Prabhakar Rakhi, Gupta Asmita, Singh Rambir, Sane Aniruddha P
Plant Gene Expression Lab, CSIR-National Botanical Research Institute (Council of Scientific and Industrial Research), Lucknow, 226001, India; Department of Biotechnology, Bundelkhand University, Jhansi, 284128, India.
Plant Gene Expression Lab, CSIR-National Botanical Research Institute (Council of Scientific and Industrial Research), Lucknow, 226001, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Biochem Biophys Res Commun. 2023 Nov 12;681:136-143. doi: 10.1016/j.bbrc.2023.09.066. Epub 2023 Sep 24.
Drought susceptibility is a major yield limiting factor in agricultural crops especially in hybrids/varieties that have been bred for high yields. We show that manipulation of the SlDREB3 gene in tomato alters ABA responses and thereby sensitivity of stomatal closure to ABA. SlDREB3 suppression lines show ABA hypersensitivity and rapid stomatal closure in response to ABA while over-expression lines show reduced sensitivity to ABA and open stomata even at high ABA levels with rapid water loss after 10 days of water stress. This is accompanied with high ROS levels and increased membrane damage due to senescence of leaves and drastically reduced survival in drought. The relative water content (RWC) of OEx lines is much reduced even when grown under well-watered conditions. In contrast, suppression lines show greater tolerance to water stress and almost complete survival to 10-day water stress. They show much reduced ROS levels, reduced membrane damage, higher RWC and reduced leaf water loss. These changes are associated with higher expression of ABA signalling pathway genes in suppression lines while these are highly reduced in OEx lines. The studies suggest that control of ABA signalling by SlDREB3 can help in withstanding severe drought.
干旱敏感性是农作物产量的主要限制因素，尤其是在为高产而培育的杂交种/品种中。我们发现，对番茄中SlDREB3基因的操控会改变脱落酸（ABA）响应，从而改变气孔关闭对ABA的敏感性。SlDREB3抑制系表现出ABA超敏感性，对ABA有快速的气孔关闭反应，而过表达系对ABA的敏感性降低，即使在高ABA水平下气孔仍开放，水分胁迫10天后水分快速流失。这伴随着高水平的活性氧（ROS）以及由于叶片衰老导致的膜损伤增加，干旱条件下存活率大幅降低。即使在水分充足的条件下生长，过表达系的相对含水量（RWC）也大幅降低。相反，抑制系对水分胁迫表现出更强的耐受性，在10天的水分胁迫下几乎完全存活。它们的ROS水平大幅降低，膜损伤减少，RWC更高，叶片水分流失减少。这些变化与抑制系中ABA信号通路基因的高表达相关，而过表达系中这些基因的表达则大幅降低。这些研究表明，SlDREB3对ABA信号的调控有助于抵御严重干旱。
