■水稻是水分利用效率最低的作物之一,水稻植物利用其大部分水分吸收通过气孔进行蒸腾冷却。为了提高水稻的水分利用效率(WUE),减少气孔密度和大小有助于优化蒸腾作用和光合作用。
■在这项研究中,我们比较了两个系列的紫色水稻气孔突变体:通过显微镜观察旗叶气孔鉴定的气孔模型突变体(SMM),以及通过在严重水分胁迫下筛选产生的干旱选择模型突变体(DMM)。在经历了-60至-80Ym之间的两轮严重水分胁迫后,就在R1-2生殖阶段之前,根据其快速回收率和%填充籽粒百分比选择了三种DMM。
■三个DMMs显示出每平方毫米618-697个气孔单位,类似于SMMs低密度气孔突变体(JHN8756(LD))。此外,四个SMM,从幼苗到收获,用两种限制水条件方案处理了三个DMM和JaoHomNin野生型(JHNWT)。在实验过程中,灌溉和降水的总量对于较少限制的水条件(LR)为78.1L/植物(69.1mm/植物),对于较多限制的水条件(MR)为47.5L/植物(42mm/植物)。水分条件处理对气孔密度和气孔指数没有影响。相比之下,基因型和限制水分条件方案影响植物高度,耕种/植物,%填充谷物和枝条干重(SDW)。三个DMM和JHN8756(LD),SMM的低密度气孔突变体,与SMM和JHN野生型相比,对更受限制的水条件表现出更大的恢复力。特别是,DMMs对更受限制的水条件处理具有耐受性,没有显示SDW处罚。一起,DMMs和JHN8756(LD)在这些限制水条件下显示出较高的WUE。
■严格的筛选过程,以区分具有快速干旱恢复率的耐性突变体与严重的水分胁迫,可以为分离出更多具有更好气孔功能和恢复能力的突变体,为即将到来的气候变化做准备。
UNASSIGNED: Rice is among the least water-use-efficient crops, and rice plants utilise most of their water uptake for transpirational cooling via stomata. To improve water-use efficiency (WUE) in rice, reducing stomatal density and size could help optimise transpiration and photosynthesis.
UNASSIGNED: In this study, we compared two series of purple rice stomata mutants: the Stomatal Model Mutant (SMM) identified by microscopic observation of flag-leaf stomata, and the Drought-selected Model Mutant (DMM) generated through screening under severe water stress. After undergoing two rounds of severe water stress between -60 to -80 Ym, right before the R1-2 reproductive stage, three DMMs were selected based on their rapid recovery rate and % filled-grain percentage.
UNASSIGNED: The three DMMs displayed 618-697 stomatal units per mm2, similar to the SMMs low-density stomata mutant (JHN 8756 (LD)). Furthermore, the four SMMs, three DMMs and the Jao Hom Nin wild type (JHN WT) were treated with two restricted water condition schemes from seedlings to harvest. The total amount of irrigation and precipitation during the experiment was 78.1 L/plant (69.1 mm/plant) for the less restricted water condition (LR) and 47.5 L/plant (42 mm/plant) for the more restricted water condition (MR). Water condition treatments had no effects on stomatal density and stomatal index. In contrast, genotypes and restricted water condition schemes affected plant height, tillers/plant, % filled grains and shoot dry weight (SDW). The three DMMs and the JHN 8756 (LD), the SMM\'s low-density stomata mutant, displayed greater resilience towards more restricted water conditions than the SMMs and the JHN wild type. Particularly, DMMs were tolerant to more restricted water condition treatments, showing no SDW penalties. Together, the DMMs and the JHN 8756 (LD) displayed higher WUE under these conditions of more restricted water conditions.
UNASSIGNED: A rigorous screening process to distinguish tolerant mutants with a rapid drought recovery rate from severe water stress could pave the way to isolate more mutants with better stomatal functionality and resilience in preparation for imminent climate changes.