Department of Ecology & Evolutionary Biology, University of Colorado, Boulder, CO 80309-0334, USA.
School of Education, University of Colorado, Boulder, CO 80309-0249, USA.
Int J Mol Sci. 2018 Aug 24;19(9):2507. doi: 10.3390/ijms19092507.
The interaction of heat stress with internal signaling networks was investigated through mutants that were deficient in either tocopherols ( mutant) or non-photochemical fluorescence quenching (NPQ; , , and mutants). Leaves of both and mutants that developed at a high temperature exhibited a significantly different leaf vascular organization compared to wild-type Col-0. Both mutants had significantly smaller water conduits (tracheary elements) of the xylem, but the total apparent foliar water-transport capacity and intrinsic photosynthetic capacity were similarly high in mutants and wild-type Col-0. This was accomplished through a combination of more numerous (albeit narrower) water conduits per vein, and a significantly greater vein density in both mutants relative to wild-type Col-0. The similarity of the phenotypes of tocopherol-deficient and NPQ-deficient mutants suggests that leaf vasculature organization is modulated by the foliar redox state. These results are evaluated in the context of interactions between redox-signaling pathways and other key regulators of plant acclimation to growth temperature, such as the C-repeat binding factor (CBF) transcription factors, several of which were upregulated in the antioxidant-deficient mutants. Possibilities for the future manipulation of the interaction between CBF and redox-signaling networks for the purpose of cooptimizing plant productivity and plant tolerance to extreme temperatures are discussed.
通过缺乏生育酚（mutant）或非光化学荧光猝灭（NPQ；mutant、mutant 和 mutant）的突变体研究了热应激与内部信号网络的相互作用。在高温下发育的和突变体的叶片与野生型 Col-0 相比，表现出明显不同的叶片脉管组织。这两个突变体的木质部输水导管（木质部）明显较小，但突变体和野生型 Col-0 的总表观叶片水分运输能力和内在光合作用能力相似较高。这是通过每根叶脉中更多（尽管更窄）的输水导管和突变体相对于野生型 Col-0 中静脉密度显著增加的组合来实现的。生育酚缺乏和 NPQ 缺乏突变体的表型相似表明，叶片脉管组织的结构受叶内氧化还原状态的调节。这些结果是在氧化还原信号通路与植物对生长温度适应的其他关键调节剂（如 C-重复结合因子（CBF）转录因子）之间相互作用的背景下进行评估的，其中一些在抗氧化剂缺乏突变体中上调。讨论了未来操纵 CBF 和氧化还原信号网络之间相互作用的可能性，目的是优化植物生产力和植物对极端温度的耐受性。
