Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan.
Plant Mol Biol. 2020 Dec;104(6):561-574. doi: 10.1007/s11103-020-01059-y. Epub 2020 Sep 27.
This study focused on the role of CLE1-CLE7 peptides as environmental mediators and indicated that root-induced CLE2 functions systemically in light-dependent carbohydrate metabolism in shoots. Plants sense environmental stimuli and convert them into cellular signals, which are transmitted to distinct cells and tissues to induce adequate responses. Plant hormones and small secretory peptides often function as environmental stress mediators. In this study, we investigated whether CLAVATA3/EMBRYO SURROUNDING REGION-RELATED proteins, CLE1-CLE7, which share closely related CLE domains, mediate environmental stimuli in Arabidopsis thaliana. Expression analysis of CLE1-CLE7 revealed that these genes respond to different environmental stimuli, such as nitrogen deprivation, nitrogen replenishment, cold, salt, dark, and sugar starvation, in a sophisticated manner. To further investigate the function of CLE2, we generated transgenic Arabidopsis lines expressing the β-glucuronidase gene under the control of the CLE2 promoter or expressing the CLE2 gene under the control of an estradiol-inducible promoter. We also generated cle2-1 and cle2-2 mutants using the CRISPR/Cas9 technology. In these transgenic lines, dark induced the expression of CLE2 in the root vasculature. Additionally, induction of CLE2 in roots induced the expression of various genes not only in roots but also in shoots, and genes related to light-dependent carbohydrate metabolism were particularly induced in shoots. In addition, cle2 mutant plants showed chlorosis when subjected to a shade treatment. These results suggest that root-induced CLE2 functions systemically in light-dependent carbohydrate metabolism in shoots.
本研究关注 CLE1-CLE7 肽作为环境介质的作用，并表明根诱导的 CLE2 在光照依赖的碳水化合物代谢中在地上部系统发挥作用。植物感知环境刺激并将其转化为细胞信号，这些信号被传递到不同的细胞和组织中，以诱导适当的反应。植物激素和小分泌肽通常作为环境应激介质发挥作用。在本研究中，我们研究了拟南芥中是否存在 CLAVATA3/EMBRYO SURROUNDING REGION-RELATED 蛋白（CLE1-CLE7），这些蛋白共享密切相关的 CLE 结构域，是否介导环境刺激。CLE1-CLE7 的表达分析表明，这些基因以复杂的方式响应不同的环境刺激，如氮饥饿、氮补充、寒冷、盐、黑暗和糖饥饿。为了进一步研究 CLE2 的功能，我们生成了在 CLE2 启动子控制下表达β-葡糖苷酸酶基因或在雌二醇诱导型启动子控制下表达 CLE2 基因的转基因拟南芥系。我们还使用 CRISPR/Cas9 技术生成了 cle2-1 和 cle2-2 突变体。在这些转基因系中，黑暗诱导 CLE2 在根脉管系统中的表达。此外，根中 CLE2 的诱导不仅在根中而且在地上部诱导各种基因的表达，并且与光照依赖的碳水化合物代谢相关的基因在地上部中特别诱导。此外，cle2 突变体植物在遮荫处理时表现出黄化。这些结果表明，根诱导的 CLE2 在地上部的光照依赖的碳水化合物代谢中系统地发挥作用。
