Yu Yongdong, Zhong Zhaochen, Ma Liuyin, Xiang Chengbin, Chen Jie, Huang Xin-Yuan, Xu Ping, Xiong Yan
College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Shanghai Key Laboratory of Plant Functional Genomics and Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China.
New Phytol. 2022 Nov;236(4):1326-1338. doi: 10.1111/nph.18441. Epub 2022 Sep 9.
Plants play a primary role for the global sulfur cycle in the earth ecosystems by reduction of inorganic sulfate from the soil to organic sulfur-containing compounds. How plants sense and transduce the sulfate availability to mediate their growth remains largely unclear. The target of rapamycin (TOR) kinase is an evolutionarily conserved master regulator of nutrient sensing and metabolic signaling to control cell proliferation and growth in all eukaryotes. By tissue-specific Western blotting and RNA-sequencing analysis, we investigated sulfate-TOR signal pathway in regulating shoot apex development. Here, we report that inorganic sulfate exhibits high potency activating TOR and cell proliferation to promote true leaf development in Arabidopsis in a glucose-energy parallel pathway. Genetic and metabolite analyses suggest that this sulfate activation of TOR is independent from the sulfate-assimilation process and glucose-energy signaling. Significantly, tissue specific transcriptome analyses uncover previously unknown sulfate-orchestrating genes involved in DNA replication, cell proliferation and various secondary metabolism pathways, which largely depends on TOR signaling. Systematic comparison between the sulfate- and glucose-TOR controlled transcriptome further reveals that TOR kinase, as the central growth integrator, responds to different nutrient signals to control both shared and unique transcriptome networks, therefore, precisely modulates plant proliferation, growth and stress responses.
植物通过将土壤中的无机硫酸盐还原为含硫有机化合物，在地球生态系统的全球硫循环中发挥着主要作用。植物如何感知并传导硫酸盐的可利用性以调节其生长，在很大程度上仍不清楚。雷帕霉素靶蛋白（TOR）激酶是一种在进化上保守的主要营养感知和代谢信号调节因子，可控制所有真核生物的细胞增殖和生长。通过组织特异性蛋白质免疫印迹和RNA测序分析，我们研究了硫酸盐-TOR信号通路在调控茎尖发育中的作用。在此，我们报告无机硫酸盐在拟南芥中通过葡萄糖-能量平行途径表现出高效激活TOR和细胞增殖以促进真叶发育的能力。遗传和代谢物分析表明，TOR的这种硫酸盐激活作用独立于硫酸盐同化过程和葡萄糖-能量信号传导。重要的是，组织特异性转录组分析揭示了参与DNA复制、细胞增殖和各种次生代谢途径的先前未知的硫酸盐调控基因，这在很大程度上依赖于TOR信号传导。硫酸盐和葡萄糖-TOR控制的转录组之间的系统比较进一步表明，TOR激酶作为中心生长整合因子，对不同的营养信号作出反应，以控制共享和独特的转录组网络，因此精确地调节植物的增殖、生长和应激反应。
