Wang Xin, Liu Zhen-Zhen, Yuan Dan-Yang, Lu Yu-Jia, Li Lin, Chen She, He Xin-Jian
College of Life Sciences, Beijing Normal University, Beijing, China.
National Institute of Biological Sciences, Beijing, China.
Nat Plants. 2025 Sep 26. doi: 10.1038/s41477-025-02107-5.
The conserved target of rapamycin (TOR) kinase acts as a master regulator of growth by integrating nutrient and environmental signals in eukaryotes. However, how TOR influences chromatin remains poorly understood. Here we identified a multi-subunit complex in Arabidopsis thaliana, termed the chromatin-associated complex for growth (CACG). Our findings indicate that under nutrient-rich conditions, active TOR kinase enhances CACG mRNA translation, which is facilitated by pyrimidine-rich motifs in their 5' untranslated regions. CACG components co-occupy stress-responsive genes marked by histone acetylation, repressing their transcription to promote growth. Conversely, under nutrient-deficient conditions, inactive TOR reduces CACG mRNA translation, relieving transcriptional repression of stress-responsive genes and leading to increased stress tolerance but impaired growth. These results indicate that the CACG complex acts as a critical nutrient-responsive transcriptional regulator that is required for coordinating plant growth and stress tolerance in a TOR-dependent manner. The molecular mechanism revealed here could aid in developing high-yield crops capable of thriving in adverse environments.
保守的雷帕霉素靶蛋白（TOR）激酶通过整合真核生物中的营养和环境信号，充当生长的主要调节因子。然而，TOR如何影响染色质仍知之甚少。在这里，我们在拟南芥中鉴定了一种多亚基复合物，称为生长相关染色质复合物（CACG）。我们的研究结果表明，在营养丰富的条件下，活性TOR激酶增强了CACG mRNA的翻译，这在其5'非翻译区富含嘧啶的基序的促进下得以实现。CACG组分共同占据以组蛋白乙酰化为特征的应激反应基因，抑制它们的转录以促进生长。相反，在营养缺乏的条件下，无活性的TOR减少了CACG mRNA的翻译，解除了应激反应基因的转录抑制，导致应激耐受性增加但生长受损。这些结果表明，CACG复合物作为一种关键的营养响应转录调节因子，以TOR依赖的方式协调植物生长和应激耐受性是必需的。这里揭示的分子机制有助于培育能够在恶劣环境中茁壮成长的高产作物。
