Modulation of nitrate-induced phosphate response by the MYB transcription factor RLI1/HINGE1 in the nucleus
Modulation of nitrate-induced phosphate response by the MYB transcription factor RLI1/HINGE1 in the nucleus
复制标题
细胞核中 MYB 转录因子 RLI1/HINGE1 对硝酸盐诱导的磷酸盐反应的调节
DOI：
10.1016/j.molp.2020.12.005
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发表时间：
2021
期刊：
影响因子：
27.5
通讯作者：
Chu Chengcai
中科院分区：
文献类型：
--
作者：
Zhang Zhihua;Li Zhao;Wang Wei;Jiang Zhimin;Guo Liping;Wang Xiaohan;Qian Yangwen;Huang Xiahe;Liu Yongqiang;Liu Xiujie;Qiu Yahong;Li Aifu;Yan Yu;Xie Junpeng;Cao Shouyun;Kopriva Stanislav;Li Legong;Kong Fanjiang;Liu Baohui;Wang Yingchun;Hu Bin;Chu Chengcai
氮、磷的协调利用是植物维持养分平衡、实现最佳生长的关键。在此之前，我们揭示了硝酸盐诱导水稻磷酸盐利用基因的一种机制，该机制依赖于NRT 1. 1B促进胞质SPX 4的降解，进而促进磷酸盐信号传导的核心转录因子PHR 2的胞质-核穿梭，从而触发水稻硝酸盐诱导的磷酸盐响应（NIPR）和N-P协调利用。在这项研究中，我们揭示了一个微调机制的NIPR在核高度诱导的硝酸盐基因1（HINGE 1，也被称为RLI 1），MYB转录因子密切相关的PHR 2的调控。RLI 1/HINGE 1在硝酸盐诱导下被PHR 2转录激活，可直接激活磷酸盐饥饿诱导基因的表达。更重要的是，RLI 1/HINGE 1与PHR 2竞争结合其细胞核中的阻遏蛋白（SPX蛋白），从而释放PHR 2以进一步增强磷酸盐反应。因此，RLI 1/HINGE 1放大了细胞质SPX 4-PHR 2级联下游细胞核中的磷酸盐反应，从而在硝酸盐供应充足时能够微调N-P平衡。
The coordinated utilization of nitrogen (N) and phosphorus (P) is vital for plants to maintain nutrient balance and achieve optimal growth. Previously, we revealed a mechanism by which nitrate induces genes for phosphate utilization; this mechanism depends on NRT1.1B-facilitated degradation of cytoplasmic SPX4, which in turn promotes cytoplasmic-nuclear shuttling of PHR2, the central transcription factor of phosphate signaling, and triggers the nitrate-induced phosphate response (NIPR) and N-P coordinated utilization in rice. In this study, we unveiled a fine-tuning mechanism of NIPR in the nucleus regulated by Highly Induced by Nitrate Gene 1 (HINGE1, also known as RLI1), a MYB-transcription factor closely related to PHR2. RLI1/HINGE1, which is transcriptionally activated by PHR2 under nitrate induction, can directly activate the expression of phosphate starvation-induced genes. More importantly, RLI1/HINGE1 competes with PHR2 for binding to its repressor proteins in the nucleus (SPX proteins), and consequently releases PHR2 to further enhance phosphate response. Therefore, RLI1/HINGE1 amplifies the phosphate response in the nucleus downstream of the cytoplasmic SPX4-PHR2 cascade, thereby enabling fine-tuning of N-P balance when nitrate supply is sufficient.