AUXIN RESPONSE FACTOR7 integrates gibberellin and auxin signaling via interactions between DELLA and AUX/IAA proteins to regulate cambial activity in poplar
AUXIN RESPONSE FACTOR7 integrates gibberellin and auxin signaling via interactions between DELLA and AUX/IAA proteins to regulate cambial activity in poplar
复制标题
AUXIN RESPONSE FACTOR7 通过 DELLA 和 AUX/IAA 蛋白之间的相互作用整合赤霉素和生长素信号传导，以调节杨树的形成层活性
DOI：
10.1093/plcell/koac107
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发表时间：
2022-06-26
期刊：
影响因子：
11.6
通讯作者：
Luo, Keming
中科院分区：
文献类型：
--
作者：
Hu, Jian;Su, Huili;Luo, Keming
Cambial development in the stems of perennial woody species is rigorously regulated by phytohormones. Auxin and gibberellin (GA) play crucial roles in stimulating cambial activity in poplar (Populus spp.). In this study, we show that the DELLA protein REPRESSOR of ga1-3 Like 1 (RGL1), AUXIN RESPONSE FACTOR 7 (ARF7), and Aux/INDOLE-3-ACETIC ACID 9 (IAA9) form a ternary complex that mediates crosstalk between the auxin and GA signaling pathways in poplar stems during cambial development. Biochemical analysis revealed that ARF7 physically interacts with RGL1 and IAA9 through distinct domains. The arf7 loss-of-function mutant showed markedly attenuated responses to auxin and GA, whereas transgenic poplar plants overexpressing ARF7 displayed strongly improved cambial activity. ARF7 directly binds to the promoter region of the cambial stem cell regulator WOX4 to modulate its expression, thus integrating auxin and GA signaling to regulate cambial activity. Furthermore, the direct activation of PIN-FORMED 1 expression by ARF7 in the RGL1-ARF7-IAA9 module increased GA-dependent cambial activity via polar auxin transport. Collectively, these findings reveal that the crosstalk between auxin and GA signaling mediated by the RGL1-ARF7-IAA9 module is crucial for the precise regulation of cambial development in poplar.The auxin response factor (ARF7) acts as a molecular bridge linking gibberellin and auxin signaling to regulate cambial activity by directly binding to the WOX4 promoter, thereby affecting wood quality in poplar.
