PIF4 interacts with ABI4 to serve as a transcriptional activator complex to promote seed dormancy by enhancing ABA biosynthesis and signaling

J Integr Plant Biol. 2024 Feb 8. doi: 10.1111/jipb.13615. Online ahead of print.ABSTRACTTranscriptional regulation plays a key role in the control of seed dormancy, and many transcription factors (TFs) have been documented. However, the mechanisms underlying the interactions between different TFs within a transcriptional complex regulating seed dormancy remain largely unknown. Here, we showed that TF PHYTOCHROME-INTERACTING FACTOR4 (PIF4) physically interacted with the abscisic acid (ABA) signaling responsive TF ABSCISIC ACID INSENSITIVE4 (ABI4) to act as a transcriptional complex to promote ABA biosynthesis and signaling, finally deepening primary seed dormancy. Both pif4 and abi4 single mutants exhibited a decreased primary seed dormancy phenotype, with a synergistic effect in the pif4/abi4 double mutant. PIF4 binds to ABI4 to form a heterodimer, and ABI4 stabilizes PIF4 at the protein level, whereas PIF4 does not affect the protein stabilization of ABI4. Subsequently, both TFs independently and synergistically promoted the expression of ABI4 and NCED6, a key gene for ABA anabolism. The genetic evidence is also consistent with the phenotypic, physiological and biochemical analysis results. Altogether, this study revealed a transcriptional regulatory cascade in which the PIF4-ABI4 transcriptional activator complex synergistically enhanced seed dormancy by facilitating ABA biosynthesis and signaling.PMID:38328870 | DOI:10.1111/jipb.13615

Source: Journal of Integrative Plant Biology - February 8, 2024 Category: Biology Authors: Xiaofeng Luo Yujia Dai Baoshan Xian Jiahui Xu Ranran Zhang Muhammad Saad Rehmani Chuan Zheng Xiaoting Zhao Kaitao Mao Xiaotong Ren Shaowei Wei Lei Wang Juan He Weiming Tan Junbo Du Weiguo Liu Shu Yuan Kai Shu Source Type: research