Zhang Lichao, He Guanhua, Li Yaping, Yang Ziyi, Liu Tianqi, Xie Xianzhi, Kong Xiuying, Sun Jiaqiang
Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
Shandong Rice Research Institute, Shandong Academy of Agricultural Sciences, Jinan, 250100, China.
New Phytol. 2022 Feb;233(3):1414-1425. doi: 10.1111/nph.17872. Epub 2021 Dec 3.
Tillering is an important parameter of plant architecture in cereal crops. In this study, we identified the PHYTOCHROME-INTERACTING FACTOR-LIKE (PIL) family transcription factors as new repressors of tillering in cereal crops. Using biochemical and genetic approaches, we explore the roles of TaPIL1 in regulating wheat plant architecture. We found that the PIL protein TaPIL1 controls tiller number in wheat. Overexpression of TaPIL1 reduces wheat tiller number; additionally, overexpression of TaPIL1-SUPERMAN repression domain increases wheat tiller number. Furthermore, we show that TaPIL1 activates the transcriptional expression of wheat TEOSINTE BRANCHED1 (TaTB1); moreover, TaPIL1 physically interacts with wheat SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (TaSPL)3/17, which are activators of TaTB1 transcription. In rice, overexpression and loss-of-function mutations of OsPIL11 reduce or increase tiller number by regulating the expression of OsTB1. In Arabidopsis, we demonstrate that PHYTOCHROME-INTERACTING FACTOR 4 interacts with SPL9 to inhibit shoot branching. This study reveals that PIL family transcription factors directly interact with SPLs and play an important role in repressing tillering/branching in plants.
分蘖是谷类作物株型的一个重要参数。在本研究中，我们鉴定出类光敏色素互作因子（PIL）家族转录因子是谷类作物分蘖的新抑制因子。利用生化和遗传学方法，我们探究了TaPIL1在调控小麦株型中的作用。我们发现PIL蛋白TaPIL1控制小麦的分蘖数。TaPIL1的过表达降低了小麦的分蘖数；此外，TaPIL1-超man抑制结构域的过表达增加了小麦的分蘖数。此外，我们表明TaPIL1激活了小麦分蘖芽抑制蛋白1（TaTB1）的转录表达；而且，TaPIL1与小麦类鳞状花序启动子结合蛋白（TaSPL）3/17发生物理相互作用，TaSPL3/17是TaTB1转录的激活因子。在水稻中，OsPIL11的过表达和功能缺失突变通过调节OsTB1的表达来减少或增加分蘖数。在拟南芥中，我们证明光敏色素互作因子4与SPL9相互作用以抑制枝条分枝。本研究揭示了PIL家族转录因子直接与SPL相互作用，并在抑制植物分蘖/分枝中发挥重要作用。
