Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), College of Life Science, China West Normal University, Nanchong, 637009, Sichuan, China.
Plant Cell Rep. 2021 Jul;40(7):1115-1126. doi: 10.1007/s00299-021-02680-x. Epub 2021 Mar 23.
The SlTCP26 negatively regulated auxin signal to relieve the apical dominance and suppressed abscisic acid signal to remove the lateral bud dormancy, promoting lateral branches development. Lateral branches formation from lateral buds is a complex regulatory process in higher plants, and the interaction between transcription factors and hormones is indispensable during this process. TCP transcription factors have been reported to regulate lateral branches development, while the detailed function, especially interacting with auxin and ABA during this process, was still ambiguous in tomato. In this study, a branch regulatory gene, SlTCP26, was identified in tomato, and its role along with its interaction to hormones during branch development, as investigated. The results indicated that overexpression of SlTCP26 would promote lateral branches development, and could suppress the expressing of the genes associated with IAA signaling, presenting similar effects in decapitated plants. Conversely, the exogenous IAA application could inhibit the expression of SlTCP26. Furthermore, the expressing of the ABA signaling-related genes was inhibited in SlTCP26 overexpressed tomato, similar to that in decapitated tomato. Our findings suggested that SlTCP26 may be a crucial adjuster for synergistic action between ABA and IAA signals during the development of lateral branches, and it could promote the lateral buds grow into lateral shoots, via inhibiting IAA signal to relieve the apical dominance and suppressing ABA signal to remove the lateral bud dormancy. Our study provided some insights for the development of tomato lateral branches to understand the apical dominance regulatory network.
SlTCP26 负调控生长素信号以缓解顶端优势，并抑制脱落酸信号以解除侧芽休眠，从而促进侧枝发育。侧芽发育成侧枝是高等植物中一个复杂的调控过程，在此过程中，转录因子和激素之间的相互作用是必不可少的。TCP 转录因子已被报道调控侧枝发育，但其在番茄中的详细功能，特别是在这个过程中与生长素和脱落酸的相互作用，仍不明确。本研究在番茄中鉴定到一个分枝调控基因 SlTCP26，并研究了其在分枝发育过程中与激素的相互作用及其功能。结果表明，过表达 SlTCP26 会促进侧枝发育，并能抑制与 IAA 信号相关的基因的表达，在去顶植株中表现出相似的效果。相反，外源 IAA 的应用会抑制 SlTCP26 的表达。此外，在 SlTCP26 过表达的番茄中，ABA 信号相关基因的表达受到抑制，与去顶番茄中的情况相似。我们的研究结果表明，SlTCP26 可能是 ABA 和 IAA 信号在侧枝发育过程中协同作用的关键调节剂，它可以通过抑制 IAA 信号来缓解顶端优势，并抑制 ABA 信号来解除侧芽休眠，从而促进侧芽生长成侧枝。我们的研究为番茄侧枝发育提供了一些见解，有助于理解顶端优势调控网络。
