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the plant journal：SNLs基因控制拟南芥在长、短日照下的成花转变

已有 4945 次阅读 2019-6-8 15:10 |个人分类:每日摘要|系统分类:论文交流

SIN3 LIKE genes mediate long‐day induction of flowering but inhibit the floral transition in short days through histone deacetylation in Arabidopsis

First author: Fei Huang; Affiliations: CAS Center for Excellence in Molecular Plant Sciences (中科院分子植物科学卓越创新中心): Shanghai, China

Corresponding author: Yuehui He

Day length or photoperiod changes are crucial for plants to align the timing of the floral transition with seasonal changes. Through the photoperiod pathway, day‐length changes induce the expression of the florigenic FLOWERING LOCUS T (FT) to promote flowering. In the facultative long‐day plant Arabidopsis thaliana, long‐day signals induce flowering, whereas short days inhibit flowering. Here, we show that in Arabidopsis SIN3 LIKE (SNL) family genes, encoding a scaffold protein for assembly of histone deacetylase complexes, directly repress the expression of an FT activator and three FT repressors to regulate the transition to flowering in short days and long days, respectively. Under inductive long days, SNLs including SIN3 LIKE 1 (SNL1) to SNL5, function in partial redundancy to repress the expression of three AP2 family transcription factors that repress FT expression, and thus mediate long‐day induction of FT expression and promote the transition to flowering. In contrast, under non‐inductive short days SNLs act to inhibit the floral transition, partly through direct repression of a MADS box transcriptional factor that promotes FT expression. Thus, our results reveal that SNLs, through histone deacetylation, play a dual role for the control of flowering in the long‐day plant Arabidopsis: inhibiting flowering when the day length is shorter and promoting the floral transition when days become longer than a threshold length.

日长或光周期的改变对于植物根据季节变化调整成花转变的时间至关重要。通过光周期途径，日长的变化会诱导开花基因FT的表达，从而促进植株开花。在兼性长日照植物拟南芥中，长日照信号会诱导开花，短日照则会抑制开花。本文中，作者研究了拟南芥SNL家族的基因，该家族的基因编码一个支架蛋白，用于组蛋白去乙酰化复合物的组装，该基因能够在短日照条件下直接抑制一个FT激活子的表达，而在长日照条件下直接抑制三个FT抑制子的表达，从而调控拟南芥的成花转变。在诱导性的长日照条件下，SNL1-5会抑制三个AP2转录因子家族基因的表达，而这三个AP2基因能够抑制FT基因的表达，不同的SNLs之间存在部分的功能冗余。因此，SNLs可以通过调控这三个AP基因来介导长日照诱导的FT表达，从而促进植株进入成花转变。相反，在非诱导性的短日照条件下，SNLs起到抑制成花转变的作用，其中部分是通过直接抑制一个能够促进FT表达的MADS-box转录因子来实现的。综上，本文的研究揭示了SNLs通过组蛋白去乙酰化在控制长日照植物拟南芥的开花控制方面发挥重要作用：在短日照时抑制开花，而在日长超过某个阈值时促进成花转变。