拟南芥成花素基因FT转录调控的组织细胞特异性机制

开花时间是影响植物环境适应性和作物产量的重要性状，成花素基因FT是开花时间调控的关键基因。FT在叶片韧皮部伴胞表达，其蛋白运输至茎尖生长点诱导开花；在角果韧皮部表达，则与花序原基稳定和果实发育相关。拟南芥FT基因转录受光照、温度、激素、年龄等多条开花途径及表观遗传调控因子的控制。我们近期的研究发现，FT核心启动子元件和上游增强子之间的染色质空间结构是FT基因表达的另一关键因素。为了进一步探讨影响FT组织特异性表达的内外因素，本研究拟采用INTACT技术分离叶片和角果中的韧皮部和表皮等特异性细胞核，重点分析光周期和温度影响下，FT表达所需的关键转录因子、顺式作用元件和表观遗传调控因子三者之间的相互作用，综合解析FT时空和组织细胞特异性表达的调控机制，从而为特异性诱导FT表达、调控开花时间和提高作物产量奠定理论基础。

Flowering time plays an important role in environmental adaption and crop yield. FLOWERING LOCUS T is a key flowering-time gene. FT expresses in the phloem companion cells of leaves and its protein moves up to shoot apical meristem to induce floral transition. While FT expresses in the fruit phloem, it controls inflorescence stabilization and fruit development. In Abrabidopsis, transcriptional level of FT is regulated by many protein factors involving in photoperiod, temperature, hormone and ageing pathways as well as epigenetic regualtion. Recently, we found that the chromatin conformation structure between FT core promoter and its upstream enhancer played an important role in determining FT expression. To further dissect the internal and external factors controlling FT tissue-specific expression, we are planning to isolate phloem and epidemal cells from leaves and fruits by INTACT. In reponse to photoperiod and temperature change, the interaction among trans-factors, cis-elements and epigenetic regulation factors will be analyzed in those isolated cells. Our study not only helps to understand the tempo-spacial expression pattern of FT, but also contributes to regulating flowering time and improving crop yield through specifically inducing FT expression.