PDF(Pubmed)
Abstract：
Histone acetyltransferases (HATs) modify the amino-terminal tails of the core histone proteins via acetylation, regulating chromatin structure and transcription. GENERAL CONTROL NON-DEREPRESSIBLE 5 (GCN5) is a HAT that specifically acetylates H3K14 residues. GCN5 has been associated with cell division and differentiation, meristem function, root, stem, foliar, and floral development, and plant environmental response. The flowers of gcn5 plants display a reduced stamen length and exhibit male sterility relative to the wild-type plants. We show that these effects may arise from gibberellin (GA)-signaling defects. The signaling pathway of bioactive GAs depends on the proteolysis of their repressors, DELLA proteins. The repressor GA (RGA) DELLA protein represses plant growth, inflorescence, and flower and seed development. Our molecular data indicate that GCN5 is required for the activation and H3K14 acetylation of genes involved in the late stages of GA biosynthesis and catabolism. We studied the genetic interaction of the RGA and GCN5; the RGA can partially suppress GCN5 action during the whole plant life cycle. The reduced elongation of the stamen filament of gcn5-6 mutants is reversed in the rga-t2;gcn5-6 double mutants. RGAs suppress the GCN5 effect on the gene expression and histone acetylation of GA catabolism and GA signaling. Interestingly, the RGA and RGL2 do not suppress ADA2b function, suggesting that ADA2b acts downstream of GA signaling and is distinct from GCN5 activity. In conclusion, we propose that the action of GCN5 on stamen elongation is partially mediated by RGA and GA signaling.
摘要：
组蛋白乙酰转移酶（HAT）通过乙酰化修饰核心组蛋白蛋白的氨基末端尾巴，调节染色质结构和转录。一般对照非限制性5(GCN5)是一种特异性乙酰化H3K14残基的帽子。GCN5与细胞分裂和分化有关，分生组织功能,根,茎,叶面，和花卉发育，和植物环境响应。相对于野生型植物,gcn5植物的花显示出减少的雄蕊长度并显示出雄性不育。我们表明，这些效应可能是由赤霉素（GA）信号缺陷引起的。生物活性GAs的信号通路依赖于其阻遏物的蛋白水解,DELLA蛋白。阻遏物GA（RGA）DELLA蛋白抑制植物生长，花序,以及花和种子的发育。我们的分子数据表明，GCN5是GA生物合成和分解代谢后期涉及的基因的激活和H3K14乙酰化所必需的。我们研究了RGA和GCN5的遗传相互作用；RGA可以在整个植物生命周期中部分抑制GCN5的作用。gcn5-6突变体的雄蕊丝伸长的降低在rga-t2中逆转;gcn5-6双突变体。RGA抑制GCN5对GA分解代谢和GA信号的基因表达和组蛋白乙酰化的影响。有趣的是,RGA和RGL2不抑制ADA2b函数，这表明ADA2b在GA信号传导的下游起作用，与GCN5活性不同。总之,我们认为GCN5对雄蕊伸长的作用部分由RGA和GA信号介导。
