毛竹赤霉素合成相关酶基因的全基因组鉴定和表达分析

Genome-wide Identification of the Enzyme Genes Involved in Gibberellin Biosynthesis and Their Expression Analyses in Moso Bamboo

赤霉素（GA）参与调节植物多种生长发育过程,其生物合成在体内受到严格的控制。研究毛竹（Phyllostachys edulis）赤霉素合成通路相关的酶基因,对于揭示其在毛竹生长发育中的作用具有重要价值。对毛竹全基因组进行分析发现,涉及赤霉素生物合成的酶基因有7类共50个,包括4个CPS、3个KS、5个KAO、1个KO、10个GA20ox、20个GA2ox、和7个GA3ox。不同酶基因的各个成员虽是比较保守的,但其基因结构、基本理化性质均存在着一定的差异。亚细胞定位预测表明,PeCPSs和PeKSs定位在叶绿体上,PeKAOs位于内质网上,PeGA20oxs、PeGA2oxs和PeGA3oxs定位于细胞质基质中。进化分析显示,毛竹GA生物合成通路相关酶与来自水稻的相应酶均具有较高的一致性,亲缘关系较近。利用转录组数据分析基因表达的组织特异性,结果表明不同类酶基因以及同一类酶基因的不同成员的表达均存在一定的差异。例如：PeCPS-1、PeCPS-4和PeKO为组成型表达,PeKAO-5主要在笋幼芽中表达,PeGA20ox-10仅在幼芽和根中表达;PeGA2oxs中有9个为组成型表达,7个为特异性表达,而PeGA3oxs中分别有5个和2个。本研究为深入了解毛竹内源GA生物合成奠定了基础,为利用GA生物合成酶基因人为调控植物生长发育提供了参考。

Gibberellin（GA） is involved in the regulation of multiple processes during plant growth and development, and its biosynthesis is strictly controlled in vivo. The study on the enzyme genes related to the synthesis of GA in moso bamboo（Phyllostachys edulis） is of great value for revealing their roles in the growth and development of bamboo. Based on the whole genome analysis of moso bamboo, there were 50 genes belonged to seven kinds of enzyme genes involved in gibberellin biosynthesis, including 4 CPSs, 3 KSs, 5 KAOs, 1 KO, 10 GA20 oxs, 20 GA2 oxs and 7 GA3 oxs. Although the different members of the enzyme gene family were relatively conservative,there were some differences in their gene structures, the basic physical and chemical properties. The prediction of subcellular localization showed that PeCPSs and PeKSs were located on the chloroplast, PeKAOs were located on the endoplasmic reticulum, and PeGA20 oxs, PeGA2 oxs and PeGA3 oxs were located in the cytoplasmic matrix.Phylogenetic analysis demonstrated that the enzymes related to GA biosynthetic pathway in moso bamboo were highly consistent with the corresponding enzymes from rice, indicating they had close relationship. Tissue specific expression of the genes was analyzed by transcriptome data. The results showed that there were some expression differences in the different enzyme genes and different members of the same enzyme gene. For examples,PeCPS-1, PeCPS-4 and PeKO-1 were constitutively expressed. PeKAO-5 was mainly expressed in shoot shoots,while PeGA20 ox-10 was expressed only in shoots and roots. Nine of PeGA2 oxs were constitutively expressed and seven were tissue specificity, those of PeGA3 oxs were 5 and 2, respectively. This result has laid a foundation for further understanding of endogenous GA biosynthesis in moso bamboo, which also provided reference for the regulation of plant growth and development using GA synthase genes.