棉花GhHMGR基因在胚珠生长发育过程中的功能

GhHMGR Gene Function in Ovule Development of Cotton(Gossypium hursutum L.)

采用植物基因工程技术,选用CaMV35S组成型启动子驱动棉花3-羟基-3-甲基-戊二酰辅酶A还原酶基因GhHMGR在棉花中表达,检测10 DPA(days post anthesis)棉花胚珠内HMGR(3-hydroxy-3-methylglutaryl coenzyme A reductase)酶及可溶性糖、脂质及蛋白质含量,同时进行了胚珠离体培养。结果显示,Gh HMGR在棉花光照部位(叶柄和铃壳)表达量相对较高,非光照部位(根及胚珠)表达量低;超量表达GhHMGR可部分恢复拟南芥hmgr突变体性状;相较野生型,超量表达株系10 DPA胚珠的HMGR含量升高,反义株系则降低;且超量表达株系总脂质及蛋白含量升高,可溶性总糖含量降低,反义株系则出现相反结果;HMGR竞争性抑制剂洛伐他汀处理会导致胚珠发育畸形。以上结果表明,GhHMGR基因在棉花胚珠生长发育过程中扮演重要角色。

The constitutive promoter CaMF35S was selected to drive the expression of GhHMGR gene in cotton by using the plant genetic engineering technology. The HMGR contents of ovule （10 DPA） of transgenic lines were detected, and the contents of total sugar, oil and protein as well. Meanwhile, we also performed ovule culture in vitro. The results showed that the expression level of GhHMGR was higher in part organ under light, such as petiole and boll shell than in root and ovule in dark. The GhHMGR gene could partly recover Arabidopsis （Arabidopsis thaliana） hmgr mutant characteristics. Compared with wild-type （WT）, the HMGR contents of ovule （10 DPA） in overexpression transgenic lines increased, whereas decreased in suppression expression lines. While the contents of total oil and protein of overexpression transgenic lines increased, and that of total sugar decreased. Meanwhile, the suppression expression lines performed in an opposite trend. The investigation of ovule culture in vitro showed that ovules became deformity after treated with the inhibitor. All of these implied that expression of GhHMGR gene plays a key role in the development of cotton ovule.