龙眼GA信号受体基因LonGID1的功能初步分析

Preliminary Function Analysis of GA Signal Receptor LonGID1 Gene of Longan

龙眼LonGID1基因编码赤霉素(gibberellin, GA)受体,是赤霉素信号途径中一个非常关键的调节基因。本研究的主要目的是探讨龙眼GA信号受体基因LonGID1的功能初步分析。通过将克隆得到的龙眼LonGID1基因转入拟南芥Atgid1b/c缺失突变,野生型植株中,观察其表型变化及GA信号途径中上下游基因的变化。结果表明:(1) Atgid1b/c缺失突变株系种子萌发率明显低于哥伦比亚野生型株系(columbia, Col-0);Atgid1 b/c×35S::LonGID1缺失突变恢复株系种子萌发率与Atgid1b/c缺失突变株系相比明显提高。10 nmol/L的GA处理可以提高4个拟南芥株系的萌发率,但是GA处理Atgid1b/c缺失突变株系种子萌发率仍然明显低于其他株系。5 nmol/L多效唑(Paclobutrazol, PAC)处理显著降低4个拟南芥株系的萌发率。(2) Atgid1b/c缺失突变株系花苞发育的时间比Atgid1 b/c×35S::LonGID1缺失突变恢复株系推迟约13～14 d。Atgid1 b/c×35S::LonGID1缺失突变恢复株系花苞发育的时间与Col-0野生型株系相比提前约5～6 d,35S::LonGID1超表达株系花苞发育的时间与Col-0野生型株系相比提前4～5 d。10 nmol/L的GA处理,35S::LonGID1超表达植株的花苞发育时间与Col-0野生型相比提前了5～6 d,Atgid1 b/c×35S::LonGID1缺失突变恢复株系的花苞发育时间与Atgid1b/c缺失突变株系相比提前了5～6 d。5 nmol/L的PAC处理使各株系花苞发育时间推迟。(3)GA处理Col-0野生型株系,AtGA4、AtSOC1、AtLFY、AtFT、AtGID1和AtGAI的表达变化明显;这种表达变化会因为GA受体基因Atgid1b/c的缺失而降低,而龙眼的LonGID1基因可以弥补拟南芥GA受体基因Atgid1b/c的缺失而引起的GA作用效果的降低。龙眼LonGID1基因功能的分析,对于我们了解龙眼GA信号传导途径具有积极的意义,也有助于我们更好的利用GA来调控龙眼的生长发育过程,为在生产上指导农户合理利用GA提供理论基础。

As the GA receptor, longan LonGIDl is an key regulatory gene of GA signaling pathway. The main purpose of this paper was to investigate the preliminary analysis of function in LonGIDl, a GA signal receptor gene in longan. We transferred longan LonGIDl gene into Arabidopsis thaliana and observed the phenotypic change and the the changes of phenotype and upstream and downstream genes in GA signal pathway from wild plant. The result showed:(1) The seed germination rate of Atgidlb/c deletion mutant was significantly lower than Col^0 wild seedling, and the germination rate of Atgidl b/c ×35Sr::LonGIDl transgenic Arabidopsis thaliana seedling was significantly higher than Atgidlblc seedling. The germination rate of 4 Arabidopsis seedling could be increased by 10 nmol/L GA treatment and significantly decreased by 5 nmol/L PAC treatment. However, the seed germination rate of Atgidlblc seedling was still significantly lower than other seedling treated with GA.(2) The time of flower bud formation oiAtgidlblc deletion mutant was delayed by 13-14 days compared with Atgidl b!c×35S::LonGIDl seedlines. The flower bud formation time of Atgidl blc×35S::LonGIDl seedlines and 35S::LonGlDl seedlines was about 5-6 days earlier and 4?5 days earlier than Col-gild seedling. The bud development time of 35S::LonGIDI Seedling was 5~6 days earlier than the wild type, the bud development time of Atgidl blcx35Sr.LonGIDl was 5?6 days earlier than Atgidlblc by 10 nmol/L GA treatment.(3) The expression of AtGA4, AtSOCl, AtLFY, AtFT, AtGIDl and were significantly changed with Col-0 wild seedling treated by GA, and the expression changes were decreased due to the deletion of GA receptor gene Atgidlb/c. The L onGIDl gene of longan could make up for the decrease of GA effect caused by the deletion of GA receptor gene Atgidlblc in Arabidopsis thaliana. The analysis of LonGIDl gene function might be helpful for us to understand GA signal transduction pathway in longan. It also might help us to use GA to regulate the growth and development of longan, so as to provide theoretical basis for the rational utilization of GA in production.