水稻转基因种质IRBB13(P_(Xa13):GFP)感病及育性突变体的筛选及鉴定

Screening and Identification of Susceptibility and Fertility Related Mutants from Transgenic Rice IRBB13 (P_(Xa13):GFP)

【目的】建立简便高效的水稻突变体筛选体系,为克隆参与调控水稻xa13/Xa13表达以及xa13/Xa13介导的抗/感病和花粉发育信号途径的基因奠定基础。【方法】利用EMS化学诱变携带显性Xa13启动子驱动绿色荧光蛋白(GFP)基因的水稻转基因种质IRBB13(PXa13:GFP),构建突变群体,分3个时期进行突变体筛选:幼苗期筛选根和芽中绿色荧光减弱或消失的突变体、成株期筛选回复感病表型的突变体和孕穗期筛选育性下降的突变体。【结果】室内检测代M2突变体株系3 000个,筛到幼根和幼芽荧光消失的突变体14个,根部荧光正常而芽无荧光的突变体9个。田间试验种植突变体株系3 000个,成株期接种PXO99初步筛到回复感病表型的突变体株系25个。孕穗期筛选到育性下降且花药中绿色荧光消失的突变体株系7个,其中,包含1个回复感病的突变体株系。【结论】建立了简便高效的筛选水稻突变体筛选体系,结合GFP表达模式异常的突变体、回复感病突变体以及育性下降的突变体分析可判断xa13/Xa13参与的水稻抗/感病与花粉发育这2条信号网络途径并不是完全独立的,而是存在一定程度的交叉。

[ Objective ] The objective of this study is to establish a simple and efficient mode office mutants selection, and lay the first stone for cloning rice genes involved in regulating xa13/ xa13 gene expression or their mediated disease resistant /susceptible and pollen development signal pathway. [Method] Using EMS treatment, a rice mutation population was constructed with IRBB13 （Pxa13：GFP） which carrying green fluorescent protein（GFP） derived with dominant Xa13 gene promoter. Then the mutants were screened out with the following three periods： At seedling stage, selecting mutants in which GFP gene expression decline either in root or bud or non-expression; At adult stage, selecting mutants restored susceptible to PXO99; At booting stage, selecting mutants reduced fertility. [Result] In total 3 000 M2 lines, 14 and 9 mutants were identified for both root and bud fluorescent declined and fluorescent normal only in root at seedling stage. At adult stage, relying on phenotype of PXO99 inoculation, a total of 25 lines were characterized to restore the susceptibility to PXO99. At booting stage, 7 mutants were identified, of which fertility declined and the green fluorescence of the anthers also disappeared and one mutant was found to restore susceptibility. [ Conclusion] A simple and efficient mode of rice mutants selection system was established. Combining the abnormal expression pattern of GFP mutants, restored susceptible phenotype mutants and reduced fertility mutants, it was preliminarily indicated that the two signal transduction pathways mediated by xa13/Xa13 genes are not only completely independent but also partially crossing between resistance/susceptibility and pollen development. Furthermore, after analysis and cloned the genes from these mutants, they will help us better understanding the functional mechanism ofxa13/Xa13 genes.