小麦生理型雄性不育花药绒毡层和孢粉素变化与RAFTIN1表达的关系

The Relationship on Anther Tapetum,Sporopollenin and Expression of RAFTIN1 in Physiological Male Sterile Wheat

【目的】研究小麦生理型雄性不育花药绒毡层变化、孢粉素累积与RAFTIN1表达间的关系,为揭示小麦生理型雄性不育的机理奠定基础。【方法】以杀雄剂SQ-1诱导的生理型雄性不育系、质核互作遗传型雄性不育系,正常可育近等基因系为试材,通过石蜡切片、细胞荧光染色和荧光定量PCR技术,研究小孢子不同发育时期花药绒毡层的形态变化、孢粉素的累积及RAFTIN1的表达。【结果】单核期生理型不育系花药绒毡层提前降解,分泌孢粉素的含量降低,RAFTIN1提前高表达,使大量孢粉素转运至花粉壁层;二核期和三核期,生理型不育系绒毡层完全退化,停止分泌孢粉素,RAFTIN1呈现明显的下调表达模式。【结论】杀雄剂SQ-1诱导的小麦生理型雄性不育其败育机理与绒毡层的提前降解和定向转运孢粉素的RAFTIN1表达高低直接相关。

【Objective】 To pave the way for revealing the mechanism of physiological male sterility in wheat,the relevance among expression of RAFTIN1,anther tapetum and sporopollenin were studied.【Method】Using physiologically male sterility induced with chemical hybridizing agent SQ-1,genetically male sterility and corresponding normal lines of complete fertility as experimental materials in wheat,morphological changes of anther tapetum from different developmental stages of microspore,sporopollenin accumulation and RAFTIN1 expression were analyzed via paraffin section,cell fluorescence staining and Real-time PCR.【Result】The results showed that anther tapetum of physiological male sterile lines pre-degraded,sporopollenin secretion decreased,while RAFTIN1 expression level was maximum at mononuclear stage,and contributed to a large number of sporopollenin to pollen intine.At binuclear and trinuclear stages,the tapeta of physiological male sterility were degraded completely,sporopollenin secretion was ceased and expression patterns of RAFTIN1 were down-regulated significantly.【Conclusion】 These data demonstrated that the mechanisms of physiologically male sterility induced by SQ-1 were associated with pre-degradation of tapetum and expression degree of RAFTIN1 with responsibility for transporting sporopollenin.