马铃薯块茎淀粉合成相关基因在脱落酸和蔗糖诱导下的表达分析

Expression Analysis of Starch Synthesis-related Genes Induced by Abscisic Acid and Sucrose in Potato Tubers

【目的】在马铃薯块茎中确定能够促进淀粉合成基因表达的脱落酸(abscisic acid,ABA)和蔗糖处理体系。【方法】利用不同的溶液和条件,对马铃薯幼嫩块茎进行ABA、蔗糖和ABA+蔗糖处理;采用实时荧光定量PCR检测处理块茎中直链淀粉合成关键酶(granule-bound starch synthaseⅠ,GBSSⅠ)基因、支链淀粉合成关键酶(starch branching enzymeⅢ,SBE3)基因和淀粉合成限速酶大亚基(ADP-glucose pyrophosphorylase large subunit 3,APL3)基因的表达,确定处理体系能否诱导基因表达;确定处理体系后,进一步检测其他9个淀粉合成基因的表达。【结果】实时荧光定量PCR检测表明:当处理溶液中包含氯化钙、琥珀酸钠和氯霉素等试剂,且马铃薯块茎置于处理溶液中28℃黑暗处理36 h时,与对照相比,ABA或蔗糖处理可明显升高GBSSⅠ和APL3的表达。对其他9个淀粉合成相关基因表达的检测结果显示:大部分合成基因正向响应ABA或蔗糖处理。【结论】本研究利用马铃薯块茎确定了能够促进淀粉合成基因表达的ABA和蔗糖处理体系,研究结果为进一步解析淀粉合成基因的转录调控机制奠定了基础。

[Purpose]To define the effective abscisic acid(ABA)and sucrose treatments that could induce the expression of starch synthesis-related genes in potato tubers.[Methods]Young tubers were subjected to ABA,sucrose,and ABA+sucrose treatments using different solutions and conditions,and the expression levels of three genes including granule-bound starch synthaseⅠ(GBSSⅠ),starch branching enzymeⅢ(SBE3)and ADP-glucose pyrophosphorylase large subunit 3(APL3)were examined by quantitative reverse transcription PCR(RT-qPCR).After defining the effective treatment,the expression levels of other nine starch synthesis-related genes were examined.[Results]RT-qPCR result showed that when the treatment solutions contained CaCl2,sodium suc-cinate,chloramphenicol and other agents,and young tubers were inoculated at 28℃in the dark for 36 hours,the expression levels of GBSSⅠand APL3 were obviously induced under ABA or sucrose treatments compared with their expression for the control.Further examination of the expression of nine starch synthesis-related genes found that most of them were positively responsive to the treat-ments.[Conclusion]Effective ABA and sucrose treatments that induce the expression of starch synthesis-related genes are defined.The results can lay a foundation for exploring the transcriptional regulation mechanism of starch synthesis in potato tuber.