外源ABA及其抑制剂钨酸钠对木薯块根类胡萝卜素相关基因和蛋白的影响

摘要

This work aims to analyze the effect of the exogenous ABA and its inhibitor sodium tungstate (Na2WO4) on carotenoid associated genes and protein of cassava tuberous root.Manihot esculenta Crantz SC9 was chosen as research subject and the β-carotene of caasava tuber root was detected by HPLC,and Western blot was used to analyze the carotenoid associated protein expression and QPCR to analyze the genes expression.The results showed that exogenous ABA and sodium tungstate increased the β-carotene content in the tuber root.Both exogenous ABA and sodium tungstate increased carotenoid biosynthesis key genes PSY2 and LCYB expressions,meanwhile they restrained the degradation genes ZEP and NCED3 expressions,which explained the change of β-carotene content at the transcription level.The LCYB and ZEP transcriptions were consistent with translations.Plastid associated gene PAP1 and enzyme FBN1a were up-regulated,which increased the number of plastidglobules.Exogenous ABA and sodium tungstate accelerated the reactive oxygen (ROS) related superoxide dismutase (Fe-SOD and Cu/Zn-SOD) expressions,keeping the carotenoid content stable.In conclusion,these three factors jointly increase the β-carotene content of tuber root.%旨在研究外源ABA及其抑制剂钨酸钠(Na2WO4)对木薯块根类胡萝卜素相关基因和蛋白的影响.以木薯品种华南9号(Manihot esculenta Crantz SC9)为材料,HPLC测定块根β-胡萝卜素;Western blot分析相关蛋白表达量;QPCR分析相关基因表达量.结果显示,外源ABA及钨酸钠能提高块根β-胡萝卜素的含量;其中外源ABA与钨酸钠都提高了类胡萝卜素合成途径基因PSY2与LCYB表达,并抑制降解相关的ZEP与NCED3基因的表达,从而能够在转录水平的变化上解释β-胡萝卜素含量的变化,且LCYB与ZEP在转录与翻译水平具有一致性;与质体相关PAP1基因和FBN1a在处理下上调表达在一定程度上增加了质体小球的数量;外源ABA及钨酸钠使活性氧(ROS)相关的超氧化物歧化酶(Fe-SOD和Cu/Zn-SOD)表达量升高保护了块根中类胡萝卜素的稳定.这三者共同作用,提高了块根β-胡萝卜素的含量.