CAJ | 학술논문

为揭示铝离子诱导大豆根尖分泌有机酸的特点及介导有机酸分泌的信号途径,采用溶液培养试验方法调查AlCl3对大豆品种(广州本地2号)根尖有机酸分泌及SGA1基因表达的影响。结果表明, AlCl3胁迫下大豆活体根尖分泌柠檬酸,且分泌量随着铝浓度(25、50μmol L–1AlCl3)和处理时间(2~12 h)的增加而增加；大豆根尖以模式II分泌柠檬酸,处理后的前4 h,分泌速率很低,其后显著提升；有机酸明显分泌的诱导期长达6 h；在50μmol L–1AlCl3的溶液中添加异三聚体G蛋白抑制剂百日咳毒素(200 ng mL–1),柠檬酸分泌减少38.7%。RT-PCR分析结果显示, AlCl3溶液诱导大豆根尖SGA1基因的表达,其表达水平随着铝处理时间(0.5~12.0 h)的延长有提升的趋势,而诱导的SGA1基因表达明显早于有机酸开始分泌时间(6 h)。这些结果表明,铝离子诱导大豆根尖分泌柠檬酸及SGA1基因的表达,异三聚体G蛋白可能作为铝胁迫信号开关器参与有机酸分泌的调控。
위게시려리자유도대두근첨분비유궤산적특점급개도유궤산분비적신호도경,채용용액배양시험방법조사AlCl3대대두품충(엄주본지2호)근첨유궤산분비급SGA1기인표체적영향。결과표명, AlCl3협박하대두활체근첨분비저몽산,차분비량수착려농도(25、50μmol L–1AlCl3)화처리시간(2~12 h)적증가이증가；대두근첨이모식II분비저몽산,처리후적전4 h,분비속솔흔저,기후현저제승；유궤산명현분비적유도기장체6 h；재50μmol L–1AlCl3적용액중첨가이삼취체G단백억제제백일해독소(200 ng mL–1),저몽산분비감소38.7%。RT-PCR분석결과현시, AlCl3용액유도대두근첨SGA1기인적표체,기표체수평수착려처리시간(0.5~12.0 h)적연장유제승적추세,이유도적SGA1기인표체명현조우유궤산개시분비시간(6 h)。저사결과표명,려리자유도대두근첨분비저몽산급SGA1기인적표체,이삼취체G단백가능작위려협박신호개관기삼여유궤산분비적조공。
The effects of Al3+ on the secretion of organic acids from root apices and the expression ofSGAIgene were investigated by hydroponics to elucidate the characteritics of organic acid secretion and Al3+ stress signal transduction pathway which mediates the secretion of organic acids in soybean Guangzhou bendi 2. The results showed that soybean root apices (in vivo) secreted citrate under Al3+ stress. The secretion of citrate increased with the increase of Al3+ concentrations (25, 50 μmol L–1AlCl3) and the prolongation (2–12 hours) of treatment with Al3+. Citrate was secreted from root apices by pattern II in soybean. The secretion rate was very low within initial four hours after Al3+ treatment but remarkably elevated thereafter. A gap of time between the secretion and Al3+ treatment reached to about six hours. On the other hand, when cholera toxin, an inhibitor of heterotrimeric G-protein, was added to Al3+solution, the amount of citrate secreted decreased by 38.7%. RT-PCR analysis results indicated that Al3+ inducedSGA1 expression. In general, the expression level was elevated with the prolongation of treatment with Al3+ (0.5 to 12 hours). Moreover, Al3+ induced expression ofSGA1 sooner than the secretion of citrate. These results imply that Al3+ induces the secretion of citrate from root apices andSGA1 expression in the soybean, and heterotrimeric G proteins may act as a switch of Al3+ stress signal to be involved in the regulation of citrate secretion from root apices under Al3+ stress.