BTH处理诱导葡萄悬浮细胞防卫反应对其蔗糖代谢的影响

Effect of defense responses induced by BTH treatment on sucrose metabolism in grape cell suspensions

【目的】为研究BTH处理诱导的葡萄悬浮细胞防卫反应对细胞蔗糖代谢的影响。【方法】以‘巨峰’葡萄(Vitis vinifera L.×V.labrusca L.‘Kyoho’)悬浮细胞为试材,将悬浮细胞继代培养一次后在其B5液体培养基中添加BTH,使培养液中BTH浓度达到0.3 mmol·L-1,随后振荡培养15 d。培养期间每隔3 d测定细胞生长量、蔗糖代谢酶活性以及H2O2、植保素单体、尿苷二磷酸葡萄糖(UDPG)和可溶性糖组分含量。【结果】0.3 mmol·L-1BTH处理对葡萄悬浮细胞生长无明显促进作用,但可诱导细胞内信号分子H2O2的迸发以及促进细胞中植保素白藜芦醇和白藜芦醇脱氢二聚体的积累,从而有效提高细胞防卫能力;同时,BTH处理可有限抑制葡萄细胞悬浮培养期间SPS和SS1(蔗糖合酶合成方向)活性的上升并提高SS2(蔗糖合酶分解方向)活性,从而使经BTH处理的葡萄悬浮细胞内蔗糖含量明显低于而果糖和UDPG含量却显著高于对照水平。【结论】BTH诱导的葡萄悬浮细胞的SAR反应可明显影响细胞中蔗糖代谢酶活性的平衡,减慢蔗糖合成速率并降解蔗糖以为植保素的合成提供底物UDPG,从而引起细胞中可溶性糖含量的变化。

[Objective]The aim of the stady is to investigate the effect of the defense responses induced by benzo-thiadiazole-7-carbothioic acid S-methyl ester （BTH） treatment on sucrose metabolism in grape cell suspensions. [Method]The ＇Kyoho＇ grape cell suspensions subcultured one generation were used as materials, and then shake-cultured for 15 d in B5 liquid medium supplemented with 0.3 mmol ~ L-1 BTH. During the culture, the cell growth, activities of sucrose metabolism related enzymes as well as contents of individual phytoalexin compounds, UDPG and soluble sugar components were measured at 3-day interval. [Result]The results exhibited that 0.3 mmol. L-1 BTH treatment had no significant influence on the growth of grape suspension cell, but remarkably induced the burst of signal molecule H202 and the accumulation of phytoalexins resveratrol and viniferin, meanwhile effectively inhibited activities of SPS and SS1 （SS synthetic direction） but increased SS2 （SS cleavage direction） activity, leading to lower contents of sucrose and higher contents of fructose and UDPG in BTH-treated cell compared to the control. [Conclusion]SAR action induced by BTH treatment could significantly influence on the balance of sucrose metabolism relat- ed enzymes, which decelerate the rate of sucrose synthesis and hydrolyze sucrose to accumulate the sub- strate UDPG for phytoalexin synthesis.