质膜流动性调节剂对白菜型冬油菜种子苗抗寒性的影响

Effects in Plasma Membrane Fluidity Involve in the Cold-resistance of Winter Turnip Rapeseed

以抗寒性不同的白菜型冬油菜为材料,采用膜流动性调节剂溶液处理萌动种子,检测低温下5 d龄种子苗质膜完整性、生理生化特性、抗寒关键基因表达等变化,分析膜试剂对白菜型冬油菜种子苗抗寒性的影响,为油菜出苗期抗寒防冻措施制定提供依据。结果表明,与对照(蒸馏水处理)相比,4%膜固化剂二甲基亚砜(DMSO)溶液处理白菜型冬油菜萌动种子后,低温下种子苗相对电导率明显降低,过氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化氢酶(APX)活性以及可溶性蛋白含量明显升高,丙二醛(MDA)含量明显降低,表明4%DMSO溶液处理能够有效增强低温下种子苗过氧化物清除和渗透调节能力,防止质膜过氧化,保持质膜结构完整性。而0.15%膜流化剂苯甲醇(BA)溶液具有与DMSO反向的作用效果。4%DMSO处理白菜型冬油菜萌动种子后,与常温条件下相比,低温下5 d龄种子苗中Ca^(2+)离子通道膜蛋白6、Ca^(2+)离子通道膜蛋白16、膜联冷应答蛋白激酶、冷信号通路关键调控因子ICE1、CBF1的表达量总体均呈明显上调趋势,抗冻蛋白BrAFP1表达显著上调。因此,4%DMSO处理可明显改善低温下白菜型冬油菜种子苗生理生化性能、促进抗寒关键基因表达。研究结果对冬油菜的耐寒育种具有重要意义。

Several cultivars of winter turnip rape with different cold-tolerance were used as materials.Changes of membrane integrity,physiological and biochemical characteristics were detected in germinating seeds treated by solutions of membrane fluidity regulators,and the expression of major genes related to cold-tolerance were measure in 5 d-old seedlings after low temperature treatment.The results showed that the relative conductivity,activity of antioxidases(SOD,POD,CAT,APX)and the content soluble of protein increased significantly in germinated seeds treated with 4%solution of membrane curing agent(DMSO).MDA content in 5 d-old seedlings from germinated seeds treated with DMSO decreased comparing with the control(distilled water)under low temperature.These results indicate that DMSO treatment can enhance the ability of superoxide removal and osmotic adjustment,prevent damage by overoxidation,and maintain the structural integrity of the plasma membrane under low temperature condition.In summary,the effect of membrane fluidizer(BA)is opposite to DMSO.In 5 d-old seedlings from germinated seeds treated with 4%DMSO,the expression of cold-related genes,Ca^(2+) ion channel membrane protein6,Ca^(2+) ion channel membrane protein 16,membrane cold-responsive protein kinase,ICE1 and CBF1 in the cold signaling pathway,and BrAFP1 encoding the protein were significant up-regulative at low temperature comparing with that at normal temperature.Those results showed that 4%DMSO treatment can significantly improve the physiological and biochemical properties,and promote the expression of cold-resistant genes in seedlings under low temperature.These results are important in cold-tolerant breeding of winter rapeseed.