GA3处理对低温胁迫条件下玉米种子呼吸代谢的影响

Effects of GA3 treatment on respiratory metabolism of maize seeds under low temperature stress

以低温敏感型的"丰禾1号"和耐低温型的"郑单958"两个玉米品种为实验材料,采用GA3浸种的处理方式("丰禾1号"为20 mg·L-1、"郑单958"为5 mg·L-1),探究了GA3对低温胁迫条件下玉米种子萌发过程中种胚中可溶性糖和可溶性蛋白含量及淀粉酶活性和呼吸途径关键酶活性的影响。结果表明:低温胁迫条件下,GA3浸种处理显著提升了玉米种胚中可溶性糖含量及可溶性蛋白的积累,增强了低温胁迫下细胞的渗透势;α-淀粉酶、β-淀粉酶和总淀粉酶活性显著提高;提高了苹果酸脱氢酶(MDH)、丙酮酸激酶(PK)、联合酶(G-6-PDH和6-PGDH)的活性,提高了糖酵解(EMP)、三羧酸循环(TCA)、磷酸戊糖途径(PPP)途径的运转效率,保证了细胞的物质代谢和能量供应;GA3浸种处理可以显著提高种子对低温的抵抗能力,从而在低温胁迫条件下促进其萌发。

We examined the effects of GA3 treatment on soluble sugar and soluble protein content,amylase activity and key enzyme activities in the embryos during germination of maize seeds under low temperature stress for two corn varieties,low temperature sensitive"FH No.1"and resistant"ZD958",with the method of GA3 soaking seeds(20 mg·L-1 for"FH No.1",5 mg·L-1 for"ZD958").The results showed that GA3 soaking treatment significantly increased the soluble sugar content and soluble protein accumulation in maize embryos,and enhanced the cell osmotic potential under low temperature stress.The activities ofα-amylase,β-amylase and total amylase were significantly increased.The activities of malate dehydrogenase(MDH),pyruvate kinase(PK),combined enzymes(G-6-PDH and 6-PGDH)were increased.The efficiency of EMP,TCA and PPP pathways was improved,which facilitates cellular material metabolism and energy supply.GA3 soaking treatment can significantly improve the resistance of seeds to low temperature,thus promoting their germination under low temperature stress.