低温胁迫对甘蔗幼苗活性氧代谢和抗氧化酶的影响

作物对低温胁迫的响应是一个复杂的生理生化过程。为了选育耐寒性强、稳产高糖的甘蔗品种,在前期区域试验的基础上,选择4个抗寒能力不同的甘蔗品种（系）作为研究材料。通过测定分析不同甘蔗品种（系）活性氧（ROS）代谢和抗氧化酶如超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和抗坏血酸过氧化物酶（APX）活性,研究其对低温的响应。结果发现：随低温胁迫时间的延长幼苗叶片ROS增加,抗氧化酶活性在一定时间范围内以较快速率提高并对低温胁迫产生的ROS进行清除,且活性出现降-升-降的响应过程;不同甘蔗品种（系）抗氧化酶对胁迫的响应存在差异。与此同时,叶片的相对电导率和丙二醛（MDA）含量也随胁迫时间延长而波动增加,根据两者的大小变化得出不同甘蔗品种（系）对低温胁迫的敏感性,即ROC22>FN39>GR2>GT28。

Effects of Cold Stress on Reactive Oxygen Metabolism and Antioxidant Enzyme Activities of Sugarcane Seedlings

The response of crops to low temperature stress is a complex process of physiological and biochemical changes. In order to breed the sugarcane varieties with strong cold resistance, stable yield and high sugar content, we selected four sugarcane varieties (lines) with different cold resistance abilities as the research materials based on the previous regional experiments. In this study, through measuring and analyzing the responses of the metabolism of reactive oxygen species (ROS) and the activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) of different sugarcane varieties (lines) to low temperature, it was found that the ROS in seedling leaves increased, and the activities of antioxidant enzymes (SOD, CAT and APX) increased at a high rate within a certain time accordingly and scavenged the ROS generated during the low temperature stress, showing a decrease-increase-decrease fluctuation. However, the activities of antioxidant enzymes to cold stress varied with sugarcane varieties (lines). In addition, the relative electrical conductivity and the malondialdehyde (MDA) content in leaves also increased in volatility as the cold stress time prolonged. According to the changes of the relative conductivity and MDA, the sensitivities to low temperature stress of different sugarcane varieties (lines) could be deduced as ROC22 > FN39 > GR2 > GT28.