低温对狗牙根根系呼吸电子传递的影响及其与抗寒性的关系  

Effects of low temperature on root respiration of Cynodon dactylon and its relationship with cold resistance

作　　者：赵尧尧 张泽程 刘美君 陈蝶 柴国梁 ZHAO Yaoyao;ZHANG Zecheng;LIU Meijun;CHEN Die;CHAI Guoliang(College of Grassland Science,Xinjiang Agricultural University,Urumqi 830052,Xingjiang,China)

机构地区：[1]新疆农业大学草业学院,新疆乌鲁木齐830052

出　　处：《草业科学》2023年第5期1258-1265,共8页Pratacultural Science

基　　金：国家级大学生创新创业训练计划(202210758005);自治区自然基金(2523ZZQZRJJ);作物生物学国家重点实验室开放课题(2021KF05)。

摘　　要：呼吸作用为狗牙根(Cynodon dactylon)根系细胞的生命活动提供能量,也是狗牙根能否正常生长和顺利越冬的关键。本研究以抗寒性不同的‘新农1号’(‘Xinnong No.1’)和矮生天堂草(C.dactylon×C.transvaalensis)为试验材料,在对照室温25℃和低温4℃处理后,研究低温对狗牙根根系呼吸作用的影响及其与抗寒性的关系。结果表明,低温胁迫会导致狗牙根根系活力下降,相对电导率和H2O_(2)含量显著上升(P<0.05),与‘新农1号’相比,低温对矮生天堂草的伤害更重。低温胁迫会导致狗牙根根系总呼吸速率、细胞色素氧化酶(COX)呼吸速率和交替氧化酶(AOX)呼吸速率均显著降低,且‘新农1号’下降程度更大,但‘新农1号’根系AOX呼吸占总呼吸的比率显著上升(P<0.05);在低温下AOX呼吸受抑,加重了‘新农1号’狗牙根根系活力的下降、相对电导率的增加以及H2O_(2)的积累,显著(P<0.05)高于室温对照,但与矮生天堂草差异不显著(P>0.05),这表明,在低温胁迫下,AOX有效地减轻了活性氧的积累,降低了细胞膜的氧化伤害,维持了较高的根系活力,从而对根系起重要保护作用。‘新农1号’狗牙根根系AOX呼吸的相对活性显著上调,增加了其对低温的抗性。Root respiration in bermudagrass(Cynodon dactylon)is the only source of energy and is crucial for normal growth and winter survival.In this study,‘Xinnong No.1’and Tifdwarf Bermudagrass with different levels of cold resistance were selected and the effect of low-temperature on root respiration of bermudagrass and its relationship with cold resistance was examined at 25℃(control)and 4℃.The results showed that low-temperature stress notably decreased the root activity of bermudagrass and increased the relative conductivity and H2O_(2) content.Compared with‘Xinnong No.1’,the effect of lowtemperature on Tifdwarf Bermudagrass was significantly more severe(P<0.05).The low-temperature exposure reduced the total respiration rate and the cytochrome oxidase and alternative oxidase(AOX)respiration rates in the roots of bermudagrass;however,the decrease in‘Xinnong No.1’was more significant(P<0.05).Furthermore,the ratio of AOX respiration to total respiration in the roots of‘Xinnong No.1’increased significantly(P<0.05).Under low-temperature,the inhibition of AOX respiration significantly decreased the root activity,increased relative conductivity,and accumulation of H2O_(2)(P<0.05)compared with those subjected to 25℃,but did not significantly differ from those of Tifdwarf Bermudagrass.These results indicate that AOX reduced reactive oxygen species accumulation,reduced oxidative damage to the cell membrane,and maintained a high root activity under low-temperature,thus playing an important role in protecting the root system.The relative activity of AOX respiration in the roots of bermudagrass was significantly increased(P<0.05)in‘Xinnong No.1’,which increased its resistance to low-temperature.

关 键 词：低温胁迫 狗牙根根系 呼吸速率 交替氧化酶呼吸 细胞色素氧化酶呼吸 活性氧 抗寒性 

分 类 号：S688.4[农业科学—观赏园艺]