低温对野生番茄和栽培番茄叶片抗氧化代谢和碳同化的影响

The Influence of Low Temperature on Antioxidant Metabolism and Carbon Assimilation in Wild Tomato and Cultivated Tomato Leaves

为了探讨番茄耐冷性的生理调控机理,以耐冷型野生番茄LA1777和低温敏感型栽培番茄LA2706为试材,研究低温对2种类型番茄叶片抗氧化代谢和碳同化的影响。结果表明:随着低温处理时间的延长,超氧阴离子自由基(O2-·)、过氧化氢(H2O2)、丙二醛(MDA)、脱氢型抗坏血酸(DHA)含量呈现上升趋势,LA2706分别比LA1777高0.3%~21.0%,1.2%~17.3%,13.4%~36.9%,13.3%~21.0%,且LA2706上升程度明显较快,加速了膜脂过氧化进程;还原型抗坏血酸(As A)含量随着低温处理时间都呈小幅上升趋势;超氧化物歧化酶(SOD)活性总体呈下降趋势,LA2706和LA1777分别比处理前下降55.3%和28.2%;LA1777叶片中抗坏血酸过氧化氢酶(APX)活性在7 d时峰值显著升高,为LA2706的4.0倍。随着低温处理时间的延长,可溶性总糖含量、酸性转化酶活性、中性转化酶活性和蔗糖磷酸合成酶活性均呈上升趋势,LA2706比LA1777更为显著,处理7 d后,LA2706分别为处理前的5.8,4.8,10.2,1.7倍,低温导致LA2706叶片中淀粉大量分解成蔗糖,以缓解低温胁迫环境对其造成的伤害。

To figure out the physiological regulation mechanism of tomato cold resistance,we used two type tomatoes which one is cold resistance wild tomato LA1777 and the other is low temperature sensitive cultivated tomatoes LA2706 as our test materials to study the influence of low temperature on antioxidant metabolism and carbon assimilation. Results showed that under the stress of low temperature,the contents of superoxide-anion radical （O 2 -[]· ）,hydrogen peroxide（H 2 O 2 ）,malondialdehyde（MDA）,dehydroascorbic acid（DHA）increased,and it that in LA2706 was about 0.3%-21.0%,1.2%-17.3%,13.4%-36.9%,and 13.3%-21.0% higher than LA1777,that speeded up the process of membrane lipid peroxidation. The contents of reduced ascorbic acid（AsA）had a slight upward trend with cryogenic processing time extended;the activity of superoxide dismutase（SOD）decreased by 55.3% and 28.2% 7 d after treatment in LA2706 and LA1777,LA2706 fell obviously than LA1777;the peak of ascorbic acid catalase（APX）in LA1777 was significantly higher than LA2706,and about is 1.7 and 4.0 times that of LA2706 in 1 and 7 d after treatment. With the extension of low temperature processing time,the total sugar content,acid invertase activity,neutral invertase activity and sucrose phosphate synthase all raised,LA2706 had a significantly higher increment than LA1777,and about was 5.8,4.8,10.2 and 1.7 times in 7 d that of 0 d after treatment.Low temperature made LA2706 to have a large number of decomposition starch into sugar,to alleviate the stress of low temperature environmental damage.