过氧化氢缓解裸燕麦幼苗低温胁迫的主成分和隶属函数分析

Principal Component and Subordinate Function of the Alleviating Effects of Hydrogen Peroxide( H_2O_2) on Low-temperature Stress in Naked Oat( Avena nuda) Seedlings

为探明信号分子过氧化氢(H_2O_2)提高裸燕麦幼苗耐冷性的作用,以‘定莜6号’沙培幼苗为材料,在3叶期喷施10μmol·L^(-1)H_2O_212 h后于8℃/5℃(昼/夜)条件下低温胁迫,以喷蒸馏水(H_2O)为对照,分别在低温处理的0、1、2、3、4、5 d取幼苗叶片测定超氧阴离子(O_2~·)、H_2O_2、丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)、抗坏血酸(AsA)、谷胱甘肽(GSH)、可溶性糖(SS)、脯氨酸(Pro)、可溶性蛋白质(SP)和热稳定性蛋白质(HSP) 13项与耐冷性有关的生理指标及低温处理5 d后植株株高和生物量增量,采用主成分和隶属函数分析综合评价H_2O_2对裸燕麦幼苗耐冷性的影响。结果表明,与对照相比,喷施H_2O_2显著提高了低温胁迫下裸燕麦幼苗株高和生物量增量,降低了裸燕麦幼苗叶片O_2~·和MDA及低温胁迫2~5 d的H_2O_2含量,促进低温胁迫期间裸燕麦幼苗叶片SOD、CAT、POD和APX活性提高及AsA、GSH、SS、Pro、SP和HSP积累。主成分分析13项生理指标离差标准化数据,提取的前4个主成分累积方差贡献率达85. 6%;隶属函数综合评价4个主成分得分值显示,喷施H_2O_2显著提高了低温胁迫0~5 d的综合评价值。表明喷施H_2O_2能够通过调控生理生化代谢提高裸燕麦幼苗的耐冷性。

In order to explore whether H 2O 2 could improve the chilling tolerance in naked oat seedlings, three-leaf period ‘Dingyou No.6’ seedlings of sand culture were sprayed with 10 μmol·L^-1 H 2O 2 for 12 h before 8℃/5℃（day/night） low temperature stress, spraying distilled water as the control, and 13 physiological indexes related to cold resistance including superoxide anion（O2）, H 2O 2, malondialdehyde（MDA）, superoxide dismutase（SOD）, catalase（CAT）, peroxidase（POD）, ascorbic acid peroxidase（APX）, ascorbic acid（AsA）, glutathione（GSH）, soluble sugar（SS）, proline（Pro）, soluble protein（SP） and heat stable protein（HSP） in the seedling leaves under low temperature stress for 0, 1, 2, 3, 4 and 5 d as well as the plant height and biomass increments of the seedlings processed for 5 d were determined, respectively. By principal component and subordinate function analyses, the effect of H 2O 2 on the cold resistance was evaluated in naked oat seedlings. Compared with the control, H 2O 2 treatment could significantly enhance the plant height increment and biomass increment of naked oat seedlings under low temperature stress, decrease O []· 2 and MDA contents in leaves during low temperature stress and H 2O 2 content of low temperature stress for 2-5 d, and increase the activities of SOD, CAT, POD, APX and contents of AsA, GSH, SS, Pro, SP and HSP of naked oat seedling leaves. From 13 physiological indexes converted data matrix and principal component analysis, the cumulative variance contribution of four principal factors extracted was 85.6%. By subordinate function analysis, spraying H 2O 2 significantly improved the comprehensive evaluation value of the naked oat seedling leaves under low temperature stress for 0-5 d. Therefore, spraying H 2O 2 can improve the cold resistance of naked oat seedlings by regulating the physiological and biochemical metabolism.