摘要
[目的]研究外源ABA处理对H_2O_2胁迫下侧柏幼苗活性氧代谢系统的影响,探讨ABA调控侧柏氧化胁迫的可能作用机制。[方法]以侧柏幼苗为试验材料,采用水培方式,研究外施低浓度(0.5μmol·L^(-1))和高浓度(200μmol·L^(-1))ABA对100 mmol·L^(-1)H_2O_2胁迫下侧柏幼苗活性氧代谢的影响。[结果](1)100 mmol·L^(-1)H_2O_2胁迫48 h显著增加了侧柏幼苗叶片过氧化氢(H_2O_2)、丙二醛(MDA)、谷胱甘肽(GSH)和脯氨酸含量、抗氧化物酶(SOD和CAT)活性,而可溶性蛋白含量降低。(2)相较于高浓度200μmol·L^(-1)ABA,施加0.5μmol·L^(-1)ABA显著减少了H_2O_2胁迫下侧柏幼苗H_2O_2和MDA的积累,进一步提高了侧柏幼苗叶片SOD、POD和CAT活性,同时促进GSH、脯氨酸和可溶性蛋白的合成。(3)100 mmol·L^(-1)H_2O_2胁迫处理48 h,侧柏幼苗叶片活性氧代谢相关基因Cu/Zn-SOD、CAT、GR、APX、MDAR和GST表达水平较对照CK均有显著性提高;正常和H_2O_2胁迫下侧柏幼苗外施0.5μmol·L^(-1)ABA相较于200μmol·L^(-1)更有利于提高侧柏叶片活性氧代谢相关基因Cu/Zn-SOD、CAT、GR、APX、MDAR和GST的表达量。[结论]低浓度0.5μmol·L^(-1)ABA有效地增强抗氧化系统的防御能力,减弱幼苗的氧化胁迫和膜脂过氧化水平,从而降低活性氧对侧柏的伤害。
[Objective] To investigate the mechanism of exogenous abscisic acid（ABA）on regulating oxidative stress of Platycladus orientalis,the effects of reactive oxygen metabolism were studied in the leaves of P. orientalis exposed to hydrogen peroxide （H2O2） stress with the application of different concentrations of ABA. [Method] P. orientalis seedlings were exposed to 100 μmol·L^-1 H2O2 were treated with 0.5 and 200 μmol·L^-1 ABA, and physiological indexes and expression levels of genes related to reactive oxygen metabolism were studied. [Result] （1） 100 mmol·L^-1 H2O2 significantly increased the contents of H2O2, malondialdehyde （MDA）, glutathione （GSH） and proline and activities of antioxidant enzymes SOD and CAT in P. orientalis leaves, while soluble protein content decreased at 48 h. （2） Compared with 200 μmol·L^-1 ABA, 0.5 μmol·L^-1 ABA significantly enhanced the activities of SOD, POD and CAT, and increased the contents of GSH, proline and soluble protein in H2O2-treated seedlings, accompanied by the reduction of H2O2 and MDA contents. （3） 100 mmol·L^-1 H2O2 up-regulated the expression levels of Cu/Zn-SOD、CAT、APX、MDAR和GST genes in P. orientalis at 48 h, and moreover, the presence of 0.5 μmol·L^-1 ABA further prompted the expression levels of Cu/Zn-SOD、CAT、GR、APX、MDAR and GST genes, compared with 200 μmol·L^-1 ABA under normal and H2O2 conditions. [Conclusion] Low concentration of 0.5 μmol·L^-1 ABA effectively enhanced antioxidant defense, reduced oxidative stress and membrane lipid peroxidation in leaves of P. orientalis under H2O2 stress, which lowered the damage of reactive oxygen species to P. orientalis leaves and improved its resistance.
出处
《林业科学研究》
CSCD
北大核心
2017年第4期624-632,共9页
Forest Research
基金
中央级公益性科研院所基本科研业务费专项资金项目(CAFYBB2014QB004)
国家自然科学基金项目(31300555)
安徽省哲学社会科学规划项目(AHSKQ2016D110)
安徽省高校质量工程项目(2014jyxm231)
国家级大学生创新训练项目(201710371036
201710371037)
关键词
侧柏
H2O2胁迫
ABA
活性氧代谢
基因表达
Platycladus orientalis
H2O2 stress
ABA
reactive oxygen metabolism
gene expression
