摘要
为探讨信号分子过氧化氢(H_2O_2)增强裸燕麦盐碱耐性的作用及其生理机制,以裸燕麦品种‘定莜6号’为材料,在日光温室内用珍珠岩培养幼苗至三叶一心期时叶面喷施0. 01 mmol·L^(-1)H_2O_2的同时根部浇灌75mmol·L^(-1)盐碱混合溶液(NaCl∶Na_2SO_4∶NaHCO_3∶Na_2CO_3=12∶8∶9∶1)或添加H_2O_2淬灭剂二甲基硫脲(DMTU),研究对幼苗生长及叶片光合色素含量、活性氧代谢和渗透调节物质积累的影响。结果表明:喷施H_2O_2能够缓解盐碱混合胁迫对裸燕麦幼苗生长的抑制,提高幼苗根长、株高和植株干重及叶片叶绿素a、叶绿素b、总叶绿素、类胡萝卜素含量和超氧化物歧化酶、过氧化物酶、过氧化氢酶、抗坏血酸过氧化物酶活性,降低超氧阴离子、H_2O_2、丙二醛、抗坏血酸、谷胱甘肽和游离氨基酸含量,促进抗氧化物质类黄酮、总酚和原花青素及渗透调节物质可溶性蛋白质、可溶性糖和脯氨酸积累。添加DMTU部分或完全逆转了H_2O_2的上述作用。采用隶属函数综合评价显示,喷施H_2O_2提高了盐碱混合胁迫下裸燕麦幼苗的综合评价值D,添加DMTU完全逆转了H_2O_2对D值的提升作用。表明外源H_2O_2通过参与活性氧代谢和渗透调节物质积累等生理代谢调控缓解盐碱混合胁迫诱导的氧化伤害和生长抑制,从而提高裸燕麦对盐碱胁迫的适应能力。
The experiment was conducted to study whether exogenous hydrogen peroxide(H2O2)could improve the saline-alkali tolerance of naked oat(Avena nuda)seedlings and its physiological mechanism.Seedlings of naked oat(‘Dingyou No.6’)at three-leaf period cultured with perlite in a solar greenhouse were irrigated with the Hoagland nutrient solution containing 75 mmol·L-1 saline-alkali mixed solution(NaCl∶Na2SO4∶NaHCO3∶Na2CO3=12∶8∶9∶1)combination with dimethylthiourea(DMTU,a quencher of H2O2),and the leaves were sprayed with0.01 mmol·L-1 H2O2.Seedlings were irrigated with Hoagland nutrient solution,and the leaves were sprayed with water served as the control.Seedlings growth,photosynthetic pigment content,active oxygen metabolism,and osmotic regulatory substance accumulation in leaves were measured.The results showed that exogenous H2O2 could alleviate the inhibition effects of saline-alkali mixed stress on seedlings growth of naked oat.Spraying H2O2 significantly increased root length,plant height,dry weight,the leaf chlorophyll a,chlorophyll b,total chlorophyll and carotenoid contents,and the superoxide dismutase,peroxidase,catalase,ascorbate peroxidase activities of naked oat seedlings under saline-alkali mixed stress,but decreased the contents of superoxide anion,H2O2,malondialdehyde,ascorbic acid,glutathione,and free amino acids.Treatments with spraying H2O2 also increased the contents of antioxidants(such as flavonoids,total phenols,procyanidins)and osmotic regulatory substance(such as soluble protein,soluble sugars,and proline)in leaves.The above effects of exogenous H2O2 were partially or completely reversed by DMTU.A comprehensive evaluation based on subordinate function analyses revealed that foliar spraying with H2O2 could improve the saline-alkali resistance of naked oat seedlings,and the promoting effect of H2O2 could be completely reversed by DMTU.Therefore,the exogenous H2O2 supply can increase saline-alkali adaptability in naked oat seedlings by regulating active oxygen metabolism and osmotic regulatory substance accumulation in leaves of naked oat plants under saline-alkali mixed stress.
作者
刘建新
欧晓彬
王金成
LIU Jian-Xin;OU Xiao-Bin;WANG Jin-Cheng(University Provincial Key Laboratory for Protection and Utilization of Longdong Bio-resources in Gansu Province,Qingyang 745000;College of Life Sciences and Technology,Longdong University,Qingyang 745000)
出处
《植物研究》
CAS
CSCD
北大核心
2019年第2期181-191,共11页
Bulletin of Botanical Research
基金
国家自然科学基金(31560125)
甘肃省庆阳市科技计划项目(KZ2014-19)~~
关键词
过氧化氢
裸燕麦
盐碱混合胁迫
活性氧代谢
渗透调节物质
H2O2
naked oat
saline-alkali mixed stress
active oxygen metabolism
osmotic regulatory substance
