摘要
为探究褪黑素(Melatonine,MT)对牡丹幼苗抗旱性的影响及生理机制,以牡丹品种凤丹(Paeonia ostii Fengdan)幼苗为试材,研究不同浓度外源褪黑素(50、100和200μmol/L)对干旱胁迫下牡丹幼苗生长及生理特性的影响。结果表明,干旱胁迫严重限制了牡丹幼苗的生长和光合作用,叶片细胞脂质过氧化及伤害指数增加,引起氧化应激及渗透调节反应。经外源褪黑素预处理能够减轻干旱胁迫对牡丹幼苗的伤害,具体表现为根系、茎叶及总干物质量提高;减少叶绿素a、叶绿素b及类胡萝卜素等光合色素降解,改善光合作用及PSⅡ电子传输能力;降低丙二醛(MDA)、过氧化氢(H2O2)、超氧阴离子(O2-)含量及细胞膜质伤害指数(MII),提高超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)及谷胱甘肽还原酶(GR)等抗氧化酶活性减少脂质过氧化;促进渗透调节物质积累。总之,以100μmol/L MT处理对牡丹幼苗抗旱性提高效果最好。外源褪黑素预处理能提高干旱胁迫下牡丹幼苗光合荧光特性、抗氧化和渗透调节能力,促进干旱胁迫下牡丹幼苗生长。
To further explore the effects of exogenous melatonine(MT)in strengthening the ability of peony seedlings resisting drought and its physiological mechanisms,Paeonia ostii(Fengdan)seedlings were selected to study the effects of different concentrations(50,100,and 200μmol/L)of exogenous MT on their growth and physiological characteristics under drought stress.The results showed that the growth and photosynthesis of the peony seedlings were significantly inhibited under drought stress,and lipid peroxidation and injury index of leaf cells increased,leading to oxidative stress and osmotic response.The damages caused by drought stress on the peony seedlings treated with the exogenous MT were alleviated,and specifically demonstrated as the mass of roots,stems,leaves and total dry matter increased,the degradation of photosynthetic pigments such as chlorophyll a,chlorophyll b and carotenoids reduced,and photosynthesis and PSⅡelectron transport ability improved,MDA,H2O2,O2-content and cell membrane damage index reduced,the activity of antioxidant enzymes such as SOD,CAT,APX and GR increased to reduce lipid peroxidation,and thus the accumulation of osmotic adjustment substances was improved.In general,100μmol/L MT is considered to be the optimal concentration on improving the drought resistance of the peony seedlings.Pretreatment with exogenous MT may effectively enhance the photosynthetic fluorescence characteristics,antioxidant capacity and osmotic adjustment ability,thus promote the growth of peony seedlings under drought stress.
作者
范海霞
赵飒
辛国奇
李静
FAN Hai-xia;ZHAO Sa;XIN Guo-qi;LI Jing(Xuchang Vocational Technical College,Xuchang 461000;Xuchang Forestry Research Institute,Xuchang 461000)
出处
《生物技术通报》
CAS
CSCD
北大核心
2020年第6期63-72,共10页
Biotechnology Bulletin
基金
许昌城市森林生态系统定位研究站平台支撑项目(豫林研[2010]270号)。
关键词
褪黑素
干旱胁迫
牡丹幼苗
光合荧光特性
抗氧化
渗透调节
melatonin
drought stress
peony seedling
photosynthetic fluorescence characteristics
anti-oxidation
osmotic adjustment
