抗氧化剂和-6-BA对根系渗透胁迫的玉米叶片光合膜特性的影响.pdf

植物学报1994,36(11):871—877
ActaBotanicaSinica

抗氧化剂和6-BA对根系渗透胁迫的
玉米叶片光合膜特性的影响
李双顺林植芳
(中国科学院华南植物研究所,广州510650)

摘要
聚乙二醇溶液处理玉米(ZeameysL.)幼苗根系,引起叶片电解质渗漏,丙二醛含量增
加,叶绿素降解,水分耗失加快,光合速率、光合电子传递活性减少和暗呼吸速率增高。叶面喷
施6-苄基氨基嘌呤及2,6-二丁基甲酚、没食子酸丙酯和抗坏血酸等抗氧化剂,可缓解渗透胁
迫引起的膜损伤,具有一定的保护作用。
关键词玉米;渗透胁迫;抗氧化剂;光合膜;6-BA⒇

EFFECTSOFANTIOXIDANTAND6-BAONTHEPROPERTIES
OFPHOTOSYNTHETICMEMBRANEOFMAIZELEAVES
UNDEROSMOTICSTRESSOFROOT

LiShuang-shunandLinZhi-fang
(SouthChinaInstituteofBotany,AcademiaSinica,Guangzhou510650)

Abstract
Osmoticstressofrootsystemofmaizeseedlingwasinducedbytreatmentwithdifferent
concentrationsofpolyethyleneglycolsolution.After1—3hoftreatment,obvious
physiologicalchangeswereobservedinleaves.Theleafwaterpotentialdecreasedwiththe
increaseofPEGconcentrationandtimeofstress.Anincreaseofmalondialdehydecontent
wasassociatedwiththehigherelectrolyteleakagethroughcellmembrane.Osmoticstressof
rootsystemcauseddegradationofchlorophyll,reductionofphotosystheticratesand
photosyntheticelectrontransport,aswellastheincreaseofrespiration/photosynthesisratio.
TheinhibitionofelectrontransportwasmoreseversinPSⅡthaninPSⅠ.Pretreatment
byleafsprayingwith6-BAandthethreekindsofantioxidants(propylgallate,dibutyl

⒇收稿日期:1993-10-16接受日期:1994-01-28
缩写:BHT.2,6-二丁基甲酚;PG.没食子酸丙酯;MDA.丙二醛;PEG6000.聚乙二醇;AsA.抗坏血酸。
872植物学报36卷

hydroxytolueneandascorbicacid)beforetherootsweresubmitedtoosmoticstressin-
0.41MPaPEGsolutionfor3himprovedalloftheaboveparameterssignificantly.The
resultsindicatedthatantioxidartpossesseddefiniteprotectiveregulativeandadaptative
effectsonphotosystheticmembraneunderwaterstressofroot.Asthedamageofwater
stresstoplantmayvolvethefreeradicalmechanism.
KeywordsMaize;Osmoticstress;Antioxidant;Photosystheticmembrane;6-BA

水分胁迫导致细胞和亚细胞膜系统损伤,影响细胞正常的生理生化过程[1,2]。叶片失
水后,水解酶和氧化酶类活性增高;气孔开度减少,光合作用各个分过程的运转受到明显
的抑制[3—6];膜透性增大引起离子平衡失调,进而造成物质代谢和能量代谢的紊乱。然而,
目前对水分胁迫下膜系统伤害的机理尚不甚了解。不少学者发现干旱引起细胞膜透性及
膜脂不饱和度降低与膜脂过氧化水平之间呈正相关,具不同耐旱性植物叶片中能消除活
性氧毒害的保护酶类,如SOD、CAT、POD等的活性大小与其在干旱时膜脂过氧化和膜透
性变化程度呈负相关性。因而认为水分胁迫引发自由基代谢异常是膜结构与功能破坏的
原因[1,7]。另