摘要
莲(Nelumbo nucifera)的种胚具有寿命长、抗逆性强的生理特征。本研究用莲种胚脱水过程中特异性富集的脱水素基因Nn Rab18遗传转化拟南芥(Arabidopsis thaliana),探究其响应逆境胁迫的抗氧化功能。NnRab18基因全长972 bp,cDNA全长835 bp,包含444 bp编码序列,编码147个氨基酸残基;NnRab18蛋白属于LEA家族YSK_(2)型脱水素。干旱、低温、渗透或高盐等单一逆境胁迫下,NnRab18转基因拟南芥的生长状态明显优于野生型,其根长提高27%~48%,莲座面积提升8%~33%,鲜重增加27%~92%。与野生型相比,胁迫下4种NnRab18转基因拟南芥的电解质渗漏率显著降低11%~38%;低温与渗透胁迫下膜脂过氧化程度显著下降19%~42%;干旱与低温胁迫下过氧化氢酶(CAT)、超氧化物歧化酶(SOD)与过氧化物酶(POD)活性均显著提高,在干旱胁迫下提升可达2.9~6倍;渗透胁迫下抗坏血酸(AsA)、还原型谷胱甘肽(GSH)含量分别显著提高9%与35%;在渗透与高盐胁迫下过氧化氢(H_(2)O_(2))含量分别降低32%与79%,羟自由基(·OH)抑制能力分别提高21%与49%。相关性分析显示转基因拟南芥体内POD、GSH等抗氧化物质在降低膜脂过氧化程度、清除H2O2等方面可能具有重要作用。上述结果表明,胁迫下脱水素NnRab18可有效维持质膜完整性,提高清除活性氧组分的能力,从而提升拟南芥的胁迫耐受能力。
Lotus(Nelumbo nucifera)embryos have long life spans and high stress resistance.Dehydrin gene Nn Rab18,specifically enriched during the dehydration and maturation,was cloned from lotus embryos and transformed into Arabidopsis thaliana to reveal the anti-oxidant function in vivo under abiotic stresses.Nn Rab18 gene is 972-bp long,with 835-bp-long cDNA and 444-bp-long coding sequence,encoding 147amino acids.NnRab18 protein belongs to YSK_(2)type dehydrin in LEA family.NnRab18-overexpressed A.thaliana seedlings showed better growth status than wild-type ones under drought,low-temperature,osmotic,and salt stress,with an increase by 27%–48%in root length,8%–33%in rosette size,and 27%–92%in fresh mass.Physiological indicators of A.thaliana indicate that compared with the wild-type,the relative electrical conductivity of Nn Rab18-transgenic A.thaliana was significantly reduced by 11%–38%under the four types of stress.Membrane lipid peroxidation was notably decreased by 19%–42%under low-temperature and osmotic stress.Catalase(CAT),superoxide dismutase(SOD),and peroxidase(POD)activities were improved under drought and low-temperature stress,up to 2.9–6 times especially under drought stress.Ascorbic acid(AsA)and glutathione(GSH)contents in transgenic A.thaliana increased by 9%and 35%,respectively,under osmotic stress.Under osmotic and salt stress,H_(2)O_(2)content was decreased by 32%and 79%,and hydroxy radical(·OH)inhibition activity was strengthened by 21%and 49%,respectively.Correlation analysis shows that POD and GSH in Nn Rab18-transgenic A.thaliana are likely to be related in reducing plasma membrane damage and lowering H_(2)O_(2)level.The above results demonstrate that NnRab18 could provide cellular protection and improve the resistance of A.thaliana against abiotic stresses by protecting plasma membrane integrity and scavenging reactive oxygen components.
作者
刘涛
盛江源
陈海荣
章毅颖
张荻
LIU Tao;SHENG Jiangyuan;CHEN Hairong;ZHANG Yiying;ZHANG Di(Landscape Architecture,School of Design,Shanghai Jiao Tong University,Shanghai 200240,China;institute for Agri-food Standards and Testing Technology,Shanghai Academy of Agricultural Sciences,Shanghai 201403,China)
出处
《植物生理学报》
CAS
CSCD
北大核心
2023年第10期1909-1922,共14页
Plant Physiology Journal
基金
国家自然科学基金(31971705)
上海市自然科学基金(21ZR1434200)。
关键词
莲
脱水素
逆境胁迫
抗逆生理
蛋白功能
Nelumbo nucifera
dehydrin
abiotic stress
resistance physiology
protein function
