聚乙二醇胁迫对人参愈伤组织皂苷合成及关键酶基因表达量的影响  

Effects of PEG Stress on Saponin Synthesis and Gene Expression of Key Enzymes in Panax ginseng Callus

作　　者：高岩 张涛[1] 杨利民[1] 马秀杰[2] 韩梅[1] GAO Yan;ZHANG Tao;YANG Limin;MA Xiujie;HAN Mei(College of Chinese Medicinal Materials,Jilin Agricultural University,Changchun 130118,China;College of Life Science,Baicheng Normal University,Baicheng 137000,China)

机构地区：[1]吉林农业大学中药材学院,长春130118 [2]白城师范学院生命科学学院,白城137000

出　　处：《吉林农业大学学报》2020年第4期395-402,共8页Journal of Jilin Agricultural University

基　　金：吉林省重点科技研发项目(20180201038YY);国家中药材产业技术体系项目(CARS-21);吉林省科技发展计划项目(20170307009YY)。

摘　　要：探究聚乙二醇(PEG)模拟干旱胁迫对人参愈伤组织的生长、皂苷合成关键酶基因表达量与皂苷含量的影响,从基因水平揭示人参皂苷合成对水分的响应。试验以人参愈伤组织为材料,通过添加不同浓度PEG(0、10%、20%、30%)模拟干旱环境,测定不同胁迫程度下愈伤组织的生长量,单体皂苷Rg1、Re含量,并以GAPDH为内参基因,实时荧光定量PCR分析人参皂苷合成途径中4个关键酶基因HMGR、DS、CYP716A52v2、CYP716A53v2表达量。结果表明:PEG浓度越高对愈伤组织鲜重的抑制作用越明显,干重则相反。短时间内一定程度干旱胁迫对人参皂苷合成具有促进作用,10%、20%PEG处理分别促进皂苷Re、Rg1的合成;各基因表达量结果显示,4个关键酶基因的表达在不同处理下均呈现不同程度的上调,10%处理使HMGR、DS基因表达量上调(P<0.05);其中DS基因在10%处理下表达量最高(P<0.05),第25天时达最大值,是ck组的6.52倍。CYP716A52v2基因在10%处理时25 d达最大值;30%处理组在5 d时与对照比促进了CYP716A53v2基因表达量,5 d时达最大值,是ck组的5.83倍。PEG模拟干旱胁迫时可激活次生代谢合成途径中多个关键酶基因协同表达,从而有效启动人参皂苷生物合成途径,影响人参皂苷的合成与积累。The study was conducted to explore the effects of PEG simulated drought stress on gene expression of key enzymes in saponin synthesis,content of saponin and growth of Panax ginseng callus,and the response of saponin synthesis to water content was revealed at the gene level.Taking Panax ginseng callus as research materials,different concentrations of PEG(0,10%,20%,30%)were added to simulate the drought environment,and to determine the growth of callus and the content of monomer saponin Rg1 and Re under different stress levels.The realtime fluorescence quantitative PCR was used to analyze the expression of four key enzyme genes HMGR,DS,CYP716A52v2 and CYP716A53v2 and the expression of GAPDH was set as a reference gene.It was found that the higher the PEG concentration,the more obvious the inhibition of fresh weight of callus,and the opposite of dry weight.The results showed that drought stress significantly improved the saponin synthesis to a certain extent,and 10%and 20%treatments respectively increased the content of Re and Rg1.The results of gene expression showed that the expression of four key enzymes was upregulated in different treatments,and the expression of HMGR,DS gene was the highest at the 25th day,and the maximum value was 6.25 times than of the ck group(P<0.05),and the CYP716A53v2 gene reached its maximum value at 25th days under 10%treatment.The 30%treatment group promoted the expression of CYP716A53v2 gene at the 5th day,and reached the maximum value of 5.83 times than ck groups at 5th days.PEG simulated drought stress can activate the secondary metabolism synthesis pathway in collaborative multiple gene expression,thus effectively start ginseng saponin biosynthesis pathway and affect the synthesis and accumulation of ginsenosides.

关 键 词：人参 愈伤组织 聚乙二醇 人参皂苷 实时荧光定量 基因表达量 

分 类 号：S567.51[农业科学—中草药栽培] R284[农业科学—作物学]