干旱胁迫对北苍术3种倍半萜类成分积累及生物合成关键酶基因表达的影响

Effects of Drought Stress on Accumulation of Three Sesquiterpenoids and Gene Expression of Key Enzymes in Biosynthesis of Atractylodes chinensis

目的:研究不同干旱胁迫对北苍术3种倍半萜类成分白术内酯Ⅱ、β-桉叶醇和苍术酮积累及其生物合成关键酶3-羟基-3-甲基戊二酸单酰辅酶A还原酶(HMGR)活性及基因表达的影响。方法:在不同干旱胁迫下,采用高效液相色谱法测定北苍术3种倍半萜类成分的含量;采用试剂盒法(双抗体夹心法)测定北苍术根茎中HMGR的活性;采用实时荧光定量PCR法测定北苍术HMGR的表达量;采用SPSS软件对两者进行相关性分析。结果:在中度干旱胁迫时,北苍术中3种倍半萜类成分含量、关键酶HMGR活性及基因表达量均显著增加;重度干旱胁迫对各指标则均表现为抑制作用。不同干旱胁迫下3种倍半萜类成分白术内酯Ⅱ、β-桉叶醇和苍术酮含量与关键酶HMGR活性及基因表达量均呈极显著正相关(P<0.01)。结论:掌握了北苍术在不同干旱胁迫条件下3种倍半萜类成分的积累及其生物合成关键酶HMGR活性及基因表达的变化规律,明确了北苍术中3种倍半萜类成分与关键酶HMGR的关系,为研究干旱条件下北苍术倍半萜类成分合成的分子调控机制奠定了基础,也为进一步提高北苍术中倍半萜类成分含量和保障药材品质提供理论依据。

Objective:To explore the effect of different drought stress on the accumulation of three sesquiterpenoids atractylenolide Ⅱ,β-eudesmol,atractylone and key enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase(HMGR)activity and gene expression in biosynthesis of Atractylodes chinensis.Methods:Under different drought stress,the contents of three sesquiterpenoids in Atractylodes chinensis were determined by HPLC;The activity of HMGR in rhizome of Atractylodes chinensis was determined by kit method(double antibody sandwich method);Real-time fluorescence quantitative PCR was used to determine the expression of HMGR in Atractylodes chinensis.SPSS software was used to analyze the correlation between them.Results:Under moderate drought stress,the contents of three sesquiterpenoids,the activity of key enzyme HMGR and the gene expression in Atractylodes chinensis were significantly increased.Severe drought stress inhibited all indexes.There was a significant positive correlation between the contents of three sesquiterpenoids atractylenolide Ⅱ,β-eudesmol,atractylone and the key enzyme HMGR activity and gene expression in Atractylodes chinensis under different drought stress(P<0.01).Conclusion:The study masters the change rules of the accumulation of three sesquiterpenoids in Atractylodes chinensis and key enzyme HMGR activity and gene expression in biosynthesis under different drought stress conditions,elucidates the relationship between three sesquiterpenoids and key enzyme HMGR in Atractylodes chinensis,which lays the foundation for studying the molecular regulation mechanism of drought conditions on the synthesis of sesquiterpenoids in Atractylodes chinensis and provides the theoretical basis for further increasing the contents of sesquiterpenoids in Atractylodes chinensis and guaranteeing the quality of medicinal materials.