青蒿HMGR基因家族克隆及对茉莉酸甲酯和损伤的响应

Molecular Cloning and Expression Analysis of HMG-CoA(3-hydroxy-3-methylglutaryl-CoA)Reductase Gene Family Upon MeJA and Mechanical Injury Treatments in Artemisia annua L.

通过全基因组序列测定和RACE技术,从青蒿(Artemisia annua L.)克隆出了3条编码HMGR的cDNA序列:AaHMGR1,AaHMGR2和AaHMGR3,并对3条基因进行生物信息学分析.结果表明:3条序列与其他物种的HMGR具有高度相似性但基因组结构不一致;组织表达分析中,AaHMGR1在茎中表达量最高,而AaHMGR2和AaHMGR3在花中表达量较高;外源茉莉酸甲酯(MeJA)诱导处理后AaHMGR1的表达在0.5h时达到最大值,AaHMGR2和AaHMGR3则轻微响应;机械损伤3h后能够使AaHMGR1的表达量上调约700倍,而AaHMGR2,AaHMGR3上调幅度却不大.综上研究结果表明,AaHMGR1基因可能在青蒿素的生物合成中起着更为重要的作用.

Three full-length cDNA of HMGR,i.e.AaHMGR1,AaHMGR2 and AaHMGR3,were cloned from Artemisia annua.Bioinformatic and phylogenetic analyses revealed that all the three AaHMGRs shared extensive homology with other plant species and belonged to the plant HMGR family;however,the corresponding coding region of the genome structure was different.The expression of AaHMGR1 was the highest in the stem,while the expression of AaHMGR2 and AaHMGR3 was relatively high in the flower.The expression of AaHMGR1 reached the maximum at 0.5 hafter MeJA induction,and then decreased gradually,while AaHMGR2 and AaHMGR3 responded but slightly.The expression of AaHMGR1 increased by about 700 times at 3 hafter mechanical injury,while that of AaHMGR2 and AaHMGR3 was not significant.The above results suggested that AaHMGR1 may play a crucial role in artemisinin biosynthesis.