水稻F3H基因的同源克隆及表达分析OA

Flavonoids play a critical role in plant resistance to various biotic and abiotic environmental stresses.Guizhou province is located in the subtropical monsoon climate zone with abundant but uneven precipitation,where spring drought frequently occurs and severely affects rice(Oryza sativa)sowing and seedling growth.In this study,the flavanone 3-hydroxylase(OsF3H)gene(GenBank No.XM_015776658)was cloned from rice leaves.Its CDS was 1 041 bp in length,encoding 346 amino acids,and the predicted protein molecular weight was 38.74 kD.Phylogenetic analysis revealed that OsF3H clusters with flavanone 3-hydroxylases from other species,indicating it was a member of the flavanone 3-hydroxylase family and shared the closest relationship with wheat(Triticum aestivum)F3H.Cis-acting element prediction indicated that the promoter region of this gene contained not only functional elements responsive to phytohormone signals,light regulation,as well as growth and development,but also cis-acting elements involved in drought and salt stress responses.Further expression analysis under drought treatment demonstrated that OsF3H could be induced by drought,suggesting its potential role in drought stress response of rice.To verify its function in drought response,OsF3H was heterologously expressed in Arabidopsis thaliana,and the transgenic plants were subjected to drought stress.The results showed that the transgenic plants exhibited significantly increased root length,greening rate,fresh weight,and dry weight relative to the wild-type plants,indicating that overexpression of OsF3H significantly enhanced drought tolerance of A.thaliana.These findings provide important data for further elucidating the physiological function of OsF3H in rice and its mechanism in response to drought stress,which will facilitate subsequent research.