番茄SlRab5b基因的克隆与表达模式分析OA

Small G protein Rab is an important molecular switch in the plants,which participates in reg-ulating plant growth and development processes,and responding to external biotic and abiotic stresses.In this study,the cDNA sequence of tomato endogenous small G protein gene SlRab5b was cloned using tomato plants as materials,and its bioinformatics analysis and expression pattern analysis were conducted.The results showed that the open reading frame(ORF)of SlRab5b was 603 bp,encoding 200 amino acids.It was a pro-tein without transmembrane structure and signal peptide.Phylogenetic tree analysis showed that SlRAB5b was a member of the RABF family with the conserved sequence similar to RABF proteins in other plants,and had 86.70％and 59.52％homology with Arabidopsis AtRABF1 and AtRABF2b proteins.The relative expression level of SlRab5b gene in different tissues of tomato showed stem＞new leaf＞old leaf＞root in the tested varie-ties except 918.After 48 h of methyl jasmonate(MeJA)treatment and 6 h of salicylic acid(SA)treatment,the relative expression level of SlRab5b gene significantly increased by 1 745.8％and 548.3％,compared with control,respectively.The relative expression level of SlRab5b gene was also up-regulated after inoculation with Phytophthora infestans,which was significantly increased in tomato varieties YS-7 and 918 by 432.7％and 426.1％,respectively,compared with control 48 h after inoculation.It could be seen that the expression of Sl-Rab5b gene was different in different tissues of tomato,and could be induced by the infection of pathogenic bacteria of late blight and the treatment of MeJA and SA.