Expression Patterns And Cloning Of 3' End Sequences Of CaCOI1 Gene In Pepper Plants

Pepper in growing stage often subjects to different pathogen's infection, leading to decreased yields and low quality. In this study, we analyzed the features of the partial cDNA sequence of COI1, the key regulatory gene in JA signaling pathway from papper(we desigated CaCOI1). We deduced its amino acid sequences, and designed a pair of specific primers for confirmation of its existence in pepper genomic DNA. By PCR, we amplified a predicted band with size of about 1200bp in length. The fragment was cloned into T vector. Sequencing determination showed its actual length is 1157 bp. To inspect CaCOI1 gene expression patterns, we isolated total RNAs from pepper leaves, stems and roots and carried on semi-quantitive RT-PCR. We detected CaCOI1 transcripts in pepper leaves, stems and roots. The most significant expression of CaCOI1 is in pepper leaves. A 445 bp fragment was obtained from the 3'end of cDNA of CaCOI1 by RACE. Finally, we compared CaCOI1 with other species'COI1 genes and constructed a phylogenetic tree with CaCOI1 and COI1s from Arabidopsis, soybean, rice, tobacco, tomato, and oak. It showed that COI1 from pepper, tomato and tobacco form a small branch; but the distance of COI1 between pepper and tomato is a bit far away, suggesting their distinct diversity. The rice COI1 form a single branch; we speculated that COI1 genes diverged when dicot and monocot occuring. This study will provide the basis for cloning of CaCOI1 full length cDNA sequence and clarifying its role in pepper disease resistance.