Chlorophyll Content, Chloroplast Ultrastructure and Transcriptome Analysis in Wild-type and Yellow-bud-mutant Hot Peppers

Abstract

The yellow-bud mutant hot pepper, 96-140YBM, which exhibits a yellow leaf phenotype in its young leaves but whose matured leaves are gr een, was isolated from wild type 96- 140 in this study. The results of photosynthetic pi gment determination and chloroplast ultrastructure observation revealed that the young mutant leaves displayed Chl a+b and Cars content, increased Chl a/b and Car/Chl a+b rat ios, and delayed chloroplast development compared with the wild type leaves. Her e, we obtained 95,714 transcripts from cultured yellow-bud mutant yellow leaves and c ultured wild-type seedling leaves using the Illumina HiSeq-2000 (Illumina Inc., USA) platform. A total of 42,384 unigenes were identified, among which 37,949 were annotated using gene descriptions or gene ontology terms. Based on Differentially Expressed G enes (DEG) analysis, 1,056 of the 1,101 DEGs were annotated in the Nr database, and 3 02 unigenes were mapped to 130 pathways using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database. Finally, we found that 6 pathways were re lated to chloroplast and chlorophyll biogenesis. Keywords: Hot pepper; Chloroplast; Transcriptome; Yellow-bud mutant; Wild type