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

The yellow-bud mutant hot pepper, 96-140YBM, which exhibits a yellow leaf phenotype in its young leaves but whose matured leaves are green, was isolated from wild type 96- 140 in this study. The results of photosynthetic pigment 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 ratios, and delayed chloroplast development compared with the wild type leaves. Here, we obtained 95,714 transcripts from cultured yellow-bud mutant yellow leaves and cultured 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 Genes (DEG) analysis, 1,056 of the 1,101 DEGs were annotated in the Nr database, and 302 unigenes were mapped to 130 pathways using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database. Finally, we found that 6 pathways were related to chloroplast and chlorophyll biogenesis.