De novo assembly of Koelreuteria transcriptome and analysis of major gene related to leaf etiolation

As an important small deciduous tree, Koelreuteria bipinnata var. integrifoliola 'Jinyan' possesses high ornamental value. Understanding its coloring processes in leaves may help scientists breed the best plant type. Here, we report the first transcriptome generated from the leaves of K. bipinnata var. integrifoliola 'Jinyan' and K. bipinnata var. integrifoliola through de novo high-throughput transcriptome sequencing. A total of 94,125 unigenes were obtained from more than 156 million of high quality reads using de novo assembly, of which 47,341 unigenes were annotated in various protein databases, including the Nr, Swiss-Prot, GO, COG, KOG and KEGG. Moreover, 482,377 SNPs and 9414 SSRs were identified in assembled unigenes, and 13,670 DEGs with up-regulated or down-regulated expression levels were detected in all samples. Finally, 9 and 14 genes, which are responsible for encoding enzyme, were screened in porphyrin and chlorophyll metabolism and carotenoid biosynthesis pathways respectively. Taken together, this transcriptome data may be further utilized in functional genomics and genetics studies on Koelreuteria.