Targeted genome editing of carotenoid isomerase gene by CRISPR/Cas9 causes color changes in tomato tissues

Targeted genome editing of Solanum lycopersicum c.v. PKM1 was carried out using guide RNAs targeted to the 5 prime UTR and Exon 1 of Carotenoid isomerase (CRTISO) gene. The resulting plants showed changes in gene expression which were analyzed by RNAseq analysis. A single event with mutation in Exon1 leading to generation of tangerine colored fruits was obtained. Another event with a deletion in the 5 prime UTR of the gene was also obtained which resulted in light red fruit phenotype compared to the bright red color in the wild type. RNA was isolated from wild type and the two genome edited events, stranded RNAseq libraries were prepared and sequenced on Illumina HiseqX.

本研究以栽培番茄（Solanum lycopersicum）品种PKM1为实验材料，针对类胡萝卜素异构酶（Carotenoid isomerase, CRTISO）基因的5'非翻译区（5' UTR）与外显子1设计向导RNA，开展靶向基因组编辑操作。编辑获得的植株出现基因表达变化，随后通过RNA测序（RNA-seq）对该表达变化进行分析。本研究筛选得到1株外显子1发生突变的编辑事件，其果实呈现橘黄色表型；同时获得另一株该基因5' UTR发生缺失的编辑事件，与野生型的亮红色果实相比，该植株的果实呈现浅红色表型。分别从野生型植株与这两株基因组编辑事件的植株中提取总RNA，构建链特异性RNA测序文库，并在Illumina HiseqX测序平台上完成测序。