Transcriptome analyses reveal photosynthesis-related genes involved in chloroplast development of the EMS-induced maize mutant

Chloroplast development together with chlorophyll biosynthesis plays an important role in plant survival and growth. Here, EMS-induced chlorophyll-deficient mutants ( wtg , wts, and wta ) were obtained from the progeny of Mt128 (MT), generated from the maize inbred line DP128 (WT). Three types of leaf color were segregated from the self-fertilized progenies of MT, including green, narrow-white striped and albino and named wtg , wts, and wta, respectively. We found that the Chl and carotenoid contents were significantly changed in wtg , wts, and wta, especially wta , compared with WT. In addition, leaf transcriptome sequencing of wtg , wts, wta, and WT were also carried out. The DEGs were identified as being related to chloroplast development and photosynthesis. By performing pairwise comparisons of each group, a total of 3685 (1181 upregulated, 2504 downregulated), 2624 (1028 upregulated, 1596 downregulated) and 6693 (3018 upregulated, 3675 downregulated) genes were found to be differentially regulated in wtg , wts, and wta, respectively, compared with WT. Of those, 75 comodulated DEGs with great alterations were identified among the comparison groups. More interestingly, most of the DEGs were found to be significantly involved in photosynthesis, including PSI, PSII, the cytochrome b6f complex, and F-type ATPase. GO enrichment of DEGs revealed that most of DEGs were involved in chloroplast development, chlorophyll biosynthesis, or photosynthesis. KEGG enrichment analysis indicated that the five significantly enriched pathways for comodulated DEGs in all EMS-induced mutant genotypes were as follows: benzoxazinoid biosynthesis, photosynthesis, starch and sucrose metabolism, phenylpropanoid biosynthesis and the photosynthesis–antenna proteins pathway. The results showed that EMS induction is a valid approach for generating mutants for crop breeding research.