Journal Article

Fine Mapping and Characterization of a Major Gene Responsible for Chlorophyll Biosynthesis in Brassica napus L

Peng, Menlu, Wu, Xu, Zhang, Wei, Sun, Chengming, Zhang, Jiefu, Wang, Xiaodong, Chen, Feng, Shi, Rui, Pang, Chengke, Zhao, Xiaozhen

2022

Overview

Rapeseed (Brassica napus L.) is mainly used for oil production and industrial purposes. A high photosynthetic efficiency is the premise of a high yield capable of meeting people’s various demands. Chlorophyll-deficient mutants are ideal materials for studying chlorophyll biosynthesis and photosynthesis. In a previous study, we obtained the mutant yl1 for leaf yellowing throughout the growth period by ethyl methanesulfonate mutagenesis of B. napus. A genetic analysis showed that the yl1 chlorophyll-deficient phenotype was controlled by one incompletely dominant gene, which was mapped on chromosome A03 by a quantitative trait loci sequencing analysis and designated as BnA03.Chd in this study. We constructed an F2 population containing 5256 individuals to clone BnA03.Chd. Finally, BnA03.Chd was fine-mapped to a 304.7 kb interval of the B. napus ‘ZS11’ genome containing 58 annotated genes. Functional annotation, transcriptome, and sequence variation analyses confirmed that BnaA03g0054400ZS, a homolog of AT5G13630, was the most likely candidate gene. BnaA03g0054400ZS encodes the H subunit of Mg-chelatase. A sequence analysis revealed a single-nucleotide polymorphism (SNP), causing an amino-acid substitution from glutamic acid to lysine (Glu1349Lys). In addition, the molecular marker BnaYL1 was developed based on the SNP of BnA03.Chd, which perfectly cosegregated with the chlorophyll-deficient phenotype in two different F2 populations. Our results provide insight into the molecular mechanism underlying chlorophyll synthesis in B. napus.

• Publisher: MDPI AG,MDPI
• Subject: Amino acid substitution / Biodiesel fuels / Biosynthesis / Brassica napus / Brassica napus - genetics / candidate gene / Chlorophyll / Chlorophyll - biosynthesis / chlorophyll deficiency / Chloroplasts / Chromosome Mapping - methods / Chromosomes / Cloning / Deficient mutant / Enzymes / Ethyl methanesulfonate / fine mapping / Gene mapping / Genes / Genes, Plant / Genetic analysis / Genomes / Genotype & phenotype / Glutamic acid / Lysine / molecular marker / Mutagenesis / Mutation / Nucleotide sequence / Phenotypes / Photosynthesis / Population / Proteins / Quantitative Trait Loci / quantitative trait loci sequencing / Rape plants / RNA polymerase / Seeds / Sequence analysis / Signal transduction / Single-nucleotide polymorphism / Transcriptomes / Yellowing