Genetic Mapping And Analysis Of Albino Gene EMS30 In Arabidopsis Thaliana

All organisms on the world depend on photosynthesis directly or indirectly,which produces organic materials and oxygen. Chloroplast is an important organelle for photosynthesis in higher plants and algae. Chloroplast development is integrated into plant growth and development, mutants with altered leaf coloration are the essential materials for study chloroplast development and function.An Arabidopsis thaliana albino mutant EMS30 in this article was obtained by ethyl methane sulphonate (EMS) mutagenesis strategy. When germinated in the soil, the mutant did not grow beyond the cotyledon stage, when plated on agar medium supplemented with 2% sucrose, it can grow with four true leaves, showing seedling lethal phenotype. EMS30 showed severe defects in chloroplast ultrastructure in concomitance with chlorophyll deficiency, only a few stroma thylakoid was observed in the EMS30 chloroplast, while the grana thylakoid was absent. In EMS30 mutant, D2 subunit of photosystem II can not be detected, and photosystem I subunits PsaA and ATP synthase subunit AtpB accumulated to similar level as in the wild-type plants, indicating that the EMS30 mutation had a severe impact on photosystem II. Genetic analysis indicated that albino phenotype was controlled by a single recessive locus. Using map-based cloning technique, EMS30 has been mapped to a region of 96 kb between molecular markers F21M12 and F14N23 on chromosome 1. In this region there are 25 genes, of which 3 genes are related with chloroplast function by bioinformatic analysis. These results are helpful for us to identify the EMS30 gene in the end and investigate its function in the chloroplast development.