| Popis: |
Background: Leaf colour mutants have reduced photosynthetic efficiency, which has a severely negative impact on crop growth and economic product yield. There are different chlorophyll mutants in Arabidopsis and crops that can be used for genetic control and molecular mechanism studies of Chl biosynthesis, chloroplast development and photoefficiency.Chlorophyll mutants in Brassica napus are mostly used for mapping and location research,but rarely used for physiological research.The chlorophyll deficient mutants in this experiment were both genetically mapped and physiologically analyzed. Results:In this study, yellow leaf mutants of Brassica napus L. mutated by ethyl methyl sulfone (EMS) had significantly lower chlorophyll a, b and carotenoid contents than the wild type, and the net photosynthetic efficiency, stomatal conductance and transpiration rate were all significantly reduced. The mutants had sparse chloroplast distribution and weak autofluorescence. The granule stacks were reduced, and the shape was extremely irregular, with more broken stromal lamella. Transcriptome data analysis enriched the differentially expressed genes mainly in phenylpropane and sugar metabolism. The mutants were mapped to a 2.72 Mb region on A01 by using BSA-Seq and the region was validated by SSR markers.Conclusions: The mutant chlorophyll content and photosynthetic efficiency were significantly reduced compared with those of the wild type. Abnormal chloroplasts and thylakoids less connected to the stroma lamella appeared in the mutant. This work on the mutant will facilitate the process of cloning the BnaA01.cd gene and provide more genetic and physiological information concerning chloroplast development in Brassica napus. |
