Genetic Analysis and Gene Mapping of Glossy Leaf in Brassica napus
[Objective]Epicuticular waxes is a hydrophobic layer covering plant leaves and stems,playing an important role in stress resistance and affecting photosynthesis,growth and development.Rapeseed(Brassica napus L.)is one of the main oil crops in the world,but the mechanism of epicuticular waxes formation on its leaves is still unclear.This study aims to reveal the genetic mechanism of epicuticular wax on leaves through a mutant,which will help to achieve high and stable yield of rapeseed.[Method]In this study,leaf of glossy leaf mutant M8 and common waxy leaf inbred lines Zhongshuang 11(ZS11)and the C20 were characterized,and its photosynthetic rate were measured by portable plant photosynthesis measurement system.Two F1 hybrids and F2 segregating populations were constructed by crossing the M8 with ZS11 and C20,respectively,and were used to analyze the heredity of leaf characters in rapeseed.The F2 population hybridized by M8 and ZS11 was constructed to analyze the genetic regulation of the glossy leaf trait in rapeseed by bulked segregation analysis(BSA)combined with Target-sequencing(Target-seq).Combined with comparative genome and transcriptome database,candidate genes were predicted and then verified by RT-PCR.[Result]The leaf stomatal conductance and photosynthetic efficiency were higher in the glossy leaf mutant M8,compared with ZS11 in rapeseed.The genetic analysis results showed that the glossy leaf was controlled by one pair of recessive genes and glossy leaf was recessive compared with waxy leaf.It was finally fine mapped in the physical region of 0.134-0.699 Mb on chromosome A08 by map based cloning method.Further analysis revealed that there was a large segmental deletion in the 0.22-0.58 Mb region of chromosome A08 in the M8 glossy leaf mutant compared to ZS11,and BnaA08G0006900ZS(BnaA08.SAGL1)in this region of the genome was identified as the candidate gene for the glossy leaf trait.This gene encodes a Kelch-F-box protein,and its deletion may lead to the observed glossy leaf trait in the M8 mutant,as it was highly expressed in ZS11 but none in M8.[Conclusion]Compared with wild-type waxy leaves,the photosynthetic rate of the new glossy leaf mutant M8 was higher,and the glossy leaf phenotype was controlled by a recessive gene.In the picture,the glossy leaf phenotype regulatory gene was identified as BnaA08.SAGL1,and deletion of the gene resulted in glossy leaf in rapeseed.
万方数据
维普
