Analysis of the BnXTH16 gene responsible for male sterility in rapeseed (Brassica napus) breeding lines.

• Applicant: Professorin Dr. Margret Sauter (†)
• Subject Area: Plant Breeding and Plant Pathology
• Term: from 2013 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 247859333

Male sterility is an economically important trait in plant breeding. It prevents self-pollination of outcrossing crops and ensures the sustainment and improvement of heterosis by cross-pollination of genetically diverse parent plants. MSL lines of Brassica napus (rapeseed) that carry a mutant form of the ms gene (ms for wildtype) are male sterile but can be reverted to fertility by prolonged heat treatment during flower development or in the presence of the restorer gene R. Recently the ms locus was mapped and the gene was identified as BnXTH16. BnXTH16 codes for a xyloglucan endotransglycosylase that is involved in cell wall metabolism. Pollen develop within anthers which possess four pollen sacs. Pollen development depends on proper function of the inner pollen sac layer termed the tapetum and on proper deposition of cell wall material to the pollen coat. The cytological, pysiological and molecular events that accompany the male-sterile phenotype of MSL lines of B. napus that carry the mutated BnXTH16 gene have not been analyzed to date. Nor do we know about the changes that allow for the heat-induced restoration of male fertility. This project will elucidate how BnXTH16 activity determines development of fertile pollen. To that end a wide spectrum of cytological, biochemical, and molecular-genetic appproaches will be used. In particular for genetic analyses the project will profit from the amenability of the close B. napus relative Arabidopsis thaliana. We expect that our analyses will help establish new breeding lines in the future.

• DFG Programme: Research Grants