Host - Prof Gerhard Leubner
Safeguarding the genome in seed germination and longevity
The plant embryo can survive for extended periods within the desiccated seed until germination, a critical event in the plant’s life cycle and important for successful crop production. However, this dry quiescent state is associated with the progressive accumulation of intracellular damage which compromises germination and seed viability. Molecular damage includes the plant’s genetic material, threatening both cellular survival and the faithful transmission of genetic information. Even high quality seeds display a striking DNA damage response within a few hours of imbibition, indicative of high levels of genotoxic stress arising as a natural consequence of desiccation. Consistent with these observations, we find that maintenance of genome integrity is of particular importance in the seed stage of the plant lifecycle, as illustrated by the ageing sensitivity of mutants defective in repair of cytotoxic chromosomal breaks. These studies established a genetic link between seed longevity and DNA repair. More recently, our studies have delineated the molecular mechanisms by which detection of DNA damage is integrated with progression of germination and seed viability, revealing the key DNA damage sensor kinases active in seeds as major factors which influence seed quality. Our findings provide new insight into the physiological roles of DNA damage responses in plants and uncover their importance in regulating germination, events that underpin plant propagation in both natural ecosystems and agriculture.