Towards Apomixis in Arabidopsis thaliana

Cloning through seeds has potential revolutionary applications in agriculture because its introduction into sexual crops would allow perpetuation of any elite heterozygous genotype. Asexual reproduction through seeds, or apomixis, results in progeny that are genetic clones of the maternal parent. However, despite the occurrence of apomixis in hundreds of plant species, very few crop species reproduce via apomixis and attempts to introduce this trait by crossing have failed. An alternative approach is to de novo engineer the production of clonal seeds. It was previously shown that one major element of apomixis, the formation of functional unreduced gametes that are genetically identical to the parent plant (apomeiosis) could be induced in the sexual plant Arabidopsis thaliana^1,2. However, these gametes participate in the normal sexual process of fertilization, leading to an increase in ploidy at the next generation. We have now shown that Arabidopsis apomeiotic gametes can be converted into clonal seeds, using a genome elimination system³. These results demonstrate that clonal reproduction through seeds can be achieved in sexual plants⁴. Several limitations need to be addressed before such an approach could be applied in practice but what was believed a distant goal now appears to be in sight.

1          d'Erfurth, I. et al. Turning meiosis into mitosis. PLoS Biol 7, e1000124 (2009).

2          Ravi, M., Marimuthu, M. P. & Siddiqi, I. Gamete formation without meiosis in Arabidopsis. Nature 451, 1121-1124 (2008).

3          Ravi, M. & Chan, S. W. Haploid plants produced by centromere-mediated genome elimination. Nature 464, 615-618 (2010).

4          Marimuthu, M. P. et al. Synthetic clonal reproduction through seeds. Science 331, 876 (2011).