The Mechanisms of Apomictic Development (MAD) project, funded by the European Union and coordinated by Olivier Leblanc, an IRD plant geneticist, was launched last December. This Marie Skłodowska-Curie Research and Innovation Staff Exchange (MSCA RISE) Action is being implemented under the Pillar 1 Excellent Science of the Horizon H2020 programme*.
Apomixis embraces reproductive strategies to allow the formation of viable seeds carrying embryos identical to the mother, a singular and exciting phenomenon for the agricultural sector. However, our understanding of the underlying processes remains desperately slim. An international Consortium?UMR DIADE (Université de Montpellier, CIRAD, IRD) ; Biosciences Department; University of Milan, Italie ; Department of Agricultural, Food and Environmental Sciences, University of Perugia, Italie ; Department of Agronomy Food Natural Resources Animals and Environment; University of Padova, Italie ; Department of Agronomy Food Natural Resources Animals and Environment, Institute of Biosciences and BioResources, National Research Council, Italie ; Crop Bioinformatics group, National Institute for Agricultural Biology, UK ; Department of Plant and Microbial Biology, University of Zürich, Suisse ; Instituto de Investigaciones en Ciencias Agrarias de Rosario, Universidad de Nacional de Rosario, Argentine ; Instituto de Botánica del Nordeste, Universidad Nacional del Noreste, Argentine ; Centro de Recursos Naturales Renovables de la Zona Semiárida, Universidad Nacional del Sur, Argentine. of scientists from 12 laboratories recently joined forces and has given itself the next four years to address this challenge.
Seeds carrying maternal clones, a botanical curiosity?
“The immense diversity of plants and their remarkable ability to adapt are the result of evolutionary innovations that affected many of their features, including their reproductive biology! “ Olivier Leblanc told. Among the most successful innovations of plant evolution, seeds and flowers boosted the expansion of plants across most terrestrial habitats. Seeds make it possible to safely escort future generations across time and space and are the sophisticated products of sexual reproduction: their precious cargo, the embryos, are derived from the union of a female reproductive cell and a male reproductive cell. Numerous groups of plants, however, have evolved ways of producing seeds harboring embryos that are genetically identical to the mother-plant, i.e. they form with no male contribution. These clonal reproductive strategies, collectively known as apomixis, have long been considered as botanical curiosities; however, their potential to revolutionize plant breeding and thereby improve food security has put them under the spotlight in recent years.
Agriculture yearns for the benefits of apomixis
Maintaining complex agronomic traits from generation to generation is a difficult task that man first faced from the beginning of agriculture to the rediscovery of Mendel’s laws in the early 1900’s. Since then, plant breeding has emerged from empiricism and, thanks to advances in quantitative genetics and biotechnologies, it has now become a scientific discipline in its own right. The toolbox of plant breeders, however, remains incomplete as only a limited number of genetic combinations can be maintained and the methods required for their selection and multiplication are time-consuming and expensive. “Apomixis offers plant breeders the opportunity to fix, multiply and distribute the best allelic assortments, while reducing the cost of access to improved seeds and helping breeding programs to better address farmers’ needs through faster variety cycling”, the geneticist explains. The harnessing of apomixis could therefore help us to tackle the global challenges faced by modern agriculture, such as the transition towards sustainability and food security in the context of climate change.
Shedding light on the mechanisms of apomixis using model systems
Common wisdom suggests that apomixis results from alterations to the finely tuned developmental programs governing sexual reproduction. Nevertheless, the underlying mechanisms remain largely unknown in molecular terms and the Mechanisms of Apomictic Development project was established to uncover the processes underlying this mystery. The MAD project aims to contribute to our understanding of the relevant genetic and molecular mechanisms, so as to allow the rewiring of sexuality to achieve apomictic reproductive development in plants. The Consortium will draw on skills and expertise in molecular and cellular biology, plant developmental biology and modeling for characterizing both sexual plant models (Arabidopsis thaliana, rice, maize) and natural apomictic systems including wild relatives of model plants (Boechera holbellii) and tropical forage grasses extensively used in South America (Paspalum and Eragrostis). The results should shed light on the molecular basis of apomixis and the requirements for its initiation and evolution in natural populations. The knowledge gained by the MAD scientific network will without doubt pave the way towards tackling the barriers that prevent plant breeders and farmers from reaping the benefits of apomixis.
* H2020-MSCA-RISE-2020 - Grant Agreement n° 872417 https://cordis.europa.eu/project/id/872417