Principal investigators: María Rosa Ponce and José Luis Micol.
Instituto de Bioingeniería. Universidad Miguel Hernández.

A large-scale and multiomic approach to the dissection of heterosis in Arabidopsis

For millennia, farmers saved seed from their own previous harvests to plant for the next season, which is still relatively common in the developing world and for some crops such as wheat. In the developed world, however, purchased seed has progressively replaced farm-saved seed for some crops as maize. Indeed, one of the great changes that agriculture underwent in the 20th century was the exploitation of F1 hybrid seeds, which produce plants that exhibit heterosis. Size, yield, development and tolerance to biotic and abiotic stress are among the traits in which heterotic F1 hybrids perform better than their inbred parental lines. Despite its enormous contribution to modern agriculture, however, knowledge on heterosis is still mostly empirical; after many decades of hypothesizing, experimental research, and some modelling, the molecular basis of heterosis remains disputed. The main objective of this project is to contribute to the understanding of heterosis in plants, by means of a large-scale analysis of the F1 progeny of as many as possible crosses involving Arabidopsis natural accessions. We will concentrate first in performing thousands of crosses, which will involve accessions (a) as divergent as possible in an easily visible morphological trait, namely, whole rosette and/or rosette leaf size, (b) as polymorphic as possible in whole genome sequence, and (c) chosen at random. A LemnaTec PhenoAIxpert robotized phenomics platform will be used to phenotype F1 hybrids; those exhibiting heterosis will be selected for further studies, which will include the characterization of their whole plant morphological, leaf histological and photosynthetic phenotypes, chloroplast ultrastructure, organellar translatomes, and cytoplasmic ribosome profiles. Transcriptomic and metabolomic analyses will also be performed with the heterotic F1 hybrids considered of interest.