Characterization of EcROS1-like, a putative gene indirectly involved in apomixis in Eragrostis curvula

CRISTIAN ALEJANDRO CHEMIN GENOVA; DAMIR SIMÓN; JOSE CARBALLO; JUAN PABLO SELVA; DIEGO ZAPPACOSTA; JIMENA GALLARDO; VIVIANA ECHENIQUE

Congreso; XXXIII Argentinian meeting of Plant Physiology (RAFV2021); 2021

Eragrostis curvula is a forage grass naturalized in semi-arid regions of Argentina that reproduces by diplosporous apomixis, having mainly facultative genotypes that retain certain percentage of sexual pistils that increase under drought and other stressful situations, indicating that some regulators activated by stress could be affecting the apomixis/sexual switch. Our previous results showed increases in the percentage of sexual embryo sacs when facultative plants were exposed to drought and other abiotic stresses. Interestingly, the EcROS1-like gene was found differentially expressed between apomictic plants growing under normal and water stress conditions, being up-regulated in stressed plants. Repressor of Silencing 1 (ROS1) is involved in DNA de-methylation on certain genes and, based on the hypothesis that sexual pathways are repressed but intact in facultative apomictic plants, it could explain the increases in sexual embryo sacs observed under stress situations. The objective of this work was to assess the genomic structure of the gen EcROS1-like and find out allelic differences in full apomictic, facultative and sexual genotypes. Genomic and transcriptomic sequences were used as templates to perform cloning validations and compare the structure between genotypes with contrasting reproductive modes. The genomic structure shows that EcROS1-like is composed by a total of 10759bp including UTRs, 20 introns and 21 exons. Five different isoforms were found in the facultative cultivar DW and four in the obligate and sexual genotypes. These results will be useful to understand the role of this gene and its alleles and its association with the reproductive mode of Eragrostis curvula.