Apomixis expression in Eragrostis curvula under water stress conditions

RODRIGO JM; ZAPPACOSTA D; SELVA JP; VIVIANA ECHENIQUE

Foz de Iguazú

Congreso; XI International Plant Molecular Biology Congress; 2015

IPMB

Stress is an important aspect to explain the evolutionary role of sex in organisms with facultative reproductive mode. There are numerous cases in which under certain stress conditions, different organisms change their reproductive mode or expression thereof. In previous assays cytoembryological studies and progeny tests in plants of in weeping lovegrass showed that under water stress situations the ratio between sexual and apomictic embryo sacs increased. To evaluate a possible epigenetic effect in controlling this ratio, genetic (AFLP) and epigenetic (MSAP) profiles were analyzed during and after a water stress period. No genetic changes over time were observed. However, the MSAP profiles showed changes in DNA methylations and de-methylations and a high correlation (R2 = 0.8) between the percentage of changes over time and the number of sexual embryo sacs. The sequencing of the differentially methylated bands showed a high number (45 %) of sequences without homology to previously annotated sequences, being probably noncoding regions or unknown genes. Most of the other sequences (39%) only showed identity with the genome of Eragrostis teff, also no annotated. The rest of the sequences were mainly transposable elements. These results indicate that both pathways -apomictic and sexual- are active and co-exist in apomictic plants and stresses de-repress sexuality probably as a survival strategy.