Phytochrome mediated effect on tomato fruit metabolism involves epigenetic regulatory mechanisms

RICARDO BIANCHETTI; NICOLAS BELLORA; LUCIANO FRESCHI; LUISA F. BERMÚDEZ; MAGDALENA ROSSI

Puerto Varas

Congreso; II Molecular Biosystems Conference Eukaryotic Gene Regulation & Functional Genomics; 2019

http://www.molbiosystems.com/

Epigenetic modifications of chromatin structure affect gene expression in plants through DNA methylation and histone modifications. Recent evidences have shown that light-mediated Arabidopsis thaliana transcriptional changes are partially explained by histone deacetylation, and consequently, chromatin remodeling. High light intensity induces a reversible increase of heterochromatin compaction, which in turn, is dependent of crosstalk between PHYTOCHROME B (PHYB) activation and histones deacetylation. However, the impact of PHYB on chromatin remodeling has been exclusively investigated in Arabidopsis. Thus, it is expectable that different mechanisms may appear in fleshy fruit model species Solanum lycopersicum, whose genome possess two PHYB paralogous tomato. Tomato fruit development is strongly regulated in an epigenetic level, it is observed a highly dynamic chromatin remodeling and several changes on cytosine methylation. Then, the enrichment of differentially methylated regions (DMR) and transposable elements into the promoter region of light-regulated genes opens a window to investigate the role of PHY-dependent light perception in the epigenetic regulation of fruit development and ripening. To access this information, transcriptome, siRNAome and meythlome profiles have been analyzed in tomato immature green and breaker fruits in loss-of-function mutants phyb1b2 and the corresponding wild-type genotype. The changes in epigenome status induced by phyb1b2 throughout fruit development will be analyzed in the context of metabolic profiles to gain further information regarding epigenetic mechanisms underneath the control of fruit quality traits. Supported by FAPESP grant Nº 2017/24354-7, 2016/01128-9.