The microsynteny of genes functionally related with the fruit ripening process in Solanaceae species.

CACCHIARELLI, P; ARCE, DÉBORA P; EZPELETA, JOAQUÍN; PRATTA, GUILLERMO; TAPIA, ELIZABETH; KRSTICEVIC, FLAVIA J

Buenos Aires

Conferencia; ISCB-Latin America Conference 2016 y 7mo CA2BC; 2016

A2B2C

Small heat shock proteins (sHSP) are induced during tomato (Solanum ycopersicum)ripening, a model species for fleshy fruits, to maintain cellular homeostasis. Previous analysis identified 4 cytosolic class I (CI) sHSP genes mapping together with a 17.9 kbp region of chromosome 6 in S. lycopersicum cv. Heinz 1706 that are highly abundant and strongly induced during ripening. We evaluated the gene microsynteny of the chromosome 6 region across related Solanaceae species. We considered the genomes (g) and transcriptomes (tr) of 2 commercial tomato cultivars (Heinz 1706 (g) and Ohio 824 (g)), 2 accessions (LA1589 (g, tr) and LA0722 (g)) of the wild red­fruited S. pimpinellifolium, 2 wild green­fruited species (S. pennelli and S. peruvianum) and 3 related Solanaceae species (S. tuberosum (g, tr), S. melongena (g) and Capsicum annuum (g)). Gene microsynteny revealed variability in the number and position of genes, frequent gene movement during evolution,showing 8 gene gain/loss events. Phylogenetic analysis suggests that new chromosome configurations originated from the tomato and potato ancestors (~8 mya). Comparison of Ka/Ks ratios indicates that orthologous and paralogous CI sHSP genes are highly conserved due to strong negative selection. Differencesin the number of CIsHSP genes were observed among S. pimpinellifolium accessions, a lower number of CI sHSP genes being putatively associated to a shorter fruit shelf life. Increasing knowledge on co­localized and functionallyrelated genes in tomato wild species facilitatesintrogression of natural genetic variations in breeding programs, allowing a more efficient development of new commercial varieties.