Characterization of the protein of unknown function DUF642 in peach fruits: analysis of your participation in cold tolerance

GABILONDO J.; DRINCOVICH M. F.; BUSTAMANTE C.; BUDDE C.; GISMONDI M.; LARA M. V.

Buenos Aires

Conferencia; Humboldt Colloquium "Shaping the future of German-Argentinian scientific cooperation - The role of curiosity - driven research"; 2018

Alexander von Humboldt Foundation

DUF642 (Domains of Unknown Function 642) is a highly conserved plant-specific family of unknown cell wall-associated proteins. Although proteins in this family have been detected in cell wall proteomes from a variety of plants and tissues, functional studies on this protein family are scarce. In this work, a DUF642 protein was identified in the extracellular proteome of peach fruits. PpDUF642 markedly decreased in Dixiland peaches subjected to heat treatment (HT, 3 days at 39°C), a postharvest storage condition that is effective in delaying softening and preventing some chilling injury (CI) symptoms that this fruit exhibits when is stored at low temperatures. Analysis of PpDUF642 sequence indicates possible posttranslational modifications and the presence of putative galactose-binding domains. In addition, PpDUF642 protein architecture was compared with the one of its orthologs and its structure was predicted by using the I-TASSER software. Relative transcript levels for PpDUF642 were analyzed during peach development and ripening, showing the highest levels at harvest. In varieties with different susceptibility to CI, PpDUF642 mRNA accumulated differentially after cold storage. Comparative promoter analysis of phylogenetic-clustered orthologues from different species allowed us to identify conserved cis elements which would account for the diversity of stimuli that may regulate DUF642 expression, especially those related with temperature stress. Finally, cell wall-localization of this protein was confirmed by transient expression of PpDUF642-GFP in tomato fruits. Overall, the results obtained indicate that PpDUF642 could be playing a role in the cell wall metabolism of peach fruit. However, additional work is required to establish the participation of this protein in the protection against CI and in the softening process.