Proteomics analysis of two peach cultivars with different susceptibility to chilling injury

FERREYRA, LAURA; GABILONDO, JULIETA; BUDDE, CLAUDIO; MÜLLER, G.L.; DRINCOVICH, MARÍA F.; BUSTAMANTE, CLAUDIA

ROSARIO

Congreso; LIX Annual Meeting SAIB 2023; 2023

Peach is a perishable fruit that deteriorates rapidly once harvested at room temperature. Storage at0°C is employed to prevent fruit decay and extend shelf life. However, this practice can inducephysiological disorders known as 'chilling injury' (CI), which results in a loss of quality. The objective of this study was to analyze and compare the proteome of two peach cultivars, one resistant to CI (Red Globe, RG), and another susceptible to CI (Flordaking, FD), exposed to various post-harvest treatments:in harvested fruits (H), the stage where it reached physiological maturity; in fruits kept in a chamber at 20◦C for 5 days (organoleptic characteristics suitable for consumption), called R (roomtemperature-storage); in fruits stored at 0◦C for 21 days (CS21, cold storage for 21 days); and in fruits stored at 0◦C for 21 days followed by 5 days at 20◦C (CS21+R). Proteins were extracted from mesocarptissue and runned on polyacrylamide gels before sending them to Proteomics Core Facility CEQUIBIEM for Mass Spectrometry analysis. Proteins containing a fold-change ≥2 and p ≤0.05 were considered for the analysis. In the comparison between CS21 and C, RG cultivar shows a high number of upregulated proteins associated with stress resistance, with respect to FD, including Pru p 1.0301, Pru p 1.0201, Stress-response A/B barrel domain-containing proteins, and Dehydrins, which play a role in cold acclimation. In the comparative analysis CS21+R vs R, an increase in the expression of cell wall proteins is observed in RG cultivar, consistent with the progressive loss of firmness during ripening. Conversely, in the case of FD, no significant changes related to these enzymes were evident, which could be indicative of damage to cell wall integrity. Furthermore, the comparison of R vs. C in FD exhibits an increase in these proteins, in accordance to the natural processes of ripening. Finally, in the RG cultivar, it is observed an increased expression of cell wall degradation enzymes in R vs. C and CS21+R vs. R comparisons, indicating a proper fruit maturation process following refrigeration. Previous results have shown that the RG cultivar exhibits an increase in raffinose and galactinol after prolonged cold treatment. As these sugars act as osmoprotectants, they could be linked to the resistance displayed by RG, along with the elevated levels of stress resistance proteins observed in the CS21 vs. C comparison. Keywords: peach, chilling injury, proteomic