Artículo de revista
Proteomic analysis of peach fruit mesocarp softening and chilling injury using difference gel electrophoresis (DIGE)
Autor
Nilo Poyanco, Ricardo
Saffie, Carlos
Lilley, Kathryn
Baeza Yates, Ricardo
Cambiazo Ayala, Liliana
Campos Vargas, Reinaldo
González Canales, Mauricio
Meisel, Lee
Retamales Aranda, Julio
Silva Ascencio, Herman
Orellana López, Ariel
Institución
Resumen
Background: Peach fruit undergoes a rapid softening process that involves a number of metabolic changes.
Storing fruit at low temperatures has been widely used to extend its postharvest life. However, this leads to
undesired changes, such as mealiness and browning, which affect the quality of the fruit. In this study, a 2-D DIGE
approach was designed to screen for differentially accumulated proteins in peach fruit during normal softening as
well as under conditions that led to fruit chilling injury.
Results: The analysis allowed us to identify 43 spots -representing about 18% of the total number analyzed- that
show statistically significant changes. Thirty-nine of the proteins could be identified by mass spectrometry. Some of
the proteins that changed during postharvest had been related to peach fruit ripening and cold stress in the past.
However, we identified other proteins that had not been linked to these processes. A graphical display of the
relationship between the differentially accumulated proteins was obtained using pairwise average-linkage cluster
analysis and principal component analysis. Proteins such as endopolygalacturonase, catalase, NADP-dependent
isocitrate dehydrogenase, pectin methylesterase and dehydrins were found to be very important for distinguishing
between healthy and chill injured fruit. A categorization of the differentially accumulated proteins was performed
using Gene Ontology annotation. The results showed that the ‘response to stress’, ‘cellular homeostasis’,
‘metabolism of carbohydrates’ and ‘amino acid metabolism’ biological processes were affected the most during the
postharvest.
Conclusions: Using a comparative proteomic approach with 2-D DIGE allowed us to identify proteins that showed
stage-specific changes in their accumulation pattern. Several proteins that are related to response to stress, cellular
homeostasis, cellular component organization and carbohydrate metabolism were detected as being differentially
accumulated. Finally, a significant proportion of the proteins identified had not been associated with softening,
cold storage or chilling injury-altered fruit before; thus, comparative proteomics has proven to be a valuable tool
for understanding fruit softening and postharvest.