ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Expansin protein levels decline with the development of mealiness in peaches.

David M. Obenland, Carlos H. Crisosto, Jocelyn K.C. Rose

Postharvest Biology and Technology 29 (2003) 11-18

2003

บทคัดย่อ

Expansin mRNA and protein expression in peaches was examined to investigate the possibility that expansins may be involved in the development of mealy flesh texture. Immunoblot analysis, using an expansin antibody, detected a 27-kDa protein corresponding to the predicted molecular mass ofexpansins in the later stages of ripening but not in fullsize green fruit and indicated that expansin is associated with the progression of ripening in peaches. Peach cultivars ‘O’Henry’ and ‘Summer Lady’ were stored at 5 ºC to induce the development of mealiness and individual fruit samples collected periodically to measure mealiness (free water) and provide samples for expansin quantification. Initially, stored fruit were juicy (50-/60% free water), but as storage progressed they became visibly mealy at free water percentages of 30% for ‘O’Henry’ and 46% for ‘Summer Lady’. In both cultivars expansin protein abundance decreased as the fruit became mealy. Development of mealiness within individual fruit was often not uniform and lead to the existence of distinct juicy and mealy regions. Immunoblot analysis indicated that mealy regions contained substantially less expansin than juicy regions. Analysis of expansin mRNA abundance using a ripening-related expansin cDNA probe from peach indicated that expansin mRNA expression was also markedly reduced in mealy tissues. The relationship observed in this study between expansin expression and mealiness suggests a possible role for expansin in the development of the disorder.