S23 - Session O3 - Effect of growing season on ethylene biosynthesis pathway during fruit ripening and post-harvest storage

Authors: Maarten Hertog *, Minh Viet Thao Nguyen , Thi Dinh Tran, Bart Nicolai

This study is devoted to understanding the effect of growing season on the ethylene biosynthesis of a heat tolerant tomato cv. Savior. Tomato grown in winter and summer were sampled from the vine from immature green, to the red ripe stage. Additionally, harvested red ripe fruit was sampled after 6 and 12 d of storage. Quality attributes, 1-Aminocyclopropane-1-carboxylic acid (ACC) and malonylaminocyclopropane-1-carboxylic (MACC), activities and gene expression of ACC oxidase (ACO) and ACC synthase (ACS) were analysed including 6 isoforms for ACO and 9 for ACS. Winter and summer tomato shared the same changes in physical property during fruit development, ripening and postharvest storage also showing a similar climacteric pattern of ethylene production throughout fruit development and ripening. During postharvest storage, ethylene production strongly increased in summer tomato whereas it declined in winter fruit as usual. The results suggest that the growing season noticeably affects the transcriptional levels of ethylene biosynthesis although there is no clear difference in phenotypes nor in ACO and ACS enzymatic activities. Work at the proteomic level is ongoing to characterise the molecular events underpinning the ripening of tomato cv. Savior grown in different seasons.