2019 ASHS Annual Conference

Proteasomes are protein complexes which degrade unneeded or damaged proteins by proteolysis and play critical roles in the control of plant development and responses to the environment stresses. However, the mechanism of how proteasome mediated targeted proteins turnover during fruit development is still unclear. Here, we tested the function of a core proteasome subunit in tomato. We generated transgenic tomato plants with repression of SlPBB2 in the fruit by RNA interference (RNAi) using a fruit-specific promoter. Down–regulation of SlPBB2 in tomato fruit delayed tomato fruit ripening, induced Blossom-end rot (BER) of tomato and reduced chlorophyll biosynthesis that is positively correlated with the nutrient content and flavor of ripe fruit. These findings provide evidence for the role of proteasome in promoting fruit ripening and establish that SlPBB2 contributes to fruit quality. The underlying mechanisms that lead to the fruit phenotypes will be discussed.