The expression of alternative oxidase and uncoupling protein during fruit ripening in mango

The expression of alternative oxidase (Aox) and uncoupling proteins (Ucp) w as investigated during ripening in mango (Mangifera indica) and compared wi th the expression of peroxisomal thiolase, a previously described ripening marker in mango. The multigene family for the Aox in mango was expressed di fferentially during ripening. Abundance of Aox message and protein both pea ked at the ripe stage. Expression of the single gene for the Ucp peaked at the turning stage and the protein abundance peaked at the ripe stage. Prote ins of the cytochrome chain peaked at the mature stage of ripening. The pat tern of protein accumulation suggested that increases in cytochrome chain c omponents played an important role in facilitating the climacteric burst of respiration and that the Aox and Ucp may play a role in post-climacteric s enescent processes. Because both message and protein for the Aox and Ucp in creased in a similar pattern, it suggests that their expression is not cont rolled in a reciprocal manner but may be active simultaneously.