allele showed attenuated catalytic efficiency and weaker promotion of ADP-glucose pyrophosphorylase and SS1, leading to less starch accumulation and allowing a greater share of carbon to bypass the starch pool and accumulate as soluble sugars in fruit cells. This study advances our understanding of carbon flux in fruits and demonstrates how a naturally occurring thioredoxin variant functions as a molecular switch for carbon partitioning, ultimately determining fruit sweetness. The derived dCAPS marker enables rapid marker-assisted selection or precision editing of fruit sweetness, offering immediate applications for apple breeding.
Yuan et al. (Fri,) studied this question.