Previous research has demonstrated that fruit load acts as a strong inhibitor of flowering in many fruit-tree species, including Citrus. Muñoz-Fambuena et al. analyse the expression of flowering-related genes at the meristem level in alternate-bearing citrus trees, and the interplay between buds and leaves in the determination of flowering. The results suggest that the presence of fruit affects flowering by greatly altering gene expression, not only at the leaf but also at the meristem level. Leaves are required for citrus flowering to occur, and their absence strongly affects the activity of floral promoters and identity genes.
