Vegetative Branching in Petunia

Abstract

Plant form is established by the response of the plant to endogenous and environmental cues. One architectural process for which genetic components have been identified is the decision for axillary buds to grow. In Petunia, a number of genes involved in the decision to branch have been identified and aspects of their functions are elucidated. The genes altered in the dad mutants appear to be involved in a single pathway that controls branching and to interact with auxin and cytokinins. These genes mediate the production and reception of hormones inducing and suppressing bud outgrowth. Among species there is a high degree of gene conservation in the pathway and the similarities and differences in gene functions have shown the power of using multiple plant systems. The understanding of developmental processes allows controlled modifications to be made, and the continuing research into axillary bud fate will have a significant impact on future improvements to crop species.