Cultivating Crop Success: The Science of Tomato Branch Control

Lateral branching in tomatoes is a complex genetic trait that directly impacts plant shape and overall productivity. Excessive branching can lead to competition for resources within the plant, ultimately reducing crop yields.

While numerous genes have been linked to branching traits, the intricate genetic network controlling this process has remained largely elusive. This research is a significant step toward unraveling this complexity, laying the groundwork for more optimized tomato plant architectures that could enhance agricultural efficiency.

The study, published in Horticulture Research, was led by a team of researchers from China Agricultural University and Northeast Agricultural University. The scientists explored how the WRKY-B transcription factor interacts with key genes such as BLIND, PIN4, and IAA15, shedding light on how these interactions control lateral branch development in tomatoes.

At the heart of the study is the role of WRKY-B, a regulator induced by auxin. The researchers discovered that WRKY-B directly activates the expression of two genes—BLIND and PIN4—which promote lateral branching. Simultaneously, WRKY-B represses IAA15, a gene known to inhibit bud growth.

By generating CRISPR/Cas9 mutants and overexpression lines, the team demonstrated how manipulating WRKY-B led to significant changes in the number and size of lateral branches. This detailed molecular insight into axillary bud development reveals WRKY-B as a central player in tomato branching, potentially enabling the creation of tomato cultivars with optimized growth patterns, higher yields, and reduced need for labor-intensive pruning.