tb1

tb1 most commonly refers to TEOSINTE BRANCHED1 (TB1), a gene in maize (Zea mays) and other grasses that encodes a TCP family transcription factor involved in regulating shoot architecture. The TB1 protein acts as a negative regulator of lateral branching, promoting apical dominance and limiting the growth of side shoots.

In maize, TB1 was a central player in domestication, helping convert the highly branched teosinte into the single-stem maize phenotype. Differences between teosinte and maize are largely attributed to changes in the regulation of TB1 expression, especially in stem nodes, which leads to reduced tillering and a more streamlined plant form. TB1 functions within a broader network of growth regulators and interacts with other factors that influence bud outgrowth and canopy architecture.

TB1 belongs to the TCP transcription factor family and is conserved across many plant species. Orthologs and functionally related TB1-like genes are found in other cereals such as sorghum and barley, where they also influence tillering or branching patterns. In these species, natural variation in TB1 or its regulatory regions can contribute to differences in plant height, yield components, and adaptation to environments.

Beyond maize and cereals, TB1 is primarily encountered within plant genetics literature as a gene name. The term tb1 may appear in other contexts or fields as an acronym, but its most established meaning remains the maize TB1 gene and its role in controlling shoot branching.