Constitutive expression of full-length or partial of genes for yield enhancement in tomato.

Manipulating the expression of flowering pathway genes holds potential for regulating tomato fruit productivity. () is a MADS-box gene that serves as a key integrator in the flowering pathway. In this study, two full-length genes cloned from maize () and soybean (), along with a partial gene from blueberry (, containing the K-domain), were individually transformed into tomato for constitutive expression. Phenotypically, the expression of and , but not , led to early flowering. Most transgenic lines carrying any of the three constructs exhibited a significant increase in fruit number per plant, with gains of 84-161% for , 72-135% for , and 55-96% for K. Notably, compared to non-transgenic controls, all three constructs enhanced fruit yield per plant to varying degrees, including by 81-169%, by 60-112%, and K by 52-88%, primarily through enhanced branching. At the transcriptomic level, comparative analysis of revealed the broader impact of the transformed genes. The increased expression of and appears to explain the unchanged flowering time of the transgenic plants, while the repressed expression of genes likely contributes to enhanced branching. Additionally, numerous genes associated with biotic and abiotic stress tolerance displayed differential expression. These findings demonstrate that constitutive expression of either full-length or partial has the potential to enhance tomato fruit production by modulating multiple pathways, at least at the transcript levels.