Comparative co-expression network analysis extracts the gene affecting to shoot elongation of tomato.

Tomato is one of vegetables crops that has the highest value in the world. Thus, researchers are continually improving the agronomical traits of tomato fruits. Auxins and gibberellins regulate plant growth and development. / () and the gene encoding the DELLA protein () are well-known genes that regulate plant growth and development, including fruit set and enlargement by cell division and cell expansion. The absence of tomato and results in abnormal shoot growth and leaf shape and giving rise to parthenocarpy. To investigate the key regulators that exist up- or downstream of and signaling pathways for tomato growth and development, we performed gene co-expression network analysis by using publicly available microarray data to extract genes that are directly connected to the and nodes, respectively. Consequently, we chose a gene in the group of ()s that was connected with the node and node in each co-expression network. To validate the extent of effect of on tomato growth and development, overexpressing lines of the target gene were generated. We found that overexpression of the targeted resulted in internode elongation, but the overexpressing lines did not show abnormal leaf shape, fruit set, or fruit size when compared with that of the wild type. Our study suggests that the targeted is likely to function in shoot growth, like and , but it does not contribute to parthenocarpy as well as fruit set. Our study also shows that only a single out of 25 homologous genes could change the shoot length.