In a recent article published in the journal Development, researchers from the University of São Paulo’s Luiz de Queiroz College of Agriculture (ESALQ-USP) in Brazil shed light on crucial mechanisms governing the development of tomato plants (Solanum lycopersicum). Their findings could pave the way for innovative technologies aimed at enhancing tomato yield.
The study focuses on processes occurring at the floral meristem—a region rich in stem cells—related to fruit development in tomato plants. The flowers of the tomato plant consist of both male (androecium) and female (gynoecium) organs, each playing a vital role in the formation of seeds and fruits. Even under ideal pollination and fertilization conditions, the tomato plant’s development relies on the correct interaction of pathways mediated by microRNAs and the hormone gibberellin to initiate ovary development.
Nearly a decade ago, the same research group highlighted the regulatory role of a microRNA called miR156 in shaping the size and structure of the tomato floral meristem. The current study builds on this foundation, revealing the intricate interaction between miR156 and gibberellin during ovary formation in the floral meristem.
To elucidate this process, the researchers analyzed the tomato plant’s transcriptome and manipulated it to modify the levels of both the phytohormone and microRNA. Transgenic plants with enhanced miR156 activity were combined with mutant plants highly responsive to gibberellin. The results demonstrated that when these pathways failed to interact effectively, the floral meristem developed abnormal structures, hindering the formation of locular cavities necessary for seed development.
Fábio Tebaldi Silveira Nogueira, the last author of the article and a researcher at the Plant Development Molecular Genetics Laboratory in ESALQ-USP’s Department of Biological Sciences, emphasized the significance of understanding the interaction between microRNAs and gibberellin. This groundbreaking insight provides a genetic and physiological foundation for manipulating seed production, potentially increasing crop yield and modulating fruit size.
The economic importance of these findings lies in their potential application to improve seed yield in tomatoes, essential for both table and industrial varieties. As the researchers delve deeper into understanding additional pathways for microRNAs and hormones, the goal is to explore ways to influence plant development further, potentially increasing both the number and size of fruits.