Fruit growth and maturation is controlled by NAC transcription factors

The fruit is a fundamental botanical organ for the protection, nutrition, and dispersion of the new progeny, which assumes an essential role in the world agricultural economy. Since fruits are important for both their role in the human diet and their biological relevance, it is of great interest to uncover the molecular processes that orchestrate fruit growth, ripening, and senescence. This will also lay the base for future improvement of critical traits, such as yield and quality. Detailed expression analyses during Arabidopsis thaliana valves development were performed in our laboratory, employing an RNA-seq strategy. From this data set, various candidate genes differentially expressed during fruit development were identified that can have a role in the control of Arabidopsis fruit development and maturation. Among all the differentially expressed genes, we focused on the NAC transcription factors family, a large family of plant-specific transcription factors involved in miscellaneous plant functions, including fruit maturation and development. Several NAC mutants, differentially expressed in the valves RNA-seq, were analyzed, and characterized to shed light on the molecular pathway that tunes the silique growth. Although NAC genes form a huge family with more than 100 members, our analyses have shown that even single mutants of some of the NAC genes can have a very strong phenotype at the level of fruit growth, ripening, or senescence. The generation of higher-order mutants will allow us to further elucidate the molecular pathway regulated by the NAC genes that control fruit development.