Involvement of CARPO-NAC in ripening progression in grapevine

E. D’Incà, C. Foresti, A. Amato, G.B. Tornielli, S. Zenoni
Grapevine is the most widely cultivated and economically important fruit crop in the world. Viticulture has been affected by the global warming currently under way over the past few decades. Improving the genetics of key grapevine functions is needed to keep producing high quality grapes and wine. In this context, a challenging task is to identify master regulators that program the development of grapevine organs and control transition from vegetative-to-mature growth featured by grape berries during the annual plant cycle. This transition (véraison) is marked by profound biochemical, physiological and transcriptomic modifications that allow vegetative green berries to enter the ripening process. Thanks to an integrated network analysis performed on the grapevine global gene expression atlas and from a large berry transcriptomic data set a new category of genes, called switch genes, was identified; they were significantly upregulated during the developmental shift and inversely correlated with many genes suppressed during the mature growth phase. Among them, plant-specific NAM/ATAF/CUC (NAC) transcription factors represent an interesting gene family due to their key role in the biological processes in plant development and stress responses. This work was focused on the study of the role of VviNAC60, which we renamed VviCARPO (controlled adjustment of ripening and maturation in plant organs), identified as a putative key regulator of grapevine maturation. We analysed its expression profile of the different grapevine organs and developmental stages, we identified its co-expressed genes and finally we transiently transformed Nicotiana benthamiana leaves to obtain an overview on its primary effects on plant. Taken together, these results suggested the ability of CARPO to affect the expression of genes involved in the organ phase transition and supported our working hypothesis proposing the transcription factor as key regulator of this transcriptome reprogramming during grapevine development by controlling different ripening- and senescence-related processes.
D’Incà, E., Foresti, C., Amato, A., Tornielli, G.B. and Zenoni, S. (2024). Involvement of CARPO-NAC in ripening progression in grapevine. Acta Hortic. 1390, 121-128
DOI: 10.17660/ActaHortic.2024.1390.15
NAC transcription factor, switch gene, phase transition, grapevine ripening, senescence

Acta Horticulturae