LONGFLOW · Role of CONSTANS in flower longevity

Flower development plays a critical role in the life cycle of seed plants. Interconnected pathways as vernalization or photoperiod control the transition from vegetative to reproductive growth. On the contrary, flower senescence is considered the final event of flower development in annual plants, because it ultimately leads to the death of the flower. Although, both processes have been extensively studied, the connection between flowering signal and senescence is not yet fully understood. The precise timing of the floral transition is a key decision for a plant that is influenced by internal and external cues. In this sense, the photoperiod pathway regulates the response of the plant to the length of the day and to changes in light-driven circadian rhythms. In Arabidopsis thaliana, the gene CONSTANS (CO) represents a central hub that controls photoperiodic flowering induction. Although poorly understood, it is interesting that CO expression remains at high levels in the shoot apical meristem and floral organs. Why is CO expression maintained in these organs even when the flower developmental program has already been activated? Does it have a second role in flower senescence? The aim of LONGFLOW project is to determine CO expression patterns in flowers, discover its role in autophagy and flower senescence, and modify flower longevity by alteration of CO expression. The hypothesis is that CO, besides inducing flowering, could also induce autophagy and flower senescence through the activation of senescence (SAGs) and autophagy (ATGs) associated genes, as well as a possible role for Jasmonic acid signalling. Thus, by decreasing CO levels specifically in flowers, it could delay autophagy and senescence processes and obtain longer-lived flowers, an interesting applied output of the research activity.