Understanding abscission is both a biological and an agronomic challenge. Flowerabscission induced independently by shade and gibberellic acid (GAc) sprays wasmonitored in grapevine (Vitis vinifera L.) growing under a soilless greenhouse systemduring two seasonal growing conditions, in an early and late production cycle.Physiological and metabolic changes triggered by each of the two distinct stimuli weredetermined. Environmental conditions exerted a signiﬁcant effect on fruit set as showedby the higher natural drop rate recorded in the late production cycle with respect tothe early cycle. Shade and GAc treatments increased the percentage of ﬂower dropcompared to the control, and at a similar degree, during the late production cycle.The reduction of leaf gas exchanges under shade conditions was not observed inGAc treated vines. The metabolic proﬁle assessed in samples collected during thelate cycle differently affected primary and secondary metabolisms and showed thatmost of the treatment-resulting variations occurred in opposite trends in inﬂorescencesunbalanced in either hormonal or energy deﬁcit abscission-inducing signals. Particularlyconcerning carbohydrates metabolism, sucrose, glucose, tricarboxylic acid metabolitesand intermediates of the rafﬁnose family oligosaccharides pathway were lower in shadedand higher in GAc samples. Altered oxidative stress remediation mechanisms andindolacetic acid (IAA) concentration were identiﬁed as abscission signatures commonto both stimuli. According to the global analysis performed, we report that grape ﬂowerabscission mechanisms triggered by GAc application and C-starvation are not basedon the same metabolic pathways.
|Numero di pagine||18|
|Rivista||Frontiers in Plant Science|
|Stato di pubblicazione||Published - 2015|
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