title: Grapevine Rootstocks Differentially Affect the Rate of Ripening and Modulate Auxin-Related Genes in Cabernet Sauvignon Berries.
abstract: In modern viticulture, grafting commercial grapevine varieties on interspecific rootstocks is a common practice required for conferring resistance to many biotic and abiotic stresses. Nevertheless, the use of rootstocks to gain these essential traits is also known to impact grape berry development and quality, although the underlying mechanisms are still poorly understood. In grape berries, the onset of ripening (véraison) is regulated by a complex network of mobile signals including hormones such as auxins, ethylene, abscisic acid, and brassinosteroids. Recently, a new rootstock, designated M4, was selected based on its enhanced tolerance to water stress and medium vigor. This study investigates the effect of M4 on Cabernet Sauvignon (CS) berry development in comparison to the commercial 1103P rootstock. Physical and biochemical parameters showed that the ripening rate of CS berries is faster when grafted onto M4. A multifactorial analysis performed on mRNA-Seq data obtained from skin and pulp of berries grown in both graft combinations revealed that genes controlling auxin action (ARF and Aux/IAA) represent one of main categories affected by the rootstock genotype. Considering that the level of auxin tightly regulates the transcription of these genes, we investigated the behavior of the main gene families involved in auxin biosynthesis and conjugation. Molecular and biochemical analyses confirmed a link between the rate of berry development and the modulation of auxin metabolism. Moreover, the data indicate that this phenomenon appears to be particularly pronounced in skin tissue in comparison to the flesh.
authors.affiliation: Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova AgripolisLegnaro, Italy; Centro Interdipartimentale per la Ricerca in Viticoltura e Enologia, University of PadovaConegliano, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Corso
authors.affiliation: Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova AgripolisLegnaro, Italy; Centro Interdipartimentale per la Ricerca in Viticoltura e Enologia, University of PadovaConegliano, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Vannozzi
authors.affiliation: Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova Agripolis Legnaro, Italy.
authors.forename: Fiorenza
authors.initials: F
authors.lastname: Ziliotto
authors.affiliation: Genomics and Biotechnology of Fruit Laboratory, Institut National Polytechnique de Toulouse Toulouse, France.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Zouine
authors.affiliation: Genomics and Biotechnology of Fruit Laboratory, Institut National Polytechnique de Toulouse Toulouse, France.
authors.forename: Elie
authors.initials: E
authors.lastname: Maza
authors.affiliation: Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova Agripolis Legnaro, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Nicolato
authors.affiliation: Centro di Ricerca Interdipartimentale per le Biotecnologie Innovative, University of Padova Padova, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Vitulo
authors.affiliation: Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova AgripolisLegnaro, Italy; Centro Interdipartimentale per la Ricerca in Viticoltura e Enologia, University of PadovaConegliano, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Meggio
authors.affiliation: Centro di Ricerca Interdipartimentale per le Biotecnologie Innovative, University of Padova Padova, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Valle
authors.affiliation: Genomics and Biotechnology of Fruit Laboratory, Institut National Polytechnique de Toulouse Toulouse, France.
authors.forename: Mondher
authors.initials: M
authors.lastname: Bouzayen
authors.affiliation: Department of Vegetal Biology, University of Barcelona Barcelona, Spain.
authors.forename: Maren
authors.initials: M
authors.lastname: Müller
authors.affiliation: Department of Vegetal Biology, University of Barcelona Barcelona, Spain.
authors.forename: Sergi
authors.initials: S
authors.lastname: Munné-Bosch
authors.affiliation: Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova AgripolisLegnaro, Italy; Centro Interdipartimentale per la Ricerca in Viticoltura e Enologia, University of PadovaConegliano, Italy.
authors.forename: Margherita
authors.initials: M
authors.lastname: Lucchin
authors.affiliation: Department of Agronomy, Food, Natural resources, Animals and Environment, University of Padova AgripolisLegnaro, Italy; Centro Interdipartimentale per la Ricerca in Viticoltura e Enologia, University of PadovaConegliano, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Bonghi
keywords: auxin conjugation; fruit development; grapevine; polyphenols biosynthesis; transcriptional program