title: Increasing the source/sink ratio in Vitis vinifera (cv Sangiovese) induces extensive transcriptome reprogramming and modifies berry ripening.
abstract: BACKGROUND
  Cluster thinning is an agronomic practice in which a proportion of berry clusters are removed from the vine to increase the source/sink ratio and improve the quality of the remaining berries. Until now no transcriptomic data have been reported describing the mechanisms that underlie the agronomic and biochemical effects of thinning.
  
  
  RESULTS
  We profiled the transcriptome of Vitis vinifera cv. Sangiovese berries before and after thinning at veraison using a genome-wide microarray representing all grapevine genes listed in the latest V1 gene prediction. Thinning increased the source/sink ratio from 0.6 to 1.2 m2 leaf area per kg of berries and boosted the sugar and anthocyanin content at harvest. Extensive transcriptome remodeling was observed in thinned vines 2 weeks after thinning and at ripening. This included the enhanced modulation of genes that are normally regulated during berry development and the induction of a large set of genes that are not usually expressed.
  
  
  CONCLUSIONS
  Cluster thinning has a profound effect on several important cellular processes and metabolic pathways including carbohydrate metabolism and the synthesis and transport of secondary products. The integrated agronomic, biochemical and transcriptomic data revealed that the positive impact of cluster thinning on final berry composition reflects a much more complex outcome than simply enhancing the normal ripening process.
authors.affiliation: Department of Fruit Tree and Woody Plant Science, University of Bologna,Viale Fanin, 46, 40126, Bologna, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Pastore
authors.forename: Sara
authors.initials: S
authors.lastname: Zenoni
authors.forename: Giovanni Battista
authors.initials: GB
authors.lastname: Tornielli
authors.forename: Gianluca
authors.initials: G
authors.lastname: Allegro
authors.forename: Silvia
authors.initials: S
authors.lastname: Dal Santo
authors.forename: Gabriele
authors.initials: G
authors.lastname: Valentini
authors.forename: Cesare
authors.initials: C
authors.lastname: Intrieri
authors.forename: Mario
authors.initials: M
authors.lastname: Pezzotti
authors.forename: Ilaria
authors.initials: I
authors.lastname: Filippetti
mesh_terms: D017343:Genes, Plant; D020411:Oligonucleotide Array Sequence Analysis; D059467:Transcriptome; D027843:Vitis / Q000235:genetics / Q000378:metabolism*