title: A comparative study of ripening among berries of the grape cluster reveals an altered transcriptional programme and enhanced ripening rate in delayed berries.
abstract: Transcriptional studies in relation to fruit ripening generally aim to identify the transcriptional states associated with physiological ripening stages and the transcriptional changes between stages within the ripening programme. In non-climacteric fruits such as grape, all ripening-related genes involved in this programme have not been identified, mainly due to the lack of mutants for comparative transcriptomic studies. A feature in grape cluster ripening (Vitis vinifera cv. Pinot noir), where all berries do not initiate the ripening at the same time, was exploited to study their shifted ripening programmes in parallel. Berries that showed marked ripening state differences in a véraison-stage cluster (ripening onset) ultimately reached similar ripeness states toward maturity, indicating the flexibility of the ripening programme. The expression variance between these véraison-stage berry classes, where 11% of the genes were found to be differentially expressed, was reduced significantly toward maturity, resulting in the synchronization of their transcriptional states. Defined quantitative expression changes (transcriptional distances) not only existed between the véraison transitional stages, but also between the véraison to maturity stages, regardless of the berry class. It was observed that lagging berries complete their transcriptional programme in a shorter time through altered gene expressions and ripening-related hormone dynamics, and enhance the rate of physiological ripening progression. Finally, the reduction in expression variance of genes can identify new genes directly associated with ripening and also assess the relevance of gene activity to the phase of the ripening programme.
authors.affiliation: Oregon Wine Research Institute, Oregon State University, Corvallis, OR 97331, USA Department of Horticulture, College of Agricultural Sciences, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Satyanarayana
authors.initials: S
authors.lastname: Gouthu
authors.affiliation: Center For Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Shawn T
authors.initials: ST
authors.lastname: O'Neil
authors.affiliation: Department of Statistics, College of Sciences, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Yanming
authors.initials: Y
authors.lastname: Di
authors.affiliation: Department of Botany and Plant Pathology, College of Agricultural Sciences, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Mitra
authors.initials: M
authors.lastname: Ansarolia
authors.affiliation: Department of Botany and Plant Pathology, College of Agricultural Sciences, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Molly
authors.initials: M
authors.lastname: Megraw
authors.affiliation: Oregon Wine Research Institute, Oregon State University, Corvallis, OR 97331, USA Department of Horticulture, College of Agricultural Sciences, Oregon State University, Corvallis, OR 97331, USA laurent.deluc@oregonstate.edu.
authors.forename: Laurent G
authors.initials: LG
authors.lastname: Deluc
mesh_terms: D005638:Fruit / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D020411:Oligonucleotide Array Sequence Analysis; D010937:Plant Growth Regulators / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic; D027843:Vitis / Q000235:genetics* / Q000254:growth & development / Q000502:physiology
chemical_list: D010937:Plant Growth Regulators
keywords: Enhanced ripening; grape; hormone; plasticity; ripening synchronization; transcriptional programme.