Jasmonic acid‐isoleucine formation in grapevine (Vitis vinifera L.) by two enzymes with distinct transcription profiles

Abstract

The plant hormone jasmonic acid (JA) is essential for stress responses and the formation of reproductive organs, but its role in fruit development and ripening is unclear. Conjugation of JA to isoleucine is a crucial step in the JA signaling pathway since only JA-Ile is recognized by the jasmonate receptor. The conjugation reaction is catalyzed by JA-amido synthetases, belonging to the family of Gretchen Hagen3 (GH3) proteins. Here, in vitro studies of two grapevine (Vitis vinifera L. cv Shiraz) GH3 enzymes, VvGH3-7 and VvGH3-9, demonstrated JA-conjugating activities with an overlapping range of amino acid substrates, including isoleucine. Expression studies of the corresponding genes in grape berries combined with JA and JA-Ile measurements suggested a primary role for JA signaling in fruit set and cell division and did not support an involvement of JA in the ripening process. In response to methyl JA (MeJA) treatment, and in wounded and unwounded (distal) leaves, VvGH3-9 transcripts accumulated, indicating a participation in the JA response. In contrast, VvGH3-7 was unresponsive to MeJA and local wounding, demonstrating a differential transcriptional regulation of VvGH3-7 and VvGH3-9. The transient induction of VvGH3-7 in unwounded, distal leaves was suggestive of the involvement of an unknown mobile wound signal.

Changes in transcription of cytokinin metabolism and signalling genes in grape (Vitis vinifera L.) berries are associated with the ripening-related increase in isopentenyladenine

“…For the analysis of developmental changes in the expression of cytokinin-related genes and cytokinin levels, Vitis vinifera L. cv. Shiraz berries from a commercial vineyard were collected at weekly intervals as described by Böttcher et al [ 39 ] in the 2010/2011 season. All tissues used for gene expression studies in various grapevine organs were collected from Shiraz plants grown in an experimental vineyard or glasshouse in Adelaide, South Australia [ 39 ].…”

“…Shiraz berries from a commercial vineyard were collected at weekly intervals as described by Böttcher et al [ 39 ] in the 2010/2011 season. All tissues used for gene expression studies in various grapevine organs were collected from Shiraz plants grown in an experimental vineyard or glasshouse in Adelaide, South Australia [ 39 ]. In addition to the Shiraz berry series, cytokinin measurements were also taken from the following samples: 1) Vitis vinifera L. cv.…”

Recent Advances in Hormonal Regulation and Cross-Talk during Non-Climacteric Fruit Development and Ripening

“…Recently, Garrido-Bigotes et al (2018) [51] observed that a synchronized downregulation of the JAs endogenous levels, including JA-Ile, and their biosynthetic genes takes place from flowering to ripening stages of strawberry fruit [51]. Also, higher levels of JA and JA-Ile have been reported in early developing grape berries followed by a sudden reduction during progression to ripe stages [178]. Thus, JA-Ile could be associated with early fruit development in both strawberry and grape berry.…”

Peduncle-girdling of Shiraz (Vitis viniferaL.) bunches and sugar concentration at the time of girdling affect wine volatile compounds

“…Extraction of RNA, cDNA synthesis and quantitative real time polymerase chain reaction Böttcher et al (2013b) have previously described the extraction of RNA, cDNA synthesis and quantitative real time polymerase chain reaction (qRT-PCR), which have been modified by Böttcher et al (2015b). The gene-specific primers and the corresponding accession number for the following genes analysed in this study have been published previously: ACT2 (reference gene, Böttcher et al 2011); ethylene-related genes (Böttcher et al 2013c); ABA-related genes (Wheeler et al 2009); auxin-related genes (Böttcher et al 2011(Böttcher et al , 2013b; and cytokinin-related genes (Böttcher et al 2015a).…”