Genes associated with the end of dormancy in grapes

Abstract

A grape bud EST library was constructed and 4270 ESTs sequenced. The library clones were arrayed for the purpose of investigating the level of gene expression over time, particularly leading up to the buds' release from dormancy. The arrays were hybridized with P(33)-labeled probes produced from samples of buds collected at weekly intervals. These probes covered the time from 9 weeks prior to bud burst until just after the emergence of the shoots. Expression patterns from these genes have been examined. It was found that 74% of the genes in the data set were homologous to known proteins. Genes were then assigned to functional categories according to their primary BLAST match. Of these 13% were involved with photosynthesis, 13% with disease resistance and defense, 5% energy, 12% metabolism, 20% protein production and processing, 25% cell structure and plant growth and the remaining 12% were unclassified The expression pattern of a selection of "candidate" genes retrieved from literature previously reporting an association with dormancy changes was assessed. On closer examination most of these genes relate to the oxidative processes and stress responses within the cell. The results of this study show that even in the dormant state, gene expression in the buds is high.

Similar mechanisms might be triggered by alternative external stimuli that induce dormancy release in grape buds

“…These studies suggest involvement of regulation of gene expression, signaling mechanisms, cell to cell communication and cell cycle in dormancy release (Arora et al 2003;Pang et al 2007;Rohde and Bhalerao 2007). Few large-scale transcription proWling studies, using EST collections and microarrays, may shed light on additional candidate proteins and pathways that might be involved in the regulation and execution of bud dormancy release such as Lea proteins, GTP-binding proteins, Xavonoid biosynthesis and auxin signaling (Pacey-Miller et al 2003;Horvath et al 2005Horvath et al , 2006Keilin et al 2007;Mazzitelli et al 2007;Ruttink et al 2007). Further studies with well deWned experimental systems are needed for the identiWcation of the core cellular processes that are connected with dormancy release.…”

Identification of cis-Elements That Regulate Gene Expression during Initiation of Axillary Bud Outgrowth in Arabidopsis

“…In addition, genes with predicted roles in DNA synthesis, protein synthesis, and cell cycle are used as molecular markers for axillary bud activity (Stafstrom and Sussex, 1992;Devitt and Stafstrom, 1995;Shimizu and Mori, 1998). A large number of genes associated with the end of dormancy have been identified in grape (Vitis vinifera) by using microarray techniques (Pacey-Miller et al, 2003). Although the expression of dormancy-or outgrowthassociated genes has been characterized, the regulatory mechanisms by which gene expression is linked to developmental phases are still unknown.…”

Molecular aspects of dormancy in peach (Prunus persica [L.] Batsch.)

“…Bud break is associated to free radical removal through the activation of peroxide scavenging systems such as catalase, ascorbate peroxidase, superoxide dismutase and glutathione reductase (Pacey Miller et al, 2003;Mazzitelli et al, 2007), when oxidative damages are more probable. (Ingram & Barteles, 1996).…”

“…Renaut et al (2004) found that deactivation of reactive oxygen species and accumulation of dehydrins were some of the most prominent changes in the transcriptomic profile of poplar trees during seasonal chilling. Bud break is associated to free radical removal through the activation of peroxide scavenging systems such as catalase, ascorbate peroxidase, superoxide dismutase and glutathione reductase (Pacey Miller et al, 2003;Mazzitelli et al, 2007), when oxidative damages are more probable.…”