The molecular mechanism regulating dormancy release in grapevine buds is as yet unclear. It has been hypothesized that (i) abscisic acid (ABA) represses bud-meristem activity; (ii) perturbation of respiration induces an interplay between ethylene and ABA metabolism, which leads to removal of repression; and (iii) gibberellin (GA)-mediated growth is resumed. The first two hypothesis have been formally supported. The current study examines the third hypothesis regarding the potential involvement of GA in dormancy release. We found that during natural dormancy induction, levels of VvGA3ox, VvGA20ox, and VvGASA2 transcripts and of GA1 were decreased. However, during dormancy release, expression of these genes was enhanced, accompanied by decreased expression of the bud-expressed GA-deactivating VvGA2ox. Despite indications for its positive role during natural dormancy release, GA application had inhibitory effects on bud break. Hydrogen cyanamide up-regulated VvGA2ox and down-regulated VvGA3ox and VvGA20ox expression, reduced GA1 levels, and partially rescued the negative effect of GA. GA had an inhibitory effect only when applied simultaneously with bud-forcing initiation. Given these results, we hypothesize that during initial activation of the dormant bud meristem, the level of GA must be restricted, but after meristem activation an increase in its level serves to enhance primordia regrowth.
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http://dx.doi.org/10.1093/jxb/ery022 | DOI Listing |
BMC Biol
January 2025
College of Life Sciences, South China Agricultural University, Guangzhou, 510642, China.
Background: Grape (Vitis vinifera) crops encounter significant challenges in overcoming bud endodormancy in warm winter areas worldwide. Research on the mechanisms governing bud dormancy release has focused primarily on stress regulation; however, cell wall regulation of bud meristem regrowth mechanism during the dormancy release remains obscure.
Results: In this study, transmission electron microscopy revealed significant changes in the grape bud cell wall following hydrogen cyanamide (HC) treatment, accompanied by an increase in β-1,3-glucanase activity.
Int J Mol Sci
December 2024
Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China.
The lily is a globally popular cut flower, and managing dormancy in lily bulblets is essential for continuous, year-round production. While nitric oxide (NO) has been shown to influence seed dormancy and germination, its role in dormancy release in lilies was previously unconfirmed. In this study, we investigated the effects of NO on dormancy release in lily bulblets using SNP and c-PTIO.
View Article and Find Full Text PDFJ Bacteriol
January 2025
College of Food Science and Nutritional Engineering, National Engineering Research Center for Fruit and Vegetable Processing, Key Laboratory of Fruit and Vegetable Processing of Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory for Food Non-Thermal Processing, China Agricultural University, Beijing, China.
Plant Cell Environ
January 2025
Laboratory of Fruit Tree Biotechnology, College of Horticulture, Nanjing Agricultural University, Nanjing, China.
Curr Issues Mol Biol
December 2024
Institute of Fruit and Floriculture Research, Gansu Academy of Agricultural Sciences, Anning, Lanzhou 730070, China.
During the dormant period of peach trees in winter, flower buds exhibit weak cold resistance and are susceptible to freezing at low temperatures. Understanding the physiological and molecular mechanisms underlying the response of local peach buds to low-temperature adversity is crucial for ensuring normal flowering, fruiting, and yield. In this study, the experimental materials included the conventional cultivar 'Xia cui' (XC) and the cold-resistant local resources 'Ding jiaba' (DJB) peach buds.
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