Journal of Experimental Botany

Kwame Acheampong, A., Institute of Plant Sciences, Department of Fruit Tree Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel;

Halaly, T., Institute of Plant Sciences, Department of Fruit Tree Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel;

Kamiya, Y., RIKEN Plant Science Center, Yokohama, Kanagawa, Japan;

Galbraith, D.W., School of Plant Sciences and Bio5 Institute, University of Arizona, Tucson, AZ, United States

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 GA 1 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 GA 1 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. © The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Institute of Plant Sciences, Department of Fruit Tree Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel; College of Life Sciences, South China Agricultural University, Guangzhou, China; RIKEN Plant Science Center, Yokohama, Kanagawa, Japan; School of Plant Sciences and Bio5 Institute, University of Arizona, Tucson, AZ, United States

פותח על ידי קלירמאש פתרונות בע"מ -
הספר "אוצר וולקני"
אודות
תנאי שימוש
Distinct gibberellin functions during and after grapevine bud dormancy release
69

Kwame Acheampong, A., Institute of Plant Sciences, Department of Fruit Tree Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel;

Halaly, T., Institute of Plant Sciences, Department of Fruit Tree Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel;

Kamiya, Y., RIKEN Plant Science Center, Yokohama, Kanagawa, Japan;

Galbraith, D.W., School of Plant Sciences and Bio5 Institute, University of Arizona, Tucson, AZ, United States

Distinct gibberellin functions during and after grapevine bud dormancy release

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 GA 1 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 GA 1 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. © The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Scientific Publication