7 research outputs found
What are the contributions of cytokinins, abscisic acid and sugars in bud outgrowth regulation by light intensity in rose?
In ornamentals, particularly in rose bush, the visual quality of a plant is an important element of its quality. Bud outgrowth, which is at the origin of branching, strongly impacts plant shape and compactness, that are two traits involved in rosebush visual quality (Boumaza et al. 2009).Changes in the environmental conditions, in particular in light intensity, can impact the number of buds that grow out and change bud outgrowth gradient along a stem in various species, including rose (Leduc et al. 2014; Furet et al. 2014). Bud outgrowth is controlled by a network of interacting hormones, the principal ones are auxin, cytokinins and strigolactones, but the role of abscisic acid is also emerging. Sugars are involved in bud outgrowth regulation too and they interact with the hormonal network. A natural hypothesis is that decreasing light intensity may limit bud outgrowth via a shortage in sugars and changes in plant hormonal content. However, the mechanisms by which light intensity affects bud outgrowth, especiallythe respective role of the different hormones and sugars in this regulation, is still poorly understood.The objective of this work was to test if the control of bud outgrowth gradient along the stem by light intensity is mediated by sugars, cytokinins and/or abscisic acid and to assess which of these actors is the main limiting actor. The study was conducted on whole plants and attention was paid to the location of bud outgrowth along the shoot
Moduler la ramification du rosier par la lumière pour pouvoir s’adapter à différentes demandes des consommateurs
Moduler la ramification du rosier par la lumière pour pouvoir s’adapter à différentes demandes des consommateurs. Journée Entreprises-Recherche sur la qualité des produits dans les filières : "arboriculture", "maraîchage", "viticulture", "ornement" et "plantes aromatiques et médicinales
Control by light intensity of bud outgrowth along the axis of Rosa hybrida"Radrazz”
National audienc
What are the contributions of cytokinins, abscisic acid and sugars in bud outgrowth regulation by light intensity in rose?
In ornamentals, particularly in rose bush, the visual quality of a plant is an important element of its quality. Bud outgrowth, which is at the origin of branching, strongly impacts plant shape and compactness, that are two traits involved in rosebush visual quality (Boumaza et al. 2009).Changes in the environmental conditions, in particular in light intensity, can impact the number of buds that grow out and change bud outgrowth gradient along a stem in various species, including rose (Leduc et al. 2014; Furet et al. 2014). Bud outgrowth is controlled by a network of interacting hormones, the principal ones are auxin, cytokinins and strigolactones, but the role of abscisic acid is also emerging. Sugars are involved in bud outgrowth regulation too and they interact with the hormonal network. A natural hypothesis is that decreasing light intensity may limit bud outgrowth via a shortage in sugars and changes in plant hormonal content. However, the mechanisms by which light intensity affects bud outgrowth, especiallythe respective role of the different hormones and sugars in this regulation, is still poorly understood.The objective of this work was to test if the control of bud outgrowth gradient along the stem by light intensity is mediated by sugars, cytokinins and/or abscisic acid and to assess which of these actors is the main limiting actor. The study was conducted on whole plants and attention was paid to the location of bud outgrowth along the shoot
Cytokinins and abscisic acid act antagonistically in the regulation of the bud outgrowth pattern by light intensity
Bud outgrowth is a key process in the elaboration of yield and visual quality in rose crops. Although light intensity is well known to affect bud outgrowth, little is known on the mechanisms involved in this regulation. The objective of this work was to test if the control of bud outgrowth pattern along the stem by photosynthetic photon flux density (PPFD) is mediated by sugars, cytokinins and/or abscisic acid in intact rose plants. Rooted cuttings of Rosa hybrida 'Radrazz' were grown in growth chambers under high PPFD (530 m mol m 2 s 1) until the floral bud visible stage. Plants were then either placed under low PPFD (90 m mol m(-2) s(-1)) or maintained under high PPFD. Bud outgrowth inhibition by low PPFD was associated with lower cytokinin and sugar contents and a higher abscisic acid content in the stem. Interestingly, cytokinin supply to the stem restored bud outgrowth under low PPFD. On the other hand, abscisic acid supply inhibited outgrowth under high PPFD and antagonized bud outgrowth stimulation by cytokinins under low PPFD. In contrast, application of sugars did not restore bud outgrowth under low PPFD. These results suggest that PPFD regulation of bud outgrowth in rose involves a signaling pathway in which cytokinins and abscisic acid play antagonistic roles. Sugars can act as nutritional and signaling compounds and may be involved too, but do not appear as the main regulator of the response to PPFD