The ratio of auxin and cytokinin plays a crucial role in regulating aerial architecture by promoting or repressing axillary bud outgrowth. We have previously identified an Arabidopsis mutant bud2 that displays altered...The ratio of auxin and cytokinin plays a crucial role in regulating aerial architecture by promoting or repressing axillary bud outgrowth. We have previously identified an Arabidopsis mutant bud2 that displays altered root and shoot architecture, which results from the loss-of-function of S-adenosylmethionine decarboxylase 4 （SAMDC4）. In this study, we demonstrate that BUD2 could be induced by auxin, and the induction is dependent on auxin signaling. The mutation of BUD2 results in hyposensitivity to auxin and hypersensitivity to cytokinin, which is confirmed by callus induction assays. Our study suggests that polyamines may play their roles in regulating the plant architecture through affecting the homeostasis of cytokinins and sensitivities to auxin and cytokinin.展开更多
To optimize the regeneration system of Bougainvillea, the effects of different hormone ratios and concentrations on axillary bud induction, proliferation and re-rooting were studied using annual semi-lignified branch ...To optimize the regeneration system of Bougainvillea, the effects of different hormone ratios and concentrations on axillary bud induction, proliferation and re-rooting were studied using annual semi-lignified branch cuttings of Bougainvillea ‘Yunnan Purple’ as experimental materials. The results showed that MS+6-BA 2.5 mg/L+NAA 0.1 mg/L was the optimal medium for stem axillary bud initiation, and the initiation rate reached 91.3%. The optimal medium for axillary bud proliferation was MS+6-BA 1.0 mg/L+NAA 0.2 mg/L, and the proliferation coefficient was 3.28. The optimal rooting medium was 1/2 MS+IBA 1.0 mg/L, with the rooting rate of 90% and the average root number of 7.4. After 15 d of hardening seedling, the survival rate of the sterile seedlings was 97.83%. This study laid a basis for rapid propagation and genetic transformation system of Bougainvillea.展开更多
基金We thank Dr Ottoline Leyser （University of York, UK） for providing axrl-3 and Dr Mark Estelle （UC, San Diego, USA） for providing tirlafb2afb3 triple mutant seeds. This work was supported by a grant from the National Natural Science Foundation of China （30830009）.
文摘The ratio of auxin and cytokinin plays a crucial role in regulating aerial architecture by promoting or repressing axillary bud outgrowth. We have previously identified an Arabidopsis mutant bud2 that displays altered root and shoot architecture, which results from the loss-of-function of S-adenosylmethionine decarboxylase 4 （SAMDC4）. In this study, we demonstrate that BUD2 could be induced by auxin, and the induction is dependent on auxin signaling. The mutation of BUD2 results in hyposensitivity to auxin and hypersensitivity to cytokinin, which is confirmed by callus induction assays. Our study suggests that polyamines may play their roles in regulating the plant architecture through affecting the homeostasis of cytokinins and sensitivities to auxin and cytokinin.
文摘To optimize the regeneration system of Bougainvillea, the effects of different hormone ratios and concentrations on axillary bud induction, proliferation and re-rooting were studied using annual semi-lignified branch cuttings of Bougainvillea ‘Yunnan Purple’ as experimental materials. The results showed that MS+6-BA 2.5 mg/L+NAA 0.1 mg/L was the optimal medium for stem axillary bud initiation, and the initiation rate reached 91.3%. The optimal medium for axillary bud proliferation was MS+6-BA 1.0 mg/L+NAA 0.2 mg/L, and the proliferation coefficient was 3.28. The optimal rooting medium was 1/2 MS+IBA 1.0 mg/L, with the rooting rate of 90% and the average root number of 7.4. After 15 d of hardening seedling, the survival rate of the sterile seedlings was 97.83%. This study laid a basis for rapid propagation and genetic transformation system of Bougainvillea.
