Related Experiment Video
Updated: Aug 17, 2025

Quantification of Endogenous Auxin and Cytokinin During Internode Culture of Ipecac
Published on: March 15, 2018
Auxin and CmAP1 regulate the reproductive development of axillary buds in Chinese chestnut (Castanea mollissima)
Yunhe Cheng1, Lili Cheng1, Guanglong Hu1
1Engineering and Technology Research Center for Chestnut of National Forestry and Grassland Administration, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China) of Ministry of Agriculture, Beijing Engineering Research Center for Deciduous Fruit Trees, Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Ruiwangfeng No. 12, Haidian, Beijing, 100093, China.
Key Message:
Auxin accumulation upregulates the expression of APETALA1 (CmAP1) and subsequently activates inflorescence primordium development in axillary buds of chestnut. The architecture of fruiting branches is a key determinant of chestnut yield. Normally, axillary buds at the top of mother fruiting branches develop into flowering shoots and bear fruits, and the lower axillary buds develop into vegetative shoots. Decapitation of the upper axillary buds induces the lower buds to develop into flowering shoots. How decapitation modulates the tradeoff between vegetative and reproductive development is unclear. We detected inflorescence primordia within both upper and lower axillary buds on mother fruiting branches. The level of the phytohormones 3-indoleacetic acid (IAA) and trans-zeatin (tZ) increased in the lower axillary buds in response to decapitation. Exogenous application of the synthetic analogues 1-naphthylacetic acid (NAA) or 6-benzyladenine (6-BA) blocked or promoted, respectively, the development of the inflorescence primordia in axillary buds. The transcript levels of the floral identity gene CmAP1 increased in axillary buds following decapitation. An auxin response element TGA-box is present in the CmAP1 promoter and influenced the CmAP1 promoter-driven expression of β-glucuronidase (GUS) in floral organs in Arabidopsis, suggesting that CmAP1 is induced by auxin. We propose that decapitation releases axillary bud outgrowth from inhibition caused by apical dominance. During this process, decapitation-induced accumulation of auxin induces CmAP1 expression, subsequently promoting the reproductive development of axillary buds.
Related Concept Videos
C4 Pathway and CAM
C4 Pathway
The C4 pathway is used by plants such as...
Primary and Secondary Growth in Roots and Shoots
Morphogenesis
Cell Signaling in Plants
Adaptations that Reduce Water Loss
Meristems and Plant Growth

