The Roles of Auxin in Regulating "Shoot Branching'' of Cremastra appendiculata

作者：Lv, Xiang; Zhang, Ming-Sheng^*; Wu, Yan-Qiu; Gao, Xiao-Feng; Li, Xiao-Lan; Wang, Wang-Zhong

来源：Journal of Plant Growth Regulation, 2017, 36(2): 281-289.

DOI：10.1007/s00344-016-9638-6

• Cremastra appendiculata
• Pseudobulb
• Auxin
• Shoot branching
• Decapitation

Cremastra appendiculata (D. Don) Makino is a mainly vegetative propagation terrestrial orchid that is a typical representative of the warm-temperate vegetation in China. In this experiment, we investigated the growth and development process of C. appendiculata leaf buds and examined their biochemical components (proteins, auxin, and cytokinin) to gain insight into the "shoot branching'' of C. appendiculata pseudobulb string. The results showed that the metabolic activity of C. appendiculata pseudobulbs became lower with the increase of pseudobulb age. However, biennial and triennial pseudobulbs have higher auxin levels than annual pseudobulbs in the intact plant (P < 0.05). After decapitation, the auxin rapidly reduces in biennials. The reduction of auxin level promotes cytokinin biosynthesis, which makes the biennial dormant buds start to germinate 18 days after decapitation. These data and phenomena suggested that auxin plays important roles in regulating shoot branching of C. appendiculata, although further studies are needed to consolidate this viewpoint. Our data indirectly support the classical apical dominance theory whereby biennial pseudobulbs are strongly dependent on reduced auxin to initiate leaf bud outgrowth.

• 出版日期2017-6
• 单位贵州大学