文献类型：期刊文献

英文题名：Cambium reactivation independent of bud unfolding involves de novo IAA biosynthesis in cambium regions in Populus tomentosa Carr.

作者：Li, Wan-Feng[1,2] Ding, Qi[1] Cui, Ke-Ming[1] He, Xin-Qiang[1]

第一作者：Li, Wan-Feng;李万峰

通信作者：He, XQ[1]

机构：[1]Peking Univ, State Key Lab Prot & Plant Gene Res, Coll Life Sci, Beijing 100871, Peoples R China;[2]Chinese Acad Forestry, Res Inst Forestry, Cell Biol Lab, Beijing 100091, Peoples R China

年份：2013

卷号：35

期号：6

起止页码：1827-1836

外文期刊名：ACTA PHYSIOLOGIAE PLANTARUM

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000319164500009)】；

基金：This work was supported by the National Key Basic Research Program of China (2012CB114500) and the National Natural Science Foundation of China (31270219, 31200464). The authors thank Ms. Hua-Jun Chen and Wen-Hong Deng (Beijing Forestry University) for help in IAA measurement, Ms. Ai-Qin Song (Peking University) for statistical and image analysis, and Dr. IC Bruce (Zhejiang University) for critical reading of the manuscript.

语种：英文

外文关键词：Cambium reactivation; IAA; De novo IAA biosynthesis; IAA conjugate; Bud unfolding; Populus tomentosa Carr

摘要：Cambium reactivation of temperate trees in spring is important for adaptation and growth. In some trees, the resumption of cambium cell division occurs before bud flush. However, knowledge about the source of the internal stimuli that promote cambium cell division during reactivation in these trees is limited. Here, the anatomical changes of cambium during reactivation along with the unfolding of vegetative buds in Populus tomentosa were examined under natural and water-culture conditions. Meanwhile, the levels of free indole-3-acetic acid (IAA) and transcripts of enzymes involved in its production were measured during cambium reactivation. The results showed that cambium cell division occurred before bud unfolding during cambium reactivation in P. tomentosa. Interestingly, the levels of IAA and the transcripts of poplar homologs of aldehyde oxidase 2 and nitrilases 2 encoding enzymes functioning in de novo IAA biosynthesis increased before bud unfolding, while the transcript levels of IAA conjugate hydrolases almost showed no increase. These results suggest that free IAA from de novo biosynthesis in cambium regions promotes cambium reactivation before bud unfolding, providing new insights into the regulatory mechanism of cambium reactivation.