文献类型：期刊文献

英文题名：The transcription factor KNAT2/6b mediates changes in plant architecture in response to drought via down-regulating GA20ox1 in Populus alba x P. glandulosa

作者：Song, Xueqin[1,2] Zhao, Yanqiu[1,3] Wang, Jinnan[1] Lu, Meng-Zhu[1,2,3]

第一作者：Song, Xueqin;宋学勤

通信作者：Lu, MZ[1];Lu, MZ[2];Lu, MZ[3]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, Natl Forestry & Grassland Adm, State Key Lab Tree Genet & Breeding,Key Lab Tree, Beijing 100091, Peoples R China;[2]Nanjing Forestry Univ, Coinnovat Ctr Sustainable Forestry Southern China, Nanjing 210037, Jiangsu, Peoples R China;[3]Zhejiang A&F Univ, Sch Forestry & Biotechnol, State Key Lab Subtrop Silviculture, Hangzhou 311300, Peoples R China

年份：2021

卷号：72

期号：15

起止页码：5625-5637

外文期刊名：JOURNAL OF EXPERIMENTAL BOTANY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000703237800026)】；

基金：We thank Professor Andrew Groover (University of California) for suggestions and comments. This work was supported by the Basic Research Fund of Research Institute of Forestry, Chinese Academy of Forestry (RIF-2014-08), the National Natural Science Foundation of China (31570676), and the Ten-thousand Talents Program of China to M-ZL.

语种：英文

外文关键词：Drought; GA20-oxidase; gibberellin; KNOX; PagKNAT2/6b; poplar

摘要：Plant architecture is genetically controlled, but is influenced by environmental factors. Plants have evolved adaptive mechanisms that allow changes in their architecture under stress, in which phytohormones play a central role. However, the gene regulators that connect growth and stress signals are rarely reported. Here, we report that a class I KNOX gene, PagKNAT2/6b, can directly inhibit the synthesis of gibberellin (GA), altering plant architecture and improving drought resistance in Populus. Expression of PagKNAT2/6b was significantly induced under drought conditions, and transgenic poplars overexpressing PagKNAT2/6b exhibited shorter internode length and smaller leaf size with short or even absent petioles. Interestingly, these transgenic plants showed improved drought resistance under both short- and long-term drought stress. Histological observations indicated that decreased internode length and leaf size were mainly caused by the inhibition of cell elongation and expansion. GA content was reduced, and the GA20-oxidase gene PagGA20ox1 was down-regulated in overexpressing plants. Expression of PagGA20ox1 was negatively related to that of PagKNAT2/6b under drought stress. ChIP and transient transcription activity assays revealed that PagGA20ox1 was directly targeted by PagKNAT2/6b. Therefore, this study provides evidence that PagKNAT2/6b mediates stress signals and changes in plant architecture via GA signaling by down-regulating PagGA20ox1.