Gibberellin promotes xylem expansion and cell lignification by regulating sugar accumulation and the expression of JcMYB43 and JcMYB63 in the woody plant Jatropha curcas

Yuwu Liao; Zhiyu Zeng; Kai Lin; Weixin Jiang; Jianzhong Wang; Lanjuan Duan; Xiuqing Liang; Yunkai Huang; Zeiwei Han; Hao Hu; Zeng-Fu Xu; Jun Ni

doi:10.1016/j.ijbiomac.2024.139434

Gibberellin promotes xylem expansion and cell lignification by regulating sugar accumulation and the expression of JcMYB43 and JcMYB63 in the woody plant Jatropha curcas

Int J Biol Macromol. 2025 Jan 3:294:139434. doi: 10.1016/j.ijbiomac.2024.139434. Online ahead of print.

Authors

Yuwu Liao¹, Zhiyu Zeng¹, Kai Lin¹, Weixin Jiang¹, Jianzhong Wang², Lanjuan Duan¹, Xiuqing Liang¹, Yunkai Huang¹, Zeiwei Han¹, Hao Hu¹, Zeng-Fu Xu³, Jun Ni⁴

Affiliations

¹ State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, China.
² Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, China; Guangxi Dongmen Forest Farm, Chongzuo 532108, China.
³ State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, China. Electronic address: zfxu@gxu.edu.cn.
⁴ State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry, Guangxi University, Nanning 530004, China; Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, China. Electronic address: nijun@gxu.edu.cn.

PMID: 39756755
DOI: 10.1016/j.ijbiomac.2024.139434

Abstract

Gibberellins (GAs) are a group of diterpene plant hormones that regulate various plant developmental processes, including wood formation. Nevertheless, the regulatory pattern and the downstream targets of GA in the regulation of xylem expansion and cell lignification in woody plants remain unclear. In transgenic Jatropha curcas with significantly increased or decreased bioactive GA content via separate overexpression of JcGA20ox1 or JcGA2ox6, comparative transcriptomic, metabolomic and physiological investigations were conducted on the young stems. Lignin quantification and ultrastructural investigations of the young stems at different development stages revealed that JcGA20ox1 plants presented much faster lignin deposition and xylem expansion even at early development stages. The transcriptomic results revealed that the majority of the differentially expressed genes (DEGs) in the JcGA20ox1 and JcGA2ox6 plants were mainly related to metabolic pathways. Analysis of the DEGs and the gene regulatory network revealed that the increased lignification in JcGA20ox1 plants was due to the activated expression of several key transcription factors and the structural genes in the lignin biosynthesis pathway, which was confirmed by the significantly increased precursors of lignin identified via metabolomic analysis. Interestingly, a total of 15 sugar-related metabolites were differentially regulated, most of which were increased in the xylem of JcGA20ox1, but decreased in JcGA2ox6 plants. Importantly, two key GA-responsive transcription factors JcMYB43 and JcMYB63 were identified to play dual roles in promoting both xylem expansion and cell lignification. Conclusively, this study provides novel insights into the molecular mechanisms of GA-regulated xylem development in the woody plants.

Keywords: GA20ox; GA2ox; Gibberellins; Lignin; MYB; Xylem development.