PagPXYs improve drought tolerance by regulating reactive oxygen species homeostasis in the cambium of Populus alba × P. glandulosa

Cheng Jiang; Jiawei Wang; Xinyue Fu; Chunyan Zhao; Weilin Zhang; Hesheng Gao; Chenhao Zhu; Xueqin Song; Yanqiu Zhao; Yi An; Lichao Huang; Ningning Chen; Meng-Zhu Lu; Jin Zhang

doi:10.1016/j.plantsci.2024.112106

PagPXYs improve drought tolerance by regulating reactive oxygen species homeostasis in the cambium of Populus alba × P. glandulosa

Plant Sci. 2024 Apr 23:344:112106. doi: 10.1016/j.plantsci.2024.112106. Online ahead of print.

Authors

Cheng Jiang¹, Jiawei Wang¹, Xinyue Fu¹, Chunyan Zhao¹, Weilin Zhang¹, Hesheng Gao¹, Chenhao Zhu¹, Xueqin Song², Yanqiu Zhao³, Yi An¹, Lichao Huang¹, Ningning Chen¹, Meng-Zhu Lu⁴, Jin Zhang⁵

Affiliations

¹ State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China.
² State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
³ The Engineering Research Institute of Agriculture and Forestry, Ludong University, 186 Hongqizhong Road, Yantai, Shandong 264025, China.
⁴ State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China. Electronic address: lumz@zafu.edu.cn.
⁵ State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A&F University, Hangzhou, China. Electronic address: zhangj@zafu.edu.cn.

PMID: 38663480
DOI: 10.1016/j.plantsci.2024.112106

Abstract

PXY (Phloem intercalated with xylem) is a receptor kinase required for directional cell division during the development of plant vascular tissue. Drought stress usually affects plant stem cell division and differentiation thereby limiting plant growth. However, the role of PXY in cambial activities of woody plants under drought stress is unclear. In this study, we analyzed the biological functions of two PXY genes (PagPXYa and PagPXYb) in poplar growth and development and in response to drought stress in a hybrid poplar (Populus alba × P. glandulosa, '84K'). Expression analysis indicated that PagPXYs, similar to their orthologs PtrPXYs in Populus trichocarpa, are mainly expressed in the stem vascular system, and related to drought. Interestingly, overexpression of PagPXYa and PagPXYb in poplar did not have a significant impact on the growth status of transgenic plants under normal condition. However, when treated with 8 % PEG6000 or 100 mM H₂O₂, PagPXYa and PagPXYb overexpressing lines consistently exhibited more cambium cell layers, fewer xylem cell layers, and enhanced drought tolerance compared to the non-transgenic control '84K'. In addition, PagPXYs can alleviate the damage caused by H₂O₂ to the cambium under drought stress, thereby maintaining the cambial division activity of poplar under drought stress, indicating that PagPXYs play an important role in plant resistance to drought stress. This study provides a new insight for further research on the balance of growth and drought tolerance in forest trees.

Keywords: Cambial activity; Drought stress; Hydrogen peroxide; PagPXY; Populus.