Potential molecular mechanism of photosynthesis regulation by PeMPK7 in poplar under para-hydroxybenzoic acid stress

• Published in: Ecotoxicology and environmental safety 2024-05, Vol.276, p.116329-116329, Article 116329
• Main Authors: Gao, Xue, Xin, Di, Zhao, Ye, Li, Junru, Cao, Yangfan, Zhang, Shuyong, Guo, Jing
• Format: Article
• Language: English
• Subjects: Allelopathy; Mitogen-activated protein kinase; Molecular mechanism; Photosynthesis; Poplar
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2024.116329

Due to continuous plantation of poplar, its growth and biomass accumulation may be negatively affected by the accumulation of allelochemicals such as para-hydroxybenzoic acid (pHBA) in soil. As photosynthesis is the most fundamental process in plants, it can be negatively impacted by pHBA stress. Therefore, it is crucial to improve photosynthetic capacity under pHBA stress to facilitate poplar plant growth. The mitogen-activated protein kinase (MAPK) cascade pathway is widely involved in environmental stress responses in plants. However, the regulation mechanisms of photosynthesis-related pathways by MAPK pathway genes under pHBA stress are still unclear. In this study, through transcriptome analysis and weighted gene co-expression network analysis, we observed that PeMPK7 overexpression in poplar can regulate the expression of photosynthesis-related genes and transcription factor genes, namely, WRKY1, WRKY33, and ERF3, during the early stage of pHBA stress. In addition, PeMPK7 can improve photosynthesis in poplar under long-term pHBA stress. Moreover, yeast two-hybrid and pull-down assays confirmed the interaction between PeMPK7 and PeMKK7/10. Based on these results, a schematic diagram of the pathways involved in the regulation of photosynthesis by PeMPK7 was constructed. This study provided novel insights into the molecular mechanisms of regulation of pHBA stress via MAPK cascade pathway. [Display omitted] •PeMPK7 regulates the expression of photosynthesis-related genes and WRKY1, WRKY33, and ERF3.•Overexpression of PeMPK7 improves photosynthesis in poplar under pHBA stress.•The interaction between PeMKK7/10 and PeMPK7 is confirmed.•A pathway of PeMKK3/7/10-PeMPK7-WRKY1/WRKY33/ERF3 respond to pHBA stress was proposed.•A model of PeMPK7 regulating photosynthesis was constructed.