J Integr Plant Biol ›› 2026, Vol. 68 ›› Issue (3): 607-627.DOI: 10.1111/jipb.70132

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  • 收稿日期:2025-11-07 接受日期:2025-12-15 出版日期:2026-03-08 发布日期:2026-03-10

The CsRAP2.12–CsERF113L/CsRAP2.7 module positively regulates chlorophyll degradation to impair saline–alkali tolerance in cucumber

Junzheng Wang1,2,3†, Zhenglun Li1,2†, Zhimei Chen1,2, Tao Liu1,2,3, Yong Zhang1,2,3, Zhen Kang1,2,3, Xiangguang Meng1,2,3, Hao Zheng1,2,3, Jiaqi Pan1,2,3, Songshen Hu1,2,3, Guobin Li1,2,3, Zheng Li1,2 and Xiaohui Hu1,2,3*   

  1. 1. College of Horticulture, Northwest A&F University, Yangling 712100, China
    2. Key Laboratory of Protected Horticultural Engineering in Northwest, Ministry of Agriculture and Rural Affairs, Yangling 712100, China
    3. Shaanxi Protected Agriculture Research Centre, Yangling 712100, China
    †These authors contributed equally to this work.
    *Correspondence: Xiaohui Hu (hxh1977@163.com)
  • Received:2025-11-07 Accepted:2025-12-15 Online:2026-03-08 Published:2026-03-10
  • Supported by:
    This work was supported by the China Agriculture Research System (CARS‐23‐D06) and Key Research and Development Program of Shaanxi Province (2024NC‐ZDCYL‐05‐08).

Abstract: Soil salinization poses a global threat to agricultural productivity by degrading arable land. Preventing the rapid degradation of chlorophyll caused by saline–alkali stress is a crucial means to improve plant resistance and productivity. In this study, RNA sequencing identified CsPPH, a pheophytinase-encoding gene that functions as a negative regulator of both photosynthesis and saline–alkali tolerance in cucumber (Cucumis sativus L.). Saline–alkali stress rapidly induces the expression of related to APETALA2 2.12 (CsRAP2.12). Subsequently, CsRAP2.12 activates the transcription of both ethylene response factor 113-like (CsERF113L) and CsRAP2.7, while CsERF113L further transcriptionally regulates CsRAP2.7. CsERF113L promotes chlorophyll degradation and reactive oxygen species (ROS) accumulation both through direct transcriptional upregulation of CsPPH, chlorophyll b reductase (CsNYC1), and chlorophyllase 2 (CsCLH2) and by indirectly stimulating ethylene synthesis via upregulation of 1-aminocyclopropane-1-carboxylic acid synthase 6/9/10 (CsACS6/9/10), thereby impairing photosynthesis and accelerating senescence. CsRAP2.7 indirectly promotes saline–alkali stress-induced chlorophyll degradation and photosynthetic inhibition by facilitating CsERF113L-mediated transcriptional activation of CsPPH, CsCLH2, and CsACS6/9/10. Therefore, knockout of either CsRAP2.12, CsERF113L, or CsRAP2.7 significantly alleviated chlorophyll degradation and enhanced photosynthetic performance under saline–alkali stress, ultimately improving antioxidant capacity and stress tolerance. These findings reveal that the CsRAP2.12–CsERF113L/CsRAP2.7 module promotes saline–alkali stress-induced chlorophyll degradation and photosynthetic inhibition via a dual regulatory mechanism. Genetic disruption of this module significantly improves cucumber tolerance to saline–alkali stress.

Key words: chlorophyll degradation, CsERF113L, cucumber, ethylene synthesis, saline–alkali stress

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