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ORIGINAL RESEARCH article

Front. Plant Sci.

Sec. Crop and Product Physiology

Volume 16 - 2025 | doi: 10.3389/fpls.2025.1653494

This article is part of the Research TopicAdvancements in Light Management Strategies for Crop ProductivityView all 6 articles

Laser diode irradiation mitigates salt stress in rice through coordinated physiological and molecular responses

Provisionally accepted
Feng  ChengFeng Cheng1Yetong  QiYetong Qi1Kangqi  LeiKangqi Lei2Han  YangHan Yang1Yumeng  LeiYumeng Lei1Temoor  AhmedTemoor Ahmed1*Xingjiang  QiXingjiang Qi1Zhitao  LiZhitao Li1
  • 1Xianghu Laboratory, Hangzhou, China
  • 2Agricultural Technology Extension Center of Zhejiang Province, Hangzhou, China

The final, formatted version of the article will be published soon.

Soil salinization affects approximately 20% of cultivated land globally, posing significant threats to rice production and food security. Although conventional approaches have been attempted to enhance salt tolerance in rice; however, several issues have arisen, such as high costs, complexity and application challenges. The potential of laser diode (LD) technology to enhance plant resilience to salinity stress remains underexplored. This study investigated the potential of red-blue LD at a 3:1 ratio and intensities of 5, 10, or 15 μmol m⁻² s⁻¹ PPFD on salt tolerance in rice seedlings using integrated phenotypic, physiological, transcriptomic, and metabolomic analyses. LD-treated seedlings exhibited significantly enhanced growth parameters, including increased plant height, stem diameter, and root morphology as compared with control. Photosynthetic efficiency was substantially improved, with elevated chlorophyll content and enhanced gas exchange parameters. LD treatment maintained ionic homeostasis by reducing Na⁺ accumulation while preserving K⁺ content, resulting in lower Na⁺/K⁺ ratios. Notably, LD treatment at 15 μmol m⁻² s⁻¹ PPFD substantially enhanced the antioxidant enzyme activities such as SOD (63%), POD (62%), CAT (54%), and APX (14%) in rice leaves as compared to control. Correspondingly, oxidative damage markers were significantly reduced, with H₂O₂ and MDA levels decreased while proline accumulation increased. Transcriptome sequencing analysis showed that the application of red-blue laser upregulated the expression of genes related to regulatory pathways such as photosynthesis (OsLhca and OsLhcb), ion homeostasis (OsNHX, OsHKT and OsHAK), and antioxidant defense (OsSOD, OsPOD, OsCAT and OsAPX).Transcriptomic analysis revealed 3,054 upregulated genes involved in photosynthesis, ion transport, and antioxidant pathways. Metabolomic profiling identified enhanced phenylpropanoid biosynthesis, glutathione metabolism, and flavonoid accumulation as key protective mechanisms. This research demonstrates that red-blue LD irradiation Formatted: Font: Italic Formatted: Font: Italic Formatted: Font: Italic Formatted: Font: Italic Formatted: Font: Italic Formatted: Font: Italic Formatted: Font: Italic Formatted: Font: Italic Formatted: Font: Italic represents a promising sustainable technology for enhancing crop resilience to salinity stress through coordinated physiological and molecular responses.

Keywords: Antioxidants, laser diode, salinity stress, rice, ion homeostasis, multi-omics

Received: 25 Jun 2025; Accepted: 25 Aug 2025.

Copyright: © 2025 Cheng, Qi, Lei, Yang, Lei, Ahmed, Qi and Li. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Temoor Ahmed, Xianghu Laboratory, Hangzhou, China

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