Humic Acid Confers Oxidative Stress Tolerance by Enhancing the Transcription of Redox Genes in Arabidopsis and Oilseed Rape

초록

Humic acid (HA), a major component of humic substances in soils, is recognized for its role in enhancing plant growth,nutrient uptake, and abiotic stress tolerance. However, the molecular mechanisms underlying HA-mediated oxidative stresstolerance remain unclear. In this study, we investigate the role of HA in enhancing oxidative stress resilience in Arabidopsisthaliana and Brassica napus. Transcriptome analysis and gene ontology enrichment revealed that HA treatment significantlyup-regulates genes associated with oxidative stress responses and cellular homeostasis. Quantitative RT-PCR confirmed theinduction of key redox-related genes, including OXS3, SEN1, and ROXY family members. Physiological assays demonstratedthat HA mitigates methyl viologen (MV)-induced oxidative stress damage, as evidenced by improved chlorophyll contentsand reduced malondialdehyde (MDA) and hydrogen peroxide (H2O2) accumulation. Notably, HA treatment also alleviatedoxidative stress symptoms and reduced MDA levels in B. napus seedlings exposed to MV, supporting HA’s protective rolebeyond model species. These findings suggest that HA primes redox-responsive gene expression and mitigates ROS-induceddamage, offering a promising strategy for improving crop resilience under climate-induced abiotic stress conditions.

키워드