Acta Agriculturae Zhejiangensis ›› 2026, Vol. 38 ›› Issue (1): 54-66.DOI: 10.3969/j.issn.1004-1524.20250366

• Horticultural Science • Previous Articles     Next Articles

The influence of Rhizophagus irregularis on the growth and gene expression of tomato under cadmium stress

LIU Junli1(), JIANG Jianfeng2, DONG Xiangwei2, YANG Haijun2, BAO Xiaoqi1,3, FU Chenxi1, GUO Bin1, TONG Wenbin2,*()   

  1. 1. Institute of Environment, Resource, Soil and Fertilizer, State Key Laboratory for Quality and Safety of Agro-Products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
    2. Qujiang District Agricultural Technology Promotion Center, Quzhou 324022, Zhejiang, China
    3. College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
  • Received:2025-03-14 Online:2026-01-25 Published:2026-02-11

Abstract:

Arbuscular mycorrhizal fungi (AMF) play a significant role in regulating plant cadmium (Cd) tolerance, but the molecular mechanisms underlying their effects on tomato growth and Cd accumulation remain unclear. To investigate the mechanisms by which AMF inoculation enhances tomato Cd tolerance, a sand culture experiment was conducted to study the effects of inoculating Rhizophagus irregularis (Ri) under 100 μmol·L-1 Cd stress on tomato growth, Cd content, antioxidant enzyme activities, root cell ultrastructure, and gene expression. The enrichment characteristics of differentially expressed genes (DEGs) were analyzed through GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses. The results showed that Cd stress inhibited tomato growth, significantly reduced root peroxidase (POD) and superoxide dismutase (SOD) activities, and caused severe damage to cell ultrastructure. Compared with non-inoculated Ri treatment, under Cd stress, Ri inoculation significantly increased tomato aboveground biomass by 27%, significantly reduced root and shoot Cd content by 40% and 38%, respectively, significantly enhanced root ascorbate peroxidase (APX) and SOD activities by 45.27% and 46.35%, respectively, and alleviated cell ultrastructure damage. GO enrichment analysis revealed that DEGs from both comparison groups (control vs. Cd treatment alone and Cd treatment alone vs. Cd+Ri co-treatment) were significantly enriched in three branches: biological processes (metabolism, stress response, etc.), cellular components (membrane, organelles, etc.), and molecular functions (catalysis, transport, antioxidant activity, etc.). Cd+Ri co-treatment group involved a greater number of DEGs across all branches. KEGG enrichment analysis indicated that DEGs from the control vs. Cd treatment alone comparison were significantly enriched in 110 metabolic pathways, while DEGs from the Cd treatment alone vs. Cd+Ri co-treatment comparison were significantly enriched in 118 metabolic pathways, primarily including key pathways such as phenylalanine metabolism, plant hormone signal transduction, and ABC transporters. Heatmap analysis showed that the specific high expression of genes containing LysM domains (upregulated 14-fold), PDR genes (upregulated 12.6-fold), and multiple kinase genes (upregulated>9-fold) were important molecular features of AMF-mediated heavy metal detoxification. This study suggests that Ri might enhance tomato physiological adaptation to Cd stress, thereby promoting growth and improving stress resistance, by coordinately regulating multiple key pathways such as phenylalanine metabolism, ABC transporters, plant hormone signal transduction, and defense responses, thereby constructing a systematic heavy metal stress response network. The findings provided a theoretical basis and candidate gene resources for the technical application of AMF in reducing Cd accumulation in crops.

Key words: tomato, arbuscular mycorrhizal fungi, growth, cadmium, differentially expressed gene

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