Root-knot nematodes (
Meloidogyne
spp.) are devastating plant pathogens that cause substantial economic losses worldwide. This study uses RNA-seq to profile the transcriptomic responses of
M. incognita
to the culture supernatant of
Streptomyces
sp. TR27, a strain previously shown to induce 67.6% calibrated mortality against
M. incognita
second-stage juveniles at 48 h. At 12 h post treatment, 231 differentially expressed genes (DEG) were identified, including 114 up-regulated and 117 down-regulated genes. Down-regulated genes were enriched in the pathways related to lysosome (lysosomal ATPase, acid hydrolase, and membrane protein) and steroid hormone metabolism. Gene set enrichment analysis (GSEA) further revealed the transcriptional suppression of oxidative phosphorylation (Complexes I-V) and ribosomal protein coding genes at 12 h post treatment. These findings suggest that the
Streptomyces
sp. TR27 supernatant is associated with multi-pathway transcriptional perturbations, including lysosomal homeostasis dysregulation, steroid hormone metabolism impairment, and potential inhibition of mitochondrial energy production and protein translation. This transcriptional signature provides candidate cellular targets and a hypothetical framework for developing actinobacteria-derived biocontrol agents, pending functional validation of direct compound-target interactions.
Results provide novel insights into the molecular mechanisms underlying microbial interactions in the tomato rhizosphere and highlight the potential of P. chlororaphis ToZa7 for effective biological control of FORL.
Christos Steppas, P. Tsalgatidou, N. Kamou et al.· Archives of Microbiology· 0 citations
A temporally ordered, multi-layered defense network in B. napus is revealed, characterized by sequential metabolic reprogramming, immune signaling activation, and structural reinforcement, providing mechanistic insights into L. biglobosa resistance.
Yong-Yi Xia, Haiyan Huangfu, Mengjiao Yan et al.· Frontiers in Plant Science· 0 citations
Banana Fusarium wilt, caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense (Foc), is a devastating disease and a major threat to global banana production. Here, we identified 24 genes predicted to encode heme-dependent peroxidase- or catalase–peroxidase-related proteins in Foc race 4 (Foc4), whereas nine genes encoding thiol-dependent peroxide-reducing proteins were catalogued separately. Phylogenetic, synteny, and Ka/Ks analyses indicated a conserved peroxidase repertoire under strong purifying selection, without substantial lineage-specific expansion. Motif, domain, gene-structure, and promoter analyses revealed subgroup-specific features and abundant putative stress- and hormone-responsive cis-regulatory motifs. Expression profiling during banana infection and H2O2 treatment showed distinct temporal and oxidative-stress responses. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses linked subsets of these genes to antioxidant activity, peroxide metabolism, peroxisomal functions, and stress signaling. A F. oxysporum f. sp. lycopersici ortholog-based interaction network combined with co-expression analysis prioritized five peroxidases potentially associated with pathogenicity-related expression programs. FoCP, selected separately based on its rapid H2O2 response and catalase–peroxidase annotation, enhanced oxidative-stress tolerance when heterologously expressed in yeast. Overall, Foc4 appears to adapt to oxidative stress through condition-specific regulation of a conserved peroxidase repertoire rather than gene-family expansion. The network-prioritized peroxidases provide candidates for further functional and pathogenicity studies.
Zhaojian Ding, Han Ouyang, Yu Chen et al.· Journal of Fungi· 0 citations
The results indicate that T. kirilowii responds to RKN infection through an integrated mechanism involving physiological regulation, hormonal coordination, metabolic reprogramming, and molecular defense, with the zeatin biosynthesis pathway serving as a central hub.
Lei Zheng, Hua-Dong Wang, Zhiqiang Zhang et al.· Frontiers in Plant Science· 0 citations
Verticillium dahliae is a destructive soil-borne fungus with a broad host range, and its persistence in soil complicates control. Current measures, mainly resistant cultivars and chemicals, are limited and environmentally risky, promoting biocontrol as a green alternative. Here, we investigated the biocontrol mechanisms of Bacillus velezensis L33a against V. dahliae JR2 in tomato. In vitro assays on PDA plates at 26°C for 9 d showed that L33a inhibited JR2 by 58.6%, caused hyphal malformation and disruption, and its volatile organic compounds suppressed pathogen growth. In pot experiments, tomato roots dipped in JR2 suspension (1 ×10⁶ CFU/mL) for 30 min at 7 d after transplanting and grown for 21 d achieved 60.9% control efficacy. Physiological assays indicated reduced peroxidase and catalase activities, while qPCR revealed that L33a alone upregulated JA signaling (SlJAZ1, SlMYC2, SlPI II) and antioxidant (SlCAT, SlAPX) genes, with further enhancement upon JR2 co-treatment. To track their interactions, we generated GFP-labeled JR2 and RFP-labeled L33a; dual fluorescence labeling showed that L33a endophytically colonized Arabidopsis thaliana roots and competed with JR2 for the same niche, correlating with reduced pathogen colonization. Integrated metabolomic and transcriptomic analysis further revealed that L33a treatment altered pathways related to ABC transporters, amino acid metabolism, cell wall integrity, and energy metabolism in JR2, with tyrosine metabolism significantly enriched at both levels. Collectively, these findings suggest that L33a is a promising biocontrol strain for green management of tomato Verticillium wilt.
