ORIGINAL RESEARCH article
Front. Plant Sci.
Sec. Plant Pathogen Interactions
Volume 16 - 2025 | doi: 10.3389/fpls.2025.1649819
Control effects and mechanisms of metabolites from Streptomyces ahygroscopicus var. gongzhulingensis strain 769 on Sclerotinia rot in sunflowers
Provisionally accepted
- 1Northeast Agricultural University, Harbin, China
- 2Jilin Academy of Agricultural Sciences (CAAS), Changchun, China
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Sunflower sclerotinia rot, caused by the fungus Sclerotinia sclerotiorum, threatens global sunflower production. While natural compounds from Streptomyces bacteria show promise in controlling plant diseases, their use against sclerotinia rot remains underexplored. This study highlights the metabolites from S. ahygroscopicus var. gongzhulingensis 769 (S769) as potential biocontrol agents. In vitro antagonism assays showed that a 100-fold dilution of S769 suppressed S. sclerotiorum mycelial growth by 65.79%. Detached leaf experiments showed both S769 soil mixing (S769-Ms) and root drenching (S769-i) reduced disease incidence from 92.53% in the control group to 52.53% and 55.16%, respectively, with lesion diameters decreasing by 42.92% and 35.65%. Pot trials conducted in Sclerotia-infested soil revealed S769-Ms reduced disease index from 83.13% (Control) to 22.51%, while S769-i reduced it to 47.53%; plant height increased by 10.10% with S769-Ms and by 36.20% with S769-i compared to the control group. Mechanistically, both S769-Ms and S769-i treatments elevated leaf/root activities of superoxide dismutase, catalase and polyphenol oxidase and enhanced rhizosphere urease, acid phosphatase and invertase activities. Field trials demonstrated that S769-Ms reduced the early-stage disease index from 14.69% in the control group to 7.36%, while S769-i further decreased it to 5.92%. Root fresh weight increased by 13.36% with S769-Ms and by 15.85% with S769-i. Additionally, the rate of shriveled seeds decreased by 31.49% with S769-Ms and by 34.26% with S769-i. In-depth mechanistic analyses focused exclusively on S769-Ms revealed an enrichment of beneficial rhizobacteria, including Sphingomonas and Chitinophagaceae, without altering microbial α-diversity, as determined by microbiome analysis. Root transcriptomics identified 6,622 upregulated genes, with upregulation of MAPK signaling, plant hormone pathways, and phenylpropanoid biosynthesis. Additionally, qPCR analysis confirmed a 4.85-fold reduction of S. sclerotiorum in the leaves and a 2.68-fold reduction in the roots of S769-Ms compared to the control group. This research provides farmers with a sustainable tool to protect sunflowers while promoting environmentally friendly agriculture.
Keywords: Streptomyces, Sclerotinia sclerotiorum, Helianthus annuus, biocontrol, microbiomics
Received: 19 Jun 2025; Accepted: 26 Aug 2025.
Copyright: © 2025 Liu, Zhang and Lu. 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: Zhengkun Zhang, Jilin Academy of Agricultural Sciences (CAAS), Changchun, China
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.