Genomic insights into Streptomyces hygroscopicus subsp.hygroscopicus SRF1: a potential biocontrol agent against fusarium wilt with plant growth-promoting abilities in tomatoes

ABSTRACT

Streptomyces sp. isolate SRF1 has previously demonstrated promising results in controlling various plant fungi under in vitro conditions. However, further exploration of its genome and its efficacy in disease control and plant growth promotion under in vivo conditions is warranted. This study aimed to utilise whole genome sequencing (WGS) to classify Streptomyces sp. isolate SRF1 at the species level and predict genes associated with antagonistic ability and plant growth promotion, thereby assessing its potential as a biocontrol agent against fusarium wilt and a promoter of plant growth. WGS was employed to elucidate the taxonomic classification of isolate SRF1 and predict genes involved in disease suppression and plant growth promotion. In vitro assays were conducted to evaluate its antagonistic activity against Fusarium oxysporum f. sp. lycopersici (Fol) and its production of cellulase, amylase, indole-3-acetic acid (IAA), and siderophores. Pot experiments were carried out using SRF1 cell suspension and culture filtrate to assess its efficacy against Fol and its impact on tomato growth. Real-time PCR analysis was performed to correlate gene expression levels with observed activities. The results showed that isolate SRF1 was classified as S. hygroscopicus subsp. hygroscopicus and demonstrated antagonism against Fol. Furthermore, WGS revealed genes or gene clusters associated with disease control, including those encoding antifungal agents such as butyrolactol A, nigericin, and hygromycin A. Additionally, genes responsible for auxin biosynthesis, siderophore production, and carbohydrate-digesting enzymes such as chitinase, cellulase, and amylase were identified, suggesting potential roles in disease suppression and plant growth promotion.

KEYWORDS:

• Biocontrol
• fusarium wilt
• gene expression
• plant growth promotion
• Streptomyces hygroscopicus subsp. hygroscopicus
• whole genome sequencing

Acknowledgments

This research project was financially supported by Mahasarakham University (MSU). The authors would also like to express their gratitude to the Faculty of Natural Resources and Agro-Industry, Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, and Mahasarakham University Faculty of Science for providing equipment and space for this study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The information, including the Bioproject number PRJNA924108, Biosample number SAMN32746339, and accession number JAQMWR000000000.1, is accessible from the NCBI database output (https://www.ncbi.nlm.nih.gov/bioproject). Additional data supporting the study’s findings can be obtained from the corresponding authors upon request.

Additional information

Funding

This work was supported by Mahasarakham University.