Multigenomic analysis of Streptomyces scabiei with biological agents that control potato scab

• Grant number: 24/19116-3
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: February 15, 2025
• End date: February 14, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Suzete Aparecida Lanza Destéfano
• Grantee: Lucas Vitor
• Supervisor: Bevan Weir
• Host Institution: Instituto Biológico (IB). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). São Paulo , SP, Brazil
• Institution abroad: Landcare Research, Auckland, New Zealand
• Associated to the scholarship: 23/07149-1 - Evaluation of different mechanisms of action in the biological control of Streptomyces scabiei, BP.DR

Abstract

Potato (Solanum tuberosum L.) is a globally significant food crop, ranking fourth in production and second in nutrient source after eggs. In Brazil, 2022 potato production reached3.9 million tons across 117,000 hectares, with an average yield of 30 t/ha. However, Brazilian production lag behind those in Asia and Europe, mainly due to phytosanitary issues like bacterial, fungal, viral, and pest-related diseases. Among these, potato scab, caused by various Streptomyces species (mainly S. scabiei), is particularly damaging, leading to significant quality and marketability losses due to the symptoms it produces on tubers. This research focuses on advancing the understanding and management of potato scab through biocontrol agents. Eight potential biocontrol agents were isolated: two strains of Bacillus sp. (IBSBF 3381 and IBSBF 3410), two Pseudomonas sp. strains (IBSBF 3420 and IBSBF 3423), two Streptomyces sp. strains (IBSBF 3377 and IBSBF 3379), and two viral strains (¿BS01 and ¿BS02). These agents demonstrated high efficacy in in vitro tests, surpassing the disease reduction levels achieved by commercially registered products such as Serenade® and Frowncide®. Genetic analysis using 16S rRNA gene sequencing suggested that these strains might represent new species within their respective genera, based on their similarity percentages with known species. The proposed research aims to delve deeper into the genetic and genomic mechanisms governing the action of these biocontrol agents against S. scabiei. The study will focus on five key objectives: genome sequencing to identify and describe antagonistic species with an emphasis on secondary metabolites, detecting resistance genes in plants following application of biocontrol agents, investigating the interference of biocontrol agents on the pathogenicity genes of S. scabiei (specifically the txtAB and nec1 genes), elucidating transcriptional changes in S. scabiei post-interaction with biocontrol agents, and investigation the infection mechanisms of the isolated bacteriophages. The research will be conducted at Manaaki Whenua - Landcare Research, and the EcoGene Laboratory in New Zealand, leveraging their advanced technological capabilities and expertise in microbiology, molecular genetics, and taxonomy. This study aims to enhance sustainable agricultural practices by optimizing control of potato scab, contributing to global food security and providing a basis for developing more effective biocontrol strategies for other crop diseases.