Subtopic Deep Dive

Succinate Dehydrogenase Inhibitor Resistance
Research Guide

What is Succinate Dehydrogenase Inhibitor Resistance?

Succinate Dehydrogenase Inhibitor (SDHI) resistance refers to genetic mutations in fungal pathogens, primarily in SdhB, SdhC, and SdhD subunits, that reduce SDHI fungicide binding and efficacy in controlling plant diseases.

SDHI fungicides target the succinate dehydrogenase enzyme (SDH, EC 1.3.5.1) in the fungal respiratory chain. Resistance arises through point mutations enabling pathogen survival under fungicide pressure (Avenot and Michailides, 2010; 492 citations). Over 20 studies document mutations in Botrytis cinerea and Mycosphaerella graminicola.

Curated Papers

Key Challenges

Why It Matters

SDHI resistance threatens control of gray mold (Botrytis cinerea) in strawberries and grapes, and Septoria leaf blotch (Mycosphaerella graminicola) in wheat, risking yield losses up to 50% in Europe (Fraaije et al., 2011; 187 citations). Multi-resistant strains with SDHI plus strobilurin resistance spread in German horticulture, complicating management (Rupp et al., 2017; 178 citations). Structure-activity studies guide novel carboxamide development to sustain this fungicide class (Scalliet et al., 2012; 189 citations).

Key Research Challenges

Characterizing Sdh Mutations

Mutations in SdhB, C, D subunits confer cross-resistance to multiple SDHIs like boscalid and fluxapyroxad. Functional validation requires mutagenesis and binding assays (Scalliet et al., 2012). Over 10 mutation sites identified in Botrytis cinerea (Avenot and Michailides, 2010).

Detecting Field Resistance

Molecular screening distinguishes resistant phenotypes amid low-frequency mutants. Field isolates show variable EC50 shifts for boscalid (Yin et al., 2011; 148 citations). Risk assessment links selection pressure to resistance spread (Fraaije et al., 2011).

Developing Durable SDHIs

Structure-based modeling predicts mutation impacts on inhibitor binding. Novel carboxamides face rapid resistance evolution in wheat pathogens (Scalliet et al., 2012). Multi-site resistance complicates rotation strategies (Hahn, 2014; 493 citations).

Essential Papers

The rising threat of fungicide resistance in plant pathogenic fungi: Botrytis as a case study

Matthias Hahn · 2014 · Journal of Chemical Biology · 493 citations

Progress in understanding molecular mechanisms and evolution of resistance to succinate dehydrogenase inhibiting (SDHI) fungicides in phytopathogenic fungi

Hervé F. Avenot, Themis J. Michailides · 2010 · Crop Protection · 492 citations

Mutagenesis and Functional Studies with Succinate Dehydrogenase Inhibitors in the Wheat Pathogen Mycosphaerella graminicola

Gabriel Scalliet, Judith Bowler, Torsten Luksch et al. · 2012 · PLoS ONE · 189 citations

A range of novel carboxamide fungicides, inhibitors of the succinate dehydrogenase enzyme (SDH, EC 1.3.5.1) is currently being introduced to the crop protection market. The aim of this study was to...

Risk assessment studies on succinate dehydrogenase inhibitors, the new weapons in the battle to control Septoria leaf blotch in wheat

B. A. Fraaije, Carlos Bayón, Sarah Atkins et al. · 2011 · Molecular Plant Pathology · 187 citations

SUMMARY Chemical control of Septoria leaf blotch, caused by Mycosphaerella graminicola , is essential to ensure wheat yield and food security in most European countries. Mycosphaerella graminicola ...

Spread of Botrytis cinerea Strains with Multiple Fungicide Resistance in German Horticulture

Sabrina Rupp, Roland W.S. Weber, Daniel Rieger et al. · 2017 · Frontiers in Microbiology · 178 citations

<i>Botrytis cinerea</i> is a major plant pathogen, causing gray mold rot in a variety of cultures. Repeated fungicide applications are common but have resulted in the development of fungal populati...

Resistance to Pyraclostrobin and Boscalid in<i>Botrytis cinerea</i>Isolates from Strawberry Fields in the Carolinas

Dolores Fernández‐Ortuño, Fengping Chen, Guido Schnabel · 2012 · Plant Disease · 161 citations

Botrytis cinerea, the causal agent of gray mold disease, is one of the most important plant-pathogenic fungi affecting strawberry. During the last decade, control of gray mold disease in the southe...

Fungi, fungicide discovery and global food security

Gero Steinberg, Sarah J. Gurr · 2020 · Fungal Genetics and Biology · 156 citations

Reading Guide

Foundational Papers

Start with Avenot and Michailides (2010; 492 citations) for molecular mechanisms overview, then Scalliet et al. (2012; 189 citations) for mutagenesis in wheat pathogens, and Hahn (2014; 493 citations) for Botrytis case study.

Recent Advances

Rupp et al. (2017; 178 citations) on German Botrytis spread; Amiri et al. (2013; 153 citations) on strawberry fluopyram resistance.

Core Methods

EC50 determination, allele-specific PCR for mutations, heterologous Sdh expression in yeast, carboxamide docking models.

How PapersFlow Helps You Research Succinate Dehydrogenase Inhibitor Resistance

Discover & Search

Research Agent uses searchPapers('SDHI resistance Botrytis cinerea Sdh mutations') to retrieve 492-citation review by Avenot and Michailides (2010), then citationGraph to map 20+ papers on SdhB/C/D mutations, and findSimilarPapers for wheat-specific studies like Fraaije et al. (2011). exaSearch uncovers low-citation field reports on fluxapyroxad resistance.

Analyze & Verify

Analysis Agent applies readPaperContent on Scalliet et al. (2012) to extract mutagenesis data on Sdh inhibitors, verifyResponse with CoVe to cross-check mutation EC50 values against Fernández-Ortuño et al. (2012), and runPythonAnalysis to plot resistance frequency distributions from strawberry isolates (Amiri et al., 2013). GRADE grading scores evidence strength for SdhD-H272 mutations.

Synthesize & Write

Synthesis Agent detects gaps in multi-resistance evolution post-2017 via Rupp et al. (2017), flags contradictions between boscalid phenotypes (Yin et al., 2011). Writing Agent uses latexEditText for mutation tables, latexSyncCitations to integrate 10 papers, latexCompile for review drafts, and exportMermaid for SDHI binding diagrams.

Use Cases

"Analyze Sdh mutation frequencies in Botrytis cinerea strawberry isolates using Python."

Research Agent → searchPapers → Analysis Agent → readPaperContent (Fernández-Ortuño et al., 2012; Amiri et al., 2013) → runPythonAnalysis (pandas histogram of EC50 data) → matplotlib plot of resistance distributions.

"Draft LaTeX review on SDHI resistance mechanisms in wheat pathogens."

Synthesis Agent → gap detection (post-Fraaije 2011) → Writing Agent → latexEditText (intro/methods) → latexSyncCitations (Scalliet et al., 2012) → latexCompile → PDF with Sdh mutation table.

"Find code for SDHI structure modeling from papers."

Research Agent → paperExtractUrls (Scalliet et al., 2012) → paperFindGithubRepo → Code Discovery → githubRepoInspect (docking scripts for carboxamide binding) → runPythonAnalysis sandbox test.

Automated Workflows

Deep Research workflow scans 50+ SDHI papers via searchPapers → citationGraph → structured report on mutation evolution (Hahn 2014 baseline). DeepScan applies 7-step CoVe analysis to validate resistance claims in Rupp et al. (2017) field data with statistical checkpoints. Theorizer generates hypotheses on Sdh multi-site resistance from Avenot (2010) mechanisms.

Try Doxa for Succinate Dehydrogenase Inhibitor Resistance Research

Frequently Asked Questions

What defines SDHI resistance?

SDHI resistance stems from amino acid substitutions in SdhB (e.g., H242), SdhC (e.g., S149), SdhD subunits altering fungicide binding (Avenot and Michailides, 2010).

What methods study SDHI resistance?

Mutagenesis screens, EC50 assays, and heterologous expression validate mutations; structure modeling predicts inhibitor fitness (Scalliet et al., 2012).

What are key papers on SDHI resistance?

Avenot and Michailides (2010; 492 citations) reviews mechanisms; Scalliet et al. (2012; 189 citations) details Mycosphaerella mutagenesis; Hahn (2014; 493 citations) covers Botrytis threats.

What open problems exist?

Predicting cross-resistance to new SDHIs like fluopyram; fitness costs of mutations in field populations; strategies against multi-class resistance (Fraaije et al., 2011; Rupp et al., 2017).