ABCG Transporter Gene PstABCG2 Contributes to Multidrug Resistance in Puccinia striiformis

Area of Science:

• Plant Pathology
• Molecular Biology
• Agricultural Science

Background:

• Triadimefon resistance in Puccinia striiformis f. sp. tritici (Pst) poses a significant threat to wheat production.
• Understanding the molecular basis of resistance to novel fungicides like flubeneteram is crucial for effective disease management.

Purpose of the Study:

• To identify the molecular mechanisms underlying triadimefon and flubeneteram resistance in Pst.
• To elucidate the role of ABC transporter genes in fungicide resistance.
• To investigate the regulatory network controlling resistance gene expression.

Main Methods:

• Transcriptomic analysis to identify differentially expressed genes under fungicide stress.
• RNA interference (RNAi) and হোস্ট-induced gene silencing (HIGS) to assess gene function.
• Heterologous expression in Fusarium graminearum to confirm gene function.
• Structural and biophysical analyses to determine fungicide binding interactions.
• Gene silencing to investigate the role of transcription factors.

Main Results:

• The ABC transporter gene PstABCG2 was identified as a key determinant of multidrug resistance (MDR) in Pst.
• PstABCG2 expression was significantly upregulated under fungicide stress.
• Silencing PstABCG2 enhanced fungal sensitivity to both triadimefon and flubeneteram.
• A mutation (E1184Y) in PstABCG2 affected triadimefon binding but not flubeneteram binding, suggesting adaptive resistance mechanisms.
• The GATA-family transcription factor PstGATA was found to directly activate PstABCG2 expression.

Conclusions:

• PstABCG2 plays a critical role in conferring resistance to fungicides in Pst.
• The findings provide a molecular basis for understanding MDR in Pst and developing strategies for resistance management.
• Targeting PstABCG2 or its regulatory elements could be a promising approach for novel fungicide development.