A new point mutation in the iron–sulfur subunit of succinate dehydrogenase confers resistance to boscalid in Sclerotinia sclerotiorum. (29th January 2015)

• Record Type: Journal Article
• Authors: Wang, Yong; Duan, Yabing; Wang, Jianxin; Zhou, Mingguo
• Is Part Of: Molecular plant pathology. Volume 16:Number 7(2015:Sep.)
• Page Start: 653
• Page End: 661
• Publication Date: 2015-01-29
• Subjects: Plant diseases -- Molecular aspects -- Periodicals; Plant-pathogen relationships -- Molecular aspects -- Periodicals; 571.936
• DOI: 10.1111/mpp.12222
• Languages: English
• ISSNs: 1464-6722

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>Research has established that mutations in highly conserved amino acids of the succinate dehydrogenase (SDH) complex in various fungi confer SDH inhibitor (SDHI) resistance. For <italic>Sclerotinia sclerotiorum</italic> (Lib.) de Bary, a necrotrophic fungus with a broad host range and a worldwide distribution, boscalid resistance has been attributed to the mutation H132R in the highly conserved SdhD subunit protein of the SDH complex. In our previous study, however, only one point mutation, A11V in SdhB (GCA to GTA change in <italic>SdhB</italic>), was detected in <italic>S. sclerotiorum</italic> boscalid‐resistant (BR) mutants. In the current study, replacement of the <italic>SdhB</italic> gene in a boscalid‐sensitive (BS) <italic>S. sclerotiorum</italic> strain with the mutant <italic>SdhB</italic> gene conferred resistance. Compared with wild‐type strains, BR and GSM (<italic>SdhB</italic> gene in the wild‐type strain replaced by the mutant <italic>SdhB</italic> gene) mutants were more sensitive to osmotic stress, lacked the ability to produce sclerotia and exhibited lower expression of the <italic>pac1</italic> gene. Importantly, the point mutation was not located in the highly conserved sequence of the iron–sulfur subunit of SDH. These results suggest that resistance based on non‐conserved vs. conserved protein domains differs in mechanism. In addition to increasing our understanding of boscalid resistance in <italic>S. sclerotiorum</italic>, the new information will be useful for the development of alternative antifungal drugs.</p> </abstract>