Prevalence and Importance of the Necrotrophic Effector Gene ToxA in Bipolaris sorokiniana Populations Collected from Spring Wheat and Barley

Fazal Manan, Gongjun Shi, Hongmei Gong, Hongyan Hou, Hannah Khan, Yueqiang Leng, Claudia Castell-Miller, Shaukat Ali, Justin D. Faris, Shaobin Zhong, Brian Joel Steffenson, Zhaohui Liu

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

Bipolaris sorokiniana is a necrotrophic fungal pathogen that causes foliar and root diseases on wheat and barley. These diseases are common in all wheat- and barley-growing regions, with more severe outbreaks occurring under warm and humid conditions. B. sorokiniana can also infect a wide range of grass species in the family Poaceae and secrete ToxA, an important necrotrophic effector also identified other wheat leaf spotting pathogens. In this study, the prevalence and virulence role of ToxA were investigated in a collection of 278 B. sorokiniana isolates collected from spring wheat and barley in the Upper Midwest of the United States or other places, including 169 from wheat leaves, 75 from wheat roots, 30 from barley leaves, and 4 from wild quack grass leaves. ToxA was present in the isolates from wheat leaves, wheat roots, and wild grass leaves but was absent from isolates collected from barley leaves. Prevalence of ToxA in wheat leaf isolates (34.3%) was much higher than that in wheat root isolates (16%). Sequencing analysis revealed the presence of two haplotypes, with the majority being BsH2. All ToxA+ isolates produced the functional effector in liquid cultures. Pathogenicity assays revealed that ToxA+ isolates caused significantly more disease on spring wheat lines harboring Tsn1 than their tsn1 mutants, suggesting that the ToxA–Tsn1 interaction plays an important role in spot blotch development. This work confirms the importance of ToxA in B. sorokiniana populations infecting wheat and, thus, the need to eliminate Tsn1 from spring wheat cultivars to reduce susceptibility to spot blotch.

Original languageEnglish (US)
Pages (from-to)2424-2430
Number of pages7
JournalPlant disease
Volume107
Issue number8
DOIs
StatePublished - Aug 2023

Bibliographical note

Publisher Copyright:
© 2023 The American Phytopathological Society.

Keywords

  • Cochliobolus sativus
  • disease susceptibility
  • host selective toxins
  • virulence factors

PubMed: MeSH publication types

  • Journal Article

Fingerprint

Dive into the research topics of 'Prevalence and Importance of the Necrotrophic Effector Gene ToxA in Bipolaris sorokiniana Populations Collected from Spring Wheat and Barley'. Together they form a unique fingerprint.

Cite this