Two Polyketide Synthase-encoding Genes are Required for Biosynthesis of the Polyketide Virulence Factor, T-toxin, by Cochliobolus heterostrophus
Abstract
Cochliobolus heterostrophus race T, causal agent of Southern Corn Leaf Blight, requires T-toxin (a family of C35 – C49 polyketides) for high virulence on T-cytoplasm maize. Production of T-toxin is controlled by two unlinked loci, Tox1A and Tox1B, carried on 1.2 Mb of DNA not found in race O, a mildly virulent form of the fungus that does not produce T-toxin, or in any other Cochliobolus spp. or closely related fungus. PKS1, a polyketide synthase (PKS)-encoding gene at Tox1A and DEC1, a decarboxylase-encoding gene at Tox1B, are necessary for T-toxin production. Although there is evidence that additional genes are required for T-toxin production, efforts to clone them have been frustrated because the genes are located in highly repeated, A+T-rich DNA. To overcome this difficulty, Ligation specificity-based Expression Analysis Display (LEAD), a comparative AFLP/gel fractionation/capillary sequencing procedure was applied to cDNAs from a near isogenic pair of race T (Tox1+) and race O (Tox1-) strains. This led to discovery of PKS2, a second PKS-encoding gene that maps at Tox1A and is required for both T-toxin biosynthesis and high virulence to maize. Thus, the carbon chain of each T-toxin family member is likely assembled by action of two PKSs, which produce twomore »
- Authors:
- Publication Date:
- Research Org.:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Org.:
- USDOE
- OSTI Identifier:
- 883207
- Report Number(s):
- PNNL-SA-46869
BM0102070
- DOE Contract Number:
- AC05-76RL01830
- Resource Type:
- Journal Article
- Journal Name:
- Molecular Plant-Microbe Interactions, MPMI, 19(2):139-49
- Additional Journal Information:
- Journal Name: Molecular Plant-Microbe Interactions, MPMI, 19(2):139-49
- Country of Publication:
- United States
- Language:
- English
Citation Formats
Baker, Scott E, Kroken, Scott, Inderbitzin, Patrik, Asvarak, Thipa, Li, Bi-Yu, Shi, Liang, Yoder, Olen C, and Turgeon, Barbara G. Two Polyketide Synthase-encoding Genes are Required for Biosynthesis of the Polyketide Virulence Factor, T-toxin, by Cochliobolus heterostrophus. United States: N. p., 2006.
Web. doi:10.1094/MPMI-19-0139.
Baker, Scott E, Kroken, Scott, Inderbitzin, Patrik, Asvarak, Thipa, Li, Bi-Yu, Shi, Liang, Yoder, Olen C, & Turgeon, Barbara G. Two Polyketide Synthase-encoding Genes are Required for Biosynthesis of the Polyketide Virulence Factor, T-toxin, by Cochliobolus heterostrophus. United States. https://doi.org/10.1094/MPMI-19-0139
Baker, Scott E, Kroken, Scott, Inderbitzin, Patrik, Asvarak, Thipa, Li, Bi-Yu, Shi, Liang, Yoder, Olen C, and Turgeon, Barbara G. 2006.
"Two Polyketide Synthase-encoding Genes are Required for Biosynthesis of the Polyketide Virulence Factor, T-toxin, by Cochliobolus heterostrophus". United States. https://doi.org/10.1094/MPMI-19-0139.
@article{osti_883207,
title = {Two Polyketide Synthase-encoding Genes are Required for Biosynthesis of the Polyketide Virulence Factor, T-toxin, by Cochliobolus heterostrophus},
author = {Baker, Scott E and Kroken, Scott and Inderbitzin, Patrik and Asvarak, Thipa and Li, Bi-Yu and Shi, Liang and Yoder, Olen C and Turgeon, Barbara G},
abstractNote = {Cochliobolus heterostrophus race T, causal agent of Southern Corn Leaf Blight, requires T-toxin (a family of C35 – C49 polyketides) for high virulence on T-cytoplasm maize. Production of T-toxin is controlled by two unlinked loci, Tox1A and Tox1B, carried on 1.2 Mb of DNA not found in race O, a mildly virulent form of the fungus that does not produce T-toxin, or in any other Cochliobolus spp. or closely related fungus. PKS1, a polyketide synthase (PKS)-encoding gene at Tox1A and DEC1, a decarboxylase-encoding gene at Tox1B, are necessary for T-toxin production. Although there is evidence that additional genes are required for T-toxin production, efforts to clone them have been frustrated because the genes are located in highly repeated, A+T-rich DNA. To overcome this difficulty, Ligation specificity-based Expression Analysis Display (LEAD), a comparative AFLP/gel fractionation/capillary sequencing procedure was applied to cDNAs from a near isogenic pair of race T (Tox1+) and race O (Tox1-) strains. This led to discovery of PKS2, a second PKS-encoding gene that maps at Tox1A and is required for both T-toxin biosynthesis and high virulence to maize. Thus, the carbon chain of each T-toxin family member is likely assembled by action of two PKSs, which produce two polyketides, one of which may act as the starter unit for biosynthesis of the mature T-toxin molecule.},
doi = {10.1094/MPMI-19-0139},
url = {https://www.osti.gov/biblio/883207},
journal = {Molecular Plant-Microbe Interactions, MPMI, 19(2):139-49},
number = ,
volume = ,
place = {United States},
year = {Wed Mar 01 00:00:00 EST 2006},
month = {Wed Mar 01 00:00:00 EST 2006}
}