Multivariate analysis of maize disease resistances suggests a pleiotropic genetic basis and implicates a GST gene

Wisser, R.J. and Kolkman, J.M. and Patzoldt, M.E. and Holland, J.B. and Yu, J. and Krakowsky, M. and Nelson, R.J. and Balint-Kurti, P.J. (2011) Multivariate analysis of maize disease resistances suggests a pleiotropic genetic basis and implicates a GST gene. PNAS - Proceedings of the National Academy of Sciences, 108 (18). pp. 7339-7344.

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Abstract

Plants are attacked by pathogens representing diverse taxonomic groups, such that genes providing multiple disease resistance (MDR) are expected to be under positive selection pressure. To address the hypothesis that naturally occurring allelic variation conditions MDR, we extended the framework of structured association mapping to allow for the analysis of correlated complex traits and the identification of pleiotropic genes. The multivariate analytical approach used here is directly applicable to any species and set of traits exhibiting correlation. From our analysis of a diverse panel of maize inbred lines, we discovered high positive genetic correlations between resistances to three globally threatening fungal diseases. The maize panel studied exhibits rapidly decaying linkage disequilibrium that generally occurs within 1 or 2 kb, which is less than the average length of a maize gene. The positive correlations therefore suggested that functional allelic variation at specific genes for MDR exists in maize. Using a multivariate test statistic, a glutathione S-transferase (GST) gene was found to be associated with modest levels of resistance to all three diseases. Resequencing analysis pinpointed the association to a histidine (basic amino acid) for aspartic acid (acidic amino acid) substitution in the encoded protein domain that defines GST substrate specificity and biochemical activity. The known functions of GSTs suggested that variability in detoxification pathways underlie natural variation in maize MDR.

Item Type: Article
Author Affiliation: Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19716-1304
Subjects: Crop Improvement
Crop Improvement > Genetics/Genomics
Divisions: Maize
Depositing User: Sandhya Gir
Date Deposited: 07 Jun 2011 10:30
Last Modified: 07 Jun 2011 10:30
URI: http://eprints.icrisat.ac.in/id/eprint/2145

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