Understanding the causal mechanisms underlying natural variation of molybdenum uptake and selection at the MOT1 locus
Abstract
Molybdenum is an essential plant micronutrient that forms the key enzymatic component in the core of several vital plant enzymes, including nitrate reductase, sulfite oxidase, xanthine dehydrogenase, and aldehyde oxidase, all of which are critical for nutrient assimilation or plant growth and development. Recently a molybdenum transporter termed (MOT1) was shown to be associated with reduced molybdenum levels in a collection of 92 A. thaliana natural accessions. Here we describe a study in which we use bulk segregant analysis, genomic expression, and population structure studies to identify several cis-regulatory polymorphisms in the MOT1 promoter region that are associated with natural variation of molybdenum uptake observed in a collection 324 A. thaliana accessions. Our lab has identified 9 MOT1 genotypes that show variable levels of MOT1 expression that suggest variation in Mo uptake as a response to altered expression level. Examination of the landscape distribution of natural populations across Europe showed clusters of MOT1 genotypes within specific isolated regions suggesting increased prevalence of a given genotype. Further inspection of the population structure revealed unusual sharing in one particular haplotype group suggesting strong selection acting upon the MOT1 locus.
Degree
M.S.
Advisors
Salt, Purdue University.
Subject Area
Genetics|Horticulture
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