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United States Department of Agriculture

Agricultural Research Service

Title: Functional Analysis of the Domestication Gene Q in Wheat.

Authors
item Zhang, Zengcui - PLNT SCI, NDSU, FARGO ND
item Tai, Yin Shan
item Simons, Kristin - PLNT PATH, KSU MANHATTAN
item Fellers, John - SCI&ENT, KSU, MANHATTAN K
item Gill, Bikram - PLNT PATH, KSU MANHATTAN
item Faris, Justin

Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 30, 2005
Publication Date: January 5, 2006
Citation: Zhang, Z., Tai, Y., Simons, K.J., Fellers, J.P., Gill, B.S., Faris, J.D. 2006. Functional analysis of the domestication gene q in wheat [abstract]. Plant and Animal Genome XIV Conference. Abstact No. P828:307.

Technical Abstract: The Q gene confers the free-threshing character of wheat and pleiotropically influences other domestication-related traits. In previous work, we showed that; Q is a member of the APETALA2 (AP2) family of transcription factors, the Q allele is more abundantly transcribed than q, and Q and q alleles differ for a single amino acid at position 329. In this study, we evaluated functional and regulatory aspects of Q using a knockout mutant, relative quantitative-PCR (RQ-PCR), and the yeast two-hybrid system. Seed of the cultivar Bobwhite was subjected to mutagenesis with EMS. One mutant possessed a speltoid spike with non free-threshing seed. This mutant was also taller with longer leaves and seed compared to the wild type. Sequence analysis of the mutant revealed a point mutation within the Q gene coding region, which induced a stop codon at position 138. RQ-PCR analysis indicated the level of Q transcription in the mutant was significantly reduced compared to the wild type. Yeast two-hybrid analysis of Q and q proteins indicated that the isoleucine at position 329 (I329) in the Q protein led to an abundance of homodimer formation, whereas the valine in the q protein limited homodimer formation. Therefore, the reduced level of transcription observed in the mutant and q genotypes may be due to the inability to form homodimers. Taken together, these results indicated that Q affects a wide range of characters and that the level of Q gene expression may depend on a self-regulatory mechanism for which I329 is critical.

Last Modified: 12/17/2014
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