Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/3/2004
Publication Date: 1/10/2005
Citation: Simons, K.J., Fellers, J.P., Trick, H.N., Gill, B.S., Faris, J.D. 2005. Isolation and characterization of the major domestication gene Q in wheat.. Plant and Animal Genome Abstracts. p. 72.
Technical Abstract: The Q gene is largely responsible for the domestication of wheat because it confers the square spike phenotype and the free-threshing character. It also pleiotropically influences many other domestication-related traits such as glume shape and tenacity, rachis fragility, spike length, plant height, and ear emergence time. We isolated the Q gene and verified its identity by analysis of knockout mutants and transformation. We found that Q is a floral homeotic gene with similarity to the AP2 class of transcription factors. Ectopic expression analysis allowed us to observe both silencing and overexpression effects of Q. Variation in spike compactness and plant height was directly correlated with the degree of ectopic expression, which verified previous results regarding the dosage effects of Q. Other characters such as rachis fragility, glume shape, and glume tenacity, mimicked the q phenotype in transgenic plants exhibiting silencing of the transgene and the endogenous Q gene. Sequence analysis of the gene in multiple free-threshing and non free-threshing genotypes suggests that Q arose from q through mutation.