RRC ID 50550
Author Sakuma S, Lundqvist U, Kakei Y, Thirulogachandar V, Suzuki T, Hori K, Wu J, Tagiri A, Rutten T, Koppolu R, Shimada Y, Houston K, Thomas WTB, Waugh R, Schnurbusch T, Komatsuda T.
Title Extreme Suppression of Lateral Floret Development by a Single Amino Acid Change in the VRS1 Transcription Factor.
Journal Plant Physiol
Abstract Increasing grain yield is an endless challenge for cereal crop breeding. In barley (Hordeum vulgare), grain number is controlled mainly by Six-rowed spike 1 (Vrs1), which encodes a homeodomain leucine zipper class I transcription factor. However, little is known about the genetic basis of grain size. Here, we show that extreme suppression of lateral florets contributes to enlarged grains in deficiens barley. Through a combination of fine-mapping and resequencing of deficiens mutants, we have identified that a single amino acid substitution at a putative phosphorylation site in VRS1 is responsible for the deficiens phenotype. deficiens mutant alleles confer an increase in grain size, a reduction in plant height, and a significant increase in thousand grain weight in contemporary cultivated germplasm. Haplotype analysis revealed that barley carrying the deficiens allele (Vrs1.t1) originated from two-rowed types carrying the Vrs1.b2 allele, predominantly found in germplasm from northern Africa. In situ hybridization of histone H4, a marker for cell cycle or proliferation, showed weaker expression in the lateral spikelets compared with central spikelets in deficiens Transcriptome analysis revealed that a number of histone superfamily genes were up-regulated in the deficiens mutant, suggesting that enhanced cell proliferation in the central spikelet may contribute to larger grains. Our data suggest that grain yield can be improved by suppressing the development of specific organs that are not positively involved in sink/source relationships.
Volume 175(4)
Pages 1720-1731
Published 2017-12-1
DOI 10.1104/pp.17.01149
PII pp.17.01149
PMID 29101279
PMC PMC5717734
MeSH Amino Acid Sequence Amino Acid Substitution Breeding Chromosome Mapping Chromosomes, Plant / genetics Gene Expression Regulation, Plant / physiology* Genetic Markers Genome-Wide Association Study Haplotypes Hordeum / genetics Hordeum / physiology* Mutation Plant Development / genetics Plant Development / physiology Plant Proteins / chemistry Plant Proteins / genetics Plant Proteins / metabolism* RNA, Messenger / genetics RNA, Messenger / metabolism RNA, Plant / genetics RNA, Plant / metabolism Transcription Factors / metabolism* Transcription, Genetic
IF 6.902
Times Cited 12
Barley Haruna Nijo H602