RRC ID 30206
Author Koppolu R, Anwar N, Sakuma S, Tagiri A, Lundqvist U, Pourkheirandish M, Rutten T, Seiler C, Himmelbach A, Ariyadasa R, Youssef HM, Stein N, Sreenivasulu N, Komatsuda T, Schnurbusch T.
Title Six-rowed spike4 (Vrs4) controls spikelet determinacy and row-type in barley.
Journal Proc Natl Acad Sci U S A
Abstract Inflorescence architecture of barley (Hordeum vulgare L.) is common among the Triticeae species, which bear one to three single-flowered spikelets at each rachis internode. Triple spikelet meristem is one of the unique features of barley spikes, in which three spikelets (one central and two lateral spikelets) are produced at each rachis internode. Fertility of the lateral spikelets at triple spikelet meristem gives row-type identity to barley spikes. Six-rowed spikes show fertile lateral spikelets and produce increased grain yield per spike, compared with two-rowed spikes with sterile lateral spikelets. Thus, far, two loci governing the row-type phenotype were isolated in barley that include Six-rowed spike1 (Vrs1) and Intermedium-C. In the present study, we isolated Six-rowed spike4 (Vrs4), a barley ortholog of the maize (Zea mays L.) inflorescence architecture gene RAMOSA2 (RA2). Eighteen coding mutations in barley RA2 (HvRA2) were specifically associated with lateral spikelet fertility and loss of spikelet determinacy. Expression analyses through mRNA in situ hybridization and microarray showed that Vrs4 (HvRA2) controls the row-type pathway through Vrs1 (HvHox1), a negative regulator of lateral spikelet fertility in barley. Moreover, Vrs4 may also regulate transcripts of barley SISTER OF RAMOSA3 (HvSRA), a putative trehalose-6-phosphate phosphatase involved in trehalose-6-phosphate homeostasis implicated to control spikelet determinacy. Our expression data illustrated that, although RA2 is conserved among different grass species, its down-stream target genes appear to be modified in barley and possibly other species of tribe Triticeae.
Volume 110(32)
Pages 13198-203
Published 2013-8-6
DOI 10.1073/pnas.1221950110
PII 1221950110
PMID 23878219
PMC PMC3740847
MeSH Amino Acid Sequence Base Sequence Chromosome Mapping Chromosomes, Plant / genetics Fertility / genetics Gene Expression Profiling Gene Expression Regulation, Plant* Haplotypes Hordeum / genetics* Hordeum / metabolism Hordeum / ultrastructure Inflorescence / genetics* Inflorescence / metabolism Inflorescence / ultrastructure Microscopy, Electron, Scanning Molecular Sequence Data Mutation Oligonucleotide Array Sequence Analysis Phenotype Phylogeny Plant Proteins / classification Plant Proteins / genetics* Plant Proteins / metabolism Reverse Transcriptase Polymerase Chain Reaction Sequence Homology, Amino Acid
IF 9.412
Times Cited 62