Differential gene expression of wheat progeny with contrasting levels of transpiration efficiency.
High water use efficiency or transpiration efficiency (TE) in wheat is a desirable physiological trait for increasing grain yield under water-limited environments. The identification of genes associated with this trait would facilitate the selection for genotypes with higher TE using molecular markers. We performed an expression profiling (microarray) analysis of approximately 16,000 unique wheat ESTs to identify genes that were differentially expressed between wheat progeny lines with contrasting TE levels from a cross between Quarrion (high TE) and Genaro 81 (low TE). We also conducted a second microarray analysis to identify genes responsive to drought stress in wheat leaves. Ninety-three genes that were differentially expressed between high and low TE progeny lines were identified. One fifth of these genes were markedly responsive to drought stress. Several potential growth-related regulatory genes, which were down-regulated by drought, were expressed at a higher level in the high TE lines than the low TE lines and are potentially associated with a biomass production component of the Quarrion-derived high TE trait. Eighteen of the TE differentially expressed genes were further analysed using quantitative RT-PCR on a separate set of plant samples from those used for microarray analysis. The expression levels of 11 of the 18 genes were positively correlated with the high TE trait, measured as carbon isotope discrimination (Delta(13)C). These data indicate that some of these TE differentially expressed genes are candidates for investigating processes that underlie the high TE trait or for use as expression quantitative trait loci (eQTLs) for TE.
Xue
Gang-Ping
GP
CSIRO Plant Industry, 306 Carmody Road, St Lucia, Qld, 4067, Australia. gang-ping.xue@csiro.au
McIntyre
C Lynne
CL
Chapman
Scott
S
Bower
Neil I
NI
Way
Heather
H
Reverter
Antonio
A
Clarke
Bryan
B
Shorter
Ray
R
D002247:Carbon Isotopes / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D005838:Genotype; D020411:Oligonucleotide Array Sequence Analysis; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D018526:Plant Transpiration / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014908:Triticum / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D014867:Water / Q000378:metabolism / Q000494:pharmacology
D002247:Carbon Isotopes; D012333:RNA, Messenger; D014867:Water