Tandemly duplicated Safener-induced glutathione S-transferase genes from Triticum tauschii contribute to genome- and organ-specific expression in hexaploid wheat.
Glutathione S-transferase (GST) gene expression was examined in several Triticum species, differing in genome constitution and ploidy level, to determine genome contribution to GST expression in cultivated, hexaploid bread wheat (Triticum aestivum). Two tandemly duplicated tau class GST genes (TtGSTU1 and TtGSTU2) were isolated from a single bacterial artificial chromosome clone in a library constructed from the diploid wheat and D genome progenitor to cultivated wheat, Triticum tauschii. The genes are very similar in genomic structure and their encoded proteins are 95% identical. Gene-specific reverse transcriptase-polymerase chain reaction analysis revealed differential transcript accumulation of TtGSTU1 and TtGSTU2 in roots and shoots. Expression of both genes was induced by herbicide safeners, 2,4-dichlorophenoxyacetic acid and abscisic acid, in the shoots of T. tauschii; however, expression of TtGSTU1 was always higher than TtGSTU2. In untreated seedlings, TtGSTU1 was expressed in both shoots and roots, whereas TtGSTU2 expression was only detected in roots. RNA gel-blot analysis of ditelosomic, aneuploid lines that are deficient for 6AS, 6BS, or 6DS chromosome arms of cultivated, hexaploid bread wheat showed differential genome contribution to safener-induced GST expression in shoots compared with roots. The GST genes from the D genome of hexaploid wheat contribute most to safener-induced expression in the shoots, whereas GSTs from the B and D genomes contribute to safener-induced expression in the roots.
Xu
Fangxiu
F
Department of Crop Sciences, University of Illinois, Urbana, Illinois 61801, USA.
Lagudah
Evans S
ES
Moose
Stephen P
SP
Riechers
Dean E
DE
D015084:2,4-Dichlorophenoxyacetic Acid / Q000494:pharmacology; D024506:5' Flanking Region / Q000235:genetics; D000040:Abscisic Acid / Q000494:pharmacology; D000595:Amino Acid Sequence; D001483:Base Sequence; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D020440:Gene Duplication / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005982:Glutathione Transferase / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010575:Pesticides / Q000494:pharmacology; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D011123:Polyploidy; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D013379:Substrate Specificity; D020080:Tandem Repeat Sequences / Q000235:genetics*; D014908:Triticum / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*
D018744:DNA, Plant; D010575:Pesticides; D010937:Plant Growth Regulators; D010940:Plant Proteins; D015084:2,4-Dichlorophenoxyacetic Acid; D000040:Abscisic Acid; D005982:Glutathione Transferase