TY - JOUR
T1 - Cloning, characterization and regulation of a family of phi class glutathione transferases from wheat
AU - Cummins, I
AU - O'Hagan, David
AU - Jablonkai, I
AU - Cole, DJ
AU - Hehn, A
AU - Werck-Reichhart, D
AU - Edwards, R
PY - 2003/6
Y1 - 2003/6
N2 - Six phi (F) class glutathione transferases (GSTs) were cloned from bread wheat (Triticum aestivum L.) treated with the herbicide safener fenchlorazole ethyl and named TaGSTF1-6. Recombinant TaGSTFs were assayed for glutathione conjugating activity towards xenobiotics including herbicides and for glutathione peroxidase (GPOX) activity. TaGSTF1, which resembled ZmGSTF1, the dominant GST in maize (Zea mays), was highly active in conjugating 1-chloro-2,4-dinitrobenezene (CDNB) but had low activities towards chloroacetanilide, diphenyl ether and aryloxphenoxypropionate herbicides. TaGSTF2, TaGSTF3 and TaGSTF4 all resembled the safener-inducible ZmGSTF2, with TaGSTF2 and TaGSTF3 being highly active GPOXs and rapidly detoxifying chloroacetanilides. TaGSTF5 resembled ZmGSTF3, having limited conjugating and GPOX activity. TaGSTF6 contained both ZmGSTF1- and ZmGSTF2-like sequences but was most similar to ZmGSTF1 in detoxifying activity. The expression of TaGSTFs in wheat seedlings was enhanced upon exposure to fenchlorazole ethyl, herbicides or other chemical inducing treatments. TaGSTFs were also enhanced by treatment with the natural products caffeic acid, 7,4-dihydroxyflavone and naringenin. The CDNB-conjugating activity of TaGSTF1, and to a lesser extent TaGSTF6, was highly sensitive to inhibition by flavonoids, particularly the chalcone isoliquiritigenin. The other TaGSTFs were much less sensitive to such inhibition. It was subsequently determined that isoliquiritigenin underwent glutathione conjugation, though this reversible reaction did not require the intervention of any TaGSTF. The potential importance of GSTFs and glutathione conjugation in flavonoid metabolism is discussed.
AB - Six phi (F) class glutathione transferases (GSTs) were cloned from bread wheat (Triticum aestivum L.) treated with the herbicide safener fenchlorazole ethyl and named TaGSTF1-6. Recombinant TaGSTFs were assayed for glutathione conjugating activity towards xenobiotics including herbicides and for glutathione peroxidase (GPOX) activity. TaGSTF1, which resembled ZmGSTF1, the dominant GST in maize (Zea mays), was highly active in conjugating 1-chloro-2,4-dinitrobenezene (CDNB) but had low activities towards chloroacetanilide, diphenyl ether and aryloxphenoxypropionate herbicides. TaGSTF2, TaGSTF3 and TaGSTF4 all resembled the safener-inducible ZmGSTF2, with TaGSTF2 and TaGSTF3 being highly active GPOXs and rapidly detoxifying chloroacetanilides. TaGSTF5 resembled ZmGSTF3, having limited conjugating and GPOX activity. TaGSTF6 contained both ZmGSTF1- and ZmGSTF2-like sequences but was most similar to ZmGSTF1 in detoxifying activity. The expression of TaGSTFs in wheat seedlings was enhanced upon exposure to fenchlorazole ethyl, herbicides or other chemical inducing treatments. TaGSTFs were also enhanced by treatment with the natural products caffeic acid, 7,4-dihydroxyflavone and naringenin. The CDNB-conjugating activity of TaGSTF1, and to a lesser extent TaGSTF6, was highly sensitive to inhibition by flavonoids, particularly the chalcone isoliquiritigenin. The other TaGSTFs were much less sensitive to such inhibition. It was subsequently determined that isoliquiritigenin underwent glutathione conjugation, though this reversible reaction did not require the intervention of any TaGSTF. The potential importance of GSTFs and glutathione conjugation in flavonoid metabolism is discussed.
KW - chalcones
KW - flavonoids
KW - glutathione transferases
KW - herbicides
KW - ligandin
KW - S-isoliquirtigenin-glutathione
KW - Triticum aestivum
KW - xenobiotics
KW - Zea mays
KW - TRITICUM-AESTIVUM L.
KW - MAIZE ZEA-MAYS
KW - S-TRANSFERASE
KW - HERBICIDE DETOXIFICATION
KW - ANTHOCYANIN SEQUESTRATION
KW - GENE FAMILY
KW - ISOFORM-II
KW - PURIFICATION
KW - XENOBIOTICS
KW - CONJUGATION
UR - http://www.scopus.com/inward/record.url?scp=0042977426&partnerID=8YFLogxK
UR - http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12956529
U2 - 10.1023/A:1024858218804
DO - 10.1023/A:1024858218804
M3 - Article
C2 - 12956529
SN - 0167-4412
VL - 52
SP - 591
EP - 603
JO - Plant Molecular Biology
JF - Plant Molecular Biology
IS - 3
ER -