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Use of the glucosyltransferase UGT71B6 to disturb abscisic acid homeostasis in Arabidopsis thaliana
Author(s) -
Priest David M.,
Ambrose Stephen J.,
Vaistij Fabián E.,
Elias Luisa,
Higgins Gillian S.,
Ross Andrew R. S.,
Abrams Suzanne R.,
Bowles Dianna J.
Publication year - 2006
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.2006.02701.x
Subject(s) - abscisic acid , arabidopsis , arabidopsis thaliana , glucosyltransferase , chemistry , biochemistry , context (archaeology) , mutant , microbiology and biotechnology , biology , enzyme , gene , paleontology
Summary A glucosyltransferase (GT) of Arabidopsis, UGT71B6, recognizing the naturally occurring enantiomer of abscisic acid (ABA) in vitro , has been used to disturb ABA homeostasis in planta . Transgenic plants constitutively overexpressing UGT71B6 (71B6‐OE) have been analysed for changes in ABA and the related ABA metabolites abscisic acid glucose ester (ABA‐GE), phaseic acid (PA), dihydrophaseic acid (DPA), 7′‐hydroxyABA and neo‐phaseic acid. Overexpression of the GT led to massive accumulation of ABA‐GE and reduced levels of the oxidative metabolites PA and DPA, but had marginal effect on levels of free ABA. The control of ABA homeostasis, as reflected in levels of the different metabolites, differed in the 71B6‐OEs whether the plants were grown under standard conditions or subjected to wilt stress. The impact of increased glucosylation of ABA on ABA‐related phenotypes has also been assessed. Increased glucosylation of ABA led to phenotypic changes in post‐germinative growth. The use of two structural analogues of ABA, known to have biological activity but to differ in their capacity to act as substrates for 71B6 in vitro , confirmed that the phenotypic changes arose specifically from the increased glucosylation caused by overexpression of 71B6 . The phenotype and profile of ABA and related metabolites in a knockout line of 71B6 , relative to wild type, has been assessed during Arabidopsis development and following stress treatments. The lack of major changes in these parameters is discussed in the context of functional redundancy of the multigene family of GTs in Arabidopsis.