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Substitution of hydrazones for the 4′ carbonyl on abscisic acid rendered it ineffective in a rapid stomatal–opening–inhibition bioassay
Author(s) -
Hite Daniel R. C.,
Outlaw William H.,
Seavy Margaret A.
Publication year - 1994
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1994.tb06657.x
Subject(s) - abscisic acid , guard cell , bioassay , chemistry , fusicoccin , stereochemistry , biochemistry , biology , enzyme , ecology , gene , atpase
A rapid stomatal bioassay to test abscisic acid (ABA)–like inhibition of stomatal opening was elaborated. The assay was sensitive to low concentrations of ABA (>50% inhibition of opening at 0.02 μ M (+)‐S‐ABA) and was insensitive to 20 μ M (+)‐S‐ABA‐1 ‐(methyl ester), which is consistent with previous work, With the original intent of developing anti‐idiotypic antibodies, we made conjugates of ABA at the 4′carbonyl because of its accessibility and known requirements for other positions of the ABA molecule in siomatal signal transduction. We found that these conjugates lacked ABA‐like activity and did not interfere with (+)‐S‐ABA in the stomatal bioassay, implying the importance of the 4′carbonyl. These observations cast doubt on the feasibility of using anti‐idiolypic antibodies produced through the use of 4′‐substituted ABA for the isolation of a guard‐cell ABA receptor.