1.Jasmonate-inducible expression of a potato cathepsin D inhibitor-GUS gene fusion in tobacco cells.
Ishikawa A1, Yoshihara T, Nakamura K. Plant Mol Biol. 1994 Oct;26(1):403-14.
A potato gene encoding cathepsin D inhibitor (CDI) is expressed constitutively in tubers and flower buds and it is inducible in leaves upon wounding of the tissue or by treatment with methyl jasmonate (MJA). A fusion gene (CDI:GUS) in which the 2.4 kb long promoter of the CDI gene was translationaly fused with the coding sequence for beta-glucuronidase (GUS) showed MJA-inducible expression in transformed tobacco cells in suspension. The maximum level of induction by MJA was obtained in the absence of auxin and repression of MJA-inducible expression of the fusion gene by auxin was released by aphidicolin, the results suggesting that MJA-inducible expression is repressed during active cell division. JA and MJA showed similar activities in inducing the expression of the fusion gene, while other JA-related compounds such as cucurbic acid, tuberonic acid and dihydrojasmonic acid neither induced expression of the fusion gene nor inhibited the MJA-inducible expression of the fusion gene.
2.Determination of jasmonic acid in Lemna minor (L.) by liquid chromatography with fluorescence detection.
Kristl J1, Veber M, Krajnicic B, Oresnik K, Slekovec M. Anal Bioanal Chem. 2005 Nov;383(5):886-93. Epub 2005 Nov 5.
A new method is described for the determination of endogenous jasmonic acid (JA) in Lemna minor plant extracts using liquid chromatography (LC) with fluorescence detection. Plant tissues were extracted and derivatised using 9-anthryldiazomethane (ADAM reagent) prepared in situ. Accuracy and precision were improved by using the internal standard dihydrojasmonic acid (dh-JA) for the correction of JA losses during sample preparation steps. Liquid chromatography-mass spectrometry (LC/MS) analysis of ADAM derivatives of JA and dh-JA confirmed that a single molecule of JA and dh-JA was coupled with one molecule of reagent. Derivatives of JA and dh-JA were separated with gradient elution on a C18 reversed-phase column using acetonitrile/water as a mobile phase and detected by a fluorescence detector at excitation and emission wavelengths of 254 and 412 nm, respectively. The detection limits of JA and dh-JA were 2.9 ng mL(-1) and 3.7 ng mL(-1) per 50-microL injection.
3.Novel jasmonate amino acid conjugates in Asparagus officinalis during harvest-induced and natural foliar senescence.
Gapper NE1, Norris GE, Clarke SF, Lill RE, Jameson PE. Physiol Plant. 2002 Jan;114(1):116-124.
Five jasmonates, including novel tryptophan conjugates of jasmonic acid and dihydrojasmonic acid, were identified in extracts from spears of Asparagus officinalis L. by electrospray tandem mass spectrometry. Spears were harvested and were held dry or with bases immersed in water. The concentrations of jasmonic acid, dihydrojasmonic acid, their tryptophan conjugates, cucurbic acid and methyl jasmonate, were measured by ELISA in spears in the 10 d following harvest. A transient increase that occurred in all spear tips immediately following harvest in the concentration of jasmonates can be attributed to a wounding response. A second increase in the concentration of jasmonates occurred from 7 d after harvest but only in dry-treated spear tips indicating that jasmonates may have accumulated in response to water stress. Jasmonate levels were also monitored during natural foliar senescence. Increased levels of jasmonates occurred after the onset of senescence, implicating them as a consequence rather than a cause of senescence.
4.[Preparation of a monoclonal antibody against methyl jasmonate and quantification of jasmonic acid in florets of wheat and Italian ryegrass].
Gan LJ1, Xia K, Wang CL, Zhou X. Shi Yan Sheng Wu Xue Bao. 2004 Oct;37(5):359-66.
A monoclonal antibody (McAb) against methyl jasmonate (MeJA) was prepared and characterized. The McAb, J2-4B, was derived from an immunogen in which the C1-COOH of jasmonic acid (JA) was conjugated to the -NH2 of keyhole limpet hemocyanin (KLH). The McAb showed a higher recognition ability to methyl esters of JA than to its free acids. The integrity of a pentenyl in JA molecule was necessary for the recognition of McAb. Hydrogenation at C-9 and C-10 (dihydrojasmonic acid, 2H-JA) or eliminating the methyl group at C-12 (JAS-25) significantly abolished the binding force of JA molecule with the McAb. Some structural or functional analogues or precursor of JA, such as cucurbic acid, theobroxide, coronatine, and linolenic acid, could not be recognized by the McAb. The McAb has been used to set up a competitive enzyme-linked immunosorbent assay (ELISA) with a linearity range from 2.06 to 500 pmol of MeJA. Using this method, the fluctuations of JA content in florets during anthesis of wheat and Italian ryegrass were analyzed.