Identification of abscisic acid, indole-3-acetic acid, jasmonic acid, indole-3-acetonitrile, methyl jasmonate and gibberellins in developing, dormant and stratified seeds of ash (Fraxinus excelsior)

Abstract

Abscisic acid (ABA), indole-3-acetic acid (IAA), indole-3-acetonitrile(IAN), jasmonic acid (JA), methyl jasmonate (MeJA) and gibberellins (GAs);GA₁, GA₃, GA₈, GA₉,GA₁₂,GA₁₅, GA₁₇, GA₁₉, GA₂₀,GA₂₄, GA₂₉, GA₄₄, GA₅₁ andGA₅₃, were identified in seeds of ash (Fraxinusexcelsior L.) by combined gas chromatography–massspectrometry.The presence of ABA, IAA, IAN, JA and MeJA was confirmed in developing, dormantand stratified seeds by comparison of Kovat's retention indices (KRI) andspectral data with those obtained for standard compounds. Also, the presence ofGA₁, GA₃, GA₉, GA₁₉,GA₂₀and GA₄₄ was confirmed by comparison of KRI and spectral data withthose of standards, while the presence of the remaining GAs was confirmed bycomparison of KRI and spectral data with literature values. All of the GAsidentified were detected in extracts of developing seeds, while onlyGA₁₇ and GA₁₉ were detected in dormant seeds andGA₁, GA₈, GA₁₉, GA₂₀ andGA₂₉ were detected in stratified seed. The results suggest it islikely that the GAs are important in development and in breaking dormancy ofashseed. While ABA, JA and MeJA may be important in control (i.e. onset andmaintenance) of dormancy. The roles of IAA and IAN are unclear, but it ispossible that they are important in the development of ash seed, and as part ofthe dormancy controlling mechanism.