title: Abscisic acid metabolite profiling as indicators of plastic responses to drought in grasses from arid Patagonian Monte (Argentina).
abstract: The identification of hormonal and biochemical traits that play functional roles in the adaptation to drought is necessary for the conservation and planning of rangeland management. The aim of this study was to evaluate the effects of drought on i) the water content (WC) of different plant organs, ii) the endogenous level of abscisic acid (ABA) and metabolites (phaseic acid-PA, dihydrophaseic acid-DPA and abscisic acid conjugated with glucose ester-ABA-GE), iii) the total carotenoid concentration and iv) to compare the traits of two desert perennial grasses (Pappostipa speciosa and Poa ligularis) with contrasting morphological and functional drought resistance traits and life-history strategies. Both species were subjected to two levels of gravimetric soil moisture (the highest near field capacity during autumn-winter and the lowest corresponding to summer drought). Drought significantly increased the ABA and DPA levels in the green leaves of P. speciosa and P. ligularis. Drought decreased ABA in the roots of P. speciosa while it increased ABA in the roots of P. ligularis. P. ligularis had the highest ABA level and WC in green leaves. While P. speciosa had the highest DPA levels in leaves. In conclusion, we found the highest ABA level in the mesophytic species P. ligularis and the lowest ABA level in the xerophytic species P. speciosa, revealing that the ABA metabolite profile in each grass species is a plastic response to drought resistance.
authors.affiliation: Laboratorio de Fisiología Vegetal, Unidad de Investigación Ecosistemas Continentales Patagónicos (ECOPAT), Centro Nacional Patagónico-Consejo Nacional de Investigaciones Científicas y Técnicas (CENPAT-CONICET), Boulevard Brown 2915, 9120 Puerto Madryn, Chubut, Argentina. Electronic address: cenzano@cenpat.edu.ar.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Cenzano
authors.affiliation: Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36, Km 601, 5800 Río Cuarto, Córdoba, Argentina. Electronic address: omasciarelli@exa.unrc.edu.ar.
authors.forename: O
authors.initials: O
authors.lastname: Masciarelli
authors.affiliation: Departamento de Ciencias Naturales, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta 36, Km 601, 5800 Río Cuarto, Córdoba, Argentina. Electronic address: vluna@exa.unrc.edu.ar.
authors.forename: M Virginia
authors.initials: MV
authors.lastname: Luna
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D000222:Adaptation, Physiological / Q000502:physiology*; D001118:Argentina; D055864:Droughts; D018515:Plant Leaves / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism*; D031785:Poa / Q000378:metabolism*
chemical_list: D000040:Abscisic Acid
keywords: Abscisic acid; Dihydrophaseic acid; Drought; Perennial grass; Plant functional type; Plastic response; Xerophytic