Olive tree is an evergreen species of economic value lacking winter dormancy and showing low tolerance to frost. This low tolerance limits its cultivation in cold regions, where, by contrast, oil quality is improved by an enrichment in unsaturated fatty acids, i.e., linoleic (C18:2) and linolenic (C18:3) acids, produced by the activity of specific fatty acid desaturases (FADs). Cold-resistant genotypes have been empirically selected from centuries however the genetic network controlling cold-tolerance in olive tree is still unknown. Transient changes in cytosolic calcium are involved in sensing the cold stress and in activating cold acclimation in numerous plants, including olive tree (1-2). A role for the PR-5 protein Osmotin (OeOSM) in olive tree cold acclimation has been suggested, possibly as transfer protein to the cell wall of cutinsomes, containing unsaturated fatty acid-derived compounds (3, 4). The expression of genes coding for specific FADs, i.e. OeFAD2.2 and OeFAD7, necessary for C18:2 and C18:3 production, respectively, has been demonstrated to be positively related to olive tree drupe cold-response. However, the expression of both genes normally occurs during oil biogenesis, and increases under cold-stress independently of the acclimation capabilities of the genotypes, suggesting that these genes are unrelated with cold acclimation (2). By contrast, in Arabidopsis thaliana and other plants, FAD8, isoform of FAD7, is specifically activated by cold (5). Moreover, FAD8 expression in maize is activated concomitantly with the beta-Zip LIP transcription factor mlip19 (6), and members of LIP19-family are activated by calcium transients (7). The research aim was to identify transcripts of an OeLIP gene in leaves and drupes of two genotypes, one incapable and the other capable of cold acclimation, by cold-stresses applied before, during and after the possible natural/artificial acquisition of cold acclimation, investigating, in parallel, the changes in OeOSM and OeFAD8 expression, the immuno-localization of OeOSM, and by detecting the levels of C18:3-compounds deriving by OeFAD8 activity. Preliminarly, leaves and drupes belonging to cv. Moraiolo and cv. Canino were exposed to cold shocks of different duration and intensity at the same developmental stages, and the cold response evaluated in their protoplasts in terms of presence/absence of cytosolic calcium transients, for determining their differences in cold acclimation under all cold conditions. Both genotypes were cold sensitive at the beginning of the oil biogenesis in the drupe (WAF 10), however Canino was able to acquire artificial acclimation at this WAF. Only cv. Moraiolo showed calcium rises, i.e. remained cold-sensitive at the end of oil biogenesis (WAF 19) in leaves and drupes, and continued to be sensitive even in full winter (WAF 26), showing its total inability to cold acclimate, differently from the other genotype. An OeLIP gene was isolated and characterized, and its changes monitored by q-PCR in both leaves and drupes under the same cold-shocks applied for monitoring cytosolic calcium changes. OeLIP was activated by cold-induced calcium signalling. Its expression increased with cold, but became stable only in Canino. OeFAD8 transcription was also induced by calcium signalling, and changed in parallel with that of OeLIP. The production of C18:3, and related compounds, by OeFAD8 activity, increased in Canino in concomitance with acclimation. Also OeOSM was activated by calcium signalling, and its transcripts were high and stable during acclimation acquisition and maintenance by Canino drupes and leaves. Moreover, both organs showed increased cutinisation of the outer cell walls of epicarp and adaxial epidermis, respectively, with this event strongly increasing in Canino, and positively coupling with an increased immunolocalization of OeOSM in the cuticle. All together, results demonstrate that OeFAD8, OeLIP and OeOSM jointly control cold-acclimation in Olea europaea drupes and leaves.

FAD8, lip and osmotin are cold-acclimation genes in Olea europaea L / D'Angeli, Simone; Matteucci, Maya; Fattorini, Laura; Gismondi, Angelo; Ludovici, Matteo; Canini, Antonella; Altamura, Maria Maddalena. - ELETTRONICO. - unico:(2015), pp. 14-14. (Intervento presentato al convegno 110° Congresso della Società Botanica Italiana onlus. II INTERNATIONAL PLANT SCIENCE CONFERENCE tenutosi a Pavia nel 14-17 settembre 2015).

FAD8, lip and osmotin are cold-acclimation genes in Olea europaea L.

D'ANGELI, Simone;FATTORINI, LAURA;LUDOVICI, MATTEO;ALTAMURA, Maria Maddalena
2015

Abstract

Olive tree is an evergreen species of economic value lacking winter dormancy and showing low tolerance to frost. This low tolerance limits its cultivation in cold regions, where, by contrast, oil quality is improved by an enrichment in unsaturated fatty acids, i.e., linoleic (C18:2) and linolenic (C18:3) acids, produced by the activity of specific fatty acid desaturases (FADs). Cold-resistant genotypes have been empirically selected from centuries however the genetic network controlling cold-tolerance in olive tree is still unknown. Transient changes in cytosolic calcium are involved in sensing the cold stress and in activating cold acclimation in numerous plants, including olive tree (1-2). A role for the PR-5 protein Osmotin (OeOSM) in olive tree cold acclimation has been suggested, possibly as transfer protein to the cell wall of cutinsomes, containing unsaturated fatty acid-derived compounds (3, 4). The expression of genes coding for specific FADs, i.e. OeFAD2.2 and OeFAD7, necessary for C18:2 and C18:3 production, respectively, has been demonstrated to be positively related to olive tree drupe cold-response. However, the expression of both genes normally occurs during oil biogenesis, and increases under cold-stress independently of the acclimation capabilities of the genotypes, suggesting that these genes are unrelated with cold acclimation (2). By contrast, in Arabidopsis thaliana and other plants, FAD8, isoform of FAD7, is specifically activated by cold (5). Moreover, FAD8 expression in maize is activated concomitantly with the beta-Zip LIP transcription factor mlip19 (6), and members of LIP19-family are activated by calcium transients (7). The research aim was to identify transcripts of an OeLIP gene in leaves and drupes of two genotypes, one incapable and the other capable of cold acclimation, by cold-stresses applied before, during and after the possible natural/artificial acquisition of cold acclimation, investigating, in parallel, the changes in OeOSM and OeFAD8 expression, the immuno-localization of OeOSM, and by detecting the levels of C18:3-compounds deriving by OeFAD8 activity. Preliminarly, leaves and drupes belonging to cv. Moraiolo and cv. Canino were exposed to cold shocks of different duration and intensity at the same developmental stages, and the cold response evaluated in their protoplasts in terms of presence/absence of cytosolic calcium transients, for determining their differences in cold acclimation under all cold conditions. Both genotypes were cold sensitive at the beginning of the oil biogenesis in the drupe (WAF 10), however Canino was able to acquire artificial acclimation at this WAF. Only cv. Moraiolo showed calcium rises, i.e. remained cold-sensitive at the end of oil biogenesis (WAF 19) in leaves and drupes, and continued to be sensitive even in full winter (WAF 26), showing its total inability to cold acclimate, differently from the other genotype. An OeLIP gene was isolated and characterized, and its changes monitored by q-PCR in both leaves and drupes under the same cold-shocks applied for monitoring cytosolic calcium changes. OeLIP was activated by cold-induced calcium signalling. Its expression increased with cold, but became stable only in Canino. OeFAD8 transcription was also induced by calcium signalling, and changed in parallel with that of OeLIP. The production of C18:3, and related compounds, by OeFAD8 activity, increased in Canino in concomitance with acclimation. Also OeOSM was activated by calcium signalling, and its transcripts were high and stable during acclimation acquisition and maintenance by Canino drupes and leaves. Moreover, both organs showed increased cutinisation of the outer cell walls of epicarp and adaxial epidermis, respectively, with this event strongly increasing in Canino, and positively coupling with an increased immunolocalization of OeOSM in the cuticle. All together, results demonstrate that OeFAD8, OeLIP and OeOSM jointly control cold-acclimation in Olea europaea drupes and leaves.
2015
110° Congresso della Società Botanica Italiana onlus. II INTERNATIONAL PLANT SCIENCE CONFERENCE
04 Pubblicazione in atti di convegno::04d Abstract in atti di convegno
FAD8, lip and osmotin are cold-acclimation genes in Olea europaea L / D'Angeli, Simone; Matteucci, Maya; Fattorini, Laura; Gismondi, Angelo; Ludovici, Matteo; Canini, Antonella; Altamura, Maria Maddalena. - ELETTRONICO. - unico:(2015), pp. 14-14. (Intervento presentato al convegno 110° Congresso della Società Botanica Italiana onlus. II INTERNATIONAL PLANT SCIENCE CONFERENCE tenutosi a Pavia nel 14-17 settembre 2015).
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/816861
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