title: OeFAD8, OeLIP and OeOSM expression and activity in cold-acclimation of Olea europaea, a perennial dicot without winter-dormancy.
abstract: Cold-acclimation genes in woody dicots without winter-dormancy, e.g., olive-tree, need investigation. Positive relationships between OeFAD8, OeOSM , and OeLIP19 and olive-tree cold-acclimation exist, and couple with increased lipid unsaturation and cutinisation. Olive-tree is a woody species with no winter-dormancy and low frost-tolerance. However, cold-tolerant genotypes were empirically selected, highlighting that cold-acclimation might be acquired. Proteins needed for olive-tree cold-acclimation are unknown, even if roles for osmotin (OeOSM) as leaf cryoprotectant, and seed lipid-transfer protein for endosperm cutinisation under cold, were demonstrated. In other species, FAD8, coding a desaturase producing α-linolenic acid, is activated by temperature-lowering, concomitantly with bZIP-LIP19 genes. The research was focussed on finding OeLIP19 gene(s) in olive-tree genome, and analyze it/their expression, and that of OeFAD8 and OeOSM, in drupes and leaves under different cold-conditions/developmental stages/genotypes, in comparison with changes in unsaturated lipids and cell wall cutinisation. Cold-induced cytosolic calcium transients always occurred in leaves/drupes of some genotypes, e.g., Moraiolo, but ceased in others, e.g., Canino, at specific drupe stages/cold-treatments, suggesting cold-acclimation acquisition only in the latter genotypes. Canino and Moraiolo were selected for further analyses. Cold-acclimation in Canino was confirmed by an electrolyte leakage from leaf/drupe membranes highly reduced in comparison with Moraiolo. Strong increases in fruit-epicarp/leaf-epidermis cutinisation characterized cold-acclimated Canino, and positively coupled with OeOSM expression, and immunolocalization of the coded protein. OeFAD8 expression increased with cold-acclimation, as the production of α-linolenic acid, and related compounds. An OeLIP19 gene was isolated. Its levels changed with a trend similar to OeFAD8. All together, results sustain a positive relationship between OeFAD8, OeOSM and OeLIP19 expression in olive-tree cold-acclimation. The parallel changes in unsaturated lipids and cutinisation concur to suggest orchestrated roles of the coded proteins in the process.
authors.affiliation: Dipartimento di Biologia Ambientale, Università 'Sapienza', P.le A. Moro 5, 00185, Rome, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: D'Angeli
authors.affiliation: Dipartimento di Biologia Ambientale, Università 'Sapienza', P.le A. Moro 5, 00185, Rome, Italy.
authors.forename: Maya
authors.initials: M
authors.lastname: Matteucci
authors.affiliation: Dipartimento di Biologia Ambientale, Università 'Sapienza', P.le A. Moro 5, 00185, Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Fattorini
authors.affiliation: Dipartimento di Biologia, Università degli Studi di Roma "Tor Vergata", Via della Ricerca Scientifica 1, 00133, Rome, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Gismondi
authors.affiliation: Dipartimento di Biologia Ambientale, Università 'Sapienza', P.le A. Moro 5, 00185, Rome, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Ludovici
authors.affiliation: Dipartimento di Biologia, Università degli Studi di Roma "Tor Vergata", Via della Ricerca Scientifica 1, 00133, Rome, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Canini
authors.affiliation: Dipartimento di Biologia Ambientale, Università 'Sapienza', P.le A. Moro 5, 00185, Rome, Italy. mariamaddalena.altamura@uniroma1.it.
authors.forename: Maria Maddalena
authors.identifier: http://orcid.org/0000-0001-9848-6579
authors.initials: MM
authors.lastname: Altamura
mesh_terms: D000064:Acclimatization / Q000235:genetics*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D003080:Cold Temperature; D003600:Cytosol / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D050356:Lipid Metabolism / Q000235:genetics; D031658:Olea / Q000166:cytology / Q000235:genetics* / Q000502:physiology; D059828:Plant Cells / Q000378:metabolism; D057445:Plant Dormancy / Q000235:genetics*; D018515:Plant Leaves / Q000378:metabolism / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D012621:Seasons
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D010940:Plant Proteins; D002118:Calcium
keywords: Cuticle; Fatty acid desaturase (FAD8); LIP transcription factor; Linolenic acid; Lipidome; Osmotin