title: Regulation of cell wall remodeling in grapevine (Vitis vinifera L.) callus under individual mineral stress deficiency.
abstract: Cell wall (CW) is a dynamic structure that determines the plant form, growth and response to environmental conditions. Vitis vinifera callus grown under nitrogen (-N), phosphorous (-P) and sulfur (-S) deficiency were used as a model system to address the influence of mineral stress in CW remodeling. Callus cells morphology was altered, mostly under -N, resulting in changes in cell length and width compared with the control. CW composition ascertained with specific staining and immuno-detection showed a decrease in cellulose and altered pattern of pectin methylesterification. Under mineral stress genes expression from candidate families disclosed mainly a downregulation of a glycosyl hydrolase family 9C (GH9C), xyloglucan transglycosylase/hydrolases (XTHs) with predicted hydrolytic activity and pectin methylesterases (PMEs). Conversely, upregulation of PMEs inhibitors (PMEIs) was observed. While methylesterification patterns can be associated to PME/PMEI gene expression, the lower cellulose content cannot be attributed to altered cellulose synthase (CesA) gene expression suggesting the involvement of other gene families. Salt extracts from -N and -P callus tissues increased plastic deformation in cucumber hypocotyls while no effect was observed with -S extracts. The lower endo-acting glycosyl hydrolase activity of -N callus extracts pinpoints a more expressive impact of -N on CW-remodeling.
authors.affiliation: DRAT/LEAF, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisbon, Portugal.
authors.forename: João C
authors.initials: JC
authors.lastname: Fernandes
authors.affiliation: BioTrop, Instituto de Investigação Científica Tropical (IICT, IP), Pólo Mendes Ferrão-Tapada da Ajuda, 1349-017 Lisbon, Portugal.
authors.forename: Luis F
authors.initials: LF
authors.lastname: Goulao
authors.affiliation: DRAT/LEAF, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisbon, Portugal. Electronic address: samport@isa.ulisboa.pt.
authors.forename: Sara
authors.initials: S
authors.lastname: Amâncio
mesh_terms: D002473:Cell Wall / Q000378:metabolism*; D003198:Computer Simulation; D018506:Gene Expression Regulation, Plant; D008903:Minerals / Q000378:metabolism*; D005810:Multigene Family; D009584:Nitrogen / Q000172:deficiency; D010758:Phosphorus / Q000172:deficiency; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013312:Stress, Physiological / Q000235:genetics; D013455:Sulfur / Q000172:deficiency; D027843:Vitis / Q000235:genetics* / Q000378:metabolism
chemical_list: D008903:Minerals; D010940:Plant Proteins; D010758:Phosphorus; D013455:Sulfur; D009584:Nitrogen
keywords: Cell wall polymers; Endoglucanase activity; Gene expression; Nutrient deficiency; Pectin desterification