title: Comparative proteomics of short and tall glandular trichomes of Nicotiana tabacum reveals differential metabolic activities.
abstract: Leaf glandular trichomes (epidermal hairs) actively synthesize secondary metabolites, many of which are the frontline of plant defense. In Nicotiana tabacum, tall and short glandular trichomes have been identified. While the former have been extensively studied and match the classic picture of trichome function, the short trichomes have remained relatively uncharacterized. We have set up a procedure based on centrifugation on Percoll density gradients to obtain separate tall and short trichome fractions purified to >85%. We then investigated the proteome of both trichome types combining 2D-LC fractionation of tryptic peptides and quantification of a set of 461 protein groups using isobaric tags for relative and absolute quantitation. Almost the entire pathway leading to the synthesis of diterpenes was identified in the tall trichomes. Indications for their key roles in the synthesis of cuticular compounds were also found. Concerning the short glandular trichomes, ribosomal proteins and enzymes such phosphoenolpyruvate carboxykinase and polyphenol oxidase were more abundant than in the tall glandular trichomes. These results are discussed in the frame of several hypotheses regarding the respective roles of short and long glandular trichomes.
authors.affiliation: Institut des Sciences de la Vie, Université catholique de Louvain , Croix du Sud, 4-5, Box L7.07.14, 1348 Louvain-la-Neuve, Belgium.
authors.forename: Adrienne
authors.initials: A
authors.lastname: Sallets
authors.forename: Maxime
authors.initials: M
authors.lastname: Beyaert
authors.forename: Marc
authors.initials: M
authors.lastname: Boutry
authors.forename: Antoine
authors.initials: A
authors.lastname: Champagne
mesh_terms: D018515:Plant Leaves / Q000166:cytology / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D020543:Proteome / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry; D014026:Nicotiana / Q000166:cytology / Q000378:metabolism*; D064201:Trichomes / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; D020543:Proteome