title: Trade-off between soluble protein production and nutritional storage in Bromeliaceae.
abstract: Bromeliads are able to occupy some of the most nutrient-poor environments especially because they possess absorptive leaf trichomes, leaves organized in rosettes, distinct photosynthetic pathways [C3, Crassulacean acid metabolism (CAM) or facultative C3-CAM], and may present an epiphytic habit. The more derived features related to these traits are described for the Tillandsioideae subfamily. In this context, the aims of this study were to evaluate how terrestrial predators contribute to the nutrition and performance of bromeliad species, subfamilies and ecophysiological types, whether these species differ in their ecophysiological traits and whether the physiological outcomes are consistent among subfamilies and types (e.g. presence/absence of tank, soil/tank/atmosphere source of nutrients, trichomes/roots access to nutrients).
  
  
  
  Isotopic (15N-enriched predator faeces) and physiological methods (analyses of plant protein, amino acids, growth, leaf mass per area and total N incorporated) in greenhouse experiments were used to investigate the ecophysiological contrasts between Tillandsioideae and Bromelioideae, and among ecophysiological types when a predatory anuran contributes to their nutrition.
  
  
  
  It was observed that Bromelioideae had higher concentrations of soluble protein and only one species grew more (Ananas bracteatus), while Tillandsioideae showed higher concentrations of total amino acids, asparagine and did not grow. The ecophysiological types that showed similar protein contents also had similar growth. Additionally, an ordination analysis showed that the subfamilies and ecophysiological types were discrepant considering the results of the total nitrogen incorporated from predators, soluble protein and asparagine concentrations, relative growth rate and leaf mass per area.
  
  
  
  Bromeliad subfamilies showed a trade-off between two strategies: Tillandsioideae stored nitrogen into amino acids possibly for transamination reactions during nutritional stress and did not grow, whereas Bromelioideae used nitrogen for soluble protein production for immediate utilization, possibly for fast growth. These results highlight that Bromeliaceae evolution may be directly associated with the ability to stock nutrients.
authors: Pós-graduação em Ecologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, CEP 13083-970, Campinas, São Paulo, Brazil.
authors: Ana Zangirolame
authors: AZ
authors: Gonçalves
authors: Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo (USP), Rua do Matão, 277, CEP 05508090, São Paulo, Brazil.
authors: Helenice
authors: H
authors: Mercier
authors: Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, CEP 13083-970, Campinas, São Paulo, Brazil.
authors: Rafael Silva
authors: RS
authors: Oliveira
authors: Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, CEP 13083-970, Campinas, São Paulo, Brazil gqromero@unicamp.br.
authors: Gustavo Quevedo
authors: GQ
authors: Romero
mesh_terms: D000596:Amino Acids / Q000378:metabolism / Q000502:physiology; D031230:Ananas / Q000378:metabolism / Q000502:physiology; D001216:Asparagine / Q000378:metabolism / Q000502:physiology; D031231:Bromelia / Q000378:metabolism / Q000502:physiology; D031229:Bromeliaceae / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D009587:Nitrogen Isotopes / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism / Q000502:physiology; D018521:Plant Physiological Phenomena; D010940:Plant Proteins / Q000378:metabolism* / Q000502:physiology; D031232:Tillandsia / Q000378:metabolism / Q000502:physiology
chemical_list: D000596:Amino Acids; D009587:Nitrogen Isotopes; D010940:Plant Proteins; D001216:Asparagine
keywords: Bromelioideae; Tillandsioideae; amino acids; asparagine; ecophysiological types; nitrogen flux; phytotelmata; stable isotopes; trichomes