Abscisic acid and nitric oxide signaling in two different portions of detached leaves of Guzmania monostachia with CAM up-regulated by drought

Autor(es)

Mioto, Paulo Tamaso ^[1] ; Mercier, Helenice ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biociencias, Dept Bot, BR-05508090 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Plant Physiology; v. 170, n. 11, p. 996-1002, JUL 15 2013.
• Citações Web of Science: 17

Resumo

Guzmania monostachia is an epiphyte tank bromeliad capable of up-regulating crassulacean acid metabolism (CAM) in response to several environmental stimuli, including drought and light stress. In other plant species, abscisic acid (ABA) and nitric oxide,(NO) seem to be involved in CAM induction. Because the leaves of tank bromeliads perform different functions along their length, this study attempted to investigate whether ABA and NO are involved in regulation of CAM expression in this species by quantifying these compounds in apical and basal portions of the leaf, and whether there would be differences in this event for each leaf portion. Detached leaves exposed to a 30% polyethylene glycol solution showed a significant upregulation of CAM on the seventh day of treatment only in the apical portion, as indicated by nocturnal acid accumulation and phosphoenolpyruvate carboxylase (PEPC) activity. On the three days prior to CAM induction, ABA, NO and H2O2 were quantified. The amounts of ABA were higher in PEG-exposed leaves, along their entire length. NO, however, was higher only in the apical portion, precisely where CAM was up-regulated. H2O2 was higher only in the basal portion of PEG-exposed leaves. Our results suggest that ABA might be a systemic signal to drought, occurring in the entire leaf. NO and H2O2, however, may be signals restricted only to the apical or basal portions, respectively. (C) 2013 Elsevier GmbH. All rights reserved. (AU)

• Processo FAPESP: 08/55894-8 - Sinalizacao do oxido nitrico na inducao do metabolismo acido das crassulaceas (cam) em guzmania monostachia, uma bromelia epifita c3-cam facultativa
• Beneficiário: Paulo Tamaso Mioto
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 11/50637-0 - Competência para a expressão do metabolismo ácido das crassuláceas (CAM) em bromélia epífita: sinalização, modulação da expressão, perfil transcricional e interação com o metabolismo de nitrogênio
• Beneficiário: Helenice Mercier
• Modalidade de apoio: Auxílio à Pesquisa - Temático