Effects of low temperature on growth and non-structural carbohydrates of the imperial bromeliad Alcantarea imperialis cultured in vitro

Autor(es)

Mollo, Luciana ^[1] ; Martins, Marina C. M. ^[2] ; Oliveira, Vanessa Fatima ^[1] ; Nievola, Catarina C. ; Figueiredo-Ribeiro, Rita de Cassia L. ^[1]

Afiliação do(s) autor(es)

^[1] Inst Bot, Biodiversidade Vegetal & Meio Ambiente Post Grad, BR-01061970 Sao Paulo - Brazil

^[2] Max Planck Inst Mol Plant Physiol, D-14468 Golm - Germany

• Tipo de documento: Artigo Científico
• Fonte: PLANT CELL TISSUE AND ORGAN CULTURE; v. 107, n. 1, p. 141-149, OCT 2011.
• Citações Web of Science: 18

Resumo

The imperial bromeliad Alcantarea imperialis grows naturally on rocky outcrops ('inselbergs') in regions where daily temperatures vary from 5 to 40A degrees C. As carbohydrate metabolism is altered in response to cold, it could lead to reprogramming of the metabolic machinery including the increase in levels of metabolites that function as osmolytes, compatible solutes, or energy sources in order to maintain plant homeostasis. The aim of this study was to evaluate the effects of different temperatures on plant growth and non-structural carbohydrates in plants of A. imperialis adapted to low temperature. Seedlings of A. imperialis were grown in vitro under a 12-h photoperiod with four different day/night temperature cycles: 5/5A degrees C, 15/15A degrees C, 15/30A degrees C (dark/light) and 30/30A degrees C. Plants were also cultivated at 26A degrees C in ex vitro conditions for comparison. The results showed an inverse relationship between temperature and germination time and no differences in the percentage of germination. Plants maintained for 9 months at 15A degrees C presented a reduced number of leaves and roots, and a dry mass four times lower than plants grown at 30A degrees C. Sugar content was higher in plants grown at 15A degrees C than at 30A degrees C. However, the highest amount of total sugar was found in plants growing under warm day/cold night conditions. Myo-inositol, glucose, fructose and sucrose were found predominantly under high temperatures, while under low temperatures, sucrose was apparently replaced by trehalose, raffinose and stachyose. Starch content was highest in plants grown under high temperatures. The lowest starch content was detected under low temperatures, suggesting its conversion into soluble carbohydrates to protect the plants against cold. These results indicated that low temperature retarded growth of A. imperialis and increased sugar levels, mainly trehalose, thus suggesting that these sugar compounds could be involved in cold tolerance. (AU)

• Processo FAPESP: 05/04139-7 - Carboidratos de plantas tropicais como moduladores de processos ecofisiológicos e indicadores de respostas a estresses ambientais
• Beneficiário: Marcia Regina Braga
• Modalidade de apoio: Auxílio à Pesquisa - Temático