Mechanisms of desiccation tolerance in the bromeliad Pitcairnia burchellii Mez: biochemical adjustments and structural changes

Autor(es)

Vieira, Evandro Alves ^[1] ; Silva, Kleber Resende ^[2] ; Oriani, Aline ^[2] ; Moro, Camila Fernandes ^[3] ; Braga, Marcia Regina ^[1]

Afiliação do(s) autor(es)

^[1] Inst Bot, Nucleo Pesquisa Fisiol & Bioquim Plantas, Sao Paulo, SP - Brazil

^[2] Univ Estadual Paulista, Inst Biociencias, Dept Bot, Rio Claro, SP - Brazil

^[3] Univ Estadual Campinas, Programa Posgrad Biol Celular & Estrutural, Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Plant Physiology and Biochemistry; v. 121, p. 21-30, DEC 2017.
• Citações Web of Science: 4

Resumo

Rocky outcrops represent the diversity center of vascular desiccation tolerant (DT) plants. Vegetation in this environment is exposed to an extended dry season and extreme conditions due to rocky soils and high sun exposure. In this study, we demonstrated that Pitcairnia burchellii, a bromeliad from rocky outcrops, tolerates intense desiccation for about 90 days due to strategies as accumulation of compatible osmolytes and antioxidant substances together with leaf morphological changes. In dehydrated plants, an increase in antioxidant activity was observed and the vacuolization of parenchyma cells was accompanied by proline accumulation in leaves and rhizomes. Precursors related to phenylpropanoid pathway increased significantly during plant dehydration. Accordingly, increases in anthocyanin and phenolic contents as well as lignin deposition were observed in leaves of dehydrated plants. Cell divisions and a decrease in stored starch were observed in the rhizomes indicating starch mobilization. Anatomical analyses revealed the presence of a more developed water-storage tissue in dehydrated leaves. During desiccation, leaves curl upwards and the adaxial V deep water-storage tissue is supported by two larger lateral vascular bundles. Cell wall folding and an increased proportion of arabinose-containing polymers was observed in leaves under dehydration, suggesting increasing of cell wall flexibility during desiccation. Such biochemical and morphological changes are consistent with the ability of P. burchellii to tolerate intense desiccation and behave as a resurrection species. (AU)

• Processo FAPESP: 12/14339-7 - Mecanismos de inativação e recuperação fisiológica envolvidos na tolerância à dessecação de Pitcairnia lanuginosa Ruiz & Pav., uma Bromeliaceae do cerrado
• Beneficiário: Evandro Alves Vieira
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 12/16332-0 - Carboidratos de reserva e de parede celular de plantas e de fungos filamentosos: alterações em resposta a aleloquímicos e a variações ambientais
• Beneficiário: Marcia Regina Braga
• Modalidade de apoio: Auxílio à Pesquisa - Regular