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

Author(s)

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

Affiliation

^[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

• Document type: Journal article
• Source: Plant Physiology and Biochemistry; v. 121, p. 21-30, DEC 2017.
• Web of Science Citations: 4

Abstract

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)

• FAPESP's process: 12/14339-7 - Mechanisms of physiological inactivation and recovery involved in tolerance to desiccation of Pitcairnia lanuginosa Ruiz Pav., a Bromeliaceae from the cerrado
• Grantee: Evandro Alves Vieira
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 12/16332-0 - Storage and cell wall carbohydrates from plants and filamentous fungi: changes in response to alelochemicals and environmental conditions
• Grantee: Marcia Regina Braga
• Support Opportunities: Regular Research Grants