Lipid composition of mangrove and its relevance to salt tolerance |
| |
Authors: | Email author" target="_blank">Hirosuke?OkuEmail author Shigeyuki?Baba Hiroya?Koga Kensaku?Takara Hironori?Iwasaki |
| |
Institution: | (1) Division of Molecular Biotechnology, Center of Molecular Bioscience, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan,;(2) College of Agriculture, University of the Ryukyus, Nishihara, Okinawa, Japan, |
| |
Abstract: | Lipid compositions of mangrove trees were studied in relation to the salt-tolerance mechanism. Leaves and roots were obtained
from seven mature mangrove trees on Iriomote Island, Okinawa: Bruguiera gymnorrhiza, Rhizophora stylosa, Kandelia candel, Lumnitzera racemosa, Avicennia marina, Pemphis acidula and Sonneratia alba. Lipids of mangrove leaves mainly consisted of 11 lipid classes: polar lipids, unknown (UK) 1–6, sterols, triacyl glycerols,
wax ester and sterol ester (UK 3 and 4 were found to be tri-terpenoid alcohol in this study). Of these lipid classes, sterol
ester was the main lipid in all species comprising 17.6–33.7% of total lipids. Analysis of the chemical structure found that
the sterol esters mainly consisted of fatty acid esters of tri-terpenoid alcohols. One major tri-terpenoid alcohol was identified
to be lupeol by interpretation of infrared resonance, nuclear magnetic resonance and mass spectrometry. Because of the unique
anatomy of the mangrove root, lipid analyses were made separately for epidermis, cortex and innermost stele, respectively.
The concentration of free tri-terpenoid alcohols showed a higher tendency in the outside part than in the inside portion of
the roots, suggesting their protective roles. Relevance of lipid composition to salt tolerance was studied with propagules
of K. candel and B. gymnorrhiza planted with varied salt concentrations. The proportions of free tri-terpenoids increased with salinity in both leaves and
roots of K. candel, and only in roots of B. gymnorrhiza. No salt-dependent changes were noted in the phospholipid and fatty acid compositions in both species. These findings suggested
that salt stress specifically modulated the terpenoid concentrations in mangroves.
Electronic Publication |
| |
Keywords: | Lipid composition Mangrove Phytosterol Root Salt tolerance Terpenoid |
本文献已被 PubMed SpringerLink 等数据库收录! |
|