The distribution and occurrence of polyisoprenoids (dolichols and polyprenols) in the leaves and roots of nine true Okinawan mangroves and the leaves of one associate mangrove were analyzed using two-dimensional thin layer chromatography. In the leaves, the distribution of three types (I, II, and III) of polyprenols and dolichols were detected. (I) The predominance of dolichols over polyprenols (more than 90%) was observed in Avicennia marina, Bruguiera gymnorrhiza, B. gymnorrhiza (yellow leaves), and Rhizophora stylosa. (II) The occurrence of both polyprenols and dolichols is observed in Excoecaria agallocha, Kandelia obovata, K. obovata (yellow leaves), Lumnitzera racemosa, Pemphis acidula, and Sonneratia alba. (III) The predominance of polyprenols over dolichols (more than 90%) is observed in Heritiera littoralis and Hibiscus tiliaceus. However, in the roots, a type-I distribution was observed in A. marina, B. gymnorrhiza, E. agallocha, H. littoralis and S. alba. A type-II distribution was observed in K. obovata, L. racemosa, P. acidula, and R. stylosa with no type-III distribution. The chain-length distribution of dolichols in the leaves and roots was C 50-C 140 and C 60-C 120 , respectively. A similar chain-length distribution of polyprenols of C 45-C 140 and C 65-C 85 was detected in the leaves and roots respectively. Taken together, sixteen out of twenty-one tissues indicated that dolichols are more abundant than polyprenols in both leaves and roots. The present study is the first to clarify the diversity of polyisoprenoids in both the leaves and roots of mangrove, suggesting the chemotaxonomic significance of polyisoprenoids in the mangrove tree species.

No abstract

Aim Mangroves are intertidal plants with sea-dispersed propagules, hence their population structure can offer valuable insights into the biogeographical processes driving population subdivision in coastal species. In this study, we used molecular markers and ocean circulation simulations to examine the effects of ocean currents and land masses on the genetic structure of the major mangrove species Rhizophora mucronata. Location Southeast Asia.Methods We assessed the genetic structure of 13 R. mucronata populations from continental Southeast Asia and Sumatra using 10 microsatellite loci. We first examined the relative effects of geographical distance and land mass (the Malay Peninsula) in shaping the genetic structure of R. mucronata in Southeast Asia. We then characterized the genetic structure of R. mucronata and compared it to the simulated ocean circulation patterns within our study region. ResultsDespite the low genetic diversity, significant genetic structuring was detected across R. mucronata populations. Contrary to observations on other mangrove species, genetic differentiation in R. mucronata was not found across the coasts of the Malay Peninsula, nor was it correlated with geographical distance. Instead, the most distinct genetic discontinuity was found at the boundary between the Andaman Sea and the Malacca Strait, and this can be explained by the prevailing ocean currents in this region.Main conclusions Our study presents novel evidence that the genetic structure of R. mucronata is maintained by ocean current-facilitated propagule dispersal.

Background. Mangrove forests have long been known as a source of phytochemical compounds producing various secondary metabolites. Despite the ubiquitous diversity of polyisoprenoids in the plant kingdom, few studies have focused on the distribution of polyisoprenoids in mangrove plants. The present study describes the distribution and occurrence of a new class of prenyl derivates -polyprenyl acetone as well as other polyisoprenoids in fourteen species of Indonesian mangroves, with an emphasis on chemotaxonomic importance. Material and methods. The leaves and roots of fourteen North Sumatran mangroves were analyzed using two-dimensional thin layer chromatography and electrospray ionization mass spectrometry. Results. In the leaves, the distribution of several types of polyprenyl acetones, polyprenols, and dolichols was detected and classified into types: type-I, having a predominance of dolichols over polyprenols (more than nine-fold), was observed in Acrostichum aureum (younger leaves), Avicennia alba, Av. lanata, Av. officinalis, Bruguiera parviflora, Ceriops tagal, Nypa fruticans, and Rhizophora mucronata; type-II, having the presence of both polyprenols and dolichols, was observed in Acanthus ilicifolius, Acr. aureum, B. cylindrica, and R. apiculata; type-III having a predominance of polyprenols over dolichols (more than nine-fold), was not observed in any North Sumatran mangroves; type-IV, having the presence of both polyprenyl acetones and dolichols, was observed in Aegiceras corniculatum; type-V, having the presence of polyprenyl acetones, polyprenols, and dolichols, was observed in Sonneratia caseolaris and Xylocarpus granatum. In the roots, type-I distribution was observed in Ae. corniculatum, Av. alba, Av. lanata, Av. officinalis, B. parviflora, C. tagal, N. fruticans, R. apiculata, R. mucronata, S. caseolaris, and X. granatum. Type-II distribution was observed in Ac. ilicifolius, Acr. aureum, and B. cylindrica. Type-III, -IV, and -V distributions were not observed in mangrove roots. Cluster analysis demonstrated that polyisoprenoid patterns in the leaves and roots form distinct separation into appropriate genera and tribe, suggesting that mangrove polyisoprenoids are chemotaxonomically significant. Conclusions. The major polyisoprenoid alcohols in Indonesian mangroves were found to be dolichols rather than polyprenols. The diversity of polyisoprenoids in both leaves and roots of mangroves may provide chemotaxonomic marker. The discovery of a new class of polyprenyl acetone is the first report from mangrove plants.

BackgroundMangrove forests are ecologically important but globally threatened intertidal plant communities. Effective mangrove conservation requires the determination of species identity, management units, and genetic structure. Here, we investigate the genetic distinctiveness and genetic structure of an iconic but yet taxonomically confusing species complex Rhizophora mucronata and R. stylosa across their distributional range, by employing a suite of 20 informative nuclear SSR markers.ResultsOur results demonstrated the general genetic distinctiveness of R. mucronata and R. stylosa, and potential hybridization or introgression between them. We investigated the population genetics of each species without the putative hybrids, and found strong genetic structure between oceanic regions in both R. mucronata and R. stylosa. In R. mucronata, a strong divergence was detected between populations from the Indian Ocean region (Indian Ocean and Andaman Sea) and the Pacific Ocean region (Malacca Strait, South China Sea and Northwest Pacific Ocean). In R. stylosa, the genetic break was located more eastward, between populations from South and East China Sea and populations from the Southwest Pacific Ocean. The location of these genetic breaks coincided with the boundaries of oceanic currents, thus suggesting that oceanic circulation patterns might have acted as a cryptic barrier to gene flow.ConclusionsOur findings have important implications on the conservation of mangroves, especially relating to replanting efforts and the definition of evolutionary significant units in Rhizophora species. We outlined the genetic structure and identified geographical areas that require further investigations for both R. mucronata and R. stylosa. These results serve as the foundation for the conservation genetics of R. mucronata and R. stylosa and highlighted the need to recognize the genetic distinctiveness of closely-related species, determine their respective genetic structure, and avoid artificially promoting hybridization in mangrove restoration programmes.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-015-0331-3) contains supplementary material, which is available to authorized users.