Keteleeria davidiana var. formosana (Pinaceae), Taiwan cow-tail fir, is an endangered species listed on the IUCN Red List of Threatened Species and only two populations remain, both on the Taiwan Island. Sixteen polymorphic microsatellite loci were developed in an endangered and endemic gymnosperm species, Keteleeria davidiana var. formosana, and were tested in an additional 6 taxa, K. davidiana var. calcarea, K. davidiana var. chienpeii, K. evelyniana, K. fortunei, K. fortunei var. cyclolepis, and K. pubescens, to evaluate the genetic variation available for conservation management and to reconstruct the phylogeographic patterns of this ancient lineage.
Variation partitioning of species composition into components explained by environmental and spatial variables is often used to identify a signature of niche- and dispersal-based processes in community assembly. Such interpretation, however, strongly depends on the quality of the environmental data available. In recent studies conducted in forest dynamics plots, the environment was represented only by readily available topographical variables. Using data from a subtropical broad-leaved dynamics plot in Taiwan, we focus on the question of how would the conclusion about importance of niche- and dispersal-based processes change if soil variables are also included in the analysis. To gain further insight, we introduced multiscale decomposition of a pure spatial component [c] in variation partitioning. Our results indicate that, if only topography is included, dispersal-based processes prevail, while including soil variables reverses this conclusion in favor of niche-based processes. Multiscale decomposition of [c] shows that if only topography was included, broad-scaled spatial variation prevails in [c], indicating that other as yet unmeasured environmental variables can be important. However, after also including soil variables this pattern disappears, increasing importance of meso- and fine-scaled spatial patterns indicative of dispersal processes.
Returning to the sea, just like invasion of land, has occurred in many groups of animals and plants. For flowering plants, traits adapted to the terrestrial environments have to change or adopt a new function to allow the plants to survive and prosper in the sea where water motion tends to rotate and move seeds. In this investigation, how seeds of the seagrass Thalassia hemprichii (Hydrocharitaceae), a common monocotyledon in the Indo-Pacific, adapt to the wavy environment was studied. Mature seeds were collected from Dongsha Atoll in South China Sea. The effects of light qualities on seed germination, the seed morphology, the unipolar distribution of starch granules in the endosperms and growth of root hair-like filamentous cells from basal surface of the seeds were all found to differ from those of terrestrial monocotyledons. Physiologically, germination of the seeds was stimulated by blue light rather than red light. Morphologically, the bell-shaped seeds coupled with the unipolar distribution of starch granules in the enlarged bases helped maintain their upright posture on the tidal seafloor. Growth of root hair-like filamentous cells from the basal surface of the seeds prior to primary root growth served to attach onto sediments, providing leverage and attachment required by the primary roots to insert into sediments. These filamentous cells grasped coral sand but not silicate sand, demonstrating a habitat preference of this species.
Type-2 ribosome-inactivating proteins, composed of a toxic A-chain and lectin-like B-chain, display various biological functions, including cytotoxicity and immunomodulation. We here cloned the lectin-like B-chain encoding fragment of a newly identified type-2 RIP gene, articulatin gene, from Viscum articulatum, into a bacterial expression vector to obtain nonglycosylated recombinant protein expressed in inclusion bodies. After purification and protein refolding, soluble refolded recombinant articulatin B-chain (rATB) showed lectin activity specific toward galactoside moiety and was stably maintained while stored in low ionic strength solution. Despite lacking glycosylation, rATB actively bound leukocytes with preferential binding to monocytes and in vitro stimulated PBMCs to release cytokines without obvious cytotoxicity. These results implicated such a B-chain fragment as a potential immunomodulator.
Stable oil bodies of smaller sizes and higher thermostability were isolated from mature cycad (Cycas revoluta) megagametophytes compared with those isolated from sesame seeds. Immunological cross-recognition revealed that cycad oil bodies contained a major protein of 27 kDa, tentatively identified as caleosin, while oleosin, the well-known structural protein, was apparently absent. Mass spectrometric analysis showed that the putative cycad caleosin possessed a tryptic fragment of 15 residues matching to that of a theoretical moss caleosin. A complete cDNA fragment encoding this putative caleosin was obtained by PCR cloning using a primer designed according to the tryptic peptide and another one designed according to a highly conservative region among diverse caleosins. The identification of this clone was subsequently confirmed by immunodetection and MALDI-MS analyses of its recombinant fusion protein over-expressed in Escherichia coli and the native form from cycad oil bodies. Stable artificial oil bodies were successfully constituted with triacylglycerol, phospholipid and the recombinant fusion protein containing the cycad caleosin. These results suggest that stable oil bodies in cycad megagametophytes are mainly sheltered by a unique structural protein caleosin.
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