Zonal distribution of coarse woody debris and its contribution to net primary production in a secondary mangrove forest

Coarse woody debris (CWD) plays an important role in long-term carbon storage in forest ecosystems. However, few studies have examined CWD in mangrove forests. A secondary mangrove forest on an estuary of the Trat River showed different structures along vegetation zones ranging from the river’s edge to inland parts of the forest (the Sonneratia–Avicennia, Avicennia, Rhizophora, and Xylocarpus zones, respectively). The mass distribution of CWD stock in downed wood and standing dead trees along these vegetation zones was evaluated. Most of the CWD stock in the Sonneratia–Avicennia and Avicennia zones was found in downed wood, while it mainly accumulated in standing dead trees in the Rhizophora and Xylocarpus zones. The total mass of CWD stock that accumulated in each zone ranged from 1.56–8.39 t ha^?1, depending on the forest structure and inundation regimes. The annual woody debris flux in each zone was calculated by summing the necromass (excluding foliage) of dead trees and coarse litter from 2010 to 2013. The average woody debris flux was 5.4 t ha^?1 year^?1, and its zonal variation principally depended on the necromass production that resulted from forest succession, high tree-density, and lightning. Over all the zones, the above- and below-ground net primary production (ANPP and BNPP, respectively) was estimated at 18.0 and 3.6 t ha^?1 year^?1, respectively. The magnitude of BNPP and its contribution to the NPP was markedly increased when fine root production was taken into consideration. The contribution of the woody debris flux without root necromass to the ANPP ranged from 12 to 28%.     

Bullera begoniae sp. nov. and Bullera setariae sp. nov., two new species of ballistoconidium-forming yeasts in the Bullera variabilis (Bulleribasidium) cluster isolated from plants in Taiwan

Two strains of xylose-containing and Q-10-having ballistoconidiogenous yeasts isolated from plant leaves collected in Taiwan were found to represent two new species of the genus Bullera. In the phylogenetic trees based on the sequence analysis of 18S rDNA and D1/D2 domain of 26S rDNA, these species are located in the Bullera variabilis (Bulleribasidum) cluster in Hymenomycetes. They are described as Bullera begoniae sp. nov. and Bullera setariae sp. nov., respectively.     

Two new anamorphic yeasts, Candida thailandica sp. nov. and Candida lignicola sp. nov., isolated from insect frass in Thailand

Two new yeast strains of the genus Candida were isolated from insect frass collected in Khao-Yai National Park, Nakhonrachasima, Thailand. Based on the morphological, physiological and chemotaxonomic characteristics, and sequence analysis of the D1/D2 domain of 26S rRNA gene, these two strains were found to represent two distinct undescribed species and were named Candida thailandica sp. nov. (ST-17 = BCC 7717(T) = NBRC 102562(T)=CBS 10 610) and Candida lignicola sp. nov. (ST-33 = BCC 7733(T) = NBRC 102564(T) = CBS 10612). In the D1/D2 domain of 26S rRNA gene, C. thailandica (GeneBank accession no. AY228491) differs from Candida tsuchiyae, the nearest species, in 66 nucleotide substitutions (10%) and C. lignicola (GeneBank accession no. AY845350) differs from Candida coipomoensis, the nearest species, in nine nucleotides (1.6%). These two new species are clearly distinguished from their closest species by the assimilation of several carbon compounds.     

Endophytic yeast diversity in leaf tissue of rice,corn and sugarcane cultivated in Thailand assessed by a culture-dependent approach

Endophytic yeasts are yeast that can colonize healthy plant tissues without causing any damage to the host plant. This work aimed to explore the diversity of endophytic yeasts in leaf tissue of main agricultural crops (rice, corn and sugarcane) in Thailand, by a culture-dependent approach. A total of 311 leaf samples, consisting of rice (n = 100), corn (n = 109) and sugarcane (n = 102). From the tissue of rice (n = 92), corn (n = 76) and sugarcane (n = 78) leaf samples, 117, 118 and 123 yeast strains were respectively isolated and identified based on the D1/D2 region of the large subunit (LSU) rRNA gene sequence analysis to be yeast species in both the phyla Basidiomycota and Ascomycota. Higher numbers of basidiomycetous yeast than ascomycetous yeast were detected in the leaf tissue of the three crops. Pseudozyma (Dirkmeia) churashimaensis (Ustilaginales) was the most prevalent yeast species in the rice and corn leaves with relative frequencies (RF) of 35.9 % and 17.8 %, respectively. Whereas the predominant species in the sugarcane leaves was Meyerozyma caribbica (Saccharomycetales) with an RF of 14.6 %. In addition, six new yeast species and one new yeast genus were proposed. Our findings suggest that these plant species are good sources from which new yeast species may be isolated.     

Observations of immature and adult stages of the myrmecophilous cetoniine beetle Campsiura nigripennis (Coleoptera: Scarabaeidae)

Several cetoniine species are known or speculated to be associated with ants, based on their specialized morphological characters. However, there are only a few species where biological information on the larval and adult stages is available. Field observations revealed that Campsiura nigripennis spends the immature stages inside elephant dung, and that adult females fly to elephant dung for oviposition. In addition, adult beetles of C. nigripennis intruded into arboreal nests of Oecophylla smaragdina. Specialized morphological characters appear to allow them to tolerate attacks from the ants. Furthermore, the distribution of the beetle in continental Asia largely overlaps that of the Asian elephant, indicating that dung of elephants, in conjunction with that of other large mammals, is fundamental to the biology of C. nigripennis.     

Candida konsanensis sp. nov., a new yeast species isolated from Jasminum adenophyllum in Thailand with potentially carboxymethyl cellulase-producing capability

A new yeast species (KKU-FW10) belonging to the Candida genus was isolated from Jasminum adenophyllum in the Plant Genetic Conservation Project under The Royal Initiative of Her Royal Highness Princess Maha Chakri Sirindhorn area, Chulabhorn Dam, Konsan district within Chaiyaphum province in Thailand. The strain was identified via analysis of nucleotide sequences from the D1/D2 domain of 26S ribosomal DNA and based on its morphological, physiological and biochemical characteristics. The sequence obtained from yeast isolate KKU-FW10 was 97 percent identical to that of Candida chanthaburiensis (GenBank accession number AB500861.1), with 506/517 (nucleotides identity/total nucleotides) matching nucleotides, nine substitutions and two gaps being detected. This species belonged to the Candida clade. Regarding morphological characteristics, isolate KKU-FW10 presents cream-colored butyrous colonies, vegetative reproduction through budding and, round cells without filaments or ascospores. The major ubiquinone detected was Q-9. The above results suggest that isolate KKU-FW10 is a new member of the genus Candida, and the name Candida konsanensis is proposed for this yeast. The type strain of the new species is KKU-FW10^T (= BCC 52588^T, = NBRC 109082^T, = CBS 12666^T). In addition, this KKU-FW10 could potentially produce 58.24 Units/ml of carboxymethyl cellulase when it was cultured in YP broth containing 1.0 % carboxymethyl cellulose for 24 h.     

Up-regulation of microsomal prostaglandin E synthase-1 in COX-1 and COX-2 knock-out mouse fibroblast cell lines

In this paper we investigated the possible involvement of prostaglandin E synthases (PGESs) in compensatory mechanism. Our findings showed that microsomal (m)PGES-1 expression was significantly up-regulated in COX knock-out (K/O) cells whereas the expression of cytosolic PGES was not changed indicating that the induction of mPGES-1 may, at least in part, contribute to the substantial increase of PGE₂ production in COX K/O cell lines. The selective up-regulation of mPGES-1 in COX-2 K/O cells suggests that mPGES-1 may be metabolically coupled with COX-1 for PGE₂ formation. Addition of arachidonic acid caused significant induction of mPGES-1 and COX-2 in WT cells, whereas COX-1 and cPGES were not affected. Our earlier and the current studies demonstrate the coregulation of cPLA₂, COX, and mPGES-1, in PGE₂ synthesis pathway, and that these enzymes contribute to the elevation of PGE₂ level when one COX isoform is absent.     

Candida siamensis sp. nov., an anamorphic yeast species in the Saturnispora clade isolated in Thailand

Three strains of a novel anamorphic yeast species were isolated from natural samples collected in Thailand, including strain EF10 isolated from sediment in a mangrove forest, strain ST-473 from rotten wood, and strain ST-479 from a wild mushroom ( Hygrophorus sp.). Analysis of the D1/D2 domains of the large-subunit rRNA gene sequence revealed that the sequence of strain EF10 differed from the other two strains (ST-473 and ST-479), which had identical sequences, by only one nucleotide (nt) substitution in 535 nt. The closest species in terms of pairwise sequence similarity was Saturnispora mendoncae , with 32 nt substitutions and seven gaps in 535 nt. Phylogenetic analysis demonstrated that the three strains form a cluster with S. mendoncae and the other eight species in the Saturnispora clade. Phenotypic characteristics of the three strains were the same including proliferation by multilateral budding, absence of ascospores and negative diazonium blue B and urease reactions. The major ubiquinone was Q-7. On this basis, the three strains were assigned to a single novel species of the genus Candida , for which the name Candida siamensis sp. nov. is proposed. The type strain is EF10^T (=BCC 29901^T=NBRC 104878^T=CBS 11022^T).     

Hypothyroid dependent myocardial angiotensin receptor trafficking is involved in improved cardiac performance after heat acclimation

AimsThe renin–angiotensin system (RAS) plays a key role in heat acclimation, a process which induces adaptive changes in cardiac function. These changes are mediated in part by reduced thyroid hormone activity and improve myocardial function during and following exposure to various (non-heat) stresses such as ischemia. The aim of this study was to examine the role of RAS in the development of the heat acclimated protected heart.Main methodsThree treatment groups were used: (1) C, controls; (2) AC, heat acclimated rats (1 mo 34 °C,); and (3) HAEL, heat acclimated euthyroid rats treated with 3 ng/ml of eltroxine. A Langendorff perfusion apparatus was used to measure hemodynamic parameters at baseline and following administration of angiotensin-II, losartan and PD123319 in isolated hearts. Protein and mRNA levels of angiotensin receptors were measured.Key findingsBoth C and HAEL animals showed increased contractility and a drop in coronary flow during angiotensin II exposure whereas AC animals did not have an inotropic response or vasoconstriction. Significantly different patterns of AT1 and AT2 receptor densities (a 50% reduction and a 30% increase in outer cell membrane AT1 and AT2 receptors respectively) were observed in AC animals compared to the other two groups. AT receptor mRNA levels were similar in all treatment groups.SignificanceThe attenuated response of heat acclimated hearts to angiotensin is mediated by reduced thyroxine levels and is associated with a shift in AT1 receptors from the outer to the inner membrane. This shift appears to be caused by modified posttranslational trafficking of AT receptors.