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Forty-five volatile organic compounds (VOCs) were identified or annotated in the mandibular gland reservoir content (MGRC) of the Southeast Asian ant Colobopsis explodens Laciny and Zettel, 2018 (Hymenoptera: Formicidae), using headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS) and liquid extraction combined with GC-MS. In extension of previous reports on VOCs of C. explodens, members of different compound classes, such as alkanes, aliphatic and aromatic carboxylic acids, and phenolics, were detected. The ketone 2-heptanone and the biochemically related phenolics benzene-1,3,5-triol (phloroglucinol, PG), 1-(2,4,6-trihydroxyphenyl)ethanone (monoacetylphloroglucinol, MAPG), 5,7-dihydroxy-2-methylchromen-4-one (noreugenin), and 1-(3-Acetyl-2,4,6-trihydroxyphenyl)ethanone (2,4-diacetylphloroglucinol, DAPG) dominated the GC-MS chromatograms. The identities of the main phenolics MAPG and noreugenin were further verified by liquid chromatography-high resolution-tandem mass spectrometry (LC-HRMS/MS). A comparative study of MGRC samples originating from three distinct field expeditions revealed differences in the VOC profiles, but the presence and relative abundances of the dominating constituents were largely consistent in all samples. Our study considerably extends the knowledge about the number and type of VOCs occurring in the MGRC of C. explodens. Based on the type of the detected compounds, we propose that the likely irritant and antibiotic phenolic constituents play a role in defense against arthropod opponents or in protection against microbial pathogens.

Functional effects of ants in rainforest canopies depend on difficult to characterize ant diets. In Bornean dipterocarp forests, certain diurnal, arboreal, territorial, and ecologically dominant ‘COCY’ ant species (Colobopsis cylindrica clade) grazed epiphytic biofilms on adaxial leaf surfaces, as well as on tree trunks and branches. Microscopic examination of worker buccal pellets revealed numerous (mainly ascomycete) fungal spores, together with insect appendages and cuticle. Direct observations, video-imaging, and δ15N isotope data rule out feeding by predation, but isotopes cannot separate fungi from plant and insect exudates as principal nitrogen sources. Lipid-rich products, extracted from pellets in situ, are hypothesized sources of essential sterols. Also present in pellets were colorful mandibular gland (MG) compounds unique to this ant clade and deployed, as a derived character state, in suicidal defense of foraging territories. Mildly antimicrobial and highly adhesive MG products also occur basally in the clade and may have first evolved for roles in microbial sterilization and food-gathering and processing. Proteomic studies of YG COCY ants detected 2% proteins in hypertrophied, product-filled MG reservoirs, but SDS-PAGE qualitative analysis revealed mostly low-molecular mass proteins and peptides (8–15 kDa), too small for enzymes but consistent with membrane-binding proteins and/or antimicrobial peptides. Breakdown of chitin and chitosan in pellets may occur with enzymes derived from molting fluids in insect cuticle (proteases and chitinases) and/or fungi and bacteria. To the extent that COCY workers collect and consume pathogenic and/or beneficial phyllosphere microbes, ant effects on plants may be mediated by these activities. Abstrak Sejauh mana terdapat kesan fungsi semut di kanopi hutan hujan berasaskan kesukaran mengkaji pemakanan semut tersebut. Di dalam hutan dipterokarp Borneo spesies tertentu dari klad Camponotus (Colobopsis) cylindricus (spesies ‘COCY’) yang giat pada siang, tinggal di pokok, mempertahankan kawasan dan berekologi dominan didapati memakan lapisan nipis (biofilem) hidupan epifit pada permukaan daun dan juga batang dan dahan pokok. Pemerhatian pelet yang masih dalam mulut pekerja semut yang belum lagi tukar kepada produk yang berlipid tinggi mendedahkan banyak spora kulat (kebanyakannya ‘ascomycete’) yang tercampur dengan bahagian badan dan kutikal serangga. Pemerhatian dan data isotop δ15N menunjukkan ketiadaan predasi tetapi tidak dapat menunjukkan bahawa kulat dan cecair dari tumbuhan merupakan punca nitrogen utama. Pelet juga mengandungi kompaun glanda mandibular (MG) yang unik kepada klad semut tersebut yang digunakan oleh spesies-spesies yang tertentu dalam pertahanan kawasan pemakanan sehingga mati, iaitu satu ciri yang kemudian muncul. Produk MG yang kuat melekat mungkin muncul untuk memainkan peranan dalam pemungutan bahan makanan dan mungkin juga merendahkan kesan mikrob semasa pemerosesan makanan untuk dapat N dan/atau lipid (misalnya sterol sejati). Kajian proteomik dapat mengesani protin sebanyak 2 peratus yang terkandung di dalam takungan MG yang diisikan dengan produk, juga penganalisis kualitatif SDS-PAGE menunjukkan protin dan peptid yang bermolekular rendah (8-15 kDa) yang terlalu halus bagi enzim tetapi boleh jadi protin pengikatan membran atau peptid antimikrob. Penghancuran kitin dan kitosan dalam bahan pelet mungkin berlaku berkesan dari enzim yang berpunca dari kutikal serangga (yang mengandungi kitinas) dan/atau kulat dan bakteria. Kesan semut ke atas tumbuh-tumbuhan kemungkinan dipengaruhi aktiviti tersebut sejauh mana pekerja COCY memungut dan makan mikrob filoplan yang patogenik dan/atau berguna.

Unlike most other fungi, molds of the genus Trichoderma (Hypocreales, Ascomycota) are aggressive parasites of other fungi and efficient decomposers of plant biomass. Although nutritional shifts are common among hypocrealean fungi, there are no examples of such broad substrate versatility as that observed in Trichoderma. A phylogenomic analysis of 23 hypocrealean fungi (including nine Trichoderma spp. and the related Escovopsis weberi) revealed that the genus Trichoderma has evolved from an ancestor with limited cellulolytic capability that fed on either fungi or arthropods. The evolutionary analysis of Trichoderma genes encoding plant cell wall-degrading carbohydrate-active enzymes and auxiliary proteins (pcwdCAZome, 122 gene families) based on a gene tree / species tree reconciliation demonstrated that the formation of the genus was accompanied by an unprecedented extent of lateral gene transfer (LGT). Nearly one-half of the genes in Trichoderma pcwdCAZome (41%) were obtained via LGT from plant-associated filamentous fungi belonging to different classes of Ascomycota, while no LGT was observed from other potential donors. In addition to the ability to feed on unrelated fungi (such as Basidiomycota), we also showed that Trichoderma is capable of endoparasitism on a broad range of Ascomycota, including extant LGT donors. This phenomenon was not observed in E. weberi and rarely in other mycoparasitic hypocrealean fungi. Thus, our study suggests that LGT is linked to the ability of Trichoderma to parasitize taxonomically related fungi (up to adelphoparasitism in strict sense). This may have allowed primarily mycotrophic Trichoderma fungi to evolve into decomposers of plant biomass., Author summary Individual fungi rely on particular host organisms or substrates for their nutrition. Therefore, the genomes of fungi feeding on plant biomass necessarily contain genes encoding plant cell wall-degrading enzymes, while animal parasites may depend on proteolytic activity. Molds in the genus Trichoderma (Ascomycota) display a unique nutritional versatility. They can feed on other fungi, attack animals, and degrade plant debris. The later property is so efficient that one species (T. reesei) is commercially used for the production of cellulolytic enzymes required for making biofuels and other industry. In this work, we have investigated the evolution of proteins required for plant cell wall degradation in nine Trichoderma genomes and found an unprecedented number of lateral gene transfer (LGT) events for genes encoding these enzymes. Interestingly, the transfers specifically occurred from Ascomycota molds that feed on plants. We detected no cases of LGT from other fungi (e.g., mushrooms or wood-rotting fungi from Basidiomycota) that are frequent hosts of Trichoderma. Therefore, we propose that LGT may be linked to the ability of Trichoderma to parasitize on related organisms. This is a characteristic ecological trait that distinguishes Trichoderma from other mycoparasitic fungi. In this report, we demonstrate that the lateral transfer of genes may result in a profound nutritional expansion and contribute to the emergence of a generalist capable of feeding on organic matter of any origin.

Goniothalamus velutinus Airy Shaw belongs to the family Annonaceae which is known to have anticancer, antitumor and many other bioactivities. Natives of Sabah and Sarawak use root decoction of G. velutinus for the treatment of headache and food poisoning while the bark was used as a mosquito repellent. Bark and leaf extracts of this plant, obtained from Brunei Darussalam, were tested for phytochemical and antioxidant activities. Phytochemical screening of plant extracts revealed the presence of alkaloids, steroids, terpenoids and cardiac glycosides. Quantitative determination of total phenolics, total flavonoids, and various in vitro antioxidant activities (DPPH, ABTS and FRAP) of methanolic extract was carried out using colorimetric methods. The total phenolic content, expressed as mg of gallic acid equivalent (GAE) per gram of extract, was found to be 68 mg GAE/g and 78 mg GAE/g for bark and leaves respectively. The radical scavenging activity measurement, expressed in terms of EC 50 (effective concentration of extract in μg/mL that reduces DPPH absorbance to 50% as compared to negative control), for leaf and bark extracts was found to be 155 μg/mL and 204 μg/mL respectively. Standards trolox and ascorbic acid show EC 50 value of 5 μg/mL and 4 μg/mL respectively. Trolox equivalent antioxidant capacity (TEAC) was measured using the ABTS and FRAP method. Result for bark and leaf extracts was 79 mg and 106 mg trolox equivalent (TE)/g respectively for the ABTS method. For FRAP assay, results for bark and leaf extracts were 80 and 89 mg TE/g respectively.

Summary: Tropical forest above-ground wood production (AGWP) varies substantially along environmental gradients. Some evidence suggests that AGWP may vary between regions and specifically that Asian forests have particularly high AGWP. However, comparisons across biogeographic regions using standardized methods are lacking, limiting our assessment of pan-tropical variation in AGWP and potential causes. We sampled AGWP in NW Amazon (17 long-term forest plots) and N Borneo (11 plots), both with abundant year-round precipitation. Within each region, forests growing on a broad range of edaphic conditions were sampled using standardized soil and forest measurement techniques. Plot-level AGWP was 49% greater in Borneo than in Amazonia (9.73 ± 0.56 vs. 6.53 ± 0.34 Mg dry mass ha -1 a -1 , respectively; regional mean ± 1 SE). AGWP was positively associated with soil fertility (PCA axes, sum of bases and total P). After controlling for the edaphic environment, AGWP remained significantly higher in Bornean plots. Differences in AGWP were largely attributable to differing height-diameter allometry in the two regions and the abundance of large trees in Borneo. This may be explained, in part, by the greater solar radiation in Borneo compared with NW Amazonia. Trees belonging to the dominant SE Asian family, Dipterocarpaceae, gained woody biomass faster than otherwise equivalent, neighbouring non-dipterocarps, implying that the exceptional production of Bornean forests may be driven by floristic elements. This dominant SE Asian family may partition biomass differently or be more efficient at harvesting resources and in converting them to woody biomass. Synthesis. N Bornean forests have much greater AGWP rates than those in NW Amazon when soil conditions and rainfall are controlled for. Greater resource availability and the highly productive dipterocarps may, in combination, explain why Asian forests produce wood half as fast again as comparable forests in the Amazon. Our results also suggest that taxonomic groups differ in their fundamental ability to capture carbon and that different tropical regions may therefore have different carbon uptake capacities due to biogeographic history. North Bornean forests have much greater AGWP rates than those in north-western Amazon when soil conditions and rainfall are controlled for. Greater resource availability and the highly productive dipterocarps may, in combination, explain why these Asian forests produce wood half as fast again as comparable forests in the Amazon. Our results also suggest that taxonomic groups differ in their fundamental ability to capture carbon and that different tropical regions may therefore have different carbon uptake capacities due to biogeographic history.

WOS: 000373538000024, Essential oils from the leaves, aerial stems, basal stems, and rhizomes of Etlingera fimbriobracteata (K.Schum.) R.M.Sm. were analyzed using a gas chromatography-flame ionization detector (GC-FID) and by gas chromatography-mass spectrometry (GC-MS). beta-Pinene (67.8%) and 1,8-cineole (37.2%) were the main components of the oils from leaves and aerial stems, respectively, whereas decanal was the main component of basal stems and rhizomes (27.5% and 34.4%, respectively). The antioxidant activities of the oils were evaluated using several in vitro assays; the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging assays, the reducing power ability (RPA) assay, and the ferric reducing antioxidant power (FRAP) assay. In all the tests, essential oils from different plant parts showed very poor antioxidant activity compared with those of the reference standards, ascorbic acid (AA) and butylated hydroxytoluene (BHT). However, all the oils exhibited moderate to potent broad-spectrum antimicrobial activity against all tested strains except for Pseudomonas aeruginosa. In disc diffusion and broth microdilution assays, the inhibition zones and MIC values of the essential oils were in the range of 8-87.7mm and 2.4-625 mu g/mL, respectively. Because of their strong antimicrobial activity, the essential oils of E. fimbriobracteata could be a potential alternative to conventional antimicrobials in food, cosmetics, and pharmaceutical industries, Government of Brunei Darussalam, We thank the Government of Brunei Darussalam for providing the scholarship to Shahid-Ud-Daula and Universiti Brunei Darussalam for the use of facilities to perform this research. The authors also thank Noramalina Ismail, Rafizah Mat Serudin, and laboratory technicians of the Environmental and Life Sciences Program for their help with collecting plant samples and facilitating laboratory work.

Two diverse population of Molinia caerulea (L.) Moench, one growing on a Ca 2+ -rich, alkaline, Leblanc waste tip, the other on an acid moorland, were investigated. It was anticipated that a comparative study of the morphology, growth and flowering patterns, protein composition, specific isoenzyme and root-surface phosphatase activities of both populations would clarify the taxonomic status of populations of Molinia and help towards understanding the ability of M. caerulea to colonize widely differing habitats. Both populations were identified as Molinia caerulea caerulea . The Molinia growing on Leblanc spoil displayed characteristics typified by r-selected plants, i.e. displaying larger flowers after faster development. Acid moorland plants showed greater vegetative development and were more typical of K-selected types. These differences between the more vigorous shoot growth of the moorland compared to the waste tip plants persisted under controlled conditions, irrespective of the media in which they were grown. Root surface phosphatase activity showed a plastic response to edaphic pH which may contribute to the success of M. caerulea caerulea in colonizing diverse habitats.

Summary • High foliar concentrations of aluminium (Al) have been reported in numerous plant species, but progress on the understanding of the functional significance of this trait is constrained by the absence of a quantitative analysis of its distribution among plant lineages and across biomes. • We constructed a global dataset of foliar Al and nutrient concentrations for 1044 plant species from literature sources and new data collections in Brunei Darussalam. • Our results provide statistical support for the existence of Al accumulators and non-Al accumulators in global, regional and local floras based on foliar Al concentrations. A value of 1 mg Al g−1 leaf dry mass is a suitable threshold to distinguish between these two groups in a sample of species that lacks any geographical reference. However, a higher threshold foliar Al concentration is required to distinguish between Al accumulators in tropical (2.3–3.9 mg Al g−1 leaf dry mass) than in temperate (1.1 mg Al g−1 leaf dry mass) floras. There was a phylogenetic signal in the foliar concentrations of Al, but phylogeny did not explain the difference in the mean foliar Al concentration between tropical and temperate floras in a phylogenetically controlled analysis. • Phylogeny and soil chemistry are potential factors driving Al accumulation in certain groups of plants.