Drastic biodiversity declines have raised concerns about the deterioration of ecosystem functions and have motivated much recent research on the relationship between species diversity and ecosystem functioning. A functional trait framework has been proposed to improve the mechanistic understanding of this relationship, but this has rarely been tested for organisms other than plants. We analysed eight datasets, including five animal groups, to examine how well a trait-based approach, compared with a more traditional taxonomic approach, predicts seven ecosystem functions below- and above-ground. Trait-based indices consistently provided greater explanatory power than species richness or abundance. The frequency distributions of single or multiple traits in the community were the best predictors of ecosystem functioning. This implies that the ecosystem functions we investigated were underpinned by the combination of trait identities (i.e. single-trait indices) and trait complementarity (i.e. multi-trait indices) in the communities. Our study provides new insights into the general mechanisms that link biodiversity to ecosystem functioning in natural animal communities and suggests that the observed responses were due to the identity and dominance patterns of the trait composition rather than the number or abundance of species per se.

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Alternaria is a cosmopolitan fungal genus widely distributing in soil and organic matter. It includes saprophytic, endophytic and pathogenic species. At least 268 metabolites from Alternaria fungi have been reported in the past few decades. They mainly include nitrogen-containing metabolites, steroids, terpenoids, pyranones, quinones, and phenolics. This review aims to briefly summarize the structurally different metabolites produced by Alternaria fungi, as well as their occurrences, biological activities and functions. Some considerations related to synthesis, biosynthesis, production and applications of the metabolites from Alternaria fungi are also discussed.

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Background Owing to their roles in tissue remodelling in health and disease, several studies have reported investigations on plant extracts as inhibitors of proteinases and as anti-oxidants. Methods The anti-ageing and anti-oxidant properties of 23 plant extracts (from 21 plant species) were assessed as anti-elastase and anti-collagenase activities and in selected anti-oxidant assays along with phenolic content. Results Anti-elastase activities were observed for nine of the extracts with inhibitory activity in the following order: white tea (approximately 89%), cleavers (approximately 58%), burdock root (approximately 51%), bladderwrack (approximately 50%), anise and angelica (approximately 32%). Anti-collagenase activities were exhibited by sixteen plants of which the highest activity was seen in white tea (approximately 87%), green tea (approximately 47%), rose tincture (approximately 41%), and lavender (approximately 31%). Nine plant extracts had activities against both elastase (E) and collagenase (C) and were ranked in the order of white tea (E:89%, C:87%) > bladderwrack (E:50%, C:25%) > cleavers (E:58%, C:7%) > rose tincture (E:22%, C:41%) > green tea (E:10%: C:47%) > rose aqueous (E: 24%, C:26%) > angelica (E:32%, C:17%) > anise (E:32%, C:6%) > pomegranate (E:15%, C:11%).Total phenolic content varied between 0.05 and 0.26 mg gallic acid equivalents (GAE)/mL with the exception of white tea (0.77 mg GAE/mL). For anti-oxidant assessment, the Trolox equivalent anti-oxidant capacity (TEAC) assay revealed activity for all extracts. White tea had the highest activity equivalent to approximately 21 microM Trolox for a 6.25 microg aliquot. In addition, seven extracts exhibited activities = 10 microM Trolox with witch hazel (6.25 microg = 13 microM Trolox) and rose aqueous (6.25 microg = 10 microM Trolox) showing very high activities at low concentrations. A high activity for white tea was also found in the superoxide dismutase (SOD) assay in which it exhibited ~88% inhibition of reduction of nitroblue tetrazolium. High activities were also observed for green tea (86.41%), rose tincture (82.77%), witch hazel (82.05%) and rose aqueous (73.86%). Conclusion From a panel of twenty three plant extracts, some one dozen exhibit high or satisfactory anti-collagenase or anti-elastase activities, with nine having inhibitory activity against both enzymes. These included white tea which was found to have very high phenolic content, along with high TEAC and SOD activities.

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The growth-inhibiting effects of indole-3-acetic acid (IAA) at high concentration and the synthetic auxins 7-chloro-3-methyl-8-quinolinecarboxylic acid (quinmerac), 2-methoxy-3,6-dichlorobenzoic acid (dicamba), 4-amino-3,6, 6-trichloropicolinic acid (picloram), and naphthalene acetic acid, were investigated in cleavers (Galium aparine). When plants were root treated with 0.5 mM IAA, shoot epinasty and inhibition of root and shoot growth developed during 24 h. Concomitantly, 1-aminocyclopropane-1-carboxylic acid (ACC) synthase activity, and ACC and ethylene production were transiently stimulated in the shoot tissue within 2 h, followed by increases in immunoreactive (+)-abscisic acid (ABA) and its precursor xanthoxal (xanthoxin) after 5 h. After 24 h of treatment, levels of xanthoxal and ABA were elevated up to 2- and 24-fold, relative to control, respectively. In plants treated with IAA, 7-chloro-3-methyl-8-quinolinecarboxylic acid, naphthalene acetic acid, 2-methoxy-3,6-dichlorobenzoic acid, and 4-amino-3,6,6-trichloropicolinic acid, levels of ethylene, ACC, and ABA increased in close correlation with inhibition of shoot growth. Aminoethoxyvinyl-glycine and cobalt ions, which inhibit ethylene synthesis, decreased ABA accumulation and growth inhibition, whereas the ethylene-releasing ethephon promoted ABA levels and growth inhibition. In accordance, tomato mutants defective in ethylene perception (never ripe) did not produce the xanthoxal and ABA increases and growth inhibition induced by auxins in wild-type plants. This suggests that auxin-stimulated ethylene triggers ABA accumulation and the consequent growth inhibition. Reduced catabolism most probably did not contribute to ABA increase, as indicated by immunoanalyses of ABA degradation and conjugation products in shoot tissue and by pulse experiments with [(3)H]-ABA in cell suspensions of G. aparine. In contrast, studies using inhibitors of ABA biosynthesis (fluridone, naproxen, and tungstate), ABA-deficient tomato mutants (notabilis, flacca, and sitiens), and quantification of xanthophylls indicate that ABA biosynthesis is influenced, probably through stimulated cleavage of xanthophylls to xanthoxal in shoot tissue.

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