2015 Research highlights

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Terrestrial carbon stock mapping is important for the successful implementation of climate change mitigation policies. Its accuracy depends on the availability of reliable allome- tric models to infer oven-dry aboveground biomass of trees from census data. The degree of uncertainty associated with previously published pantropical aboveground biomass allometries is large.
Mésange charbonnière
Microorganisms constitute the major part of the earth biomass. The host microbiome, defined as the whole community of microorganisms in contact with an organism, includes pathogenic and commensal microorganisms that are remarkable in their diversity and ubiquity. Parasites influence allocation trade-offs between reproduction and self-maintenance, and many beneficial microorganisms are essential for instance to host digestion and nutrient synthesis. The host microbiome is thus expected to shape the evolution of host life-history traits, although experimental studies from natural systems are still lacking.
Plant resistance (R) genes are a crucial component in plant defence against pathogens. Although R genes often fail to provide durable resistance in an agricultural context, they frequently persist as long-lived balanced polymorphisms in nature. Standard theory explains the maintenance of such polymorphisms through a balance of the costs and benefits of resistance and virulence in a tightly coevolving host–pathogen pair. However, many plant-pathogen interactions lack such specificity.
Native from Australia, the genus Eucalyptus encompasses more than 700 species. With 20 million hectares of industrial plantations, Eucalyptus (mainly E. grandis and E. globulus species) are the most planted hardwoods in the world mainly for the production of pulp and paper. With the increasing need for renewable energy to the replace fossil resources in a sustainable way, the use of Eucalyptus lignocellulosic biomass is an attractive alternative for the production of second generation biofuels.
MicroRNAs are small RNAs (approximately 21 nucleotides) that control most biological processes, negatively regulating the expression of many target genes. They are present in plants and animals, inclu- ding humans, in which they are involved in many diseases when their expression is dere- gulated. MicroRNAs are derived from primary transcripts, which are larger RNA molecules produced by transcription of the DNA. Prima- ry transcripts of microRNAs have long been regarded as non-coding RNAs.
Microbial pathogens infect host cells by delivering virulence factors (effectors) that interfere with defenses. In plants, intracellular nucleotide-binding/oligomeriza- tion domain (NOD)-like receptors (NLRs) detect specific effector interference and trigger immu- nity by an unknown mechanism. The Arabidopsis interacting NLR pair, RRS1-R with RPS4, confers resistance to different pathogens including Ralstonia solanacearum bacteria expressing the acetyltransferase effector, PopP2. We show that PopP2 directly acetylates a key lysine within an additional C-terminal WRKY transcription factor DNA-binding domain of RRS1-R. This disrupts RRS1-R DNA association and activates RPS4-dependent immunity...
Many animal species, including humans, live and breed in groups with complex social organizations. The impact of this social structure on the genetic diversity of animals has been a source of disagreement between scientists. This new study shows that social structure can in itself maintain the genetic diversity within species. It provides a new mathematical model that can be used by population geneticists and ecologists to better predict how social groups influence the way species maintain genetic diversity and evolve, and ultimately help in the conservation of species.
While Amazonian forests are extraordinarily diverse, the abundance of trees is skewed strongly towards relatively few ‘hyperdominant’ species. In addition to their diversity, Amazonian trees are a key component of the global carbon cycle, assimilating and storing more carbon than any other ecosystem on Earth.
The “mustard oil bomb” is a major defense mechanism in the Brassicaceae, which includes crops such as canola and the model plant Arabidopsis thaliana. These plants produce and store blends of amino acid-derived secondary metabolites called glucosinolates. Upon tissue rupture by natural enemies, the myrosinase enzyme hydrolyses glucosinolates, releasing defense molecules. Brassicaceae display extensive variation in the mixture of glucosinolates that they produce.
Despite the huge diversity of ecological communities, they can have unexpected patterns in common. Hatton et al. describe a general scaling law that relates total predator and prey biomass in terrestrial and aquatic animal communities (see the Perspective by Cebrian). They draw on data from many thousands of population counts of animal communities ranging from plankton to large mammals, across a wide range of biomes. They find a ubiquitous pattern of biomass scaling, which may suggest an underlying organization in ecosystems. It seems that communities follow systematic changes in structure and dynamics across environmental gradients.
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Modification date: 07 June 2023 | Publication date: 23 June 2016 | By: TULIP Communication