What Determines Successful Colonization and Expression of Biocontrol Traits at the Belowground Level?

Editor: Antonieta De Cal, Paloma Melgarejo, Naresh Magan.Plants and their associated microbial communities are continuously interacting. The consequences of this complex, multi-actor dialogue are of utmost relevance for the health and development of the plant holobiont. The plant-associated microbiota is a natural source of microorganisms with plant growth-promoting abilities, including biological control agents (BCA). Plant roots are the main entrance for soilborne phytopathogens, which are also components of the belowground plant-associated microbiota. Successful root colonization by BCA is thus key for effective biocontrol against these pathogens. Colonization and biocontrol are complex processes influenced by many (a)biotic factors. Upon colonization of the target niche, effective biocontrol is then the result of diverse modes of action that BCA may display, thereby eliminating pathogens’ propagules, reducing their number, or alleviating their deleterious effects. These mechanisms are not mutually exclusive and can operate either individually or in combination, varying in time and space. Inconsistencies usually observed in biocontrol effectiveness is a consequence of numerous (a)biotic and environmental factors affecting BCA performance. A more comprehensive knowledge of colonization processes and biocontrol modes of action of BCA, and that of the diverse factors influencing them, is now possible with the support of the currently-available -omics approaches. They will definitively offer a more holistic perspective that will help to overcome the lack of success sometimes observed when implementing biocontrol measures, particularly at the field scale.Our work is currently supported by grant AGL2016-75729-C2-1-R from the Spanish Ministerio de Economía, Industria y Competitividad/Agencia Estatal de Investigación, co-financed by the European Regional Development Fund (ERDF), and by the Horizon 2020 Project ‘Microbial Uptakes for Sustainable Management of Major Banana Pests and Diseases’ (MUSA; grant number 727624)

Antimalarial agents from medicinal plant and fungal sources

Malaria is the fourth major parasitic infectious disease for humans, causing severe symptoms and life-threatening complications, which, if untreated within 24–48 h may evolve in the fatality. In the past five decades, major initiatives in the treatment and prevention of this devastating disease have been implemented in endemic areas, leading to significant progress and declining trends. The majority of the reports presented here are focused on the activity of the extracts and fractions of plant or fungal origin: this approach has its rationale in the observation that crude materials are often more active than isolated compounds, due to the manifestation of beneficial synergistic and additional effects and/or pharmacokinetic/pharmacodynamic interactions. Consideration has been given to the antiplasmodial activities in relation to the different herbal part and nature of extracting solvents and to safety studies; whenever available, phytochemical fingerprint has been reported, disclosing a variety of unique molecular scaffolds with a potential as new pharmacophores. Despite the general lack of mechanistic information for the curative effects of the reported plants and fungi, these studies may undoubtedly pave the way to a new generation of antimalarial agents