Novozymes (Canada)

Abstract One of the key components to the commercial success of a biological control agent for plant pathogens is formulation. Formulation of biocontrol agents can be used to: stabilize the organisms during production, distribution and storage; aid in the handling and application of the product; protect the agent from harmful environmental factors; and enhance the activity of the organisms (Jones & Burges, Citation1998). From a technical efficacy standpoint, an effective formulation requires thorough knowledge of the biocontrol organism, pathogen, environment, and interactions with other organisms. The development of a commercially-viable formulation also requires an understanding of common application practices and equipment, as well as the desires of customers for formulation handling. It is important to develop a clear vision of the product specifications before formulation research is started. Ingredients must be safe and acceptable to regulatory agencies in all areas where the product will be used. This review will focus on microbial biocontrol of plant pathogens, as seen from an industrial formulation-development standpoint. Résumé Une des composantes clés essentielles au succès commercial d'un produit de lutte biologique contre les agents pathogènes des plantes est sa préparation. La préparation des agents de lutte biologique peut être utilisée dans le but de : stabiliser les organismes lors de la production, de la distribution et de l'entreposage; servir lors de la manipulation et de l'utilisation du produit; protéger l'agent contre des conditions environnementales adverses; et renforcer l'activité des organismes (Jones et Burges, Citation1998). Sur le plan de l'efficacité technique, une préparation efficace requiert une connaissance approfondie de l'organisme de lutte, de l'agent pathogène, de l'environnement et des interactions avec les autres organismes. L'élaboration d'une préparation commercialement viable requiert également une compréhension des pratiques d'application et des équipements utilisés ainsi que des besoins des utilisateurs potentiels. Il importe de développer une vision précise des spécifications du produit avant même d'amorcer la recherche sur la préparation. Les ingrédients doivent être sûrs et conformes aux exigences des organismes de réglementation de toutes les régions où le produit sera utilisé. Cette synthèse mettra l'accent sur la lutte microbiologique contre les agents pathogènes des plantes, abordée sous l'angle du développement industriel de la préparation. Keywords: biological controlformulationpathogen controlMots clés: lutte biologiquelutte contre les agents pathogènespréparation

Core Ideas Soybean seed inoculation with Bradyrhizobium japonicum enhances grain production. Greater inoculation response happens in Argentinean sites than in the United States. Several soil properties and crop management practices are related with the responses to inoculation. Although the relevance of biological N nutrition of soybean [ Glycine max (L.) Merr.] is recognized worldwide, inoculation with Bradyrhizobium japonicum shows variable results and the benefit needs to be validated under current crop production practices. We conducted statistical analysis of soybean field trial data to provide insight into factors affecting the efficacy of soybean inoculation under contrasting crop production conditions. Most experimental sites, 187 trials in the United States and 152 trials in Argentina, were in soils with soybean history and naturalized B. japonicum strains. Yield increases were greater in Argentina (190 kg ha −1 equivalent to 6.39%) than in the United States (60 kg ha −1 equivalent to 1.67%). Tillage methods did not affect inoculant performance. In the United States, inoculation was more effective in soils with higher pH (>6.8) while in Argentina the greatest inoculation effect on crop production occurred in soils with a lower pH (<5.5). In the United States, where most of the trials were in rotation with corn ( Zea mays L), the greatest positive effect of inoculation was observed in late planted soybean crops and independent of soil organic matter (SOM). In Argentina, the inoculant had its greatest effect in soils with no soybean history, a relatively high SOM, higher levels of soil extractable P and S, and in areas with greater precipitation during early reproductive growing stages. In both regions, the yield increases due to B. japonicum inoculation support the regular use of this practice to help provide adequate conditions for soybean production.

The genome of the pathogenic oomycete Hyaloperonospora arabidopsidis is predicted to encode at least 134 high-confidence effectors (HaRxL) carrying the RxLR motif implicated in their translocation into plant cells. However, only four avirulence genes (ATR1, ATR13, ATR5, and ATR39) have been isolated. This indicates that identification of HaRxL effectors based on avirulence is low throughput. We aimed at rapidly identifying H. arabidopsidis effectors that contribute to virulence by developing methods to detect and quantify multiple candidates in bacterial mixed infections using either Illumina sequencing or capillary electrophoresis. In these assays, referred to here as in planta effector competition assays, we estimate the contribution to virulence of individual effectors by calculating the abundance of each HaRxL in the bacterial population recovered from leaves 3 days after inoculation relative to abundance in the initial mixed inoculum. We identified HaRxL that enhance Pseudomonas syringae pv. tomato DC3000 growth in some but not all Arabidopsis accessions. Further analysis showed that HaRxLL464, HaRxL75, HaRxL22, HaRxLL441, and HaRxL89 suppress pathogen-associated molecular pattern-triggered immunity (PTI) and localize to different subcellular compartments in Nicotiana benthamiana, providing evidence for a multilayered suppression of PTI by pathogenic oomycetes and molecular probes for the dissection of PTI.

Lipochitooligosaccharides (LCOs), including Nod factors and Myc factors, are signal molecules produced by rhizobia and arbuscular mycorrhizae, respectively, that are essential for plant infection by these symbiotic microorganisms. Basic research has identified the structure of these LCO molecules and the mechanisms by which they bind to specific root hair receptors activating plant genes. A common plant gene pathway for both Nod factors, leading to nodule formation in legumes, and Myc factors, essential for plant root mycorrhization, has been extensively reported. Applied research investigating LCO direct plant growth responses in greenhouse and field trials has been less common and will be reported in this review. Nod factors, combined with the host-specific rhizobium and applied to legume seeds, or in-furrow with seeds at planting, have led to improved seed germination, enhanced lateral root development, and better early season growth, which lead to frequent greater crop yields. The benefits of combining Nod factors with the rhizobial inoculant in field studies have been observed in studies with soybeans (Glycine max (L.) Merrill] and peas (Pisum sativum). Further field studies with LCOs alone, both as a seed treatment and in-furrow, with legumes (soybeans) and nonlegumes [corn (Zea mays L.) and cotton (Gossypium hirsutum)] also frequently demonstrate enhanced growth parameters and yield increases. In addition, foliar applications of LCOs on legumes (soybeans) and nonlegumes (corn) in greenhouse and field trials improved various plant growth parameters, including grain yields. LCO applications with legumes and nonlegumes applied as seed treatments, as in-furrow, and as a foliar spray have provided improved plant growth and yield increases with important agronomic crops in both North American and South American field trials.

The overwhelming volume of molecular data generated over the last 30 years and the need to understand the messages coded by DNA has lead to the development of global bioinformatics resources. The scientific community has collaborated worldwide toward developing and linking computer database DNA and protein repositories and providing computer-based analysis tools that are publicly available on the Internet. Central to these collaborations are institutions such as the National Institutes of Health (NIH) in the United States, which created the National Center for Biotechnology Information (NCBI) and the European Molecular Biology Laboratory (EMBL) located in England that created the European Bioinformatics Institute (EBI). This chapter is a general introduction to using Internet based computing resources to support research in molecular biology. An overview of four popular biological data retrieval systems and five commonly used computer-based molecular analysis tools are discussed.