Safety of Pseudomonas chlororaphis as a gene source for genetically modified crops

Abstract

Genetically modified crops undergo extensive evaluation to characterize their food, feed and environmental safety prior to commercial introduction, using a well-established, science-based assessment framework. One component of the safety assessment includes an evaluation of each introduced trait, including its source organism, for potential adverse pathogenic, toxic and allergenic effects. Several Pseudomonas species have a history of safe use in agriculture and certain species represent a source of genes with insecticidal properties. The ipd072Aa gene from P. chlororaphis encodes the IPD072Aa protein, which confers protection against certain coleopteran pests when expressed in maize plants. P. chlororaphis is ubiquitous in the environment, lacks known toxic or allergenic properties, and has a history of safe use in agriculture and in food and feed crops. This information supports, in part, the safety assessment of potential traits, such as IPD072Aa, that are derived from this source organism.

Bacteria from the Midgut of Common Cockchafer (Melolontha melolontha L.) Larvae Exhibiting Antagonistic Activity Against Bacterial Symbionts of Entomopathogenic Nematodes: Isolation and Molecular Identification

“…Importantly, 10 of the 12 selected isolates, i.e., representatives of the genera Acinetobacter, Citrobacter, Pseudomonas, and Serratia, belong to γ-proteobacteria, i.e., a class that comprises a number of human and animal pathogens, including many insect species. Various studies have reported the production of many compounds that inhibit the development of fungi, insects, and nematodes (e.g., phenazine-type antibiotics, hydrogen cyanide, chitinases, and proteases) by P. chlororaphis [48,49]. It has been evidenced that P. chlororaphis injected directly into the hemocoel caused the high mortality of Galleria mellonella (Lepidoptera: Pyralidae) larvae [50].…”

Systems Biology of Plant-Microbiome Interactions

“…As a consequence of these similar requirements, in essentially all phyla of host-associated microbiomes, closely related species with pathogenic and beneficial lifestyles can be found (Figure 1). Frequently, relatives with opposite effects are found within the same genus, e.g., among the Paenibacilleae: P. azotofixans and P. amylolyticus (Grady et al, 2016), among Bacilleae: B. velezensis and B. cereus (Radhakrishnan et al, 2017), among Pseudomonas: P. simiae and P. syringae (Anderson et al, 2018) and even within the same species, e.g., Pseudomonas aeruginosa (Steindler et al, 2009;Ndeddy Aka and Babalola, 2016 Phylogenetic tree of plant growth-promoting (black) and pathogenic bacteria (red), and their corresponding phyla (in different shades of gray) mentioned in the text. The tree is supplemented with sequences from some widely applied PGPRs and closely related plant and human pathogens for comparison.…”

Insights into plant-beneficial traits of probiotic Pseudomonas chlororaphis isolates

“…This has been successful in maize, in which the expression of an insecticidal protein reduces insect pest damage [61]. Another example is the expression of a gene from the P. chlororaphis isolate G65 to control ethylene production in transformed plants, as summarized in the discussion by Anderson et al [98]. Carlson et al [99] have covered the extensive testing required to demonstrate that genetic modifications are not likely to adversely affect human health.…”

“…Studies performed to EPA standards indicate that P. chlororaphis isolates pose limited risks to humans and the environment [98]. The supporting evidence includes the absence of pathogenicity islands and type III/IV transfer systems in bacterial pathogens and that no genes required for the production of toxins characterized from pseudomonad plant pathogens are found in P. chlororaphis isolates.…”

“…Currently, as reviewed by Anderson et al [98], there are several commercial formulations of different P. chlororaphis isolates for agriculture: AtEze for greenhouse use, Cedemon and Cerall for use in cereals, and Howler formulations sold as fungicides. An additional P. chlororaphis formulation based on P. chlororaphis subsp.…”