Editorial: Exploring Plant Rhizosphere, Phyllosphere and Endosphere Microbial Communities to Improve the Management of Polluted Sites

Advances in amelioration of air pollution using plants and associated microbes: An outlook on phytoremediation and other plant-based technologies

Globally, air pollution is an unfortunate aftermath of rapid industrialization and urbanization. Although the best strategy is to prevent air pollution, it is not always feasible. This makes it imperative to devise and implement techniques that can clean the air continuously. Plants and microbes have a natural potential to transform or degrade pollutants. Hence, strategies that use this potential of living biomass to remediate air pollution seem to be promising. The simplest future trend can be planting suitable plant-microbe species capable of removing air pollutants like SO2, CO2, CO, NOX and particulate matter (PM) along roadsides and inside the buildings. Established wastewater treatment strategies such as microbial fuel cells (MFC) and constructed wetlands (CW) can be suitably modified to ameliorate air pollution. Green architecture involving green walls and green roofs is facile and aesthetic, providing urban ecosystem services. Certain microbe-based bioreactors such as bioscrubbers and biofilters may be useful in small confined spaces. Several generative models have been developed to assist with planning and managing green spaces in urban locales. The physiological limitations of using living organisms can be circumvent by applying biotechnology and transgenics to improve their potential. This review provides a comprehensive update on not just the plants and associated microbes for the mitigation of air pollution, but also lists the technologies that are available and/or can be modified and used for air pollution control. The article also gives a detailed analysis of this topic in the form of strengths-weaknesses-opportunities-challenges (SWOC). The strategies mentioned in this review would help to attain corporate Environmental Social and Governance (ESG) and Sustainable Development Goals (SDGs), while reducing carbon footprint in the urban scenario. The review aims to emphasise that urbanization is possible while tackling air pollution using facile, green techniques involving plants and associated microbes.

Genetic architecture of the response of Arabidopsis thaliana to a native plant-growth-promoting bacterial strain

By improving plant nutrition and alleviating abiotic and biotic stresses, plant growth-promoting bacteria (PGPB) can help to develop eco-friendly and sustainable agricultural practices. Besides climatic conditions, soil conditions, and microbe-microbe interactions, the host genotype influences the effectiveness of PGPB. Yet, most GWAS conducted to characterize the genetic architecture of response to PGPB are based on non-native interactions between a host plant and PGPB strains isolated from the belowground compartment of other plants. In this study, a GWAS was set up under in vitro conditions to describe the genetic architecture of the response of Arabidopsis thaliana to the PGPB Pseudomonas siliginis, by inoculating seeds of 162 natural accessions from the southwest of France with one strain isolated from the leaf compartment in the same geographical region. Strong genetic variation of plant growth response to this native PGPB was observed at a regional scale, with the strain having a positive effect on the vegetative growth of small plants and a negative effect on the vegetative growth of large plants. The polygenic genetic architecture underlying this negative trade-off showed suggestive signatures of local adaptation. The main eco-evolutionary relevant candidate genes are involved in seed and root development.

Microbial endophytes: application towards sustainable agriculture and food security

Microbial endophytes are ubiquitous and exist in each recognised plant species reported till date. Within the host plant, the entire community of microbes lives non-invasively within the active internal tissues without causing any harm to the plant. Endophytes interact with their host plant via metabolic communication enables them to generate signal molecules. In addition, the host plant's genetic recombination with endophytes helps them to imitate the host's physicochemical functions and develop identical active molecules. Therefore, when cultured separately, they begin producing the host plant phytochemicals. The fungal species Penicillium chrysogenum has portrayed the glory days of antibiotics with the invention of the antibiotic penicillin. Therefore, fungi have substantially supported social health by developing many bioactive molecules utilised as antioxidant, antibacterial, antiviral, immunomodulatory and anticancerous agents. But plant-related microbes have emanated as fountainheads of biologically functional compounds with higher levels of medicinal perspective in recent years. Researchers have been motivated by the endless need for potent drugs to investigate alternate ways to find new endophytes and bioactive molecules, which tend to be a probable aim for drug discovery. The current research trends with these promising endophytic organisms are reviewed in this review paper. KEY POINTS: • Identified 54 important bioactive compounds as agricultural relevance • Role of genome mining of endophytes and "Multi-Omics" tools in sustainable agriculture • A thorough description and graphical presentation of agricultural significance of plant endophytes.