Seed Endophytes of Jasione montana: Arsenic Detoxification Workers in an Eco-friendly Factory
Arsenic (As) is a toxic compound for human health and ecosystems. Some organisms have developed different strategies to live in environments contaminated with arsenic (As-tolerant organisms). Some prokaryotes are able to use arsenic as a donor or acceptor of electrons through respiratory processes (arsenic oxidizer and reducer bacteria). Certain plants can accumulate it in their tissues (accumulative plants) or imply their uptake and favor their exclusion (exclusion plants). Some fungi and bacteria are able to metabolize organic forms less toxic and volatile it. These mechanisms allow plants, prokaryotes and fungi to develop in environments with high concentrations of As. It is known that microbiota (especially rhizosphere and endosphere) can help plants to survive under arsenic stress conditions. However, little is known about the contribution of seed endophytes in the germination capacity and early development of seedling plants under As conditions. This chapter shows a brief review on the role of endophytic bacteria in the adaptation of plants to As stress conditions. Endophytic bacteria from seeds, obtained from plants that grow in As-contaminated soils, have showed that many of them promote the growth of the plant, have antifungal activity, and are AsV reducer bacteria, with the ability to metabolize arsenic to organic forms. We suggest that they have an important role in germination and early development when the seeds fall into an As-contaminated environment.
KeywordsEndophyte Arsenic stress Seed Plant growth promoting bacteria Metaorganism
The authors thank Dr. M. Bergen (Rutgers University) and Dr. S.K. Verma (Banaras Hindu University) for his invaluable help and collaboration. Molina, M.C. greatly thanks Rutgers University for her time there as a Visiting Scientist.
- Asher CJ, Reay PF (1979) Arsenic uptake by barley seedlings. Aust J Plant Physiol 6:459–466Google Scholar
- Gutiérrez-Ginés MJ, Pastor J, Hernández AJ (2015) Heavy metals in native mediterranean grassland species growing at abandoned mine sites: ecotoxicological assessment and phytoremediation of polluted soils. In: Sherameti I, Varma A (eds) Heavy metal contamination of soils. Soil biology, vol 44. Springer, Cham, pp 159–178Google Scholar
- Mallick I, Bhattacharyya C, Mukherji S et al (2018) Effective rhizoinoculation and biofilm formation by arsenic immobilizing halophilic plant growth promoting bacteria (PGPB) isolated from mangrove rhizosphere: a step towards arsenic rhizoremediation. Sci Total Environ 610–611:1239–1250. https://doi.org/10.1016/j.scitotenv.2017.07.234CrossRefPubMedGoogle Scholar
- Mukhopadhyay R, Rosen BP, Phung LT et al (2002) Microbial arsenic: from geocycles to genes and enzymes. FEMS Microbiol Rev 26:311–325. https://doi.org/10.1111/j.1574-6976.2002.tb00617.xCrossRefPubMedGoogle Scholar
- Pikovskaya RI (1948) Mobilization of phosphorus in soil in connection with vital activity of some microbial species. Mikrobiologiya 17:362–370Google Scholar
- Raab A, Schat H, Meharg AA et al (2005) Uptake, translocation and transformation of arsenate and arsenite in sunflower (Helianthus annuus): formation of arsenic–phytochelatin complexes during exposure to high arsenic concentrations. New Phytol 168:551–558. https://doi.org/10.1111/j.1469-8137.2005.01519.xCrossRefPubMedGoogle Scholar
- Sun W, Xionga Z, Chua L et al (2018) Bacterial communities of three plant species from Pb-Zn contaminated sites and plant-growth promotional benefits of endophytic Microbacterium sp. (strain BXGe71). J Hazard Mater. https://doi.org/10.1016/j.jhazmat.2018.02.003
- Truyens S, Jambon I, Croes S et al (2014) The effect of long-term Cd and Ni exposure on seed endophytes of Agrostis capillaris and their potential application in phytoremediation of metal-contaminated soils. Int J Phytoremediation 16:643–659. https://doi.org/10.1080/15226514.2013.837027CrossRefPubMedGoogle Scholar
- White J, Kingsley K, Verma S et al (2018b) Rhizophagy cycle: an oxidative process in plants for nutrient extraction from symbiotic microbes. Microorganisms 6:95. https://doi.org/10.3390/microorganisms6030095
- Zhao FJ, McGrath SP, Meharg AA (2010) Arsenic as a food chain contaminant: mechanisms of plant uptake and metabolism and mitigation strategies. Annu Rev Plant Biol 61:535–559. https://doi.org/10.1146/annurev-arplant-042809-112152CrossRefGoogle Scholar