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Samaddar S, Karp DS, Schmidt R, Devarajan N, McGarvey JA, Pires AFA, Scow K. Role of soil in the regulation of human and plant pathogens: soils' contributions to people. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200179. [PMID: 34365819 DOI: 10.1098/rstb.2020.0179] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Soil and soil biodiversity play critical roles in Nature's Contributions to People (NCP) # 10, defined as Nature's ability to regulate direct detrimental effects on humans, and on human-important plants and animals, through the control or regulation of particular organisms considered to be harmful. We provide an overview of pathogens in soil, focusing on human and crop pathogens, and discuss general strategies, and examples, of how soils' extraordinarily diverse microbial communities regulate soil-borne pathogens. We review the ecological principles underpinning the regulation of soil pathogens, as well as relationships between pathogen suppression and soil health. Mechanisms and specific examples are presented of how soil and soil biota are involved in regulating pathogens of humans and plants. We evaluate how specific agricultural management practices can either promote or interfere with soil's ability to regulate pathogens. Finally, we conclude with how integrating soil, plant, animal and human health through a 'One Health' framework could lead to more integrated, efficient and multifunctional strategies for regulating detrimental organisms and processes. This article is part of the theme issue 'The role of soils in delivering Nature's Contributions to People'.
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Affiliation(s)
- Sandipan Samaddar
- Department of Land, Air and Water Resources, University of California, Davis, Davis, CA, USA
| | - Daniel S Karp
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, Davis, CA, USA
| | - Radomir Schmidt
- Department of Land, Air and Water Resources, University of California, Davis, Davis, CA, USA
| | - Naresh Devarajan
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, Davis, CA, USA
| | - Jeffery A McGarvey
- Agricultural Research Service, US Department of Agriculture, Albany, CA, USA
| | - Alda F A Pires
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - Kate Scow
- Department of Land, Air and Water Resources, University of California, Davis, Davis, CA, USA
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Plett JM, Solomon J, Snijders F, Marlow-Conway J, Plett KL, Bithell SL. Order of microbial succession affects rhizobia-mediated biocontrol efforts against Phytophthora root rot. Microbiol Res 2020; 242:126628. [PMID: 33153885 DOI: 10.1016/j.micres.2020.126628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/13/2020] [Accepted: 10/14/2020] [Indexed: 02/07/2023]
Abstract
The management of soilborne root diseases in pulse crops is challenged by a limited range of resistance sources and often a complete absence of in-crop management options. Therefore, alternative management strategies need to be developed. We evaluated disease limiting interactions between the rhizobia species Mesorhizobium ciceri, and the oomycete pathogen Phytophthora medicaginis, which causes Phytophthora root rot (PRR) of chickpea (Cicer arietinum). For the PRR susceptible var. Sonali plants, post-pathogen M. ciceri inoculation significantly improved probability of plant survival when compared to P. medicaginis infected plants only pre-inoculated with M. ciceri (75 % versus 35 %, respectively). Potential mechanisms for these effects were investigated: rhizobia inoculation benefits to plant nodulation were not demonstrated, but the highest nodule N-fixation activity of P. medicaginis inoculated plants occurred for the post-pathogen M. ciceri treatment; rhizobia inoculation treatment did not reduce lesion development but certain combinations of microbial inoculation led to significant reduction in root growth. Microcosm studies, however, showed that the presence of M. ciceri reduced growth of P. medicaginis isolates. Putative chickpea disease resistance gene expression was evaluated using qPCR in var. Sonali roots. When var. Sonali plants were treated with M. ciceri post-P. medicaginis inoculation, the gene regulation in the plant host became more similar to PRR moderately resistant var. PBA HatTrick. These results suggest that M. ciceri application post P. medicaginis inoculation may improve plant survival by inducing defense responses similar to a PRR moderately resistant chickpea variety. Altogether, these results indicate that order of microbial succession can significantly affect PRR plant survial in susceptible chickpea under controlled conditions and improved plant survival effects are due to a number of different mechanisms including improved host nutrition, through direct inhibiton of pathogen growth, as well as host defense priming.
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Affiliation(s)
- J M Plett
- Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW, 2753, Australia.
| | - J Solomon
- Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW, 2753, Australia
| | - F Snijders
- Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW, 2753, Australia
| | - J Marlow-Conway
- Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW, 2753, Australia
| | - K L Plett
- Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW, 2753, Australia
| | - S L Bithell
- New South Wales Department of Primary Industries, Tamworth, NSW, 2340, Australia
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Mabrouk Y, Hemissi I, Salem IB, Mejri S, Saidi M, Belhadj O. Potential of Rhizobia in Improving Nitrogen Fixation and Yields of Legumes. Symbiosis 2018. [DOI: 10.5772/intechopen.73495] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Rhizobia: a potential biocontrol agent for soilborne fungal pathogens. Folia Microbiol (Praha) 2017; 62:425-435. [DOI: 10.1007/s12223-017-0513-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 03/02/2017] [Indexed: 01/31/2023]
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Hilali A, Prévost D, Broughton WJ, Antoun H. Effets de l'inoculation avec des souches deRhizobium leguminosarumbiovartrifoliisur la croissance du blé dans deux sols du Maroc. Can J Microbiol 2001. [DOI: 10.1139/w01-068] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
One hundred strains of Rhizobium leguminosarum bv. trifolii were isolated from roots of wheat cultivated in rotation with clover in two different regions of Morocco. The isolates were first screened for their effect on the growth of the cultivar Rihane of wheat cultivated in an agricultural soil under greenhouse conditions. After 5 weeks of growth, 14 strains stimulating the fresh or dry matter yield of shoots were selected and used in a second pot inoculation trial performed with two different agricultural soils. The results show that the strains behaved differently according to the soil used. In the loamy sand Rabat, strain IAT 168 behaved potentially like a plant growth promoting rhizobacteria (PGPR), as indicated by the 24% increases (P < 0.1) observed in wheat shoot dry matter and grain yields. In the silty clay Merchouch, no PGPR activity was observed, and 6 strains showed a significant deleterious effect on yields. These observations suggest that it is very important in a crop rotation system to choose a R. leguminosarum bv. trifolii strain that is effective with clover and shows PGPR activity with wheat to avoid deleterious effects on wheat yields.Key words: deleterious bacteria, PGPR (plant growth promoting rhizobacteria), Trifolium alexandrinum, Triticum aestivum.
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Investigations on some of the mechanisms by which bioenhanced mulches can suppress Phytophthora root rot of avocado. Microbiol Res 1996. [DOI: 10.1016/s0944-5013(96)80043-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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