1
|
Jaiswal SK, Dakora FD. Seed-Coat Pigmentation Plays a Crucial Role in Partner Selection and N 2 Fixation in Legume-Root-Microbe Associations in African Soils. PLANTS (BASEL, SWITZERLAND) 2024; 13:1464. [PMID: 38891273 PMCID: PMC11175086 DOI: 10.3390/plants13111464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 05/17/2024] [Accepted: 05/22/2024] [Indexed: 06/21/2024]
Abstract
Legume-rhizobia symbiosis is the most important plant-microbe interaction in sustainable agriculture due to its ability to provide much needed N in cropping systems. This interaction is mediated by the mutual recognition of signaling molecules from the two partners, namely legumes and rhizobia. In legumes, these molecules are in the form of flavonoids and anthocyanins, which are responsible for the pigmentation of plant organs, such as seeds, flowers, fruits, and even leaves. Seed-coat pigmentation in legumes is a dominant factor influencing gene expression relating to N2 fixation and may be responsible for the different N2-fixing abilities observed among legume genotypes under field conditions in African soils. Common bean, cowpea, Kersting's groundnut, and Bambara groundnut landraces with black seed-coat color are reported to release higher concentrations of nod-gene-inducing flavonoids and anthocyanins compared with the Red and Cream landraces. Black seed-coat pigmentation is considered a biomarker for enhanced nodulation and N2 fixation in legumes. Cowpea, Bambara groundnut, and Kersting's bean with differing seed-coat colors are known to attract different soil rhizobia based on PCR-RFLP analysis of bacterial DNA. Even when seeds of the same legume with diverse seed-coat colors were planted together in one hole, the nodulating bradyrhizobia clustered differently in the PCR-RFLP dendrogram. Kersting's groundnut, Bambara groundnut, and cowpea with differing seed-coat colors were selectively nodulated by different bradyrhizobial species. The 16S rRNA amplicon sequencing also found significant selective influences of seed-coat pigmentation on microbial community structure in the rhizosphere of five Kersting's groundnut landraces. Seed-coat color therefore plays a dominant role in the selection of the bacterial partner in the legume-rhizobia symbiosis.
Collapse
Affiliation(s)
- Sanjay K. Jaiswal
- Department of Chemistry, Tshwane University of Technology, Arcadia Campus, Pretoria 0183, South Africa
| | - Felix D. Dakora
- Department of Chemistry, Tshwane University of Technology, Arcadia Campus, Pretoria 0183, South Africa
| |
Collapse
|
2
|
Odeku OA, Ogunniyi QA, Ogbole OO, Fettke J. Forgotten Gems: Exploring the Untapped Benefits of Underutilized Legumes in Agriculture, Nutrition, and Environmental Sustainability. PLANTS (BASEL, SWITZERLAND) 2024; 13:1208. [PMID: 38732424 PMCID: PMC11085438 DOI: 10.3390/plants13091208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 04/16/2024] [Accepted: 04/22/2024] [Indexed: 05/13/2024]
Abstract
In an era dominated by conventional agricultural practices, underutilized legumes termed "Forgotten Gems" represent a reservoir of untapped benefits with the unique opportunity to diversify agricultural landscapes and enhance global food systems. Underutilized crops are resistant to abiotic environmental conditions such as drought and adapt better to harsh soil and climatic conditions. Underutilized legumes are high in protein and secondary metabolites, highlighting their role in providing critical nutrients and correcting nutritional inadequacies. Their ability to increase dietary variety and food security emerges as a critical component of their importance. Compared to mainstream crops, underutilized legumes have been shown to reduce the environmental impact of climate change. Their capacity for nitrogen fixation and positive impact on soil health make them sustainable contributors to biodiversity conservation and environmental balance. This paper identifies challenges and proposes strategic solutions, showcasing the transformative impact of underutilized legumes on agriculture, nutrition, and sustainability. These "Forgotten Gems" should be recognized, integrated into mainstream agricultural practices, and celebrated for their potential to revolutionize global food production while promoting environmental sustainability.
Collapse
Affiliation(s)
- Oluwatoyin A. Odeku
- Department of Pharmaceutics and Industrial Pharmacy, University of Ibadan, Ibadan 200132, Nigeria;
| | - Queeneth A. Ogunniyi
- Department of Pharmacognosy, University of Ibadan, Ibadan 200132, Nigeria; (Q.A.O.); (O.O.O.)
| | - Omonike O. Ogbole
- Department of Pharmacognosy, University of Ibadan, Ibadan 200132, Nigeria; (Q.A.O.); (O.O.O.)
| | - Joerg Fettke
- Biopolymer Analytics, Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam, Germany
| |
Collapse
|
3
|
Bitire TD, Abberton M, Tella EO, Edemodu A, Oyatomi O, Babalola OO. Impact of nitrogen-fixation bacteria on nitrogen-fixation efficiency of Bambara groundnut [ Vigna subterranea (L) Verdc] genotypes. Front Microbiol 2023; 14:1187250. [PMID: 37822737 PMCID: PMC10562726 DOI: 10.3389/fmicb.2023.1187250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 08/24/2023] [Indexed: 10/13/2023] Open
Abstract
Nitrogen fixation by bacteria is essential for sustaining the growth, development, and yield of legumes. Pot experiments were carried out at the International Institute of Tropical Agriculture (IITA) in the glasshouse between August to December 2018/2019 cropping season in Ibadan, Nigeria. Field studies were also performed in two different agroecological zones, "Ibadan and Ikenne" between August and December of 2019/2020 cropping season. The studies were set up to determine the potential of nitrogen-fixation bacteria strain inoculation on the nitrogen-fixation potential of 10 Bambara groundnut (BGN) genotypes, namely, TVSu-378, TVSu-506, TVSu-787, TVSu-1,606, TVSu-1,698, TVSu-1739, TVSu-710, TVSu-365, TVSu-475, and TVSu-305. The strains were inoculated as a broth to seedlings of each BGN genotype in the pot experiment. While six seeds from each BGN genotype were coated with each of the following nitrogen-fixation bacteria (Bradyrhizobium japonicum strains), FA3, USDA110, IRJ2180A, and RACA6, nitrogen fertilizer (urea, 20 kg/ha) was applied as a check to the nitrogen-fixation bacteria to seedlings of BGN genotypes 2 weeks after planting in both glasshouses and fields. Uninoculated plants served as controls (zero inoculation and zero fertilization). The field experiments were arranged in Randomized Complete Block Design (RCBD), while the glasshouse experiments were arranged in Complete Randomized Design (CRD) in triplicate. The result gotten showed that higher nodule numbers and weight were recorded in TVSu-1739 and TVSu-475 in both locations and seasons compared to other genotypes; the highest nitrogen fixed values were recorded among BGN genotypes TVSu-1739, TVSu-1,698, TVSu-787, TVSu-365, TVSu-305, TVSu-710, and TVSu-1,606, with a range of (62-67 kg ha-1), and were mostly enhanced by RACA6 and USDA110 strains compared to other strains that were used.
Collapse
Affiliation(s)
- Tope Daniel Bitire
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho, South Africa
- Genetic Resources Center, International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | - Michael Abberton
- Genetic Resources Center, International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | - Esther Oluwabukunola Tella
- Department of Microbiology, Faculty of Natural and Applied Science, Lead City University, Ibadan, Nigeria
| | - Alex Edemodu
- Yam Breeding Unit, International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | - Olaniyi Oyatomi
- Genetic Resources Center, International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | - Olubukola Oluranti Babalola
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho, South Africa
| |
Collapse
|
4
|
Bouhnik O, Alami S, Lamin H, Lamrabet M, Bennis M, Ouajdi M, Bellaka M, Antri SE, Abbas Y, Abdelmoumen H, Bedmar EJ, Idrissi MME. The Fodder Legume Chamaecytisus albidus Establishes Functional Symbiosis with Different Bradyrhizobial Symbiovars in Morocco. MICROBIAL ECOLOGY 2022; 84:794-807. [PMID: 34625829 DOI: 10.1007/s00248-021-01888-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 09/29/2021] [Indexed: 06/13/2023]
Abstract
In this work, we analyzed the symbiotic performance and diversity of rhizobial strains isolated from the endemic shrubby legume Chamaecytisus albidus grown in soils of three different agroforestry ecosystems representing arid and semi-arid forest areas in Morocco. The analysis of the rrs gene sequences from twenty-four representative strains selected after REP-PCR fingerprinting showed that all the strains belong to the genus Bradyrhizobium. Following multi-locus sequence analysis (MLSA) using the rrs, gyrB, recA, glnII, and rpoB housekeeping genes, five representative strains, CA20, CA61, CJ2, CB10, and CB61 were selected for further molecular studies. Phylogenetic analysis of the concatenated glnII, gyrB, recA, and rpoB genes showed that the strain CJ2 isolated from Sahel Doukkala soil is close to Bradyrhizobium canariense BTA-1 T (96.95%); that strains CA20 and CA61 isolated from the Amhach site are more related to Bradyrhizobium valentinum LmjM3T, with 96.40 and 94.57% similarity values; and that the strains CB10 and CB60 isolated from soil in the Bounaga site are more related to Bradyrhizobium murdochi CNPSo 4020 T and Bradyrhizobium. retamae Ro19T, with which they showed 95.45 and 97.34% similarity values, respectively. The phylogenetic analysis of the symbiotic genes showed that the strains belong to symbiovars lupini, genistearum, and retamae. All the five strains are able to nodulate Lupinus luteus, Retama monosperma, and Cytisus monspessilanus, but they do not nodulate Glycine max and Phaseolus vulgaris. The inoculation tests showed that the strains isolated from the 3 regions improve significantly the plant yield as compared to uninoculated plants. However, the strains of Bradyrhizobium sp. sv. retamae isolated from the site of Amhach were the most performing. The phenotypic analysis showed that the strains are able to use a wide range of carbohydrates and amino acids as sole carbon and nitrogen source. The strains isolated from the arid areas of Bounaga and Amhach were more tolerant to salinity and drought stress than strains isolated in the semi-arid area of Sahel Doukkala.
Collapse
Affiliation(s)
- Omar Bouhnik
- Centre de Biotechnologies Végétale Et Microbienne, Biodiversité Et Environnement, Faculté Des Sciences, Université Mohammed V de Rabat, 4, Avenue Ibn Battouta, Agdal, BP 1014 RP, Rabat, Morocco.
| | - Soufiane Alami
- Centre de Biotechnologies Végétale Et Microbienne, Biodiversité Et Environnement, Faculté Des Sciences, Université Mohammed V de Rabat, 4, Avenue Ibn Battouta, Agdal, BP 1014 RP, Rabat, Morocco
| | - Hanane Lamin
- Centre de Biotechnologies Végétale Et Microbienne, Biodiversité Et Environnement, Faculté Des Sciences, Université Mohammed V de Rabat, 4, Avenue Ibn Battouta, Agdal, BP 1014 RP, Rabat, Morocco
| | - Mouad Lamrabet
- Centre de Biotechnologies Végétale Et Microbienne, Biodiversité Et Environnement, Faculté Des Sciences, Université Mohammed V de Rabat, 4, Avenue Ibn Battouta, Agdal, BP 1014 RP, Rabat, Morocco
| | - Meryeme Bennis
- Centre de Biotechnologies Végétale Et Microbienne, Biodiversité Et Environnement, Faculté Des Sciences, Université Mohammed V de Rabat, 4, Avenue Ibn Battouta, Agdal, BP 1014 RP, Rabat, Morocco
| | - Mohammed Ouajdi
- Centre de Recherche Forestière, Département Des Eaux Et Forêts, Avenue Omar Ibn El KhattabAgdal, BP 763, 10050, Rabat, Morocco
| | - Mhammed Bellaka
- Centre de Recherche Forestière, Département Des Eaux Et Forêts, Avenue Omar Ibn El KhattabAgdal, BP 763, 10050, Rabat, Morocco
| | - Salwa El Antri
- Centre de Recherche Forestière, Département Des Eaux Et Forêts, Avenue Omar Ibn El KhattabAgdal, BP 763, 10050, Rabat, Morocco
| | - Younes Abbas
- Faculté Polydiciplinaire, Université Sultan Moulay Slimane, Beni Mellal, Morocco
| | - Hanaa Abdelmoumen
- Centre de Biotechnologies Végétale Et Microbienne, Biodiversité Et Environnement, Faculté Des Sciences, Université Mohammed V de Rabat, 4, Avenue Ibn Battouta, Agdal, BP 1014 RP, Rabat, Morocco
| | - Eulogio J Bedmar
- Departamento de Microbiología del Suelo y Sistemas Simbióticos Estación Experimental del Zaidín, CSIC Apartado Postal 419, Granada, 18008, Spain
| | - Mustapha Missbah El Idrissi
- Centre de Biotechnologies Végétale Et Microbienne, Biodiversité Et Environnement, Faculté Des Sciences, Université Mohammed V de Rabat, 4, Avenue Ibn Battouta, Agdal, BP 1014 RP, Rabat, Morocco
| |
Collapse
|
5
|
Adjei JA, Aserse AA, Yli-Halla M, Ahiabor BDK, Abaidoo RC, Lindstrom K. Phylogenetically diverse Bradyrhizobium genospecies nodulate Bambara groundnut (Vigna subterranea L. Verdc) and soybean (Glycine max L. Merril) in the northern savanna zones of Ghana. FEMS Microbiol Ecol 2022; 98:fiac043. [PMID: 35404419 PMCID: PMC9329091 DOI: 10.1093/femsec/fiac043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 03/30/2022] [Accepted: 04/08/2022] [Indexed: 11/25/2022] Open
Abstract
A total of 102 bacterial strains isolated from nodules of three Bambara groundnut and one soybean cultivars grown in nineteen soil samples collected from northern Ghana were characterized using multilocus gene sequence analysis. Based on a concatenated sequence analysis (glnII-rpoB-recA-gyrB-atpD-dnaK), 54 representative strains were distributed in 12 distinct lineages, many of which were placed mainly in the Bradyrhizobium japonicum and Bradyrhizobium elkanii supergroups. Twenty-four of the 54 representative strains belonged to seven putative novel species, while 30 were conspecific with four recognized Bradyrhizobium species. The nodA phylogeny placed all the representative strains in the cosmopolitan nodA clade III. The strains were further separated in seven nodA subclusters with reference strains mainly of African origin. The nifH phylogeny was somewhat congruent with the nodA phylogeny, but both symbiotic genes were mostly incongruent with the core housekeeping gene phylogeny indicating that the strains acquired their symbiotic genes horizontally from distantly related Bradyrhizobium species. Using redundancy analysis, the distribution of genospecies was found to be influenced by the edaphic factors of the respective sampling sites. In general, these results mainly underscore the high genetic diversity of Bambara groundnut-nodulating bradyrhizobia in Ghanaian soils and suggest a possible vast resource of adapted inoculant strains.
Collapse
Affiliation(s)
- Josephine A Adjei
- Department of Crop and Soil Sciences, Faculty of Agriculture, Kwame Nkrumah University of Science and Technology, PMB, Kumasi, Ghana
- Faculty of Biological and Environmental Sciences, University of Helsinki, FIN-00014 Helsinki, Finland
- Council for Scientific and Industrial Research, Savanna Agricultural Research Institute, PO Box 52, Tamale, Ghana
| | - Aregu A Aserse
- Faculty of Biological and Environmental Sciences, University of Helsinki, FIN-00014 Helsinki, Finland
| | - Markku Yli-Halla
- Department of Agricultural Sciences, University of Helsinki, FIN-00014 Helsinki, Finland
| | - Benjamin D K Ahiabor
- Council for Scientific and Industrial Research, Savanna Agricultural Research Institute, PO Box 52, Tamale, Ghana
| | - Robert C Abaidoo
- Department of Theoretical and Applied Biology, Kwame Nkrumah University of Science and Technology, PMB, Kumasi, Ghana
- International Institute of Tropical Agriculture, PMB 5320, Ibadan, Nigeria
| | - Kristina Lindstrom
- Faculty of Biological and Environmental Sciences, University of Helsinki, FIN-00014 Helsinki, Finland
| |
Collapse
|
6
|
Ayuba J, Jaiswal SK, Mohammed M, Denwar NN, Dakora FD. Adaptability to local conditions and phylogenetic differentiation of microsymbionts of TGx soybean genotypes in the semi-arid environments of Ghana and South Africa. Syst Appl Microbiol 2021; 44:126264. [PMID: 34601230 DOI: 10.1016/j.syapm.2021.126264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/30/2021] [Accepted: 09/10/2021] [Indexed: 11/15/2022]
Abstract
The study of the nitrogen fixation and phylogenetic diversity of nodule microsymbionts of grain legumes in many parts of the globe is often carried out in order to identify legume-rhizobia combinations for agricultural sustainability. Several reports have therefore found that rhizobial species diversity is shaped by edapho-climatic conditions that characterize different geographic locations, suggesting that rhizobial communities often possess traits that aid their adaptation to their habitat. In this study, the soybean-nodulating rhizobia from semi-arid savannahs of Ghana and South Africa were evaluated. The authenticated rhizobial isolates were highly diverse based on their colony characteristics, as well as their BOX-PCR profiles and gene sequences. In the 16S rRNA phylogeny, the isolates were placed in the different clades Bradyrhizobium iriomotense and Bradyrhizobium jicamae together with two superclades Bradyrhizobium japonicum and Bradyrhizobium elkanii. The multilocus (atpD, glnII, gyrB, recA) phylogenetic analyses indicated the dominance of Bradyrhizobium diazoefficiens and putative new Bradyrhizobium species in the semi-arid Ghanaian region. The phylogenetic analyses based on the symbiotic genes (nifH and nodC) clustered the test isolates into different symbiovars (sv. glycinearum, sv. retame and sv. sojae). Principal component analysis (PCA) showed that soil factors played a significant role in favoring the occurrence of soybean-nodulating microsymbionts in the tested local conditions. The results suggested that isolates had marked local adaptation to the prevailing conditions in semi-arid regions but further studies are needed to confirm new Bradyrhizobium species.
Collapse
Affiliation(s)
- Jalilatu Ayuba
- Department of Crop Sciences, Tshwane University of Technology, Pretoria, South Africa; CSIR-Savanna Agric Research Institute, Tamale, Ghana; Department of Sustainable Agriculture, Tamale Technical University, Tamale, Ghana
| | - Sanjay K Jaiswal
- Department of Chemistry, Tshwane University of Technology, Arcadia Campus Pretoria, South Africa.
| | - Mustapha Mohammed
- Department of Chemistry, Tshwane University of Technology, Arcadia Campus Pretoria, South Africa; Department of Crop Science, University for Development Studies, Tamale, Ghana
| | | | - Felix D Dakora
- Department of Chemistry, Tshwane University of Technology, Arcadia Campus Pretoria, South Africa.
| |
Collapse
|
7
|
Avontuur JR, Palmer M, Beukes CW, Chan WY, Tasiya T, van Zyl E, Coetzee MPA, Stepkowski T, Venter SN, Steenkamp ET. Bradyrhizobium altum sp. nov., Bradyrhizobium oropedii sp. nov. and Bradyrhizobium acaciae sp. nov. from South Africa show locally restricted and pantropical nodA phylogeographic patterns. Mol Phylogenet Evol 2021; 167:107338. [PMID: 34757168 DOI: 10.1016/j.ympev.2021.107338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/22/2021] [Accepted: 10/27/2021] [Indexed: 10/20/2022]
Abstract
Africa is known for its rich legume diversity with a significant number of endemic species originating in South Africa. Many of these legumes associate with rhizobial symbionts of the genus Bradyrhizobium, of which most represent new species. Yet, none of the Bradyrhizobium species from South Africa have been described. In this study, phylogenetic analysis of 16S rRNA gene sequences of fourteen strains isolated in southern Africa from root nodules of diverse legumes (i.e., from the tribes Crotalarieae, Acacieae, Genisteae, Phaseoleae and Cassieae) revealed that they belong to the Bradyrhizobium elkanii supergroup. The taxonomic position and possible novelty of these strains were further interrogated using genealogical concordance of five housekeeping genes (atpD, dnaK, glnII, gyrB and rpoB). These phylogenies consistently recovered four monophyletic groups and one singleton within Bradyrhizobium. Of these groups, two were conspecific with Bradyrhizobium brasilense UFLA 03-321T and Bradyrhizobium ivorense CI-1BT, while the remaining three represented novel taxa. Their existence was further supported with genome data, as well as metabolic and physiological traits. Analysis of nodA gene sequences further showed that the evolution of these bacteria likely involved adapting to local legume hosts and environmental conditions through the acquisition, via horizontal gene transfer, of optimal symbiotic loci. We accordingly propose the following names Bradyrhizobium acaciae sp. nov. 10BBT (SARCC 730T = LMG 31409T), Bradyrhizobium oropedii sp. nov. Pear76T (SARCC 731T = LMG 31408T), and Bradyrhizobium altum sp. nov. Pear77T (SARCC 754T = LMG 31407T) to accommodate three novel species, all of which are symbionts of legumes in South Africa.
Collapse
Affiliation(s)
- Juanita R Avontuur
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Marike Palmer
- School of Life Sciences, University of Nevada, Las Vegas, Nevada, United States
| | - Chrizelle W Beukes
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Wai Y Chan
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa; National Institute for Communicable Disease, National Health Laboratory Service, Johannesburg, South Africa
| | - Taponeswa Tasiya
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Elritha van Zyl
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Martin P A Coetzee
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Tomasz Stepkowski
- Department of Biochemistry and Microbiology, Institute of Biology, Warsaw University of Life Sciences (SGGW), Poland
| | - Stephanus N Venter
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa.
| | - Emma T Steenkamp
- Department of Biochemistry, Genetics and Microbiology (BGM), Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| |
Collapse
|
8
|
Dlamini ST, Jaiswal SK, Mohammed M, Dakora FD. Studies of Phylogeny, Symbiotic Functioning and Ecological Traits of Indigenous Microsymbionts Nodulating Bambara Groundnut (Vigna subterranea L. Verdc) in Eswatini. MICROBIAL ECOLOGY 2021; 82:688-703. [PMID: 33606087 DOI: 10.1007/s00248-021-01684-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 01/06/2021] [Indexed: 06/12/2023]
Abstract
Rhizobial microsymbionts of grain legumes are ubiquitous in soils and exhibit a wide range of diversity with respect to colony morphology, genetic variability, biochemical characteristics, and phylogenetic relationships. This study assessed the phylogenetic positions of rhizobial microsymbionts of Bambara groundnut from Eswatini exhibiting variations in morpho-physiology, adaptive characteristics, and N2-fixing efficiency. The isolates' ERIC-PCR profiles revealed the presence of high genetic variation among them. These test isolates also exhibited differences in pH tolerance and IAA production. Multilocus sequence analysis based on the 16S rRNA, atpD, glnII, gyrB, and recA gene sequences of representative test isolates closely aligned them to the type strains of Bradyrhizobium arachidis, B. manausense, B. guangdongense, B. elkanii, and B. pachyrhizi. However, some isolates showed a high divergence from the known reference type strains, indicating that they may represent species yet to be properly characterized and described. Functional characterization in the glasshouse revealed that most of the isolates from the contrasting Agro-ecologies of Eswatini were efficient in N2 fixation, and therefore elicited greater stomatal conductance and photosynthetic rates in the homologous Bambara groundnut. Of the 75 isolates tested, 51% were more effective than the commercial Bradyrhizobium sp. strain CB756, with relative symbiotic effectiveness ranging from 138 to 308%. The findings of this study indicated that the analysis of housekeeping genes and functional traits of Bambara-nodulating microsymbionts can provide a clear view for understanding and predicting rhizobial community structure across environmental gradients.
Collapse
Affiliation(s)
- Sibusiso T Dlamini
- Department of Crop Sciences, Tshwane University of Technology, Pretoria, South Africa
| | - Sanjay K Jaiswal
- Department of Chemistry, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa.
| | - Mustapha Mohammed
- Department of Crop Sciences, Tshwane University of Technology, Pretoria, South Africa
- Department of Chemistry, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa
| | - Felix D Dakora
- Department of Chemistry, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa.
| |
Collapse
|
9
|
Lengwati DM, Mathews C, Dakora FD. Rotation Benefits From N2-Fixing Grain Legumes to Cereals: From Increases in Seed Yield and Quality to Greater Household Cash-Income by a Following Maize Crop. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2020. [DOI: 10.3389/fsufs.2020.00094] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
10
|
Ibny FYI, Jaiswal SK, Mohammed M, Dakora FD. Symbiotic effectiveness and ecologically adaptive traits of native rhizobial symbionts of Bambara groundnut (Vigna subterranea L. Verdc.) in Africa and their relationship with phylogeny. Sci Rep 2019; 9:12666. [PMID: 31477738 PMCID: PMC6718677 DOI: 10.1038/s41598-019-48944-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 08/13/2019] [Indexed: 11/09/2022] Open
Abstract
Bambara groundnut (Vigna subterranea L. Verdc.) is an indigenous, drought-tolerant, underutilized African food legume, with the ability to fix atmospheric N2 in symbiosis with soil bacteria called rhizobia. The aim of this study was to assess the morpho-physiological, symbiotic and phylogenetic characteristics of rhizobia nodulating Bambara groundnut in Ghana, Mali and South Africa. The morpho-physiologically diverse isolates tested were also found to exhibit differences in functional efficiency and phylogenetic positions. Based on Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR banding patterns, the isolates were grouped into eight major clusters. The concentrations of Ca, Na and K in soils had a significant (p ≤ 0.01) effect on the distribution of rhizobia. Though many isolates were symbiotically very effective, the effectiveness index varied markedly (p ≤ 0.05) among them. Moreover, the isolates also exhibited tolerance to a wide range of NaCl (0.5–7%), streptomycin (50–500 µg.ml−1), and kanamycin (25–150 µg.ml−1) concentrations. Additionally, these isolates could produce 0.02 to 69.71 µg.ml−1 of indole-3-acetic acid (IAA) in tryptophan-supplemented medium, as well as solubilize tri-calcium phosphate. Phylogenetic analysis of these rhizobial isolates using 16S rRNA, atpD, glnII, gyrB, recA and symbiotic (nifH and nodC) gene sequences revealed distinct and novel evolutionary lineages related to the genus Bradyrhizobium, with some of them being very close to Bradyrhizobium vignae, B. kavangense, B. subterraneum, B. elkanii and B. pachyrhizi.
Collapse
Affiliation(s)
- Fadimata Y I Ibny
- Department of Crop Sciences, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa
| | - Sanjay K Jaiswal
- Chemistry Department, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa.
| | - Mustapha Mohammed
- Department of Crop Sciences, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa
| | - Felix D Dakora
- Chemistry Department, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa.
| |
Collapse
|
11
|
Adebiyi JA, Njobeh PB, Kayitesi E. Assessment of nutritional and phytochemical quality of Dawadawa (an African fermented condiment) produced from Bambara groundnut (Vigna subterranea). Microchem J 2019. [DOI: 10.1016/j.microc.2019.104034] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
12
|
Insights into the Phylogeny, Nodule Function, and Biogeographic Distribution of Microsymbionts Nodulating the Orphan Kersting's Groundnut [ Macrotyloma geocarpum (Harms) Marechal & Baudet] in African Soils. Appl Environ Microbiol 2019; 85:AEM.00342-19. [PMID: 30952658 PMCID: PMC6532025 DOI: 10.1128/aem.00342-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 03/23/2019] [Indexed: 02/06/2023] Open
Abstract
Kersting's groundnut [Macrotyloma geocarpum (Harms) Marechal & Baudet] is a neglected indigenous African legume adapted to growth in N-deficient soils due to its ability to fix atmospheric N2 via symbiosis with rhizobia. Despite its nutritional and medicinal uses, to date there is little information on the phylogeny and functional traits of its microsymbionts, aspects that are much needed for its conservation and improvement. This study explored the morphogenetic diversity, phylogenetic relationships, and N2-fixing efficiency of Kersting's groundnut rhizobial isolates from contrasting environments in Ghana, South Africa, and Mozambique. BOX-PCR fingerprinting revealed high diversity among the rhizobial populations, which was influenced by geographic origin. Of the 164 isolates evaluated, 130 BOX-PCR types were identified at a 70% similarity coefficient, indicating that they were not clones. Soil pH and mineral concentrations were found to influence the distribution of bradyrhizobial populations in African soils. Phylogenetic analysis of 16S rRNA genes and multilocus sequence analysis of protein-coding genes (atpD, glnII, gyrB, and rpoB) and symbiotic genes (nifH and nodC) showed that Kersting's groundnut is primarily nodulated by members of the genus Bradyrhizobium, which are closely related to Bradyrhizobium vignae 7-2T, Bradyrhizobium kavangense 14-3T, Bradyrhizobium subterraneum 58-2-1T, Bradyrhizobium pachyrhizi PAC48T, the type strain of Bradyrhizobium elkanii, and novel groups of Bradyrhizobium species. The bradyrhizobial populations identified exhibited high N2 fixation and induced greater nodulation, leaf chlorophyll concentration, and photosynthetic rates in their homologous host than did the 5 mM KNO3-fed plants and/or the commercial Bradyrhizobium sp. strain CB756, suggesting that they could be good candidates for inoculant formulations upon field testing.IMPORTANCE Rhizobia play important roles in agroecosystems, where they contribute to improving overall soil health through their symbiotic relationship with legumes. This study explored the microsymbionts nodulating Kersting's groundnut, a neglected orphan legume. The results revealed the presence of different bradyrhizobial populations with high N2-fixing efficiencies as the dominant symbionts of this legume across diverse agroecologies in Africa. Our findings represent a useful contribution to the literature in terms of the community of microsymbionts nodulating a neglected cultivated legume and its potential for elevation as a major food crop. The presence of potentially novel bradyrhizobial symbionts of Kersting's groundnut found in this study offers an opportunity for future studies to properly describe, characterize, and delineate these isolates functionally and phylogenetically for use in inoculant production to enhance food/nutritional security.
Collapse
|
13
|
Puozaa DK, Jaiswal SK, Dakora FD. Phylogeny and distribution of Bradyrhizobium symbionts nodulating cowpea (Vigna unguiculata L. Walp) and their association with the physicochemical properties of acidic African soils. Syst Appl Microbiol 2019; 42:403-414. [PMID: 30803810 PMCID: PMC6542415 DOI: 10.1016/j.syapm.2019.02.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 02/11/2019] [Accepted: 02/11/2019] [Indexed: 11/24/2022]
Abstract
In the N2-fixing symbiosis, the choice of a symbiotic partner is largely influenced by the host plant, the rhizobial symbiont, as well as soil factors. Understanding the soil environment conducive for the survival and multiplication of root-nodule bacteria is critical for microbial ecology. In this study, we collected cowpea-nodules from acidic soils in Ghana and South Africa, and nodule DNA isolates were characterized using 16S-23S rRNA-RFLP, phylogenetic analysis of housekeeping and symbiotic genes, and bradyrhizobial community structure through canonical correspondence analysis (CCA). The CCA ordination plot results showed that arrow of soil pH was overlapping on CCA2 axis and was the most important to the ordination. The test nodule DNA isolates from Ghana were positively influenced by soil Zn, Na and K while nodule DNA isolates from South Africa were influenced by P. The amplified 16S-23S rRNA region yielded single polymorphic bands of varying lengths (573-1298bp) that were grouped into 28 ITS types. The constructed ITS-dendrogram placed all the nodule DNA isolates in five major clusters at low cut-off of approx. 0.1 Jaccard's similarity coefficient. The phylogenetic analysis of 16S rRNA and housekeeping genes (glnII, gyrB, and atpD) formed distinct Bradyrhizobium groups in the phylogenetic trees. It revealed the presence of highly diverse bradyrhizobia (i.e. Bradyrhizobium vignae, Bradyrhizobium elkanii, Bradyrhizobium iriomotense, Bradyrhizobium pachyrhizi, and Bradyrhizobium yuanmingense) together with novel/unidentified bradyrhizobia in the acidic soils from Ghana and South Africa. Discrepancies noted in the phylogenies of some nodule DNA isolates could be attributed to horizontal gene transfer or recombination.
Collapse
Affiliation(s)
- Doris K Puozaa
- Department of Crop Sciences, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa
| | - Sanjay K Jaiswal
- Department of Chemistry, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa.
| | - Felix D Dakora
- Department of Chemistry, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa.
| |
Collapse
|
14
|
Jaiswal SK, Dakora FD. Widespread Distribution of Highly Adapted Bradyrhizobium Species Nodulating Diverse Legumes in Africa. Front Microbiol 2019; 10:310. [PMID: 30853952 PMCID: PMC6395442 DOI: 10.3389/fmicb.2019.00310] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 02/05/2019] [Indexed: 11/17/2022] Open
Abstract
Bradyrhizobium is one of the most cosmopolitan and diverse bacterial group nodulating a variety of host legumes in Africa, however, the diversity and distribution of bradyrhizobial symbionts nodulating indigenous African legumes are not well understood, though needed for increased food legume production. In this review, we have shown that many African food legumes are nodulated by bradyrhizobia, with greater diversity in Southern Africa compared to other parts of Africa. From a few studies done in Africa, the known bradyrhizobia (i.e., Bradyrhizobium elkanii, B. yuanmingense) along with many novel Bradyrhizobium species are the most dominant in African soils. This could be attributed to the unique edapho-climatic conditions of the contrasting environments in the continent. More studies are needed to identify the many novel bradyrhizobia resident in African soils in order to better understand the biogeography of bradyrhizobia and their potential for inoculant production.
Collapse
Affiliation(s)
- Sanjay K. Jaiswal
- Department of Chemistry, Faculty of Science, Tshwane University of Technology, Pretoria, South Africa
| | - Felix D. Dakora
- Department of Chemistry, Faculty of Science, Tshwane University of Technology, Pretoria, South Africa
| |
Collapse
|
15
|
Mohammed M, Jaiswal SK, Dakora FD. Distribution and correlation between phylogeny and functional traits of cowpea (Vigna unguiculata L. Walp.)-nodulating microsymbionts from Ghana and South Africa. Sci Rep 2018; 8:18006. [PMID: 30573737 PMCID: PMC6302100 DOI: 10.1038/s41598-018-36324-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 09/18/2018] [Indexed: 12/03/2022] Open
Abstract
Cowpea (Vigna unguiculata L. Walp.) is indigenous to Africa, and highly valued for its N2-fixing trait and the nutritional attributes of its grain and leaves. The species' ability to establish effective symbiosis with diverse rhizobial populations gives it survival and growth advantage in N-limited environments. To explore the functional diversity and phylogenetic positions of rhizobia nodulating cowpea in Africa, nodules were collected from various cowpea varieties grown in soils from the Guinea savanna and Sudano-sahelian agroecologies of Northern Ghana, and from the lowveld and middleveld areas of Mpumalanga Province in South Africa. Box-PCR profiling and multilocus sequence analysis revealed the presence of diverse microsymbionts responsible for cowpea nodulation across the study sites. BOX-PCR amplifications yielded variable band sizes, ranging from 618 bp to 5354 bp, which placed the isolates in six major clusters (Cluster A-F). Phylogenetic analysis based on 16S rRNA, atpD, glnII, gyrB, rpoB, nifH and nodC genes revealed the presence of diverse Bradyrhizobium sp. closely related to Bradyrhizobium daqingense, Bradyrhizobium subterraneum, Bradyrhizobium yuanmingense, Bradyrhizobium embrapense, Bradyrhizobium pachyrhizi, Bradyrhizobium elkanii and novel Bradyrhizobium species in the soils studied, a finding that could be attributed to the unique edapho-climatic conditions of the contrasting environments. The test isolates exhibited distinct symbiotic efficiencies, and also induced variable (p ≤ 0.001) photosynthetic rates, leaf transpiration, total chlorophyll and shoot biomass accumulation on cowpea (their homologous host). Canonical correspondence analysis showed that the distribution of these microsymbionts was influenced by the concentrations of macro- and micronutrients in soils. The pairwise genetic distances derived from phylogenies and nodule functioning showed significant (p < 0.05) correlation, which suggests that local environmental factors played a major role in the cowpea-Bradyrhizobium symbiosis.
Collapse
Affiliation(s)
- Mustapha Mohammed
- Department of Crop Sciences, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa
| | - Sanjay K Jaiswal
- Chemistry Department, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa.
| | - Felix D Dakora
- Chemistry Department, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa.
| |
Collapse
|
16
|
Grönemeyer JL, Reinhold-Hurek B. Diversity of Bradyrhizobia in Subsahara Africa: A Rich Resource. Front Microbiol 2018; 9:2194. [PMID: 30294308 PMCID: PMC6158577 DOI: 10.3389/fmicb.2018.02194] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 08/27/2018] [Indexed: 01/08/2023] Open
Abstract
Making use of biological nitrogen fixation (BNF) with pulses and green manure legumes can help to alleviate nitrogen deficiencies and increase soil fertility, problems faced particularly in smallholder agriculture in Subsahara Africa (SSA). The isolation of indigenous rhizobia provides a basis for the formulation of rhizobial inoculants. Moreover, their identification and characterization contribute to the general understanding of species distribution and ecology. Here we discuss global species discovery of Bradyrhizobium spp. Although recently the number of validly published Bradyrhizobium species is rapidly increasing, their diversity in SSA is not well-represented. We summarize the recent knowledge on species diversity in the Bradyrhizobium yuanmingense lineage to which most SSA isolates belong, and their biogeographic distribution and adaptations. Most indigenous rhizobia appear to differ from species found on other continents. We stress that an as yet hidden diversity may be a rich resource for inoculant development in future. As some species are exceptionally temperature tolerant, they may be potential biofertilizer candidates for global warming scenarios.
Collapse
Affiliation(s)
| | - Barbara Reinhold-Hurek
- Department of Microbe-Plant Interactions, Faculty of Biology and Chemistry, Center for Biomolecular Interactions Bremen, University of Bremen, Bremen, Germany
| |
Collapse
|
17
|
Gyogluu C, Jaiswal SK, Kyei-Boahen S, Dakora FD. Identification and distribution of microsymbionts associated with soybean nodulation in Mozambican soils. Syst Appl Microbiol 2018; 41:506-515. [PMID: 29853205 PMCID: PMC6150944 DOI: 10.1016/j.syapm.2018.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 05/03/2018] [Accepted: 05/04/2018] [Indexed: 12/05/2022]
Abstract
Indigenous soybean rhizobial strains were isolated from root nodules sampled from farmers' fields in Mozambique to determine their identity, distribution and symbiotic relationships. Plant infection assays revealed variable nodulation and symbiotic effectiveness among the 43 bacterial isolates tested. Strains from Ruace generally promoted greater whole-plant growth than the others. 16S rRNA-RFLP analysis of genomic DNA extracted from the rhizobial isolates produced different banding patterns, a clear indication of high bacterial diversity. However, the multilocus sequence analysis (MLSA) data showed alignment of the isolates with B. elkanii species. The 16S rRNA sequences of representative soybean isolates selected from each 16S rRNA-RFLP cluster showed their relatedness to B. elkanii, as well as to other Bradyrhizobium species. But a concatenated phylogeny of two housekeeping genes (glnII and gyrB) identified the soybean nodulating isolates as Bradyrhizobium, with very close relatedness to B. elkanii. The nifH and nodC sequences also showed that the majority of the test soybean isolates were closely related to B. elkanii, albeit the inconsistency with some isolates. Taken together, these findings suggest that the B. elkanii group are the preferred dominant microsymbiont of soybean grown in Mozambican soils. Furthermore, the distribution of soybean rhizobia in the agricultural soils of Mozambique was found to be markedly influenced by soil pH, followed by the concentrations of plant-available P and Mn. This study suggested that the identified isolates TUTMJM5, TUTMIITA5A and TUTLBC2B can be used as inoculants for increased soybean production in Mozambique.
Collapse
Affiliation(s)
- Cynthia Gyogluu
- Department of Crop Sciences, TshwaneUniversity of Technology, Pretoria, South Africa; Department of Chemistry, Tshwane University of Technology, Pretoria, South Africa
| | - Sanjay K Jaiswal
- Department of Chemistry, Tshwane University of Technology, Pretoria, South Africa.
| | | | - Felix D Dakora
- Department of Chemistry, Tshwane University of Technology, Pretoria, South Africa.
| |
Collapse
|