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Kumar A, Naroju SP, Kumari N, Arsey S, Kumar D, Gubre DF, Roychowdhury A, Tyagi S, Saini P. The role of drought response genes and plant growth promoting bacteria on plant growth promotion under sustainable agriculture: A review. Microbiol Res 2024; 286:127827. [PMID: 39002396 DOI: 10.1016/j.micres.2024.127827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 06/28/2024] [Accepted: 06/30/2024] [Indexed: 07/15/2024]
Abstract
Drought is a major stressor that poses significant challenges for agricultural practices. It becomes difficult to meet the global demand for food crops and fodder. Plant physiology, physico-chemistry and morphology changes in plants like decreased photosynthesis and transpiration rate, overproduction of reactive oxygen species, repressed shoot and root shoot growth and modified stress signalling pathways by drought, lead to detrimental impacts on plant development and output. Coping with drought stress requires a variety of adaptations and mitigation techniques. Crop yields could be effectively increased by employing plant growth-promoting rhizobacteria (PGPR), which operate through many mechanisms. These vital microbes colonise the rhizosphere of crops and promote drought resistance by producing exopolysaccharides (EPS), 1-aminocyclopropane-1-carboxylate (ACC) deaminase and phytohormones including volatile compounds. The upregulation or downregulation of stress-responsive genes causes changes in root architecture due to acquiring drought resistance. Further, PGPR induces osmolyte and antioxidant accumulation. Another key feature of microbial communities associated with crops includes induced systemic tolerance and the production of free radical-scavenging enzymes. This review is focused on detailing the role of PGPR in assisting plants to adapt to drought stress.
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Affiliation(s)
- Ashok Kumar
- School of Life Science and Technology, IIMT University, Meerut, Uttar Pradesh, India.
| | - Sai Prakash Naroju
- Department of Agricultural and Environmental Sciences, Tennessee State University, Nashville, USA
| | - Neha Kumari
- Department of Genetics and Plant Breeding (Plant Biotechnology), Institute of Agricultural Sciences, Rajiv Gandhi South Campus, Banaras Hindu University, Mirzapur, Uttar Pradesh, India
| | - Shivani Arsey
- Department of Genetics and Plant Breeding (Plant Biotechnology), Institute of Agricultural Sciences, Rajiv Gandhi South Campus, Banaras Hindu University, Mirzapur, Uttar Pradesh, India
| | - Deepak Kumar
- Plant Biotechnology, Gujarat Biotechnology University, Near Gujarat International Finance Tec (GIFT)-City, Gandhinagar, Gujarat, India
| | - Dilasha Fulchand Gubre
- Department of Crop Improvement, Indian Council of Agricultural Research Indian Institute of Soybean Research, Indore, Madhya Pradesh, India
| | - Abhrajyoti Roychowdhury
- Department of Microbiology, University of North Bengal, Raja Rammohunpur, West Bengal, India
| | - Sachin Tyagi
- School of Life Science and Technology, IIMT University, Meerut, Uttar Pradesh, India
| | - Pankaj Saini
- School of Life Science and Technology, IIMT University, Meerut, Uttar Pradesh, India
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Srivastava S, Bhattacharjee A, Dubey S, Sharma S. Bacterial exopolysaccharide amendment improves the shelf life and functional efficacy of bioinoculant under salinity stress. J Appl Microbiol 2024; 135:lxae166. [PMID: 38960398 DOI: 10.1093/jambio/lxae166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 06/20/2024] [Accepted: 07/02/2024] [Indexed: 07/05/2024]
Abstract
AIM Bacterial exopolysaccharides (EPS) possess numerous properties beneficial for the growth of microbes and plants under hostile conditions. The study aimed to develop a bioformulation with bacterial EPS to enhance the bioinoculant's shelf life and functional efficacy under salinity stress. METHODS AND RESULTS High EPS-producing and salt-tolerant bacterial strain (Bacillus haynessi SD2) exhibiting auxin-production, phosphate-solubilization, and biofilm-forming ability, was selected. EPS-based bioformulation of SD2 improved the growth of three legumes under salt stress, from which pigeonpea was selected for further experiments. SD2 improved the growth and lowered the accumulation of stress markers in plants under salt stress. Bioformulations with varying EPS concentrations (1% and 2%) were stored for 6 months at 4°C, 30°C, and 37°C to assess their shelf life and functional efficacy. The shelf life and efficacy of EPS-based bioformulation were sustained even after 6 months of storage at high temperature, enhancing pigeonpea growth under stress in both control and natural conditions. However, the efficacy of non EPS-based bioformulation declined following four months of storage. The bioformulation (with 1% EPS) modulated bacterial abundance in the plant's rhizosphere under stress conditions. CONCLUSION The study brings forth a new strategy for developing next-generation bioformulations with higher shelf life and efficacy for salinity stress management in pigeonpea.
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Affiliation(s)
- Sonal Srivastava
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Annapurna Bhattacharjee
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Shubham Dubey
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Shilpi Sharma
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi 110016, India
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Dong H, Wang Y, Di Y, Qiu Y, Ji Z, Zhou T, Shen S, Du N, Zhang T, Dong X, Guo Z, Piao F, Li Y. Plant growth-promoting rhizobacteria Pseudomonas aeruginosa HG28-5 improves salt tolerance by regulating Na +/K + homeostasis and ABA signaling pathway in tomato. Microbiol Res 2024; 283:127707. [PMID: 38582011 DOI: 10.1016/j.micres.2024.127707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 03/19/2024] [Accepted: 03/27/2024] [Indexed: 04/08/2024]
Abstract
Salinity stress badly restricts the growth, yield and quality of vegetable crops. Plant growth-promoting rhizobacteria (PGPR) is a friendly and effective mean to enhance plant growth and salt tolerance. However, information on the regulatory mechanism of PGPR on vegetable crops in response to salt stress is still incomplete. Here, we screened a novel salt-tolerant PGPR strain Pseudomonas aeruginosa HG28-5 by evaluating the tomatoes growth performance, chlorophyll fluorescence index, and relative electrolyte leakage (REL) under normal and salinity conditions. Results showed that HG28-5 colonization improved seedling growth parameters by increasing the plant height (23.7%), stem diameter (14.6%), fresh and dry weight in the shoot (60.3%, 91.1%) and root (70.1%, 92.5%), compared to salt-stressed plants without colonization. Likewise, HG28-5 increased levels of maximum photochemical efficiency of PSII (Fv/Fm) (99.3%), the antioxidant enzyme activities as superoxide dismutase (SOD, 85.5%), peroxidase (POD, 35.2%), catalase (CAT, 20.6%), and reduced the REL (48.2%), MDA content (41.3%) and ROS accumulation in leaves of WT tomatoes under salt stress in comparison with the plants treated with NaCl alone. Importantly, Na+ content of HG28-5 colonized salt-stressed WT plants were decreased by15.5% in the leaves and 26.6% in the roots in the corresponding non-colonized salt-stressed plants, which may be attributed to the higher K+ concentration and SOS1, SOS2, HKT1;2, NHX1 transcript levels in leaves of colonized plants under saline condition. Interestingly, increased abscisic acid (ABA) content and upregulation of ABA pathway genes (ABA synthesis-related genes NCED1, NCED2, NCED4, NECD6 and signal genes ABF4, ABI5, and AREB) were observed in HG28-5 inoculated salt-stressed WT plants. ABA-deficient mutant (not) with NCED1 deficiency abolishes the effect of HG28-5 on alleviating salt stress in tomato, as exhibited by the substantial rise of REL and ROS accumulation and sharp drop of Fv/Fm in the leaves of not mutant plants. Notably, HG28-5 colonization enhances tomatoes fruit yield by 54.9% and 52.4% under normal and saline water irrigation, respectively. Overall, our study shows that HG28-5 colonization can significantly enhance salt tolerance and improved fruit yield by a variety of plant protection mechanism, including reducing oxidative stress, regulating plant growth, Na+/K+ homeostasis and ABA signaling pathways in tomato. The findings not only deepen our understanding of PGPR regulation plant growth and salt tolerance but also allow us to apply HG28-5 as a microbial fertilizer for agricultural production in high-salinity areas.
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Affiliation(s)
- Han Dong
- College of Landscape Architecture and Art, Henan Agricultural University, Zhengzhou 450002, PR China; College of Horticulture, Henan Agricultural University, Zhengzhou 450002, PR China
| | - Yuanyuan Wang
- College of Horticulture, Henan Agricultural University, Zhengzhou 450002, PR China
| | - Yancui Di
- College of Horticulture, Henan Agricultural University, Zhengzhou 450002, PR China
| | - Yingying Qiu
- College of Horticulture, Henan Agricultural University, Zhengzhou 450002, PR China
| | - Zelin Ji
- College of Horticulture, Henan Agricultural University, Zhengzhou 450002, PR China
| | - Tengfei Zhou
- College of Horticulture, Henan Agricultural University, Zhengzhou 450002, PR China
| | - Shunshan Shen
- College of Horticulture, Henan Agricultural University, Zhengzhou 450002, PR China
| | - Nanshan Du
- College of Horticulture, Henan Agricultural University, Zhengzhou 450002, PR China
| | - Tao Zhang
- College of Horticulture, Henan Agricultural University, Zhengzhou 450002, PR China
| | - Xiaoxing Dong
- College of Horticulture, Henan Agricultural University, Zhengzhou 450002, PR China
| | - Zhixin Guo
- College of Horticulture, Henan Agricultural University, Zhengzhou 450002, PR China; International Joint Laboratory of Henan Horticultural Crop Biology, Henan Provincial Facility Horticulture Engineering Technology Research Center, Zhengzhou 450002, PR China.
| | - Fengzhi Piao
- College of Horticulture, Henan Agricultural University, Zhengzhou 450002, PR China; International Joint Laboratory of Henan Horticultural Crop Biology, Henan Provincial Facility Horticulture Engineering Technology Research Center, Zhengzhou 450002, PR China.
| | - Yonghua Li
- College of Landscape Architecture and Art, Henan Agricultural University, Zhengzhou 450002, PR China.
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Luo H, Win CS, Lee DH, He L, Yu JM. Microbacterium azadirachtae CNUC13 Enhances Salt Tolerance in Maize by Modulating Osmotic and Oxidative Stress. BIOLOGY 2024; 13:244. [PMID: 38666856 PMCID: PMC11048422 DOI: 10.3390/biology13040244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 04/03/2024] [Accepted: 04/05/2024] [Indexed: 04/28/2024]
Abstract
Soil salinization is one of the leading threats to global ecosystems, food security, and crop production. Plant growth-promoting rhizobacteria (PGPRs) are potential bioinoculants that offer an alternative eco-friendly agricultural approach to enhance crop productivity from salt-deteriorating lands. The current work presents bacterial strain CNUC13 from maize rhizosphere soil that exerted several PGPR traits and abiotic stress tolerance. The strain tolerated up to 1000 mM NaCl and 30% polyethylene glycol (PEG) 6000 and showed plant growth-promoting (PGP) traits, including the production of indole-3-acetic acid (IAA) and siderophore as well as phosphate solubilization. Phylogenetic analysis revealed that strain CNUC13 was Microbacterium azadirachtae. Maize plants exposed to high salinity exhibited osmotic and oxidative stresses, inhibition of seed germination, plant growth, and reduction in photosynthetic pigments. However, maize seedlings inoculated with strain CNUC13 resulted in significantly improved germination rates and seedling growth under the salt-stressed condition. Specifically, compared with the untreated control group, CNUC13-treated seedlings exhibited increased biomass, including fresh weight and root system proliferation. CNUC13 treatment also enhanced photosynthetic pigments (chlorophyll and carotenoids), reduced the accumulation of osmotic (proline) and oxidative (hydrogen peroxide and malondialdehyde) stress indicators, and positively influenced the activities of antioxidant enzymes (catalase, superoxide dismutase, and peroxidase). As a result, CNUC13 treatment alleviated oxidative stress and promoted salt tolerance in maize. Overall, this study demonstrates that M. azadirachtae CNUC13 significantly enhances the growth of salt-stressed maize seedlings by improving photosynthetic efficiency, osmotic regulators, oxidative stress resilience, and antioxidant enzyme activity. These findings emphasize the potential of utilizing M. azadirachtae CNUC13 as a bioinoculant to enhance salt stress tolerance in maize, providing an environmentally friendly approach to mitigate the negative effects of salinity and promote sustainable agriculture.
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Affiliation(s)
- Huan Luo
- Department of Applied Biology, Chungnam National University, Daejeon 34134, Republic of Korea; (H.L.); (C.S.W.); (D.H.L.); (L.H.)
- College of Resources and Environment, Southwest University, Chongqing 400716, China
| | - Chaw Su Win
- Department of Applied Biology, Chungnam National University, Daejeon 34134, Republic of Korea; (H.L.); (C.S.W.); (D.H.L.); (L.H.)
| | - Dong Hoon Lee
- Department of Applied Biology, Chungnam National University, Daejeon 34134, Republic of Korea; (H.L.); (C.S.W.); (D.H.L.); (L.H.)
| | - Lin He
- Department of Applied Biology, Chungnam National University, Daejeon 34134, Republic of Korea; (H.L.); (C.S.W.); (D.H.L.); (L.H.)
| | - Jun Myoung Yu
- Department of Applied Biology, Chungnam National University, Daejeon 34134, Republic of Korea; (H.L.); (C.S.W.); (D.H.L.); (L.H.)
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Taj Z, Bakka K, Challabathula D. Halotolerant PGPB Staphylococcus sciuri ET101 protects photosynthesis through activation of redox dissipation pathways in Lycopersicon esculentum. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 208:108482. [PMID: 38492488 DOI: 10.1016/j.plaphy.2024.108482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 02/27/2024] [Accepted: 02/29/2024] [Indexed: 03/18/2024]
Abstract
Photosynthesis is known to be seriously affected by salt stress. The stress induced membrane damage leads to disrupted photosynthetic components causing imbalance between production and utilization of ATP/NADPH with generation of ROS leading to photoinhibition and photodamage. In the current study, role of halotolerant plant growth promoting bacteria (PGPB) Staphylococcus sciuri ET101 in protection of photosynthesis in tomato plants during salinity stress was evaluated by analysing changes in antioxidant defense and activation of redox dissipation pathways. Inoculation of S. sciuri ET101 significantly enhanced the growth of tomato plants with significantly higher photosynthetic rates (PN) under normal and salinity stress conditions. Further, increased membrane stability, soluble sugar accumulation and significant decrease in malondialdehyde (MDA) content in leaves of ET101 inoculated tomato plants under normal and salinity were observed along with increased expression of antioxidant genes for efficient ROS detoxification and suppression of oxidative damage. Additionally, salinity induced decrease in rate of photosynthesis (PN) due to lowered chloroplastic CO2 concentration (Cc) attributed by low mesophyll conductance (gm) in uninoculated plants was alleviated by ET101 inoculation showing significantly higher carboxylation rate (Vcmax), RuBP generation (Jmax) and increased photorespiration (PR). The genes involved in photorespiratory process, cyclic electron flow (CEF), and alternative oxidase (AOX) pathway of mitochondrial respiration were abundantly expressed in leaves of ET101 inoculated plants indicating their involvement in protecting photosynthesis from salt stress induced photoinhibition. Collectively, our results indicated that S. sciuri ET101 has the potential in protecting photosynthesis of tomato plants under salinity stress through activation of redox dissipation pathways.
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Affiliation(s)
- Zarin Taj
- Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610 005, India
| | - Kavya Bakka
- Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610 005, India
| | - Dinakar Challabathula
- Department of Life Sciences, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610 005, India; Department of Biotechnology, School of Integrative Biology, Central University of Tamil Nadu, Thiruvarur, 610 005, India.
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Ben Gaied R, Sbissi I, Tarhouni M, Brígido C. Bacterial Endophytes from Legumes Native to Arid Environments Are Promising Tools to Improve Mesorhizobium-Chickpea Symbiosis under Salinity. BIOLOGY 2024; 13:96. [PMID: 38392314 PMCID: PMC10886315 DOI: 10.3390/biology13020096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/26/2024] [Accepted: 02/01/2024] [Indexed: 02/24/2024]
Abstract
Symbiotic nitrogen fixation is a major contributor of N in agricultural ecosystems, but the establishment of legume-rhizobium symbiosis is highly affected by soil salinity. Our interest is focused on the use of non-rhizobial endophytes to assist the symbiosis between chickpea and its microsymbiont under salinity to avoid loss of production and fertility. Our aims were (1) to investigate the impact of salinity on both symbiotic partners; including on early events of the Mesorhizobium-chickpea symbiosis, and (2) to evaluate the potential of four non-rhizobial endophytes isolated from legumes native to arid regions (Phyllobacterium salinisoli, P. ifriqiyense, Xanthomonas translucens, and Cupriavidus respiraculi) to promote chickpea growth and nodulation under salinity. Our results show a significant reduction in chickpea seed germination rate and in the microsymbiont Mesorhizobium ciceri LMS-1 growth under different levels of salinity. The composition of phenolic compounds in chickpea root exudates significantly changed when the plants were subjected to salinity, which in turn affected the nod genes expression in LMS-1. Furthermore, the LMS-1 response to root exudate stimuli was suppressed by the presence of salinity (250 mM NaCl). On the contrary, a significant upregulation of exoY and otsA genes, which are involved in exopolysaccharide and trehalose biosynthesis, respectively, was registered in salt-stressed LMS-1 cells. In addition, chickpea co-inoculation with LMS-1 along with the consortium containing two non-rhizobial bacterial endophytes, P. salinisoli and X. translucens, resulted in significant improvement of the chickpea growth and the symbiotic performance of LMS-1 under salinity. These results indicate that this non-rhizobial endophytic consortium may be an appropriate ecological and safe tool to improve chickpea growth and its adaptation to salt-degraded soils.
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Affiliation(s)
- Roukaya Ben Gaied
- Laboratory of Pastoral Ecosystems and Promotion of Spontaneous Plants and Associated Micro-Organisms, Institute of Arid Lands, University of Gabes, Medenine 4119, Tunisia
- MED-Mediterranean Institute for Agriculture, Environment and Development, Universidade de Évora, Pólo da Mitra, Ap. 94, 7006-554 Évora, Portugal
| | - Imed Sbissi
- Laboratory of Pastoral Ecosystems and Promotion of Spontaneous Plants and Associated Micro-Organisms, Institute of Arid Lands, University of Gabes, Medenine 4119, Tunisia
| | - Mohamed Tarhouni
- Laboratory of Pastoral Ecosystems and Promotion of Spontaneous Plants and Associated Micro-Organisms, Institute of Arid Lands, University of Gabes, Medenine 4119, Tunisia
| | - Clarisse Brígido
- MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE-Global Change and Sustainability Institute, Institute for Advanced Studies and Research, Universidade de Évora, Pólo da Mitra, Ap. 94, 7006-554 Évora, Portugal
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Wang M, Sun H, Xu Z. Characterization of Rhizosphere Microbial Diversity and Selection of Plant-Growth-Promoting Bacteria at the Flowering and Fruiting Stages of Rapeseed. PLANTS (BASEL, SWITZERLAND) 2024; 13:329. [PMID: 38276786 PMCID: PMC10819753 DOI: 10.3390/plants13020329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 01/27/2024]
Abstract
Plant rhizosphere microorganisms play an important role in modulating plant growth and productivity. This study aimed to elucidate the diversity of rhizosphere microorganisms at the flowering and fruiting stages of rapeseed (Brassica napus). Microbial communities in rhizosphere soils were analyzed via high-throughput sequencing of 16S rRNA for bacteria and internal transcribed spacer (ITS) DNA regions for fungi. A total of 401 species of bacteria and 49 species of fungi in the rhizosphere soil samples were found in three different samples. The composition and diversity of rhizosphere microbial communities were significantly different at different stages of rapeseed growth. Plant-growth-promoting rhizobacteria (PGPRs) have been widely applied to improve plant growth, health, and production. Thirty-four and thirty-one PGPR strains were isolated from the rhizosphere soil samples collected at the flowering and fruiting stages of rapeseed, respectively. Different inorganic phosphorus- and silicate-solubilizing and auxin-producing capabilities were found in different strains, in addition to different heavy-metal resistances. This study deepens the understanding of the microbial diversity in the rapeseed rhizosphere and provides a microbial perspective of sustainable rapeseed cultivation.
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Affiliation(s)
- Mengjiao Wang
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong 723000, China;
- Collaborative Innovation Center for Comprehensive Development of Biological Resources in Qinling-Ba Mountains, Hanzhong 723000, China
- Shaanxi Key Laboratory Bioresources, Hanzhong 723000, China
| | - Haiyan Sun
- School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong 723000, China;
- Shaanxi Key Laboratory Bioresources, Hanzhong 723000, China
| | - Zhimin Xu
- School of Nutrition and Food Sciences, Louisiana State University, Baton Rouge, LA 70809, USA;
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Giannelli G, Mattarozzi M, Gentili S, Fragni R, Maccari C, Andreoli R, Visioli G. A novel PGPR strain homologous to Beijerinckia fluminensis induces biochemical and molecular changes involved in Arabidopsis thaliana salt tolerance. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 206:108187. [PMID: 38100889 DOI: 10.1016/j.plaphy.2023.108187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 10/17/2023] [Accepted: 11/08/2023] [Indexed: 12/17/2023]
Abstract
The use of PGPR is widely accepted as a promising tool for a more sustainable agricultural production and improved plant abiotic stress resistance. This study tested the ability of PVr_9, a novel bacterial strain, homologous to Beijerinckia fluminensis, to increase salt stress tolerance in A. thaliana. In vitro plantlets inoculated with PVr_9 and treated with 150 mM NaCl showed a reduction in primary root growth inhibition compared to uninoculated ones, and a leaf area significantly less affected by salt. Furthermore, salt-stressed PVr_9-inoculated plants had low ROS and 8-oxo-dG, osmolytes, and ABA content along with a modulation in antioxidant enzymatic activities. A significant decrease in Na+ in the leaves and a corresponding increase in the roots were also observed in salt-stressed inoculated plants. SOS1, NHX1 genes involved in plant salt tolerance, were up-regulated in PVr_9-inoculated plants, while different MYB genes involved in salt stress signal response were down-regulated in both roots and shoots. Thus, PVr_9 was able to increase salt tolerance in A. thaliana, thereby suggesting a role in ion homeostasis by reducing salt stress rather than inhibiting total Na+ uptake. These results showed a possible molecular mechanism of crosstalk between PVr_9 and plant roots to enhance salt tolerance, and highlighted this bacterium as a promising PGPR for field applications on agronomical crops.
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Affiliation(s)
- Gianluigi Giannelli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Monica Mattarozzi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Silvia Gentili
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy
| | - Rosaria Fragni
- SSICA, Experimental Station for the Food Preserving Industry, Parma, Italy
| | - Chiara Maccari
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Roberta Andreoli
- Department of Medicine and Surgery, University of Parma, Parma, Italy; Centre for Research in Toxicology (CERT), University of Parma, Parma, Italy
| | - Giovanna Visioli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy.
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BiBi A, Bibi S, Al-Ghouti MA, Abu-Dieyeh MH. Isolation and evaluation of Qatari soil rhizobacteria for antagonistic potential against phytopathogens and growth promotion in tomato plants. Sci Rep 2023; 13:22050. [PMID: 38086854 PMCID: PMC10716397 DOI: 10.1038/s41598-023-49304-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 12/06/2023] [Indexed: 12/18/2023] Open
Abstract
Plant growth promoting rhizobacteria are a diverse group of microorganisms that enhance the growth of plants under various conditions. In this study, 55 isolates of endogenous rhizobacteria were collected from the rhizosphere of Avicennia marina, Suaeda vermiculata, Salsola soda, Anabasis setifera, Salicornia europaea, Arthrocnemum macrostachyum, Limonium axillare, Tetraena qatarensis, Aeluropus lagopoides, and Prosopis juliflora. The isolates were evaluated in-vitro for their antagonist potential against Fusarium oxysporum and Botrytis cinerea using the dual culture technique, where the maximum growth inhibition reached 49% and 57%, respectively. In-vivo evaluation was accomplished to determine the growth-promoting potential of the rhizobacteria under greenhouse conditions where the strain ANABR3 (Bacillus subtilis) showed the strongest growth-promoting effects. Further in-vivo testing regarding the effectiveness of rhizobacteria in the presence of the phytopathogen was also completed using the Hoagland medium. LEMR3 and SALIR5 (both identified as two strains of B. subtilis) supported the tomato seedlings to overcome the disease and significantly (p ≤ 0.05) increased above and belowground biomass compared to the control. Additionally, several characterizing tests were carried out on the selected strains, these strains were found to possess numerous features that promote plant growth directly and indirectly such as the production of IAA, HCN, hydrolytic enzymes, ACC deaminase, NH3, and some rhizobacteria were capable of phosphate solubilization. In conclusion, this study showed that local rhizobacterial isolates collected from arid lands possess valuable traits, making them promising bio-control agents and bio-fertilizers for agricultural purposes.
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Affiliation(s)
- Amina BiBi
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, P.O. Box: 2713, Doha, Qatar
| | - Shazia Bibi
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, P.O. Box: 2713, Doha, Qatar
| | - Mohammad A Al-Ghouti
- Environmental Science Program, Department of Biological and Environmental Sciences, College of Arts and Scieances, Qatar University, P.O. Box: 2713, Doha, Qatar
| | - Mohammed H Abu-Dieyeh
- Biological Science Program, Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, P.O. Box: 2713, Doha, Qatar.
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Guo X, Peng W, Xu X, Xie K, Yang X. The Potential of Endophytes in Improving Salt-Alkali Tolerance and Salinity Resistance in Plants. Int J Mol Sci 2023; 24:16917. [PMID: 38069239 PMCID: PMC10706814 DOI: 10.3390/ijms242316917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/17/2023] [Accepted: 11/01/2023] [Indexed: 12/18/2023] Open
Abstract
Ensuring food security for the global population is a ceaseless and critical issue. However, high-salinity and high-alkalinity levels can harm agricultural yields throughout large areas, even in largely agricultural countries, such as China. Various physical and chemical treatments have been employed in different locations to mitigate high salinity and alkalinity but their effects have been minimal. Numerous researchers have recently focused on developing effective and environmentally friendly biological treatments. Endophytes, which are naturally occurring and abundant in plants, retain many of the same characteristics of plants owing to their simultaneous evolution. Therefore, extraction of endophytes from salt-tolerant plants for managing plant growth in saline-alkali soils has become an important research topic. This extraction indicates that the soil environment can be fundamentally improved, and the signaling pathways of plants can be altered to increase their defense capacity, and can even be inherited to ensure lasting efficacy. This study discusses the direct and indirect means by which plant endophytes mitigate the effects of plant salinity stress that have been observed in recent years.
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Affiliation(s)
- Xueying Guo
- College of Pharmacy, Chengdu University, Chengdu 610106, China; (X.G.); (W.P.); (X.X.); (K.X.)
- College of Life Sciences, Chongqing Normal University, Chongqing 401331, China
| | - Wanrong Peng
- College of Pharmacy, Chengdu University, Chengdu 610106, China; (X.G.); (W.P.); (X.X.); (K.X.)
- College of Life Sciences, Chongqing Normal University, Chongqing 401331, China
| | - Xinyi Xu
- College of Pharmacy, Chengdu University, Chengdu 610106, China; (X.G.); (W.P.); (X.X.); (K.X.)
| | - Kangwei Xie
- College of Pharmacy, Chengdu University, Chengdu 610106, China; (X.G.); (W.P.); (X.X.); (K.X.)
| | - Xingyong Yang
- College of Pharmacy, Chengdu University, Chengdu 610106, China; (X.G.); (W.P.); (X.X.); (K.X.)
- Antibiotics Research and Re-Evaluation Key Laboratory of Sichuan Province, Chengdu University, Chengdu 610106, China
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Xiao S, Wan Y, Zheng Y, Wang Y, Fan J, Xu Q, Gao Z, Wu C. Halomonas ventosae JPT10 promotes salt tolerance in foxtail millet ( Setaria italica) by affecting the levels of multiple antioxidants and phytohormones. PLANT-ENVIRONMENT INTERACTIONS (HOBOKEN, N.J.) 2023; 4:275-290. [PMID: 37822729 PMCID: PMC10564379 DOI: 10.1002/pei3.10122] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/31/2023] [Accepted: 08/05/2023] [Indexed: 10/13/2023]
Abstract
Plant growth-promoting bacterias (PGPBs) can increase crop output under normal and abiotic conditions. However, the mechanisms underlying the plant salt tolerance-promoting role of PGPBs still remain largely unknown. In this study, we demonstrated that Halomonas ventosae JPT10 promoted the salt tolerance of both dicots and monocots. Physiological analysis revealed that JPT10 reduced reactive oxygen species accumulation by improving the antioxidant capability of foxtail millet seedlings. The metabolomic analysis of JPT10-inoculated foxtail millet seedlings led to the identification of 438 diversely accumulated metabolites, including flavonoids, phenolic acids, lignans, coumarins, sugar, alkaloids, organic acids, and lipids, under salt stress. Exogenous apigenin and chlorogenic acid increased the salt tolerance of foxtail millet seedlings. Simultaneously, JPT10 led to greater amounts of abscisic acid (ABA), indole-3-acetic acid (IAA), salicylic acid (SA), and their derivatives but lower levels of 12-oxo-phytodienoic acid (OPDA), jasmonate (JA), and JA-isoleucine (JA-Ile) under salt stress. Exogenous JA, methyl-JA, and OPDA intensified, whereas ibuprofen or phenitone, two inhibitors of JA and OPDA biosynthesis, partially reversed, the growth inhibition of foxtail millet seedlings caused by salt stress. Our results shed light on the response of foxtail millet seedlings to H. ventosae under salt stress and provide potential compounds to increase salt tolerance in foxtail millet and other crops.
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Affiliation(s)
- Shenghui Xiao
- National Key Laboratory of Wheat Improvement, Shandong Engineering Research Center of Plant‐Microbial Restoration for Saline‐Alkali Land, College of Life SciencesShandong Agricultural UniversityTai'anShandong provinceChina
| | - Yiman Wan
- National Key Laboratory of Wheat Improvement, Shandong Engineering Research Center of Plant‐Microbial Restoration for Saline‐Alkali Land, College of Life SciencesShandong Agricultural UniversityTai'anShandong provinceChina
| | - Yue Zheng
- National Key Laboratory of Wheat Improvement, Shandong Engineering Research Center of Plant‐Microbial Restoration for Saline‐Alkali Land, College of Life SciencesShandong Agricultural UniversityTai'anShandong provinceChina
| | - Yongdong Wang
- National Key Laboratory of Wheat Improvement, Shandong Engineering Research Center of Plant‐Microbial Restoration for Saline‐Alkali Land, College of Life SciencesShandong Agricultural UniversityTai'anShandong provinceChina
| | - Jiayin Fan
- National Key Laboratory of Wheat Improvement, Shandong Engineering Research Center of Plant‐Microbial Restoration for Saline‐Alkali Land, College of Life SciencesShandong Agricultural UniversityTai'anShandong provinceChina
| | - Qian Xu
- National Key Laboratory of Wheat Improvement, Shandong Engineering Research Center of Plant‐Microbial Restoration for Saline‐Alkali Land, College of Life SciencesShandong Agricultural UniversityTai'anShandong provinceChina
| | - Zheng Gao
- National Key Laboratory of Wheat Improvement, Shandong Engineering Research Center of Plant‐Microbial Restoration for Saline‐Alkali Land, College of Life SciencesShandong Agricultural UniversityTai'anShandong provinceChina
| | - Changai Wu
- National Key Laboratory of Wheat Improvement, Shandong Engineering Research Center of Plant‐Microbial Restoration for Saline‐Alkali Land, College of Life SciencesShandong Agricultural UniversityTai'anShandong provinceChina
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