1
|
Dessauvages K, Scheifler M, Francis F, Ben Fekih I. A New Isolate Beauveria bassiana GxABT-1: Efficacy against Myzus persicae and Promising Impact on the Beet Mild Yellow Virus-Aphid Association. INSECTS 2024; 15:697. [PMID: 39336665 PMCID: PMC11432153 DOI: 10.3390/insects15090697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2024] [Revised: 09/06/2024] [Accepted: 09/10/2024] [Indexed: 09/30/2024]
Abstract
Within the context of ecofriendly alternatives to neonicotinoids, we explored the direct and endophytic potential of two Beauveria bassiana isolates, GHA from BotaniGard and the new endemic isolate GxABT-1, against the Sugar Beet Mild Yellow Virus (BMYV)-Myzus persicae pathosystem. A mortality rate of 96 and 91% was registered after 8 days of treatment with GHA and Gx-ABT-1, respectively. To assess the endophytic impact, sugar beet seeds were treated, and the ability of the fungi to colonize the plant was assessed and correlated with the aphids' (1) life cycle, (2) attraction towards the plants, and (3) ability to transmit BMYV. Both fungi colonized the plants, and the GxABT-1 isolate impaired the aphids' life cycle. Myzus persicae were more attracted to leaf discs from non-treated plants than to the fungal-treated ones. Interestingly, when the choice test dealt only with the fungal treatments, aphids were more attracted to leaves from plants harboring Gx-ABT-1 than those with GHA. Moreover, no significant impact was observed for BMYV transmission despite the slight decrease in the viral load in GxABT-1 isolate-treated plants. Our findings constitute a baseline to delve more into the performance of the new endemic isolate B. bassiana in other pathosystems using different treatment methods.
Collapse
Affiliation(s)
- Kenza Dessauvages
- Functional and Evolutionary Entomology, Terra, Gembloux Agro-Bio Tech, University of Liege, Passage des Déportés 2, 5030 Gembloux, Belgium
| | - Mathilde Scheifler
- Evolution and Ecophysiology Group, Functional and Evolutionary Entomology, Terra, Gembloux Agro-Bio Tech, University of Liege, 5030 Gembloux, Belgium
| | - Frédéric Francis
- Functional and Evolutionary Entomology, Terra, Gembloux Agro-Bio Tech, University of Liege, Passage des Déportés 2, 5030 Gembloux, Belgium
| | - Ibtissem Ben Fekih
- Functional and Evolutionary Entomology, Terra, Gembloux Agro-Bio Tech, University of Liege, Passage des Déportés 2, 5030 Gembloux, Belgium
| |
Collapse
|
2
|
George J, Glover JP, Perera OP, Reddy GVP. Role of Endophytic Entomopathogenic Fungi in Mediating Host Selection, Biology, Behavior, and Management of Tarnished Plant Bug, Lygus lineolaris (Hemiptera: Miridae). PLANTS (BASEL, SWITZERLAND) 2024; 13:2012. [PMID: 39124130 PMCID: PMC11313774 DOI: 10.3390/plants13152012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2024] [Revised: 07/19/2024] [Accepted: 07/21/2024] [Indexed: 08/12/2024]
Abstract
Non-insecticidal control strategies using entomopathogens, nematodes, and endophytes provide sustainable and safer alternatives for managing crop pests. This study investigated the potential of different fungal endophytes, specifically Beauveria bassiana strains, in colonizing cotton plants and their efficacy against tarnished plant bug, Lygus lineolaris. The effect of endophytes on plant growth parameters and cotton yield were measured during different plant growth stages. The entomopathogenicity of these fungi was studied in diet cup bioassays using L. lineolaris adults. The behavior of adult males and females toward endophytic cotton squares was analyzed using olfactometer assays. The experiments showed that the fungal endophytes colonized the plant structures of cotton plants, which resulted in an increase in the number of cotton squares, plant height, and weight compared to control plants. B. bassiana strains/isolates such as GHA, NI-8, and JG-1 caused significant mortality in Lygus adults compared to controls. Also, male and female Lygus adults exhibited repellence behavior towards endophytic cotton squares containing JG-1 isolate of B. bassiana and to other B. bassiana strains such as NI-8, GHA, and SPE-120. No differences were observed in the survival and development of L. lineolaris second-instar nymphs on endophytic cotton, and no yield differences were observed in the field experiments.
Collapse
Affiliation(s)
- Justin George
- Southern Insect Management Research Unit, Agricultural Research Service, United States Department of Agriculture, Stoneville, MS 38776, USA; (J.P.G.); (O.P.P.); (G.V.P.R.)
| | | | | | | |
Collapse
|
3
|
Cunha JCS, Rivera Vega LJ, Torres JB, Suh CPC, Sword GA. Fungal seed treatments of cotton affect boll weevil development. PEST MANAGEMENT SCIENCE 2024; 80:1566-1576. [PMID: 37966378 DOI: 10.1002/ps.7890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 10/17/2023] [Accepted: 11/15/2023] [Indexed: 11/16/2023]
Abstract
BACKGROUND Nonpathogenic fungi associated with plants can enhance plant defenses against stress factors, including herbivory. This study assessed whether cotton plants grown from seeds treated with different fungi affected boll weevil, Anthonomus grandis grandis Boheman, development and reproduction along with plant tolerance. We used whole plants grown from seeds treated with different fungi (Chaetomium globosum TAMU520 and TAMU559, Phialemonium inflatum TAMU490, and Beauveria bassiana) versus non-treated controls to test insect growth, reproduction, and plant tolerance assays in a greenhouse. RESULTS Regarding boll weevil reproduction, fewer larvae hatched and fewer adults emerged from fungal-treated plants. In addition, the developmental time from oviposition to adult emergence was delayed in the plants treated with all fungi. For plant tolerance, B. bassiana-treated plants attacked by boll weevils shed fewer squares than nonfungal-treated plants. CONCLUSION Fungal treatments can affect boll weevil performance and reproduction on cotton plants, with potentially negative effects on population growth. Collectively, these results support the potential for cottonseed treatments with fungi as a novel tool for boll weevil management in the field. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Collapse
Affiliation(s)
- Janaina C S Cunha
- Department of Entomology, Texas A&M University, College Station, Texas, USA
| | - Loren J Rivera Vega
- Department of Entomology, Texas A&M University, College Station, Texas, USA
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Jorge B Torres
- Departamento de Agronomia-Entomologia, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | - Charles P C Suh
- Insect Control and Cotton Disease Research Unit, USDA-ARS, College Station, Texas, USA
| | - Gregory A Sword
- Department of Entomology, Texas A&M University, College Station, Texas, USA
| |
Collapse
|
4
|
Wilberts L, Vuts J, Caulfield JC, Thomas G, Withall DM, Wäckers F, Birkett MA, Jacquemyn H, Lievens B. Effects of root inoculation of entomopathogenic fungi on olfactory-mediated behavior and life-history traits of the parasitoid Aphidius ervi (Haliday) (Hymenoptera: Braconidae). PEST MANAGEMENT SCIENCE 2024; 80:307-316. [PMID: 37682693 DOI: 10.1002/ps.7762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 08/23/2023] [Accepted: 09/08/2023] [Indexed: 09/10/2023]
Abstract
BACKGROUND Although most biological control programs use multiple biological agents to manage pest species, to date only a few programs have combined the use of agents from different guilds. Using sweet pepper (Capsicum annuum L.), the entomopathogenic fungus Akanthomyces muscarius ARSEF 5128, the tobacco peach aphid Myzus persicae var. nicotianae and the aphid parasitoid Aphidius ervi as the experimental model, we explored whether root inoculation with an entomopathogenic fungus is compatible with parasitoid wasps for enhanced biocontrol of aphids. RESULTS In dual-choice behavior experiments, A. ervi was significantly attracted to the odor of M. persicae-infested C. annuum plants that had been inoculated with A. muscarius, compared to noninoculated infested plants. There was no significant difference in attraction to the odor of uninfested plants. Myzus persicae-infested plants inoculated with A. muscarius emitted significantly higher amounts of indole, (E)-nerolidol, (3E,7E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene and one unidentified terpene compared to noninoculated infested plants. Coupled gas chromatography-electroantennography, using the antennae of A. ervi, confirmed the physiological activity of these elevated compounds. Inoculation of plants with A. muscarius did not affect parasitism rate nor parasitoid longevity, but significantly increased the speed of mummy formation in parasitized aphids on fungus-inoculated plants. CONCLUSION Our data suggest that root inoculation of C. annuum with A. muscarius ARSEF 5128 alters the olfactory-mediated behavior of parasitoids, but has little effect on parasitism efficiency or life-history parameters. However, increased attraction of parasitoids towards M. persicae-infested plants when inoculated by entomopathogenic fungi can accelerate host localization and hence improve biocontrol efficacy. © 2023 Society of Chemical Industry.
Collapse
Affiliation(s)
- Liesbet Wilberts
- CMPG Laboratory for Process Microbial Ecology and Bioinspirational Management, Department of Microbial and Molecular Systems, KU Leuven, Leuven, Belgium
- Leuven Plant Institute, KU Leuven, Leuven, Belgium
| | - József Vuts
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, UK
| | - John C Caulfield
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, UK
| | - Gareth Thomas
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, UK
| | - David M Withall
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, UK
| | - Felix Wäckers
- Biobest, Westerlo, Belgium
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Michael A Birkett
- Protecting Crops and the Environment, Rothamsted Research, Harpenden, UK
| | - Hans Jacquemyn
- Leuven Plant Institute, KU Leuven, Leuven, Belgium
- Laboratory of Plant Conservation and Population Biology, Biology Department, KU Leuven, Leuven, Belgium
| | - Bart Lievens
- CMPG Laboratory for Process Microbial Ecology and Bioinspirational Management, Department of Microbial and Molecular Systems, KU Leuven, Leuven, Belgium
- Leuven Plant Institute, KU Leuven, Leuven, Belgium
| |
Collapse
|
5
|
Meesters C, Weldegergis BT, Dicke M, Jacquemyn H, Lievens B. Limited effects of plant-beneficial fungi on plant volatile composition and host-choice behavior of Nesidiocoris tenuis. FRONTIERS IN PLANT SCIENCE 2024; 14:1322719. [PMID: 38235197 PMCID: PMC10791865 DOI: 10.3389/fpls.2023.1322719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 12/11/2023] [Indexed: 01/19/2024]
Abstract
Biological control using plant-beneficial fungi has gained considerable interest as a sustainable method for pest management, by priming the plant for enhanced defense against pathogens and insect herbivores. However, despite promising outcomes, little is known about how different fungal strains mediate these beneficial effects. In this study, we evaluated whether inoculation of tomato seeds with the plant-beneficial fungi Beauveria bassiana ARSEF 3097, Metarhizium brunneum ARSEF 1095 and Trichoderma harzianum T22 affected the plant's volatile organic compound (VOC) profile and the host-choice behavior of Nesidiocoris tenuis, an emerging pest species in NW-European tomato cultivation, and the related zoophytophagous biocontrol agent Macrolophus pygmaeus. Results indicated that fungal inoculation did not significantly alter the VOC composition of tomato plants. However, in a two-choice cage assay where female insects were given the option to select between control plants and fungus-inoculated plants, N. tenuis preferred control plants over M. brunneum-inoculated plants. Nearly 72% of all N. tenuis individuals tested chose the control treatment. In all other combinations tested, no significant differences were found for none of the insects. We conclude that inoculation of tomato with plant-beneficial fungi had limited effects on plant volatile composition and host-choice behavior of insects. However, the observation that N. tenuis was deterred from the crop when inoculated with M. brunneum and attracted to non-inoculated plants may provide new opportunities for future biocontrol based on a push-pull strategy.
Collapse
Affiliation(s)
- Caroline Meesters
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), Department of Microbial and Molecular Systems (MS), KU Leuven, Leuven, Belgium
- Leuven Plant Institute (LPI), KU Leuven, Leuven, Belgium
| | | | - Marcel Dicke
- Laboratory of Entomology, Wageningen University & Research, Wageningen, Netherlands
| | - Hans Jacquemyn
- Leuven Plant Institute (LPI), KU Leuven, Leuven, Belgium
- Laboratory of Plant Conservation and Population Biology, Biology Department, KU Leuven, Leuven, Belgium
| | - Bart Lievens
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), Department of Microbial and Molecular Systems (MS), KU Leuven, Leuven, Belgium
- Leuven Plant Institute (LPI), KU Leuven, Leuven, Belgium
| |
Collapse
|
6
|
Wilberts L, Vuts J, Caulfield JC, Thomas G, Birkett MA, Herrera-Malaver B, Verstrepen KJ, Sobhy IS, Jacquemyn H, Lievens B. Impact of endophytic colonization by entomopathogenic fungi on the behavior and life history of the tobacco peach aphid Myzus persicae var. nicotianae. PLoS One 2022; 17:e0273791. [PMID: 36067150 PMCID: PMC9447930 DOI: 10.1371/journal.pone.0273791] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/16/2022] [Indexed: 11/19/2022] Open
Abstract
Entomopathogenic fungi can adopt an endophytic lifestyle and provide protection against insect herbivores and plant pathogens. So far, most studies have focused on Beauveria bassiana to increase plant resistance against abiotic and biotic stresses, while only little is known for other entomopathogenic fungi. In this study, we investigated whether root inoculation of sweet pepper (Capsicum annuum L.) by the entomopathogenic fungi Akanthomyces muscarius ARSEF 5128 and B. bassiana ARSEF 3097 can improve resistance against the tobacco peach aphid Myzus persicae var. nicotianae. First, dual-choice experiments were performed to test the hypothesis that the fungi deter aphids via modifying plant volatile profiles. Next, we tested the hypothesis that endophytic colonization negatively affects aphid life history traits, such as fecundity, development and mortality rate. Aphids were significantly attracted to the odor of plants inoculated with A. muscarius over non-inoculated plants. Plants inoculated with A. muscarius emitted significantly higher amounts of β-pinene than non-inoculated plants, and significantly higher amounts of indole than B. bassiana-inoculated and non-inoculated plants. Inoculation with the fungal strains also caused significantly higher emission of terpinolene. Further, both aphid longevity and fecundity were significantly reduced by 18% and 10%, respectively, when feeding on plants inoculated with A. muscarius, although intrinsic rate of population increase did not differ between inoculated and non-inoculated plants. Sweet pepper plants inoculated with B. bassiana ARSEF 3097 did not elicit a significant behavioral response nor affected the investigated life history traits. We conclude that endophytic colonization by entomopathogenic fungi has the potential to alter olfactory behavior and performance of M. persicae var. nicotianae, but effects are small and depend on the fungal strain used.
Collapse
Affiliation(s)
- Liesbet Wilberts
- Department of Microbial and Molecular Systems (M2S), CMPG Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), KU Leuven, Leuven, Belgium
- Leuven Plant Institute (LPI), KU Leuven, Leuven, Belgium
| | - József Vuts
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - John C. Caulfield
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Gareth Thomas
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Michael A. Birkett
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Beatriz Herrera-Malaver
- Department M2S, CMPG Laboratory of Genetics and Genomics, KU Leuven, Leuven, Belgium
- Flanders Institute for Biotechnology (VIB), KU Leuven Center for Microbiology, Leuven, Belgium
| | - Kevin J. Verstrepen
- Department M2S, CMPG Laboratory of Genetics and Genomics, KU Leuven, Leuven, Belgium
- Flanders Institute for Biotechnology (VIB), KU Leuven Center for Microbiology, Leuven, Belgium
| | - Islam S. Sobhy
- Department of Microbial and Molecular Systems (M2S), CMPG Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), KU Leuven, Leuven, Belgium
- Faculty of Agriculture, Department of Plant Protection, Suez Canal University, Ismailia, Egypt
| | - Hans Jacquemyn
- Leuven Plant Institute (LPI), KU Leuven, Leuven, Belgium
- Laboratory of Plant Conservation and Population Biology, Biology Department, KU Leuven, Leuven, Belgium
| | - Bart Lievens
- Department of Microbial and Molecular Systems (M2S), CMPG Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), KU Leuven, Leuven, Belgium
- Leuven Plant Institute (LPI), KU Leuven, Leuven, Belgium
| |
Collapse
|
7
|
Assessing the Endophytic Potential of a Commercially Available Entomopathogenic Beauveria bassiana Strain in Various Citrus Rootstocks. Appl Microbiol 2022. [DOI: 10.3390/applmicrobiol2030044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The citrus industry is challenged by numerous arthropods, yet extensive research has not been conducted to determine the potential use of entomopathogenic fungi as endophytes in pest management strategies. Two inoculation methods (i.e., soil drench and foliar spray) using a suspension of Beauveria bassiana (strain PPRI 5339 contained in Velifer®) containing 4 × 107 conidia mL−1 in 0.01% Tween 80 were conducted on three commercially available citrus rootstocks (i.e., ‘US-942’, ‘US-812’, ‘Swingle’). Seedlings were grown under greenhouse-controlled conditions over a 7-week observation period. Similarly, a third inoculation method (seed soaking) was conducted using seeds from the same three rootstocks. The fungus was re-isolated post-inoculation from ‘US-942’ and ‘US-812’ in the foliar spray and seed soaking treatments. In addition, the fungus was recovered from root tissue in the foliar-sprayed seedlings, suggesting possible systemic movement from leaves to roots. The fungus was not recovered from soil-drench-treated seedlings, nor from any of the ‘Swingle’ cultivars. This study assessed the potential of B. bassiana to endophytically colonize certain citrus rootstocks in planta.
Collapse
|
8
|
Gupta R, Keppanan R, Leibman-Markus M, Rav-David D, Elad Y, Ment D, Bar M. The Entomopathogenic Fungi Metarhizium brunneum and Beauveria bassiana Promote Systemic Immunity and Confer Resistance to a Broad Range of Pests and Pathogens in Tomato. PHYTOPATHOLOGY 2022; 112:784-793. [PMID: 34636647 DOI: 10.1094/phyto-08-21-0343-r] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Biocontrol agents can control pathogens by reenforcing systemic plant resistance through systemic acquired resistance (SAR) or induced systemic resistance (ISR). Trichoderma spp. can activate the plant immune system through ISR, priming molecular mechanisms of defense against pathogens. Entomopathogenic fungi (EPF) can infect a wide range of arthropod pests and play an important role in reducing pests' population. Here, we investigated the mechanisms by which EPF control plant diseases. We tested two well studied EPF, Metarhizium brunneum isolate Mb7 and Beauveria bassiana as the commercial product Velifer, for their ability to induce systemic immunity and disease resistance against several fungal and bacterial phytopathogens, and their ability to promote plant growth. We compared the activity of these EPF to an established biocontrol agent, Trichoderma harzianum T39, a known inducer of systemic plant immunity and broad disease resistance. The three fungal agents were effective against several fungal and bacterial plant pathogens and arthropod pests. Our results indicate that EPF induce systemic plant immunity and disease resistance by activating the plant host defense machinery, as evidenced by increases in reactive oxygen species production and defense gene expression, and that EPF promote plant growth. EPF should be considered as control means for Tuta absoluta. We demonstrate that, with some exceptions, biocontrol in tomato can be equally potent by the tested EPF and T. harzianum T39, against both insect pests and plant pathogens. Taken together, our findings suggest that EPF may find use in broad-spectrum pest and disease management and as plant growth promoting agents.
Collapse
Affiliation(s)
- Rupali Gupta
- Department of Plant Pathology and Weed Research, Plant Protection Institute, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Ravindran Keppanan
- Department of Plant Pathology and Weed Research, Plant Protection Institute, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Meirav Leibman-Markus
- Department of Plant Pathology and Weed Research, Plant Protection Institute, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Dalia Rav-David
- Department of Plant Pathology and Weed Research, Plant Protection Institute, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Yigal Elad
- Department of Plant Pathology and Weed Research, Plant Protection Institute, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Dana Ment
- Department of Plant Pathology and Weed Research, Plant Protection Institute, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| | - Maya Bar
- Department of Plant Pathology and Weed Research, Plant Protection Institute, Agricultural Research Organization, Volcani Institute, Rishon LeZion, Israel
| |
Collapse
|
9
|
Olfactometer Responses of Convergent Lady Beetles Hippodamia convergens (Coleoptera: Coccinellidae) to Odor Cues from Aphid-Infested Cotton Plants Treated with Plant-Associated Fungi. INSECTS 2022; 13:insects13020157. [PMID: 35206730 PMCID: PMC8876858 DOI: 10.3390/insects13020157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/14/2022] [Accepted: 01/25/2022] [Indexed: 12/04/2022]
Abstract
Simple Summary The cotton aphid Aphis gossypii is a serious agricultural pest. Microbes associated with plants can affect the behavior and performance of insect herbivores and their natural enemies. Phialemonium inflatum and Chaetomium globosum fungi can reduce cotton aphid reproduction when applied as a seed treatment to cotton. We evaluated whether these fungi might affect the interaction between cotton aphids and a natural enemy, the convergent lady beetle Hippodamia convergens. We used dual-choice olfactometer experiments to assess lady beetle behavioral responses to cues from fungal-treated cotton plants in the presence or absence of aphid infestations. In the absence of fungal treatments, males preferred odors from aphid-infested relative to non-infested plants, and females spent more time associated with olfactory stimuli from aphid-infested versus non-infested plants. When cues from fungal-treated plants infested with aphids were assessed, there were no differences in lady beetle responses. The only fungal treatment-related effects involved plants without aphids. In the absence of aphids, males responded slower to P. inflatum-treated plants compared to control, and females preferred P. inflatum-treated plants. Treating cotton with these potentially beneficial fungi had minor effects on lady beetle behavioral responses and would not be expected to disrupt this predator–prey–plant interaction as part of an integrated pest management strategy. Abstract Microbes have the potential to affect multitrophic plant–insect–predator interactions. We examined whether cotton plants treated with potentially beneficial fungi affect interactions between cotton aphids Aphis gossypii and predatory lady beetles Hippodamia convergens. We used Y-tube olfactometer assays to test lady beetle behavioral responses to stimuli emitted by aphid-infested and non-infested cotton plants grown from seeds treated with either Phialemonium inflatum (TAMU490) or Chaetomium globosum (TAMU520) versus untreated control plants. We tested a total of 960 lady beetles (480 males and 480 females) that had been deprived of food for approximately 24 h. In the absence of any fungal treatments, males preferred stimuli from aphid-infested plants, and females spent more time associated with stimuli from aphid-infested versus non-infested plants. When fungal treatments were added, we observed that lady beetles preferred non-aphid-infested P. inflatum plants, and males responded slower to plants treated with P. inflatum in the absence of aphids. We found some evidence to suggest that lady beetle behavioral responses to plants might vary according to the fungal treatment but not strongly impact their use as part of an insect pest management strategy.
Collapse
|
10
|
Rivera-Vega LJ, Grunseich JM, Aguirre NM, Valencia CU, Sword GA, Helms AM. A Beneficial Plant-Associated Fungus Shifts the Balance toward Plant Growth over Resistance, Increasing Cucumber Tolerance to Root Herbivory. PLANTS 2022; 11:plants11030282. [PMID: 35161264 PMCID: PMC8838125 DOI: 10.3390/plants11030282] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/28/2021] [Accepted: 01/18/2022] [Indexed: 11/21/2022]
Abstract
Plants allocate their limited resources toward different physiological processes, dynamically adjusting their resource allocation in response to environmental changes. How beneficial plant-associated microbes influence this allocation is a topic that continues to interest plant biologists. In this study, we examined the effect of a beneficial fungus, Phialemonium inflatum, on investment in growth and anti-herbivore resistance traits in cucumber plants (Cucumis sativus). We inoculated cucumber seeds with P. inflatum spores and measured several growth parameters, including germination rate, above and belowground biomass, and number of flowers. We also examined plant resistance to adult and larval striped cucumber beetles (Acalymma vitattum), and quantified levels of defense hormones in leaves and roots. Our results indicate that P. inflatum strongly enhances cucumber plant growth and reproductive potential. Although fungus treatment did not improve plant resistance to cucumber beetles, inoculated plants were more tolerant to root herbivory, experiencing less biomass reduction. Together, these findings document how a beneficial plant-associated fungus shifts plant investment in growth over herbivore resistance, highlighting the importance of microbes in mediating plant-herbivore interactions. These findings also have important implications for agricultural systems, where beneficial microbes are often introduced or managed to promote plant growth or enhance resistance.
Collapse
Affiliation(s)
- Loren J. Rivera-Vega
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA;
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (J.M.G.); (C.U.V.); (G.A.S.)
| | - John M. Grunseich
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (J.M.G.); (C.U.V.); (G.A.S.)
| | - Natalie M. Aguirre
- Ecology and Evolutionary Biology Program, Texas A&M University, College Station, TX 77843, USA;
| | - Cesar U. Valencia
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (J.M.G.); (C.U.V.); (G.A.S.)
| | - Gregory A. Sword
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (J.M.G.); (C.U.V.); (G.A.S.)
- Ecology and Evolutionary Biology Program, Texas A&M University, College Station, TX 77843, USA;
| | - Anjel M. Helms
- Department of Entomology, Texas A&M University, College Station, TX 77843, USA; (J.M.G.); (C.U.V.); (G.A.S.)
- Ecology and Evolutionary Biology Program, Texas A&M University, College Station, TX 77843, USA;
- Correspondence:
| |
Collapse
|
11
|
González-Mas N, Gutiérrez-Sánchez F, Sánchez-Ortiz A, Grandi L, Turlings TCJ, Manuel Muñoz-Redondo J, Moreno-Rojas JM, Quesada-Moraga E. Endophytic Colonization by the Entomopathogenic Fungus Beauveria Bassiana Affects Plant Volatile Emissions in the Presence or Absence of Chewing and Sap-Sucking Insects. FRONTIERS IN PLANT SCIENCE 2021; 12:660460. [PMID: 34381470 PMCID: PMC8350324 DOI: 10.3389/fpls.2021.660460] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/11/2021] [Indexed: 05/31/2023]
Abstract
Entomopathogenic fungi are gaining acceptance in Integrated Pest Management (IPM) systems as effective and environmental safety biological control agents to protect a great variety of crops against pest insects. Many of these insect-pathogenic fungi can establish themselves as endophytes and thereby may induce the plant immune system. The activation of plant defenses by the fungal endophytic colonization can have a direct impact on herbivores and plant pathogens. An integral component of many plant defense responses is also the release of volatile organic compounds, which may serve as an indirect defense by attracting the natural enemies of herbivores. Here we investigated the effect of endophytic colonization by the entomopathogenic fungus Beauveria bassiana on the volatile emission by melon and cotton plants, either unharmed or after being damaged by sap-sucking aphids or leaf chewing caterpillars. We found that when the plants are colonized by B. bassiana they emit a different blend of volatile compounds compared to uncolonized control plants. Some of the emitted compounds have been reported previously to be released in response to herbivory and have been implicated in natural enemy attraction. Several of the compounds are also known to have antimicrobial properties. Therefore, endophytic colonization by B. bassiana might help to not only direct control insect pests but also increase the resistance of plants against agronomically important pests and phytopathogens.
Collapse
Affiliation(s)
- Natalia González-Mas
- Departamento de Agronomía, Escuela Técnica Superior de Ingeniería Agronómica y de Montes (ETSIAM), Universidad de Córdoba, ceiA3, Campus Rabanales, Córdoba, Spain
| | - Fernando Gutiérrez-Sánchez
- Departamento de Agronomía, Escuela Técnica Superior de Ingeniería Agronómica y de Montes (ETSIAM), Universidad de Córdoba, ceiA3, Campus Rabanales, Córdoba, Spain
| | - Araceli Sánchez-Ortiz
- Department of Food Science and Health, Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA), Ctr Venta del Llano, Jaén, Spain
| | - Luca Grandi
- Fundamental and Applied Research in Chemical Ecology (FARCE Lab), Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Ted C. J. Turlings
- Fundamental and Applied Research in Chemical Ecology (FARCE Lab), Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - José Manuel Muñoz-Redondo
- Department of Food Science and Health, Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA), Alameda del Obispo, Córdoba, Spain
| | - José Manuel Moreno-Rojas
- Department of Food Science and Health, Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA), Alameda del Obispo, Córdoba, Spain
| | - Enrique Quesada-Moraga
- Departamento de Agronomía, Escuela Técnica Superior de Ingeniería Agronómica y de Montes (ETSIAM), Universidad de Córdoba, ceiA3, Campus Rabanales, Córdoba, Spain
| |
Collapse
|
12
|
Valencia CU, Sword GA. Resin cast impressions as a tool for microscopic observations of fungal epiphytes on leaves. J Microbiol Methods 2021; 186:106237. [PMID: 33984390 DOI: 10.1016/j.mimet.2021.106237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/06/2021] [Accepted: 05/09/2021] [Indexed: 11/28/2022]
Abstract
A simple method for fungal epiphyte microscopic observations and preservation is described. A two-part clear casting resin, cotton leaves and two species of fungi were used to validate this protocol. We obtained very detailed images of fungal structures using this approach in addition to retaining the impressions for future reference.
Collapse
Affiliation(s)
- Cesar U Valencia
- Department of Entomology, Texas A&M University, College Station, TX, USA.
| | - Gregory A Sword
- Department of Entomology, Texas A&M University, College Station, TX, USA
| |
Collapse
|
13
|
Rasool S, Vidkjaer NH, Hooshmand K, Jensen B, Fomsgaard IS, Meyling NV. Seed inoculations with entomopathogenic fungi affect aphid populations coinciding with modulation of plant secondary metabolite profiles across plant families. THE NEW PHYTOLOGIST 2021; 229:1715-1727. [PMID: 33006149 DOI: 10.1111/nph.16979] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 09/14/2020] [Indexed: 06/11/2023]
Abstract
Entomopathogenic fungi (EPF) can display a plant-associated lifestyle as endophytes. Seed application of EPF can affect insect herbivory above ground, but the mechanisms behind this are not documented. Here we applied three EPF isolates, Beauveria bassiana, Metarhizium brunneum and M. robertsii, as seed inoculation of wheat and bean, and evaluated the effects on population growth of aphids, Rhopalosiphum padi and Aphis fabae, respectively. In wheat and bean leaves, we quantified benzoxazinoids and flavonoids, respectively, in response to EPF inoculation and aphid infestation to elucidate the role of specific plant secondary metabolites (PSMs) in plant-fungus-herbivore interactions. Inoculations of wheat and bean with M. robertsii and B. bassiana reduced aphid populations compared with control treatments, whereas M. brunneum unexpectedly increased the populations of both aphids. Concentrations of the majority of PSMs were differentially altered in EPF-treated plants infested with aphids. Changes in aphid numbers were associated with PSMs regulation rather than EPF endophytic colonisation capacity. This study links the effects of EPF seed inoculations against aphids with unique PSM accumulation patterns in planta. The understanding of PSM regulation in tri-trophic interactions is important for the future development of EPF for pest management.
Collapse
Affiliation(s)
- Shumaila Rasool
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldesensvej 40, Frederiksberg C, 1871, Denmark
| | - Nanna H Vidkjaer
- Department of Agroecology, Aarhus University, Forsøgsvej 1, Slagelse, 4200, Denmark
| | - Kourosh Hooshmand
- Department of Agroecology, Aarhus University, Forsøgsvej 1, Slagelse, 4200, Denmark
| | - Birgit Jensen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldesensvej 40, Frederiksberg C, 1871, Denmark
| | - Inge S Fomsgaard
- Department of Agroecology, Aarhus University, Forsøgsvej 1, Slagelse, 4200, Denmark
| | - Nicolai V Meyling
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldesensvej 40, Frederiksberg C, 1871, Denmark
| |
Collapse
|
14
|
Lahiri S, Reisig DD, Dean LL, Reay-Jones FPF, Greene JK, Carter TE, Mian R, Fallen BD. Mechanisms of Soybean Host-Plant Resistance Against Megacopta cribraria (Hemiptera: Plataspidae). ENVIRONMENTAL ENTOMOLOGY 2020; 49:876-885. [PMID: 32623469 DOI: 10.1093/ee/nvaa075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Indexed: 06/11/2023]
Abstract
A number of soybean varieties traditionally bred for resistance to various soybean arthropod pests have been identified as resistant to Megacopta cribraria (F.) (Hemiptera: Plataspidae). However, the mechanisms of host-plant resistance (HPR) in this system are not understood. The goal of this study was to identify the mechanisms of resistance by examining the role of plant volatile organic compounds (VOCs) and free amino acids (FAAs) among 16 soybean varieties. Choice and no-choice cage experiments identified several soybean varieties that demonstrated antixenosis as well as antibiosis. However, resistance varied over time in certain soybean varieties, such as N02-7002 and PI567352B. Mean nymph number from choice experiments had positive correlations with the FAAs asparagine, tryptophan, alanine, phenylanaline, and serine; negative correlation with leucine and threonine. Four plant volatiles, hexanal, 2-pentylfuran, beta-cyclocitral, and cis-9-hexadecenal, were positively correlated with subsequent nymph development, whereas n-hexadecenoic acid was negatively correlated with nymph number only, in adult choice cage experiments. This study contributes to understanding the mechanisms of HPR through associations with plant VOCs and FAAs in relation to M. cribraria development and provides useful knowledge for developing soybean varieties for M. cribraria management.
Collapse
Affiliation(s)
- S Lahiri
- Department of Entomology and Plant Pathology, North Carolina State University, Vernon G. James Research and Extension Center, Plymouth, NC
| | - D D Reisig
- Department of Entomology and Plant Pathology, North Carolina State University, Vernon G. James Research and Extension Center, Plymouth, NC
| | - Lisa L Dean
- USDA-ARS, Market Quality and Handling Research Unit, Raleigh, NC
| | - F P F Reay-Jones
- Department of Plant and Environmental Sciences, Clemson University, Pee Dee Research and Education Center, Florence, SC
| | - J K Greene
- Department of Plant and Environmental Sciences, Clemson University, Edisto Research and Education Center, Blackville, SC
| | - T E Carter
- USDA-ARS, Soybean and Nitrogen Fixation Research Unit, Raleigh, NC
| | - R Mian
- USDA-ARS, Soybean and Nitrogen Fixation Research Unit, Raleigh, NC
| | - B D Fallen
- Department of Plant and Environmental Sciences, Clemson University, Pee Dee Research and Education Center, Florence, SC
| |
Collapse
|
15
|
Dacosta-Aguayo R, Wylie G, DeLuca J, Genova H. Changes in plant function and root mycobiome caused by flood and drought in a riparian tree. Behav Neurol 2020; 40:886-903. [PMID: 32175581 PMCID: PMC7775148 DOI: 10.1093/treephys/tpaa031] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 02/21/2020] [Accepted: 02/26/2020] [Indexed: 06/10/2023] Open
Abstract
Under increasingly harsh climatic conditions, conservation of threatened species requires integrative studies to understand stress tolerance. Riparian Ulmus minor Mill. populations have been massively reduced by Dutch Elm disease (DED). However, resistant genotypes were selected to restore lost populations. To understand the acclimation mechanisms to the succession of abiotic stresses, ramets of five DED-tolerant U. minor genotypes were subjected to flood and subsequently to drought. Physiological and biochemical responses were evaluated together with shifts in root-fungal assemblages. During both stresses, plants exhibited a decline in leaf net photosynthesis and an increase in percentage loss of stem hydraulic conductivity and in leaf and root proline content. Stomatal closure was produced by chemical signals during flood and hydraulic signals during drought. Despite broad similarities in plant response to both stresses, root-mycobiome shifts were markedly different. The five genotypes were similarly tolerant to moderate drought, however, flood tolerance varied between genotypes. In general, flood did not enhance drought susceptibility due to fast flood recovery, nevertheless, different responses to drought after flood were observed between genotypes. Associations were found between some fungal taxonomic groups and plant functional traits varying with flood and drought (e.g. proline, chlorophyll and starch content) indicating that the thriving of certain taxa depends on host responses to abiotic stress.
Collapse
Affiliation(s)
- Rosalia Dacosta-Aguayo
- Neuropsychology and Neuroscience, Kessler Foundation, 120 Eagle Rock Avenue, Suite 100, East Hanover, New Jersey 07936, USA
- Department of Physical Medicine and Rehabilitation, Rutgers University, New Jersey Medical School, Newark, NJ 07101, USA
| | - Glenn Wylie
- Department of Physical Medicine and Rehabilitation, Rutgers University, New Jersey Medical School, Newark, NJ 07101, USA
- Rocco Ortenzio Neuroimaging Center, Kessler Foundation, West Orange, NJ, USA
| | - John DeLuca
- Neuropsychology and Neuroscience, Kessler Foundation, 120 Eagle Rock Avenue, Suite 100, East Hanover, New Jersey 07936, USA
- Department of Physical Medicine and Rehabilitation, Rutgers University, New Jersey Medical School, Newark, NJ 07101, USA
- Rocco Ortenzio Neuroimaging Center, Kessler Foundation, West Orange, NJ, USA
| | - Helen Genova
- Neuropsychology and Neuroscience, Kessler Foundation, 120 Eagle Rock Avenue, Suite 100, East Hanover, New Jersey 07936, USA
- Department of Physical Medicine and Rehabilitation, Rutgers University, New Jersey Medical School, Newark, NJ 07101, USA
| |
Collapse
|
16
|
Endophytic Beauveria bassiana promotes drought tolerance and early flowering in corn. World J Microbiol Biotechnol 2020; 36:47. [PMID: 32144505 DOI: 10.1007/s11274-020-02823-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Accepted: 02/27/2020] [Indexed: 12/24/2022]
Abstract
Beauveria bassiana (Bals.) Vuillemin (B. bassiana) is an entomopathogenic fungus that establishes endophytic symbiosis with plants. In the present study, the effects of B. bassiana strains colonization in growing Zea mays L. (Z. mays), crop production, and drought tolerance were evaluated. Z. mays seeds were inoculated with B. bassiana strains (GHA, PTG4, and PTG6), using 1 × 106 blastospores/mL and methyl cellulose (MC) or cornstarch (CS) as adherents. Colonization was determined by B. bassiana recovery from plant tissues plated on PDA medium. Plant height, fresh and dry weight, and flowering time were analyzed to assess plant performance. Drought tolerance was evaluated by stopping watering for 10 days, watering again, and determining vigor recovery after 24 h. Results showed 100% endophytic roots colonization, regardless of adherent type or strain tested. Colonization was variable in shoots and leaves, but GHA strain achieved the highest inoculation rates, including 88% in stems and 50% in leaves, which did not depend on adherent type used; for PTG4 strain, adherent type had an important effect (MC = 100% stems and leaves; CS = 63% stems and 25% leaves). For PTG6 strain, the best adherent type was CS (71% stems and 75% leaves), whereas MC showed variable inoculation percentage (25% stems and 75% leaves). Interestingly, only MCPTG4 treatment showed consistent positive effects on germination percentage (day 5 = 46 ± 2%; day 14 = 87 ± 7%) compared with controls (CC = 63 ± 4%, CMC = 50 ± 3%, CCS = 47 ± 0%). In addition, the other treatments showed low germination percentages at day 5 (7 ± 7% to 46 ± 2%), which recovered at day 14 (53 ± 0% to 73 ± 8%), except for MCPTG6 treatment with 23 ± 10% germination. About plant performance, not significant effects on plant height and fresh/dry weight in all the treatments were observed. However, B. bassiana-treated plants, using either GHA, PTG4 or PTG6 strains, and MC as adherent, showed tolerance to drought and flowered one to two weeks earlier, providing evidence supporting further applications of these seed treatments in agricultural systems, for abiotic stress sustainable management practices.
Collapse
|
17
|
González-Mas N, Sánchez-Ortiz A, Valverde-García P, Quesada-Moraga E. Effects of Endophytic Entomopathogenic Ascomycetes on the Life-History Traits of Aphis gossypii Glover and Its Interactions with Melon Plants. INSECTS 2019; 10:insects10060165. [PMID: 31185669 PMCID: PMC6627330 DOI: 10.3390/insects10060165] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/01/2019] [Accepted: 06/05/2019] [Indexed: 11/16/2022]
Abstract
Entomopathogenic fungi are sprayed commercially for aphid control in greenhouses. Recently, their ability to grow endophytically within plants was discovered, offering the opportunity for systemic biological control. Endophytic colonization of host plants could also influence life-table parameters and behavior of herbivores. We investigated lethal and pre-mortality effects of Beauveria bassiana and Metarhizium brunneum on Aphis gossypii; aphids either received inoculum while feeding on recently sprayed leaves (surface inoculum and endophytically-colonized) or while feeding on unsprayed but endophytically-colonized leaves. We used choice assays to identify any preferences for endophytically-colonized or control plants. Volatile emissions from endophytically-colonized plants and control plants were also compared. Aphid mortality rates ranged between 48.2 and 56.9% on sprayed leaves, and between 37.7 and 50.0 on endophytically-colonized leaves. There was a significant effect of endophytic colonization on the rate of nymph production, but this did not result in an overall increase in the aphid population. Endophytic colonization did not influence host-plant selection even though there were qualitative and quantitative differences in the blend of volatiles released by endophytically-colonized and control plants. Although endophytic colonization did not change herbivore behavior, plants still benefit via indirect defense, resistance to plant pathogens or abiotic stress tolerance.
Collapse
Affiliation(s)
- Natalia González-Mas
- Departamento de Agronomía, Universidad de Córdoba, ETSIAM, Campus Rabanales, Edificio C4 Celestino Mutis, E-14071 Córdoba, Spain.
| | | | - Pablo Valverde-García
- Departamento de Agronomía, Universidad de Córdoba, ETSIAM, Campus Rabanales, Edificio C4 Celestino Mutis, E-14071 Córdoba, Spain.
| | - Enrique Quesada-Moraga
- Departamento de Agronomía, Universidad de Córdoba, ETSIAM, Campus Rabanales, Edificio C4 Celestino Mutis, E-14071 Córdoba, Spain.
| |
Collapse
|
18
|
Raad M, Glare TR, Brochero HL, Müller C, Rostás M. Transcriptional Reprogramming of Arabidopsis thaliana Defence Pathways by the Entomopathogen Beauveria bassiana Correlates With Resistance Against a Fungal Pathogen but Not Against Insects. Front Microbiol 2019; 10:615. [PMID: 30984142 PMCID: PMC6449843 DOI: 10.3389/fmicb.2019.00615] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/11/2019] [Indexed: 01/17/2023] Open
Abstract
The entomopathogenic fungus Beauveria bassiana can adopt an endophytic lifestyle by colonising a wide array of plant species. Beauveria-colonised plants can show enhanced resistance against insects and plant pathogens alike. However, little is known about the molecular and physiological mechanisms that govern such interactions. Here, we assessed the effects of two B. bassiana strains (BG11, FRh2) on the growth of Arabidopsis thaliana and its resistance against two herbivore species and a phytopathogen. Plant responses were studied on the transcriptomic and metabolic level using microarrays and by measuring changes in defence-related phytohormones and glucosinolates (GLSs). Root inoculation with B. bassiana BG11 significantly increased plant growth, while FRh2 had no such effect. Both Beauveria strains decreased leaf lesion area caused by the phytopathogen Sclerotinia sclerotiorum but did not affect population growth of the aphid Myzus persicae or the growth of Plutella xylostella caterpillars. Microarray analyses of leaves from endophyte-inoculated A. thaliana provided evidence for transcriptional reprogramming of plant defence pathways, with strain-specific changes in the expression of genes related to pathogenesis, phytoalexin, jasmonic (JA), and salicylic acid (SA) signalling pathways. However, B. bassiana colonisation did not result in higher concentrations of JA and SA or major changes in leaf GLS profiles. We conclude that the endophyte B. bassiana induces plant defence responses and hypothesise that these contribute to enhanced resistance against S. sclerotiorum.
Collapse
Affiliation(s)
- Maya Raad
- Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand
| | - Travis R Glare
- Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand
| | - Helena L Brochero
- Facultad de Ciencias Agrarias, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Caroline Müller
- Department of Chemical Ecology, Bielefeld University, Bielefeld, Germany
| | - Michael Rostás
- Bio-Protection Research Centre, Lincoln University, Lincoln, New Zealand.,Department of Crop Sciences, Agricultural Entomology, University of Göttingen, Göttingen, Germany
| |
Collapse
|
19
|
Moloinyane S, Nchu F. The Effects of Endophytic Beauveria bassiana Inoculation on Infestation Level of Planococcus ficus, Growth and Volatile Constituents of Potted Greenhouse Grapevine ( Vitis vinifera L.). Toxins (Basel) 2019; 11:toxins11020072. [PMID: 30696046 PMCID: PMC6409710 DOI: 10.3390/toxins11020072] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 01/20/2019] [Accepted: 01/22/2019] [Indexed: 11/16/2022] Open
Abstract
Endophytic entomopathogenic fungi are being explored for the management of phytophagous insect pests. The effects of Beauveria bassiana (Hypocreales) inoculation of grape plants on the infestation level of P. ficus, tissue nutrient contents, and growth and volatile constituents of potted grape plants were assessed. Grapevine plants were individually inoculated with a suspension of 1 × 108 conidia mL−1 of B. bassiana by drenching before experimentally infesting each of them with thirty adult females of P. ficus. At four weeks post-treatment, the fungus was re-isolated from leaves of 50% of the fungus-exposed plants. However, no significant difference (p > 0.05) was observed in all the plant growth parameters measured in the fungus-treated and control plants. Plant tissue analysis revealed markedly higher contents of calcium (Ca) and magnesium (Mg) in the leaf tissue of plants exposed to the B. bassiana relative to the control. Gas chromatography mass spectrometry (GC-MS) analyses showed that a significantly (X2 = 5.1; p < 0.02) higher number of known anti-insect volatile compounds (nine) were present among fungus treated plants compared to the control plants (five). Naphthalene, which is toxic to insects and humans, was detected only in the volatiles of the fungus-exposed plants. B. bassiana did not have any significant effect on total polyphenol, alkaloid, and flavonoids. Overall, treatment with fungus did not inhibit the infestation by P. ficus. In conclusion, these findings shed light on some of the mechanisms involved in endophytic fungus-plant-insect interactions.
Collapse
Affiliation(s)
- Siphokazi Moloinyane
- Department of Horticultural Sciences, Cape Peninsula University of Technology, Symphony Way, Bellville, P.O. Box 1906, Bellville 7535, South Africa.
| | - Felix Nchu
- Department of Horticultural Sciences, Cape Peninsula University of Technology, Symphony Way, Bellville, P.O. Box 1906, Bellville 7535, South Africa.
| |
Collapse
|
20
|
Endophytic entomopathogenic fungi enhance the growth of Phaseolus vulgaris L. (Fabaceae) and negatively affect the development and reproduction of Tetranychus urticae Koch (Acari: Tetranychidae). Microb Pathog 2018; 125:385-392. [PMID: 30290267 DOI: 10.1016/j.micpath.2018.09.044] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Revised: 09/29/2018] [Accepted: 09/30/2018] [Indexed: 01/27/2023]
Abstract
Entomopathogenic fungi (EPF) have primarily been applied as an inundative approach to manage pests. However, in recent decade multifunctional role of EPF have been documented which provide multiple benefits to host plants when colonized as an endophyte. In this study five fungal isolates from the genus Beauveria (three), Isaria (one) and Lecanicillium (one) were evaluated for their ability to colonize common bean, Phaseolus vulgaris and to assess their effects in planta on plant growth promotion and possible negative effects on the two-spotted spider mites, Tetranychus urticae. All the tested isolates in this study were able to endophytically colonize root, stem and even leaves of inoculated plants examined at 7 and 14 days post inoculation, indicating the systemic colonization of EPF. Colonized plants showed increased plant heights, fresh shoot and root weights compared to plants without inoculation. Survivorship of T. urticae significantly differed among the treatments with higher survival probability in control plants. Significant reduction in larval development, adult longevity and female fecundity of spider mites were observed when fed on treated plants compared to control plants. The negative effects were found to be carried over the second generation fed on fresh plants. Overall, our results show (i) the positive effects of fungal endophytes on plant growth, (ii) reduction in population growth rate and (iii) negative effects of endophytes on growth and reproduction of spider mites in successive generations. The study presents reports on the endophytic management of plant-feeding mites and highlights the possibility of utilizing entomopathogenic fungal endophytes in the integrated pest management program.
Collapse
|