Arbuscular mycorrhizal fungi and potassium fertilizer as plant biostimulants and alternative research for enhancing plants adaptation to drought stress: Opportunities for enhancing drought tolerance in cocoa (Theobroma cacao L.)

Mitogen-activated protein kinase (MAPK) cascades play important roles in the stress response in both plants and microorganisms. The mycorrhizal symbiosis established between arbuscular mycorrhizal fungi (AMF) and plants can enhance plant drought tolerance, which might be closely related to the fungal MAPK response and the molecular dialogue between fungal and soybean MAPK cascades. To verify the above hypothesis, germinal Glomus intraradices (syn. Rhizophagus irregularis) spores and potted experiments were conducted. The results showed that AMF GiMAPKs with high homology with MAPKs from Saccharomyces cerevisiae had different gene expression patterns under different conditions (nitrogen starvation, abscisic acid treatment, and drought). Drought stress upregulated the levels of fungi and soybean MAPK transcripts in mycorrhizal soybean roots, indicating the possibility of a molecular dialogue between the two symbiotic sides of symbiosis and suggesting that they might cooperate to regulate the mycorrhizal soybean drought-stress response. Meanwhile, the changes in hydrogen peroxide, soluble sugar, and proline levels in mycorrhizal soybean as well as in the accelerated exchange of carbon and nitrogen in the symbionts were contributable to drought adaptation of the host plants. Thus, it can be preliminarily inferred that the interactions of MAPK signals on both sides, symbiotic fungus and plant, might regulate the response of symbiosis and, thus, improve the resistance of mycorrhizal soybean to drought stress.

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Mechanistic Insights into Arbuscular Mycorrhizal Fungi-Mediated Drought Stress Tolerance in Plants

International Journal of Molecular Sciences ◽

10.3390/ijms20174199 ◽

2019 ◽

Vol 20 (17) ◽

pp. 4199 ◽

Cited By ~ 19

Author(s):

Ali Bahadur ◽

Asfa Batool ◽

Fahad Nasir ◽

Shengjin Jiang ◽

Qin Mingsen ◽

...

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Plant Growth ◽

Arbuscular Mycorrhizal Fungi ◽

Stress Tolerance ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Innovative Approach ◽

Drought Stress Tolerance ◽

Mycorrhizal Association

Arbuscular mycorrhizal fungi (AMF) establish symbiotic interaction with 80% of known land plants. It has a pronounced impact on plant growth, water absorption, mineral nutrition, and protection from abiotic stresses. Plants are very dynamic systems having great adaptability under continuously changing drying conditions. In this regard, the function of AMF as a biological tool for improving plant drought stress tolerance and phenotypic plasticity, in terms of establishing mutualistic associations, seems an innovative approach towards sustainable agriculture. However, a better understanding of these complex interconnected signaling pathways and AMF-mediated mechanisms that regulate the drought tolerance in plants will enhance its potential application as an innovative approach in environmentally friendly agriculture. This paper reviews the underlying mechanisms that are confidently linked with plant–AMF interaction in alleviating drought stress, constructing emphasis on phytohormones and signaling molecules and their interaction with biochemical, and physiological processes to maintain the homeostasis of nutrient and water cycling and plant growth performance. Likewise, the paper will analyze how the AMF symbiosis helps the plant to overcome the deleterious effects of stress is also evaluated. Finally, we review how interactions between various signaling mechanisms governed by AMF symbiosis modulate different physiological responses to improve drought tolerance. Understanding the AMF-mediated mechanisms that are important for regulating the establishment of the mycorrhizal association and the plant protective responses towards unfavorable conditions will open new approaches to exploit AMF as a bioprotective tool against drought.

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Growth response of cacao (Theobroma cacao L.) plant as affected by bamboo biochar and arbuscular mycorrhizal fungi in sterilized and unsterilized soil

Biocatalysis and Agricultural Biotechnology ◽

10.1016/j.bcab.2019.101347 ◽

2019 ◽

Vol 22 ◽

pp. 101347 ◽

Cited By ~ 2

Author(s):

Nelly S. Aggangan ◽

Angelbert D. Cortes ◽

Consorcia E. Reaño

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Theobroma Cacao ◽

Growth Response ◽

Arbuscular Mycorrhizal ◽

Unsterilized Soil ◽

Theobroma Cacao L

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Asociación simbiótica entre hongos micorrízicos arbusculares y el sistema radicular de plántulas de cacao (Theobroma cacao L.): efecto de la formononetina y la disponibilidad de fósforo en el suelo.

Ciencia y Tecnología Agropecuaria ◽

10.21930/rcta.vol12_num1_art:217 ◽

2010 ◽

Vol 12 (1) ◽

pp. 77 ◽

Cited By ~ 2

Author(s):

Guillermo Andrés Cuadros G. ◽

Raúl Gómez S

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Theobroma Cacao ◽

Arbuscular Mycorrhizal ◽

Morphological Characters ◽

Randomized Design ◽

El Sistema ◽

Mycorrhizal Interactions ◽

Relationship Of ◽

Theobroma Cacao L

La simbiosis entre plantas de cacao y hongos micorrízicos arbusculares (HFMA) confiere beneficios nutricionales y competitivos a la planta, especialmente en condiciones de baja disponibilidad de nutrientes. Se evaluó tres niveles de fósforo (5, 20 y 40 ppm) y la presencia o ausencia de isoflavonoide formononetina. El nivel 14 ppm de P sin el isoflavonoide fue el tratamiento testigo. Todos los tratamientos fueron inoculados con HFMA a excepción del tratamiento control. Se utilizó un diseño completamente al azar y se determinaron caracteres morfológicos de la planta a los 70, 110 y 150 días después de la inoculación. Los resultados no mostraron respuesta diferencial a los caracteres morfológicos de la planta por la disponibilidad del isoflavonoide durante los tres muestreos. La longitud radicular presentó diferencias significativas en los muestreo (70, 110 y 150 días de inoculación), siendo esta respuesta dependiente de la disponibilidad de P y la interacción plantamicorriza. El número de esporas mostró diferencias entre los muestreos de 110 y 150 días de inoculación en presencia y ausencia del isoflavonoide, sugiriendo una rápida estimulación en el establecimiento de la relación simbiótica por la formononetina en el proceso de germinación y formación de estructuras fúngicas. Symbiotic asociation of arbuscular mycorrhizal fungi and the root system of cocoa (Theobroma cacao L.) seedlings: effect of formononetin and phosphorus availability at soil level.The symbiosis established between cacao plants and arbuscular mycorrhizal fungi (AMF) adds nutritional and competitive benefits for the plant, especially in conditions with a low availability of nutrients. We evaluated three levels of phosphorus (5, 20 and 40 ppm) and the presence or absence of isoflavone formononetin. A Phosphorus level of 14 ppm, without isoflavone or inoculation was the control. All treatments were inoculated with HFMA with the exception of the control. A completely randomized design was used. The morphological characters of the plant at 70, 110 and 150 days after inoculation were determined. The results showed no difference in the response to the morphological characters of the plant with the varied availability of isoflavone during the three sampling. The root length showed significant differences in the different sampling times (70, 110 and 150 days of inoculation), this response being dependent on the availability of P and plant-mycorrhizal interactions. The number of spores demonstrated differences between the samples of 110 and 150 days of inoculation in the presence and absence of isoflavone, suggesting an early stimulation in the establishment of the symbiotic relationship of formononetin in the process of germination and formation of fungal structures.

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Alleviation of Drought Stress in White Clover after Inoculation with Arbuscular Mycorrhizal Fungi

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha45110709 ◽

2017 ◽

Vol 45 (1) ◽

pp. 220-224 ◽

Cited By ~ 5

Author(s):

Xiao-Qing TUO ◽

Li HE ◽

Ying-Ning ZOU

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Arbuscular Mycorrhizal Fungi ◽

White Clover ◽

Mycorrhizal Fungi ◽

Soluble Protein ◽

Water Status ◽

Arbuscular Mycorrhizal ◽

Mycorrhizal Plants ◽

Amf Inoculation

White clover is extremely susceptive to drought stress (DS), while it is not clear whether arbuscular mycorrhizal fungi (AMF) enhance drought tolerance of the plant. This study was carried out to evaluate effects of two AMF species, Funneliformis mosseae and Paraglomus occultum, on flavonoid, soluble protein, proline, and nutrient uptake in roots of white clover under well-watered (WW) and DS conditions. Root colonization by F. mosseae and P. occultum was heavily decreased by 7-week DS treatment. Mycorrhizal plants showed considerably greater biomass production in shoot, root, and total (shoot+root) than non-mycorrhizal plants, irrespective of soil water status. AMF inoculation led to significantly higher root soluble protein and proline accumulation under WW and DS and root flavonoid level under DS, regardless of AMF species. Root N, P, K and Cu concentrations were dramatically increased by mycorrhization under WW and DS, and root Ca, Mg, Fe, and Mn levels were significantly higher in AMF plants than in non-AMF plants under WW. It concluded that AMF strongly enhanced plant growth and drought tolerance of white clover by greater nutrient absorption and protective substances (soluble protein, proline, and flavonoid) accumulation.

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Evaluation of the Inoculation Effect of Arbuscular Mycorrhizal Fungi on the Growth of Cocoa Seedlings (Theobroma cacao L.) in the Nursery

International Journal of Sciences ◽

10.18483/ijsci.2352 ◽

2020 ◽

Vol 9 (07) ◽

pp. 6-13

Author(s):

Pélagie Djenatou ◽

Jules Patrick Ngoh Dooh ◽

Kosma Philippe ◽

Eddy Léonard Ngonkeu Mangaptche

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Theobroma Cacao ◽

Arbuscular Mycorrhizal ◽

Theobroma Cacao L ◽

Cocoa Seedlings

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Physiological and biochemical responses of soybean plants inoculated with Arbuscular mycorrhizal fungi and Bradyrhizobium under drought stress

BMC Plant Biology ◽

10.1186/s12870-021-02949-z ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Mohamed S. Sheteiwy ◽

Dina Fathi Ismail Ali ◽

You-Cai Xiong ◽

Marian Brestic ◽

Milan Skalicky ◽

...

Keyword(s):

Drought Stress ◽

Arbuscular Mycorrhizal Fungi ◽

Secondary Metabolism ◽

Mycorrhizal Fungi ◽

Plant Biomass ◽

Arbuscular Mycorrhizal ◽

Growth And Yield ◽

Relative Expression ◽

Reverse Trend ◽

Soybean Plants

Abstract Background The present study aims to study the effects of biofertilizers potential of Arbuscular Mycorrhizal Fungi (AMF) and Bradyrhizobium japonicum (B. japonicum) strains on yield and growth of drought stressed soybean (Giza 111) plants at early pod stage (50 days from sowing, R3) and seed development stage (90 days from sowing, R5). Results Highest plant biomass, leaf chlorophyll content, nodulation, and grain yield were observed in the unstressed plants as compared with water stressed-plants at R3 and R5 stages. At soil rhizosphere level, AMF and B. japonicum treatments improved bacterial counts and the activities of the enzymes (dehydrogenase and phosphatase) under well-watered and drought stress conditions. Irrespective of the drought effects, AMF and B. japonicum treatments improved the growth and yield of soybean under both drought (restrained irrigation) and adequately-watered conditions as compared with untreated plants. The current study revealed that AMF and B. japonicum improved catalase (CAT) and peroxidase (POD) in the seeds, and a reverse trend was observed in case of malonaldehyde (MDA) and proline under drought stress. The relative expression of the CAT and POD genes was up-regulated by the application of biofertilizers treatments under drought stress condition. Interestingly a reverse trend was observed in the case of the relative expression of the genes involved in the proline metabolism such as P5CS, P5CR, PDH, and P5CDH under the same conditions. The present study suggests that biofertilizers diminished the inhibitory effect of drought stress on cell development and resulted in a shorter time for DNA accumulation and the cycle of cell division. There were notable changes in the activities of enzymes involved in the secondary metabolism and expression levels of GmSPS1, GmSuSy, and GmC-INV in the plants treated with biofertilizers and exposed to the drought stress at both R3 and R5 stages. These changes in the activities of secondary metabolism and their transcriptional levels caused by biofertilizers may contribute to increasing soybean tolerance to drought stress. Conclusions The results of this study suggest that application of biofertilizers to soybean plants is a promising approach to alleviate drought stress effects on growth performance of soybean plants. The integrated application of biofertilizers may help to obtain improved resilience of the agro ecosystems to adverse impacts of climate change and help to improve soil fertility and plant growth under drought stress.

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