Arbuscular mycorrhizal fungi improving drought tolerance of maize plants by up-regulation of aquaporin gene expressions in roots and the fungi themselves

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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Combined Heat and Drought Tolerance of Tomato Plants when Treated with different Arbuscular Mycorrhizal Fungi

Proceedings of the 6th World Congress on Civil, Structural, and Environmental Engineering ◽

10.11159/iceptp21.lx.101 ◽

2021 ◽

Author(s):

Imane Haddidi ◽

Bence Gajdics ◽

Nguyen Hong Duc ◽

Katalin Posta

Keyword(s):

Drought Tolerance ◽

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Tomato Plants

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The Role of the external mycelial network of arbuscular mycorrhizal fungi: III. a study of nitrogen transfer between plants interconnected by a common mycelium

Revista de Microbiologia ◽

10.1590/s0001-37141998000400011 ◽

1998 ◽

Vol 29 (4) ◽

pp. 289-294 ◽

Cited By ~ 11

Author(s):

Marco A. Martins ◽

Andre F. Cruz

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Dry Weight ◽

Plant Roots ◽

Nitrogen Transfer ◽

Nylon Mesh ◽

Mycelium Network ◽

Maize Plants ◽

Mycelial Network

An experiment under greenhouse conditions was carried out to evaluate the relative contribuition of arbuscular mycorrhizal fungi (AMF) in the process of nitrogen transfer from cowpea to maize plants, using the isotope 15N. Special pots divided in three sections (A, B and C), were constructed and a nylon mesh screen of two diameters: 40µm (which allowed the AMF hyphae to pass but not the plant roots) or 1µm (which acted as a barrier to AM hyphae and plant roots) was inserted between the sections B and C. Section A had 25.5 mg of N/kg using (15NH4)2SO4 as N source. Two cowpea seedlings inoculated with Rhizobium sp. were transplanted with their root systems divided between the sections A and B. Ten days later, 2 seeds of maize were sown into the section C which was inoculated with Glomus etunicatum. Thirty-five days after transplanting, the maize plants were harvested. AMF inoculation increased dry weight and 15N and P content of maize plant shoots. Direct transfer of 15N via AMF hyphae was 21.2%; indirect transfer of 15N mediated by AMF mycelium network, was 9.6%, and indirect transfer not mediated by AM mycelium network , was 69.2%.

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Arbuscular Mycorrhizal Fungi Mediate Drought Tolerance and Recovery in Two Contrasting Carob (Ceratonia siliqua L.) Ecotypes by Regulating Stomatal, Water Relations, and (In)Organic Adjustments

Plants ◽

10.3390/plants9010080 ◽

2020 ◽

Vol 9 (1) ◽

pp. 80 ◽

Cited By ~ 11

Author(s):

Abderrahim Boutasknit ◽

Marouane Baslam ◽

Mohamed Ait-El-Mokhtar ◽

Mohamed Anli ◽

Raja Ben-Laouane ◽

...

Keyword(s):

Stomatal Conductance ◽

Drought Tolerance ◽

Arbuscular Mycorrhizal Fungi ◽

Oxidative Damage ◽

Water Content ◽

Mycorrhizal Fungi ◽

Early Stage ◽

Arbuscular Mycorrhizal ◽

Ceratonia Siliqua ◽

Improvement Programs

Irregular precipitation and drought caused an increase in tree mortality rates in multiple forest biomes with alterations in both ecosystem services and carbon balance. Carob (Ceratonia siliqua) growth and production in arid and semi-arid ecosystems are likely affected by climate change-induced droughts. Understanding the physiological responses of drought-induced early-stage tree death and strategies to enhance drought tolerance and optimize growth will help tree improvement programs. Mycorrhizal inoculation has a pronounced impact on plant growth, water absorption, mineral nutrition, and protection from abiotic stresses. However, a better understanding of these complex interconnected cellular processes and arbuscular mycorrhizal fungi (AMF)-mediated mechanisms regulating drought tolerance in plants will enhance its potential application as an efficient approach for bio-amelioration of stresses. The objectives of this work were to elucidate the different effects of autochthone AMF on inorganic solute and water content uptakes, organic adjustments (sugar and proteins content), leaf gas exchange (stomatal conductance and efficiency of photosystems I and II), and oxidative damage of two contrasting ecotypes of carob seedlings: coastal (southern ecotype (SE)) and in-land (northern ecotype (NE)) under control (C), drought (by cessation of irrigation for 15 days (15D)), and recovery (R) conditions. Our findings showed that AMF promoted growth, nutrient content, and physiological and biochemical parameters in plants of both ecotypes during C, 15D, and R conditions. After four days of recovery, stomatal conductance (gs), the maximum photochemical efficiency of PSII (Fv/Fm), water content, and plant uptake of mineral nutrients (P, K, Na, and Ca) were significantly higher in shoots of mycorrhizal (AM) than non-mycorrhizal (NM) control plants. Consequently, AMF reduced to a greater degree the accumulation of hydrogen peroxide (H2O2) and oxidative damage to lipid (malondialdehyde (MDA)) content in AM than NM plants in NE and SE, after recovery. Altogether, our findings suggest that AMF can play a role in drought resistance of carob trees at an early stage by increasing the inorganic solutes (P, K, Na, and Ca), water content uptake, organic solutes (soluble sugars and protein content), stomatal conductance, and defense response against oxidative damage during re-watering after drought stress.

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