scholarly journals Mycorrhizae Applications in Sustainable Forestry

2020 ◽  
Author(s):  
Dayakar Govindu ◽  
Anusha Duvva ◽  
Srinivas Podeti

Arbuscular mycorrhizal (AM) association is the most common symbiotic association of plants with microbes. AM fungi occur in the majority of natural habitats and they provide a range of important biological services, in particular by improving plant nutrition, abiotic resistance, and soil structure and fertility. AM fungi also interact with most crop varieties and forest plants. The possible benefit of AM fungi in forestry can be achieved through a combination of inoculum methods. The mycorrhizal inoculum levels in the soil and their colonization in different forest plant roots which leads to reduce the fertilizers, pathogen effects and fungicides and to protect topsoil, soil erosion, and water-logging. Currently, several reports were suggested that AM symbiosis can improve the potential for different plant species. Two steps could be used to produce high yielding of different plant biomass that would be both mycorrhizal dependency and suitability for sowing into the field with high inoculum levels Therefore, the wide-scale inoculation of AM fungi on forest trees will become economically important. The successful research is required in the area of mass production of AM fungal inoculum and AM fungi associated with roots which will contribute to sustainable forestry.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manoj-Kumar Arthikala ◽  
Kalpana Nanjareddy ◽  
Lourdes Blanco ◽  
Xóchitl Alvarado-Affantranger ◽  
Miguel Lara

AbstractTarget of rapamycin (TOR) is a conserved central growth regulator in eukaryotes that has a key role in maintaining cellular nutrient and energy status. Arbuscular mycorrhizal (AM) fungi are mutualistic symbionts that assist the plant in increasing nutrient absorption from the rhizosphere. However, the role of legume TOR in AM fungal symbiosis development has not been investigated. In this study, we examined the function of legume TOR in the development and formation of AM fungal symbiosis. RNA-interference-mediated knockdown of TOR transcripts in common bean (Phaseolus vulgaris) hairy roots notably suppressed AM fungus-induced lateral root formation by altering the expression of root meristem regulatory genes, i.e., UPB1, RGFs, and sulfur assimilation and S-phase genes. Mycorrhized PvTOR-knockdown roots had significantly more extraradical hyphae and hyphopodia than the control (empty vector) roots. Strong promoter activity of PvTOR was observed at the site of hyphal penetration and colonization. Colonization along the root length was affected in mycorrhized PvTOR-knockdown roots and the arbuscules were stunted. Furthermore, the expression of genes induced by AM symbiosis such as SWEET1, VPY, VAMP713, and STR was repressed under mycorrhized conditions in PvTOR-knockdown roots. Based on these observations, we conclude that PvTOR is a key player in regulating arbuscule development during AM symbiosis in P. vulgaris. These results provide insight into legume TOR as a potential regulatory factor influencing the symbiotic associations of P. vulgaris and other legumes.


Botany ◽  
2014 ◽  
Vol 92 (4) ◽  
pp. 241-251 ◽  
Author(s):  
Ylva Lekberg ◽  
Roger T. Koide

Our knowledge of arbuscular mycorrhizal (AM) function is largely based on results from short-term studies in controlled environments. While these have provided many important insights into the potential effects of the symbiosis on the two symbionts and their communities, they may have also inadvertently led to faulty assumptions about the function of the symbiosis in natural settings. Here we highlight the consequences of failing to consider the AM symbiosis from the perspectives of community ecology and evolutionary biology. Also, we argue that by distinguishing between physiological and evolutionary viewpoints, we may be able to resolve controversies regarding the mutualistic vs. parasitic nature of the symbiosis. Further, while most AM research has emphasized resource transfers, primarily phosphate and carbohydrate, our perceptions of parasitism, cheating, bet-hedging, and partner choice would most likely change if we considered other services. Finally, to gain a fuller understanding of the role of the AM symbiosis in nature, we need to better integrate physiological processes of plants and their AM fungi with their naturally occurring temporal and spatial patterns. It is our hope that this article will generate some fruitful discussions and make a contribution toward this end.


2016 ◽  
Vol 4 (2) ◽  
pp. 191-197 ◽  
Author(s):  
Gamal M. Abdel-Fattah ◽  
Wafaa M. Shukry ◽  
Mahmoud M.B. Shokr ◽  
Mai A. Ahmed

This study aimed to investigate the effects of arbuscular mycorrhizal (AM) fungi with different levels of NPK fertilizers on yield production of common bean plants which common bean plants were subjected to five levels of NPK fertilizers (0, 25, 50, 75, 100 %). Application of AMF significantly increased the growth and yield components of common beans with minimized the levels of NPK comparing to equivalents non-mycorrhizal ones. The results obtained revealed that inoculation with AMF and the concentrations 50% and 75% of NPK with AMF are the greater than other concentrations and non-mycorrhizal plants. Mycorrhizal Common bean plants had significantly higher number of pods, length of one pod, pods weight, 100 seeds weight, weight of seed/plant and intensity of mycorrhizal colonization(M%) . Concentrations of nutrients (N, P, K, Ca and Mg) and total carbohydrates, crude protein and mycorrhizal dependency of some yield parameters were significantly increased in mycorrhizal plants at different NPK levels when comparing to those of non-mycorrhizal plants paticularly at (50% and 75%) concentration of NPK, but lower Na concentration in mycorrhizal common bean seeds than those of non-mycorrhizal.Int J Appl Sci Biotechnol, Vol 4(2): 191-197


2021 ◽  
Vol 7 (8) ◽  
pp. 671
Author(s):  
Xiao Lou ◽  
Xiangyu Zhang ◽  
Yu Zhang ◽  
Ming Tang

The simultaneous effects of arbuscular mycorrhizal (AM) fungi and abscisic acid (ABA) on the tolerance of plants to heavy metal (HM) remain unclear. A pot experiment was carried out to clarify the effects of simultaneous applications of AM fungi and ABA on plant growth, Zn accumulation, endogenous ABA contents, proline metabolism, and the oxidative injury of black locust (Robinia pseudoacacia L.) exposed to excess Zn stress. The results suggested that exogenously applied ABA positively enhanced AM colonization, and that the growth of plants only with AM fungi was improved by ABA application. Under Zn stress, AM inoculation and ABA application increased the ABA content in the root/leaf (increased by 48–172% and 92%, respectively) and Zn content in the root/shoot (increased by 63–152% and 61%, respectively) in AM plants, but no similar trends were observed in NM plants. Additionally, exogenous ABA addition increased the proline contents of NM roots concomitantly with the activities of the related synthases, whereas it reduced the proline contents and the activity of Δ1-pyrroline-5-carboxylate synthetase in AM roots. Under Zn stress, AM inoculation and ABA application decreased H2O2 contents and the production rate of O2, to varying degrees. Furthermore, in the roots exposed to Zn stress, AM inoculation augmented the activities of SOD, CAT, POD and APX, and exogenously applied ABA increased the activities of SOD and POD. Overall, AM inoculation combined with ABA application might be beneficial to the survival of black locust under Zn stress by improving AM symbiosis, inhibiting the transport of Zn from the roots to the shoots, increasing the distribution of ABA in roots, and stimulating antioxidant defense systems.


2017 ◽  
Vol 9 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Khirood DOLEY ◽  
Mayura DUDHANE ◽  
Mahesh BORDE

Sclerotium rolfsii (Sacc.) is the causal agent of stem-rot in groundnut (Arachis hypogaea L.)crop. With the increase in demand for the groundnut, control of stem-rot efficiently by microbial strains is fast becoming inevitable as the conventional system of chemicals is degrading our ecosystem. This investigation here emphasizes on inoculation of arbuscular mycorrhizal fungi (AMF) and Trichoderma species for growth achievement and disease control. The present investigation showed that these microbial strains were found to be worth applying as they stimulated growth and decreased harmful effects of S. rolfsii (cv. ‘Western-51’). The increased biochemical parameters and antioxidant activities also indicated their defence related activities in groundnut plants. In spite of positive attributes meted out by these microbial strains towards groundnut crop, the interaction among AM fungi and Trichoderma species seemed to be less co-operative between each other which were noted when mycorrhizal dependency and percent root colonization were observed. However, in summary more practical application of low-input AM fungi along with Trichoderma species may be needed for the advancement of modern agricultural systems.


2003 ◽  
Vol 83 (4) ◽  
pp. 337-342 ◽  
Author(s):  
A. Liu ◽  
C. Hamel ◽  
S. H. Begna ◽  
B. L. Ma ◽  
D. L. Smith

The ability of arbuscular mycorrhizal (AM) fungi to help their host plant absorb soil P is well known, but little attention has been paid to the effect of AM fungi on soil P depletion capacity. A greenhouse experiment was conducted to assess, under different P levels, the effects of mycorrhizae on extractable soil P and P uptake by maize hybrids with contrasting phenotypes. The experiment had three factors, including two mycorrhizal treatments (mycorrhizal and non-mycorrhizal), three P fertilizer rates (0, 40, and 80 mg kg-1) and three maize hybrids [leafy normal stature (LNS), leafy reduced stature (LRS) and a conventional hybrid, Pioneer 3979 (P3979)]. Extractable soil P was determined after 3, 6 and 9 wk of maize growth. Plant biomass, P concentration and total P content were also determined after 9 wk of growth. Fertilization increased soil extractable P, plant biomass, P concentration in plants and total P uptake. In contrast to P3979, the LNS and LRS hybrids had higher biomass and total P content when mycorrhizal. Mycorrhizae had less influence on soil extractable P than on total P uptake by plants. The absence of P fertilization increased the importance of AM fungi for P uptake, which markedly reduced soil extractable P under AM plants during growth. This effect was strongest for LNS, the most mycorrhizae-dependent hybrid, intermediate for LRS, and not significant for the commercial hybrid P3979, which did not respond to AM inoculation. Key words: Arbuscular mycorrhizal fungi, extraradical hyphae, maize hybrid,plant biomass, P uptake, soil extractable P


2022 ◽  
Vol 5 (1) ◽  
Author(s):  
Sachiko Tanaka ◽  
Kayo Hashimoto ◽  
Yuuki Kobayashi ◽  
Koji Yano ◽  
Taro Maeda ◽  
...  

AbstractArbuscular mycorrhizal (AM) symbiosis is a mutually beneficial interaction between fungi and land plants and promotes global phosphate cycling in terrestrial ecosystems. AM fungi are recognised as obligate symbionts that require root colonisation to complete a life cycle involving the production of propagules, asexual spores. Recently, it has been shown that Rhizophagus irregularis can produce infection-competent secondary spores asymbiotically by adding a fatty acid, palmitoleic acid. Furthermore, asymbiotic growth can be supported using myristate as a carbon and energy source for their asymbiotic growth to increase fungal biomass. However, the spore production and the ability of these spores to colonise host roots were still limited compared to the co-culture of the fungus with plant roots. Here we show that a combination of two plant hormones, strigolactone and jasmonate, induces the production of a large number of infection-competent spores in asymbiotic cultures of Rhizophagus clarus HR1 in the presence of myristate and organic nitrogen. Inoculation of asymbiotically-generated spores promoted the growth of host plants, as observed for spores produced by symbiotic culture system. Our findings provide a foundation for the elucidation of hormonal control of the fungal life cycle and the development of inoculum production schemes.


2021 ◽  
Vol 12 ◽  
Author(s):  
Shen Cheng ◽  
Ying-Ning Zou ◽  
Kamil Kuča ◽  
Abeer Hashem ◽  
Elsayed Fathi Abd_Allah ◽  
...  

Plants are often subjected to various environmental stresses during their life cycle, among which drought stress is perhaps the most significant abiotic stress limiting plant growth and development. Arbuscular mycorrhizal (AM) fungi, a group of beneficial soil fungi, can enhance the adaptability and tolerance of their host plants to drought stress after infecting plant roots and establishing a symbiotic association with their host plant. Therefore, AM fungi represent an eco-friendly strategy in sustainable agricultural systems. There is still a need, however, to better understand the complex mechanisms underlying AM fungi-mediated enhancement of plant drought tolerance to ensure their effective use. AM fungi establish well-developed, extraradical hyphae on root surfaces, and function in water absorption and the uptake and transfer of nutrients into host cells. Thus, they participate in the physiology of host plants through the function of specific genes encoded in their genome. AM fungi also modulate morphological adaptations and various physiological processes in host plants, that help to mitigate drought-induced injury and enhance drought tolerance. Several AM-specific host genes have been identified and reported to be responsible for conferring enhanced drought tolerance. This review provides an overview of the effect of drought stress on the diversity and activity of AM fungi, the symbiotic relationship that exists between AM fungi and host plants under drought stress conditions, elucidates the morphological, physiological, and molecular mechanisms underlying AM fungi-mediated enhanced drought tolerance in plants, and provides an outlook for future research.


2021 ◽  
Author(s):  
Kyoichi Kodama ◽  
Mélanie K. Rich ◽  
Akiyoshi Yoda ◽  
Shota Shimazaki ◽  
Xiaonan Xie ◽  
...  

AbstractIn flowering plants, carotenoid-derived strigolactones (SLs) have dual functions as hormones that regulate growth and development, and as rhizosphere signaling molecules that induce symbiosis with arbuscular mycorrhizal (AM) fungi. Here, we report the identification of bryosymbiol (BSB), a previously unidentified SL from the bryophyte Marchantia paleacea. BSB is also found in vascular plants, indicating that it is ancestral in land plants. BSB synthesis is enhanced at AM symbiosis permissive conditions and BSB deficient mutants are impaired in AM symbiosis. In contrast, the absence of BSB synthesis has little effect on the growth and gene expression. We show that the introduction of the SL receptor of Arabidopsis renders M. paleacea cells BSB-responsive. These results suggest that BSB is not perceived by M. paleacea cells due to the lack of cognate SL receptors. We propose that SLs originated as AM symbiosis-inducing rhizosphere signaling molecules and were later recruited as plant hormone.


HortScience ◽  
1996 ◽  
Vol 31 (3) ◽  
pp. 366-369 ◽  
Author(s):  
Amelia Camprubí ◽  
Cinta Calvet

The selection of the most effective arbuscular mycorrhizal (AM) fungi for growth enhancement of citrus cultivars used as rootstocks was the first step toward development of an AM inoculation system in citrus nurseries in Spain. AM fungi were isolated from citrus nurseries and orchards in the major citrus-growing areas of eastern Spain. The most common AM fungi found in citrus soils belonged to Glomus species, and G. mosseae (Nicol. & Gerd.) Gerdemann & Trappe and G. intraradices Schenck & Smith were the AM fungi most frequently associated with citrus roots. The most effective fungus for growth enhancement of citrus rootstocks was G. intraradices. Significant differences in mycorrhizal dependency among rootstocks were confirmed. Sour orange (Citrus aurantium L.) and Cleopatra mandarin (C. reshni L.) were more dependent than Troyer citrange [C. sinensis (L.) Obs. × Poncirus trifoliata (L.) Raf.] and Swingle citrumelo (C. paradisi Macf. × P. trifoliata). Moreover, several inoculation systems for plant production were evaluated for their effectiveness in promoting root colonization of the rootstock cultivars.


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