Interaction between arbuscular mycorrhizal fungi and Bacillus spp. in soil enhancing growth of crop plants

Abstract

Soil microorganisms play an important role in enhancing soil fertility and plant health. Arbuscular mycorrhizal fungi and plant growth promoting rhizobacteria form a key component of the soil microbial population. Arbuscular mycorrhizal fungi form symbiotic association with most of the cultivated crop plants and they help plants in phosphorus nutrition and protecting them against biotic and abiotic stresses. Many species of Bacillus occurring in soil are also known to promote plant growth through phosphate solubilization, phytohormone production and protection against biotic and abiotic stresses. Synergistic interaction between AMF and Bacillus spp. in promoting plant growth compared to single inoculation with either of them has been reported. This is because of enhanced nutrient uptake, protection against plant pathogens and alleviation of abiotic stresses (water, salinity and heavy metal) through dual inoculation compared to inoculation with either AMF or Bacillus alone.

Species-Specific Interactions of Bacillus Innocula and Arbuscular Mycorrhizal Fungi Symbiosis with Winter Wheat

“…An increase in plant biomass from the inoculation of soils with select Bacilli spp . is also reported by [ 43 ]. Application of the Bonferroni factor to the data and Bacilli spp .…”

“…Xie et al [ 42 ] also report an increase in AM fungal symbiosis due to the presence of B. amyloliquefaciences using other plant species ( Lotus corniculatus , Thymus serpyllum , and Trifolium repens ) instead of wheat. While their study did not use soil glomalin as an indicator of AM fungal growth, their findings were comparable with B. amyloliquefaciences applications noted to increase AM fungal biomass due to its MHB properties, with some literature indicating AM fungi benefit from the presence of B. amyloliquefaciences [ 42 , 43 , 44 , 45 , 46 ]. The significant increase in glomalin in soils from both tillage treatments reported in the current study further supports this conclusion.…”

“…Arbuscules facilitate the transfer of soil nutrients acquired by AM fungal mycelia to the plant roots [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ], as well as further enhancing glomalin due to increasing the fungal biomass. The greater proliferation of AM fungi root symbiotic structures increases the plant root surface area, allowing for less plant derived resources required for root growth and development to assimilate the same quantity of nutrients.…”

“…Furthermore, B. amyloliquefaciens is reported by [ 50 ] and [ 51 ] to suppress plant and fungal pathogenic nematodes and fungal pathogens such as Fusarium [ 52 ]. The AM fungus, R. irregularis, is reported to benefit directly from the presence of B. amyloliquefaciences [ 42 , 43 ] acting as MHB facilitating colonisation of the host plant. The beneficial impact to the wheat plant from B. amyloliquefaciens inoculation observed here supports the observation of [ 42 ], with both an increase in glomalin production and root arbuscules evident.…”

Effects of Nitroxin and arbuscular mycorrhizal fungi on the agro-physiological traits and grain yield of sorghum (Sorghum bicolor L.) under drought stress conditions

“…Plants, AMF and bacteria can therefore be considered tripartite associations leading to a consortium promoting plant growth [18]. The interaction between the micro-organisms in the rhizosphere influences plant growth and production and health directly or indirectly in agricultural and natural habitats by providing nutritional elements and resistance to biotic and abiotic stresses [19]. Therefore these symbiotic relationships between the soil microbes are known to have an advantageous effect on plants by improving the accessibility of the nutrients to the host plants and inducing the plant defenses against different stresses such as drought and salinity [17].…”