Co-inoculation of arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria can mitigate the effects of drought in wheat plants (Triticum durum)

Drought stress (DS) is one of the severe abiotic stresses that cause reductions in agricultural production. This study was conducted to examine the efficiency of arbuscular mycorrhizal fungi (M: consortium) and plant growth-promoting rhizobacteria (R: Z2 and Z4 strains, B: CHIN14, AAP22, AAP2, and CHIN15 strains), individually or in combination, as an appropriate strategy to improve durum wheat productivity under two water regimes: well-watered (75% FC) and DS (25% FC). DS exhibition reduced biomass, stomatal conductance, stem water potential, and increased malondialdehyde and hydrogen peroxide content. Under DS, AMF or B promoted plant growth, such as shoot height by 49 and 17%, respectively; by activating the photosynthetic mechanism and increasing the synthesis of proline content by 369% in plants treated with AMF, and antioxidant enzyme activities, such as polyphenoloxydase (PPO), in leaves by 36% in plant inoculated with B. After the experiment, total organic matter and carbon of the soil were improved by single application of B by 99 and 317%, respectively. This finding implies that the combination of mycorrhiza and PGPR regulates the physiological and biochemical processes utilized by wheat to cope with drought and improves the comprehension of the soil-plant relationship.