The role of arbuscular mycorrhizal fungus (AMF, Glomus versiforme) in amelioration of drought-induced effects on growth and physio-biochemical attributes in maize (Zea mays L.) was studied. Maize plants were exposed to two drought regimes, i.e., moderate drought (MD) and severe drought (SD), with and without AMF inoculation. Drought at both levels reduced plant height, and chlorophyll and carotenoid content, thereby impeding photosynthesis. In addition, drought stress enhanced the generation of toxic reactive oxygen species (ROS), including H₂O₂, resulting in membrane damage reflected as increased electrolyte leakage and lipid peroxidation. Such negative effects were much more apparent under SD conditions that those of MD and the control, however, AMF inoculation significantly ameliorated the deleterious effects of drought-induced oxidative damage. Under control conditions, inoculation of AMF increased growth and photosynthesis by significantly improving chlorophyll content, mineral uptake and assimilation. AMF inoculation increased the content of compatible solutes, such as proline, sugars and free amino acids, assisting in maintaining the relative water content. Up-regulation of the antioxidant system was obvious in AMF-inoculated plants, thereby mediating quick alleviation of oxidative effects of drought through elimination of ROS. In addition, AMF mediated up-regulation of the antioxidant system contributed to maintenance of redox homeostasis, leading to protection of major metabolic pathways, including photosynthesis, as observed in the present study. Total phenols increased due to AMF inoculation under both MD and SD conditions. The present study advocates the beneficial role of G. versiforme inoculation in maize against drought stress.

The aim of this research was to examine the relationships among Pseudomonas fluorescens (YX2) plant growth promoting rhizobacteria (PGPR), phosphorus (P) absorption by plants, and root system architecture in apple seedlings exposed to mild, moderate or severe drought stresses. All the treatments were divided into two groups: 1) inoculated with a plant rhizobacterial strain (YX2), and 2) the non-inoculated control. Under drought stress, the YX2 inoculation improved root growth, root activity by 6%, and uptake of P, thereby promoting apple seedling growth along with the dry weight of above-ground plant parts in the mild and moderate water stress regimes. Furthermore, the inoculation also promoted total P contents in plants under both mild and moderate drought stresses. Overall, application of Pseudomonas fluorescens (YX2) is a promising approach to enhance apple production in agricultural production systems.

The current study aimed to study the effect of foliar application of nano-NPK fertilizer to one-year-old Fig trees (cv. Black Mission) in terms of tree growth performance as well as on soil microbial activity. The investigated concentrations of nano-NPK were 100, 200, 300, 400 and 500 ppm in addition to the control treatment applied for two seasons. The obtained results for both seasons indicated that all concentrations of nano-fertilizers significantly improved parameters of vegetative growth and soil health compared to the control group. However, the highest values for leaf wet and dry weight, leaf area, and leaf water content were recorded as a result of foliar fertilization at a concentration of 300 ppm. While 400 and 500 ppm nano-NPK gave the highest values for the contents of N, P, K, Ca, Mg and chlorophyll in the leaves. On the other hand, the highest bacterial activity was found in Fig’s rhizosp here subjected to foliar application with nano-NPK at concentrations of 300, 400 and 500 ppm. In addition, the highest POX and PPO isozyme activities were scored in 200 and 300 ppm. In general, foliar fertilization with nano-NPK can be recommended as it enhances vegetative growth, leaf chlorophyll and mineral contents without negative impact on soil microbial activity.