Morphophysiological and Biochemical Responses of Zea mays L. under Cadmium and Drought Stresses Integrated with Fungal and Bacterial Inoculation

Abstract

Cadmium and drought stress are the most destructive of the abiotic stresses with negative effects on both metabolism and photosynthesis. The present experiment aimed to analyze the impact of inoculation with Bacillus paralicheniformis and Trichoderma asperellum on the growth and antioxidant response modulation of maize (Zea mays L.), under drought and Cadmium (Cd) stresses. Regarding plant biomass analysis, fungi inoculation increased leaf dry biomass significantly (11.92%) towards uninoculated ones. The leaf area was affected significantly by bacterial application, 12.15% more than the control. A significant trend (drought+ Cd stress) was observed between fungi-inoculated maize leaves (15.07 µmol/g FW) and bacterial-inoculated leaves (18.71 µmol/g FW) regarding the malondialdehyde quantity. Furthermore, the activities of superoxide dismutase were notably higher (9.63–40.88%) in microorganism-inoculated roots. Similarly, under drought + Cd stress, peroxidase demonstrated a higher activity under bacterial inoculation than fungal ones (92.11% more). The maximum translocation factor was observed in the uninoculated group (under Cd stress), while the bioconcentration factor under drought stress showed a significant increase by microorganisms. The maximum relative water content under bacterial inoculation (82.66%) was achieved. The fungi and bacterial inoculation minimized Cd accumulation in the leaf significantly under drought and drought + Cd stress. Generally, the microorganism inoculation positively and partially maintained the plant’s performance, despite the presence of drought and Cd stress.