Thermal infrared imaging study of water status and growth of arbuscular mycorrhizal soybean (Glycine max) under drought stress

The influence of arbuscular mycorrhizal fungi (AMF) on plant water status and growth under drought stress were investigated using soybean subjected to drought stress (40% of soil water-holding capacity (WHC)) and control conditions (60% WHC) either inoculated with AMF or uninoculated controls. Leaf temperature (T-leaf) and stomatal conductance (gs) were determined at 10:00, 12:00 and 18:00 on the harvest day. The effects of AMF on the water physiological status and growth of soybeans under drought stress were examined using thermal infrared imaging technology (TIIT). AMF inoculation under drought stress increased plant above-and below-ground biomass, nutritional status, and nitrogen, phosphorus and potassium uptake rates, and reduced plant root/shoot ratio. Monitoring T-leaf reflected the effect of AMF on plant water physiological status under drought stress. AMF inoculation resulted in a decline in T-leaf of 0.1-0.4 degrees C as water uptake proceeded compared with an increase of 0.2-1.4 degrees C in uninoculated controls. Thus, the effects of AMF on soybean drought resistance changed from positive to negative. AMF reduced plant T-leaf, promoted the accumulation of photosynthetic products, reduced malondialdehyde accumulation, and increased stomatal regulation and T-leaf. These preliminary results provide a basis for further studies on the effects of AMF on the water and growth status of plants under drought stress in arid areas. (C) 2021 SAAB. Published by Elsevier B.V. All rights reserved.

Automated summary

Inoculation with AMF increased the biomass, nutritional status, and nutrient uptake rates of soybeans under drought stress, while decreasing the root/shoot ratio. The effect of AMF on plant water physiological status was reflected by monitoring leaf temperature (T-leaf). The results showed that AMF reduced plant T-leaf, promoted photosynthetic product accumulation, reduced malondialdehyde accumulation, and increased stomatal regulation and T-leaf.