Ionomic and biochemical responses of maize plant (Zea mays L.) inoculated with Funneliformis mosseae to water-deficit stress

Abstract

The response of arbuscular mycorrhizal fungi (AMF)-inoculated plants to environmental stresses including drought stress is a complex phenomenon that involves activation or modification of processes occurring at physiological, biochemical, and molecular levels. However, the information on the ionomic and biochemical responses of AMF-inoculated plants under drought stress is limited. This study aimed to investigate the effect of AM fungus Funneliformis mosseae on maize plant growth, uptake of nutrients, and antioxidant responses of the plant to water-deficit stress under greenhouse conditions in a sterilized calcareous soil(Typic Calcixerepts). The experiment was laid out in a two-factor experiment in a completely randomized design with four replicates. The experimental factors included three different water regimes (100%, 70%, and 50% field capacity (FC)) and AM fungus at two levels (inoculated with or without F. mosseae). Water-deficit stress reduced plant biomass, chlorophyll index, nutrients uptake (P, K, Ca, Mg, Fe, Zn, Mn and Cu in shoots and roots), root colonization but increased malondialdehyde content. Inoculation with F. mosseae had a positive effect on plant growth, chlorophyll index, and nutrients uptake. Activities of guaiacol peroxidase (12.4%), superoxide dismutase (6.5%), and catalase (21.6%) as well as total phenolic content (62.5%) were higher in mycorrhizal plants as compared to non-mycorrhizal plants at 50% FC level. Lipid peroxidation (36.6% and 39.4% at 70 and 50% FC levels, respectively) was higher in non-AM plants as compared to AM plants. Under non-stress conditions, growth and nutrients uptake of mycorrhizal plants were greater than non-mycorrhizal ones. In general, the results of this study indicated that inoculation with F. mosseae through the improvement of ionomic and biochemical status of the plant can mitigate the detrimental effects of water-deficit stress on maize plants. The results of this study also suggest that the shoot and root ionome could be a useful phenotype for understanding the complicated interaction between F. mosseae and maize plant by providing readouts indicative of the biochemical processes occurring in the roots and shoots.