Arbuscular mycorrhizal fungi protects maize plants from high temperature stress by regulating photosystem II heterogeneity

Although protective role of arbuscular mycorrhizal fungi (AMF) during abiotic stress condition is well known, however, the mechanism of it is still unclear. In order to elucidate the role of AMF in regulating photosystem (PS) II heterogeneity, experiments were carried out with maize plants grown in soil enriched with AMF that experienced high temperature (HT) stress. Chlorophyll a fluorescence induction kinetics were performed to measure PSII heterogeneity for control, AMF, AMF + HT, and HT in maize plants. Presence of AMF was able to provide conditions that favour conversion of inactive beta and gamma centers to active alpha centers, and Q(B) non-reducing centers to reducing centers in maize plants. Such possibility of AMF action was not reported earlier in maize plants under high temperature stress. This is first ever study to report role of AMF in regulating PSII heterogeneity under high temperature stress in maize plants. The study will be helpful to use PSII heterogeneity as a bioindicator to know about level of stress in plants.