The role of arbuscular mycorrhizal fungi in refining plant photosynthesis and water status under drought stress: a meta-analysis

Due to increased climate change, crop productivity worldwide is in danger. Drought stress is considered one of the major environmental factors in relation to world food security. Previous studies showed that arbuscular mycorrhizal fungi (AMF) inoculation alleviates drought stress in various plants. However, whether AMF inoculation efficiency is based on gas exchange or water status and whether the effects differ among plants and AMF species remain unclear. To evaluate the effect of AMF on drought stress alleviation, a meta -analysis was conducted based on random -effect models accounting for effect size variation. Results revealed that photosynthetic rate had the highest effect size among gas exchange traits compared to stomatal conductance and transpiration rate. Our results also showed a significant positive impact on relative water content, water potential, and water use efficiency in AMFinoculated plants compared to non -inoculated plants. Furthermore, among AMF species, Funneliformis mosseae, , followed by Rhizophagus irrgularis, , was an efficient AM fungi for drought stress alleviation. Therefore, this study suggests that a higher water use efficiency supports water transport to the leaf surface and keeps the stomatal opening, enhancing photosynthetic responses.