Tracking water transport to the host plants by arbuscular mycorrhizal fungi (New Phytol)

In spite of several years of observation of the symbiotic relationship between plants and arbuscular mycorrhizal fungi, we are still learning about the intricate mechanisms and processes behind their relationship. Symbiotic fungi provide nutrients (mainly phosphorus and nitrogen), stress tolerance, and water to the host plant in return for sugars and lipids. While there have been significant advances in our knowledge about the nutrient exchange mechanisms, understanding of water transportat by fungi to the host plant has remained elusive. Kakouridis et al. demonstrated that the fungal hyphae act as an extension of the root system, driving water flow along hyphae under the influence of plant transpirational pull. Using 18O-labeled water and a fluorescent dye, they demonstrated that hyphae could assist in increasing water accessibility to the roots by overcoming the discontinuity in the water film caused by air pockets or/and variable soil particle size. This study aids to our understanding of drought stress tolerance in a symbiotic system. (Summary by Chandan Kumar Gautam @chandan_gautam) New Phytol. 10.1111/nph.18281