Water redistribution in mycorrhizosphere of trifoliate orange

Abstract

Mycorrhizal hyphae possess the ability of absorbing water directly from the surrounding matrix to root, whereas it is not clear whether water flow redistributes from hyphae to surrounding matrix. In this study, potted trifoliate orange (Poncirus trifoliata) seedlings were inoculated with an arbuscular mycorrhizal (AM) fungus Funneliformis mosseae and grown under well-watered (WW) and drought stress (DS) in Jingzhou, China. A 12.5-mL safety glass bottle with open mouth and growth substrate was placed into the pot, combining a root system in-situ. The bottle was sealed and collected after 6-week DS treatment. The soil DS-treatment strongly reduced root mycorrhizal colonization and soilhyphal length, relative to WW-treatment. A significantly higher soil water content of the bottle was found in AMtreated seedlings than in non-AM seedlings, irrespective of WW and DS, confirming the presence of hyphal water redistribution in AM-plants. Considerable reduction of hyphal water redistribution under DS only, but not under WW, implies that greater water status in AM-plants under DS would benefit plant biomass production uninterruptedly.