title: Trichoderma spp. Improve growth of Arabidopsis seedlings under salt stress through enhanced root development, osmolite production, and Na⁺ elimination through root exudates.
abstract: Salt stress is an important constraint to world agriculture. Here, we report on the potential of Trichoderma virens and T. atroviride to induce tolerance to salt in Arabidopsis seedlings. We first characterized the effect of several salt concentrations on shoot biomass production and root architecture of Arabidopsis seedlings. We found that salt repressed plant growth and root development in a dose-dependent manner by blocking auxin signaling. Analysis of the wild type and eir1, aux1-7, arf7arf19, and tir1abf2abf19 auxin-related mutants revealed a key role for indole-3-acetic acid (IAA) signaling in mediating salt tolerance. We also found that T. virens (Tv29.8) and T. atroviride (IMI 206040) promoted plant growth in both normal and saline conditions, which was related to the induction of lateral roots and root hairs through auxin signaling. Arabidopsis seedlings grown under saline conditions inoculated with Trichoderma spp. showed increased levels of abscissic acid, L-proline, and ascorbic acid, and enhanced elimination of Na⁺ through root exudates. Our data show the critical role of auxin signaling and root architecture to salt tolerance in Arabidopsis and suggest that these fungi may enhance the plant IAA level as well as the antioxidant and osmoprotective status of plants under salt stress.
authors: Hexon Angel
authors: HA
authors: Contreras-Cornejo
authors: Lourdes
authors: L
authors: Macías-Rodríguez
authors: Ruth
authors: R
authors: Alfaro-Cuevas
authors: José
authors: J
authors: López-Bucio
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001692:Biological Transport; D018533:Biomass; D002241:Carbohydrates; D002364:Caseins / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D008055:Lipids; D009154:Mutation; D053147:Plant Exudates / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism*; D014674:Plant Proteins, Dietary / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000382:microbiology; D018520:Plant Shoots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000382:microbiology; D055049:Salt Tolerance; D036226:Seedlings / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000382:microbiology; D015398:Signal Transduction; D012965:Sodium Chloride / Q000378:metabolism / Q000494:pharmacology; D013312:Stress, Physiological; D014242:Trichoderma / Q000502:physiology*
chemical_list: D000975:Antioxidants; D029681:Arabidopsis Proteins; D002241:Carbohydrates; D002364:Caseins; D007210:Indoleacetic Acids; D008055:Lipids; D053147:Plant Exudates; D010937:Plant Growth Regulators; D014674:Plant Proteins, Dietary; C080652:Osmolite; D012965:Sodium Chloride; C030737:indoleacetic acid