title: Autochthonous arbuscular mycorrhizal fungi and Bacillus thuringiensis from a degraded Mediterranean area can be used to improve physiological traits and performance of a plant of agronomic interest under drought conditions.
abstract: Studies have shown that some microorganisms autochthonous from stressful environments are beneficial when used with autochthonous plants, but these microorganisms rarely have been tested with allochthonous plants of agronomic interest. This study investigates the effectiveness of drought-adapted autochthonous microorganisms [Bacillus thuringiensis (Bt) and a consortium of arbuscular mycorrhizal (AM) fungi] from a degraded Mediterranean area to improve plant growth and physiology in Zea mays under drought stress. Maize plants were inoculated or not with B. thuringiensis, a consortium of AM fungi or a combination of both microorganisms. Plants were cultivated under well-watered conditions or subjected to drought stress. Several physiological parameters were measured, including among others, plant growth, photosynthetic efficiency, nutrients content, oxidative damage to lipids, accumulation of proline and antioxidant compounds, root hydraulic conductivity and the expression of plant aquaporin genes. Under drought conditions, the inoculation of Bt increased significantly the accumulation of nutrients. The combined inoculation of both microorganisms decreased the oxidative damage to lipids and accumulation of proline induced by drought. Several maize aquaporins able to transport water, CO2 and other compounds were regulated by the microbial inoculants. The impact of these microorganisms on plant drought tolerance was complementary, since Bt increased mainly plant nutrition and AM fungi were more active improving stress tolerance/homeostatic mechanisms, including regulation of plant aquaporins with several putative physiological functions. Thus, the use of autochthonous beneficial microorganisms from a degraded Mediterranean area is useful to protect not only native plants against drought, but also an agronomically important plant such as maize.
authors: Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Prof. Albareda 1, 18008 Granada, Spain.
authors: Elisabeth
authors: E
authors: Armada
authors: Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Prof. Albareda 1, 18008 Granada, Spain. Electronic address: rosario.azcon@eez.csic.es.
authors: Rosario
authors: R
authors: Azcón
authors: Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Prof. Albareda 1, 18008 Granada, Spain.
authors: Olga M
authors: OM
authors: López-Castillo
authors: Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Prof. Albareda 1, 18008 Granada, Spain.
authors: Mónica
authors: M
authors: Calvo-Polanco
authors: Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Prof. Albareda 1, 18008 Granada, Spain.
authors: Juan Manuel
authors: JM
authors: Ruiz-Lozano
mesh_terms: D000222:Adaptation, Physiological; D020346:Aquaporins / Q000378:metabolism; D001413:Bacillus thuringiensis; D018556:Crops, Agricultural / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology; D055864:Droughts; D005658:Fungi; D019083:Mediterranean Region; D038821:Mycorrhizae; D013312:Stress, Physiological; D013559:Symbiosis; D014867:Water / Q000378:metabolism; D003313:Zea mays / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology*
chemical_list: D020346:Aquaporins; D014867:Water
keywords: AM fungi; Aquaporin; Bacillus thuringiensis; Drought; Maize; Plant growth promoting microorganism