title: Dark septate endophyte decreases stress on rice plants.
abstract: Abiotic stress is one of the major limiting factors for plant development and productivity, which makes it important to identify microorganisms capable of increasing plant tolerance to stress. Dark septate endophytes can be symbionts of plants. In the present study, we evaluated the ability of dark septate endophytes isolates to reduce the effects of water stress in the rice varieties Nipponbare and Piauí. The experiments were performed under gnotobiotic conditions, and the water stress was induced with PEG. Four dark septate endophytes were isolated from the roots of wild rice (Oryza glumaepatula) collected from the Brazilian Amazon. Plant height as well as shoot and root fresh and dry matter were measured. Leaf protein concentrations and antioxidant enzyme activity were also estimated. The dark septate endophytes were grown in vitro in Petri dishes containing culture medium; they exhibited different levels of tolerance to salinity and water stress. The two rice varieties tested responded differently to inoculation with dark septate endophytes. Endophytes promoted rice plant growth both in the presence and in the absence of a water deficit. Decreased oxidative stress in plants in response to inoculation was observed in nearly all inoculated treatments, as indicated by the decrease in antioxidant enzyme activity. Dark septate endophytes fungi were shown to increase the tolerance of rice plants to stress caused by water deficiency.
authors.affiliation: Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ, Brazil. Electronic address: silvanagomess@yahoo.com.br.
authors.forename: Silvana Gomes Dos
authors.initials: SGD
authors.lastname: Santos
authors.affiliation: Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ, Brazil.
authors.forename: Paula Renata Alves da
authors.initials: PRAD
authors.lastname: Silva
authors.affiliation: Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ, Brazil.
authors.forename: Andres Calderin
authors.initials: AC
authors.lastname: Garcia
authors.affiliation: Embrapa Agrobiologia, Seropédica, RJ, Brazil.
authors.forename: Jerri Édson
authors.initials: JÉ
authors.lastname: Zilli
authors.affiliation: Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ, Brazil.
authors.forename: Ricardo Luis Louro
authors.initials: RLL
authors.lastname: Berbara
mesh_terms: D000975:Antioxidants / Q000032:analysis; D001938:Brazil; D003681:Dehydration; D060026:Endophytes / Q000254:growth & development* / Q000302:isolation & purification; D012275:Oryza / Q000201:enzymology / Q000382:microbiology* / Q000502:physiology*; D010940:Plant Proteins / Q000032:analysis; D018517:Plant Roots / Q000382:microbiology; D013312:Stress, Physiological
chemical_list: D000975:Antioxidants; D010940:Plant Proteins
keywords: DSE; Oryza sativa L.; Water stress tolerance