Seedborne fungal contamination: consequences in space-grown wheat

• Published in: Phytopathology Vol. 87; no. 11; pp. 1125 - 1133
• Main Authors: Bishop, D.L, Levine, H.G, Kropp, B.R, Anderson, A.J
• Format: Journal Article
• Language: English
• Published: Kennedy Space Center American Phytopathological Society 01.11.1997
• Subjects: AGENT PATHOGENE; analysis; APESANTEUR; Biological and medical sciences; CELL CULTURE; CHAMPIGNON; CHEMICAL COMPOSITION; chemical constituents of plants; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; CONIDIA; CONTROL DE ENFERMEDADES; CONTROLE DE MALADIES; CRECIMIENTO; CROISSANCE; CULTIVO DE CELULAS; CULTURE DE CELLULE; cultured cells; DIAGNOSIS; DIAGNOSTIC; diagnostic techniques; DIAGNOSTICO; DISEASE CONTROL; Edible Grain; Edible Grain - microbiology; ENDOFITAS; ENDOPHYTE; ENDOPHYTES; ENFERMEDADES FUNGOSAS; Environment, Controlled; enzymology; ESPACEMENT; ESPACIAMIENTO; ESPORAS; ESPORAS FUNGICAS; FEUILLE; FRUCTOSA; FRUCTOSE; Fundamental and applied biological sciences. Psychology; FUNGAL DISEASES; FUNGAL MORPHOLOGY; Fungal plant pathogens; FUNGAL SPORES; FUNGI; Fungi - isolation & purification; GERMINACION; GERMINATION; GLUCOSA; GLUCOSE; GROWTH; growth & development; HOJAS; HONGOS; Hot Temperature; INFECTIVITY; INGRAVIDEZ; INOCULUM DENSITY; Isoenzymes; Isoenzymes - metabolism; isolation & purification; LEAVES; Life Sciences (General); MALADIE FONGIQUE; MANNOSE; MANOSA; metabolism; methods; MICELIO; microbiology; MORFOLOGIA FUNGICA; MORPHOLOGIE DE CHAMPIGNON; MYCELIUM; NEOTYPHODIUM CHILENSE; ORGANISME TRANSMISSIBLE PAR SEMENCE; ORGANISMOS PATOGENOS; ORGANISMOS TRANSMITIDOS POR SEMILLA; PATHOGENICITY; PATHOGENS; Pathology, epidemiology, host-fungus relationships. Damages, economic importance; PATOGENICIDAD; PEROXIDASAS; peroxidase; PEROXIDASES; Peroxidases - analysis; Peroxidases - metabolism; PEROXYDASE; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases; plant diseases and disorders; plant pathogenic fungi; Poaceae; Poaceae - microbiology; POUVOIR PATHOGENE; RACINE; RAICES; ROOTS; ROW SPACING; SACCHAROSE; seed-borne fungi; SEEDBORNE ORGANISMS; Seeds; Seeds - microbiology; SINTOMAS; SPACE FLIGHT; SPACE SHUTTLE EXPERIMENTS; SPACING; SPORE; SPORE DISPERSAL; SPORE FONGIQUE; spore germination; SPORES; Sterilization; Sterilization - methods; SUCROSA; SUCROSE; SYMPTOME; SYMPTOMS; TEMPERATURA; TEMPERATURE; Triticum; Triticum - enzymology; Triticum - growth & development; Triticum - microbiology; TRITICUM AESTIVUM; Weightlessness; XILOSA; XYLOSE; ZERO GRAVITY; Support, U.s. Gov't, Non-P.h.s; Triticum/enzymology/growth & Development/microbiology; Support, Non-U.s. Gov't; Comparative Study; Non-Nasa Center; Sterilization/methods; Weightlessness; Space Flight; Short Duration; Environment, Controlled; Flight Experiment; Nasa Discipline Plant Biology; Seeds/microbiology; Heat; Cereals/microbiology; Peroxidases/analysis/metabolism; Sts-63 Shuttle Project; Poaceae/microbiology; Plant Diseases; Manned; Fungi/isolation & Purification; Isoenzymes/metabolism; Monocotyledones; Heat treatment; Plant pathogen; Disinfection; Space flight; Cereal crop; Fungi; Symptomatology; Gramineae; Artificial medium; Seed; Angiospermae; Endophyte; Spermatophyta; Biological contamination; Microgravity; Triticum aestivum; Thallophyta; NASA Discipline Plant Biology; Non-NASA Center
• ISSN: 0031-949X; 1943-7684
• DOI: 10.1094/phyto.1997.87.11.1125

Plants grown in microgravity are subject to many environmental stresses that may promote microbial growth and result in disease symptoms. Wheat (cv. Super Dwarf) recovered from an 8-day mission aboard a NASA (National Aeronautics and Space Administration) space shuttle showed disease symptoms, including girdling of leaf sheaths and chlorosis and necrosis of leaf and root tissues. A Neotyphodium species was isolated from the seed and leaf sheaths of symptomatic wheat used in the spaceflight mission. Certain isozymes of a peroxidase unique to extracts from the microgravity-grown plants were observed in extracts from earth-grown Neotyphodium-infected plants but were not present in noninfected wheat. The endophytic fungus was eliminated from the wheat seed by prolonged heat treatment at 50 degrees C followed by washes with water at 50 degrees C. Plants from wheat seed infected with the Neotyphodium endophyte were symptomless when grown under greenhouse conditions, whereas symptoms appeared after only 4 days of growth in closed containers. Disease spread from an infected plant to noninfected plants in closed containers. Dispersion via spores was found on asymptomatic plants at distances of 7 to 18 cm from infected plants. The size and shape of the conidia, mycelia, and phialide-bearing structures and the ability to grow rapidly on carbohydrates, especially xylose, resembled the characteristics of N. chilense, which is pathogenic on orchard grass, Dactylis glomerata. The Neotyphodium wheat isolate caused disease symptoms on other cereals (wheat cv. Malcolm, orchard grass, barley, and maize) grown in closed containers