Growth in microgravity increases susceptibility of soybean [Glycine max] to a fungal pathogen

• Published in: Plant and cell physiology Vol. 42; no. 6; pp. 657 - 664
• Main Authors: Ryba-White, M. (Kansas State Univ., Manhattan (USA)), Nedukha, O, Hilaire, E, Guikema, J.A, Kordyum, E, Leach, J.E
• Format: Journal Article
• Language: English
• Published: Legacy CDMS Oxford University Press 01-06-2001; Oxford Publishing Limited (England)
• Subjects: Biological Research in Canister; BRIC; CELSS; Collaborative Ukrainian Experiment; Controlled Ecological Life Support Systems; CUE; DISEASE RESISTANCE; ETHYLENE; GLYCINE MAX; Glycine max - growth & development; GROWTH; Kennedy Fixation Tube; Kennedy Space Center; Key words: Ethylene — Microgravity — Phytophthora sojae — Williams 82; KFT; KSC; Life Sciences (General); MICROSCOPY; OES; Orbiter Environmental Simulator; PHYTOPHTHORA; Phytophthora - physiology; Plant Diseases; ROOTS; SEEDLINGS; soybean pathology; SOYPAT; Space Flight; SYMPTOMS; TEM; transmission electron microscopy; Weightlessness - adverse effects; ZERO GRAVITY; Nasa Discipline Plant Biology; Sts-87 Shuttle Project; Non-Nasa Center; Manned; Short Duration; Flight Experiment; Nasa Experiment Number 9600003; NASA Discipline Plant Biology; NASA Experiment Number 9600003; Non-NASA Center
• ISSN: 0032-0781; 1471-9053
• DOI: 10.1093/pcp/pce082

The influence of microgravity on the susceptibility of soybean roots to Phytophthora sojae was studied during the Space Shuttle Mission STS-87. Seedlings of soybean cultivar Williams 82 grown in spaceflight or at unit gravity were untreated or inoculated with the soybean root rot pathogen P. sojae. At 3, 6 and 7 d after launch wbile still in microgravity, seedlings were photographed and then fixed for subsequent microscopic analysis. Post-landing analysis of the seedlings revealed that at harvest day 7 the length of untreated roots did not differ between flight and ground samples. However, the fiight-grown roots infected with P sojae showed more disease symptoms (percentage of brown and macerated areas) and the root tissues were more extensively colonized relative to the ground controls exposed to the fungus. Ethylene levels were higher in spacefiight when compared to ground samples. These data suggest that soybean seedlings grown in microgravity are more susceptible to colonization by a fungal pathogen relative to ground controls.