title: Ethylene production by plants in a closed environment.
abstract: Ethylene production by 20-m2 stands of wheat, soybean, lettuce and potato was monitored throughout growth and development in NASA's Controlled Ecological Life Support System (CELSS) Biomass Production Chamber.  Chamber ethylene concentrations rose during periods of rapid growth for all four species, reaching 120 parts per billion (ppb) for wheat, 60 ppb for soybean, and 40 to 50 ppb for lettuce and potato.  Following this, ethylene concentrations declined during seed fill and maturation (wheat and soybean), or remained relatively constant (potato).  Lettuce plants were harvested during rapid growth and peak ethylene production.  The highest ethylene production rates (unadjusted for chamber leakage) ranged from 0.04 to 0.06 ml m-2 day-1 during rapid growth of lettuce and wheat stands, or approximately 0.8 to 1.1 nl g-1 fresh weight h-1.  Results suggest that ethylene production by plants is a normal event coupled to periods of rapid metabolic activity, and that ethylene removal or control measures should be considered for growing crops in a tightly closed CELSS.
authors.affiliation: NASA Office of Biological Research and Life Support, Kennedy Space Center, FL 32899, USA.
authors.forename: R M
authors.initials: RM
authors.lastname: Wheeler
authors.forename: B V
authors.initials: BV
authors.lastname: Peterson
authors.forename: J C
authors.initials: JC
authors.lastname: Sager
authors.forename: W M
authors.initials: WM
authors.lastname: Knott
mesh_terms: D000388:Air / Q000032:analysis; D000389:Air Conditioning; D018504:Ecological Systems, Closed; D004780:Environment, Controlled; D005030:Ethylenes / Q000032:analysis / Q000096:biosynthesis*; D018545:Lactuca / Q000254:growth & development / Q000378:metabolism; D008021:Life Support Systems; D010788:Photosynthesis; D063245:Plant Development; D010937:Plant Growth Regulators / Q000032:analysis / Q000096:biosynthesis*; D010944:Plants / Q000378:metabolism*; D011198:Solanum tuberosum / Q000254:growth & development / Q000378:metabolism; D013025:Glycine max / Q000254:growth & development / Q000378:metabolism; D014908:Triticum / Q000254:growth & development / Q000378:metabolism
chemical_list: D005030:Ethylenes; D010937:Plant Growth Regulators; C036216:ethylene