title: Interactive effects of temperature and UVB radiation on methane emissions from different organs of pea plants grown in hydroponic system.
abstract: There is no information on variation of methane (CH4) emissions from plant organs exposed to multiple environmental factors. We investigated the interactive effects of temperature and ultraviolet-B (UVB) radiation on CH4emissions from different organs of pea (Pisum sativum L. var. UT234 Lincoln). Plants were grown hydroponically under two temperatures (22/18°C and 28/24°C; 16h day/8h night) and two levels of UVB radiation [0 and 5kJm-2d-1] in controlled-environment growth chambers for ten days, after two weeks of initial growth under ambient temperatures. Methane emission, dry mass, growth index, electrical conductivity (EC), pectin, total chlorophyll content, gas exchange and flavonoids were measured in the appropriate plant organs - leaf, stem and root. Higher temperatures increased CH4emissions, leaf mass ratio, and shoot: root mass ratio. Neither temperature nor UVB had significant effects on leaf, stem, root and total dry mass, EC, pectin, total chlorophyll, as well as specific leaf mass. Among plant organs, there were differences in CH4, EC, pectin and total chlorophyll. Methane and EC were highest for the stem and lowest for the leaf; leaf had highest, but stem had lowest, pectin content; total chlorophyll was highest in the leaf but lowest in the root. Higher temperatures decreased leaf flavonoids, net carbon dioxide assimilation, and water use efficiency. Overall, environmental stressors increased aerobic CH4emission rates, which varied with plant organs.
authors.affiliation: Department of Biology, Life Science Centre, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia B3H 4R2, Canada.
authors.forename: Awatif M
authors.initials: AM
authors.lastname: Abdulmajeed
authors.affiliation: Department of Biology, Mount Saint Vincent University, 166 Bedford Highway, Halifax, Nova Scotia B3M 2J6, Canada.
authors.forename: Samantha R
authors.initials: SR
authors.lastname: Derby
authors.affiliation: Department of Biology, Mount Saint Vincent University, 166 Bedford Highway, Halifax, Nova Scotia B3M 2J6, Canada.
authors.forename: Samantha K
authors.initials: SK
authors.lastname: Strickland
authors.affiliation: Department of Biology, Life Science Centre, Dalhousie University, 1355 Oxford Street, Halifax, Nova Scotia B3H 4R2, Canada; Department of Biology, Mount Saint Vincent University, 166 Bedford Highway, Halifax, Nova Scotia B3M 2J6, Canada. Electronic address: mirwais.qaderi@msvu.ca.
authors.forename: Mirwais M
authors.initials: MM
authors.lastname: Qaderi
mesh_terms: D018527:Hydroponics; D008697:Methane / Q000378:metabolism*; D018532:Pisum sativum / Q000254:growth & development / Q000378:metabolism*; D013696:Temperature; D014466:Ultraviolet Rays
chemical_list: D008697:Methane
keywords: Aerobic methane; Climate change; Environmental factors; Hydroponic system; Physiological response; Plant growth