生物谷報道：5月8日，一個多國聯(lián)合小組研究表明大量海藻的存在可以影響附近的天氣變化,。
研究人員在研究褐藻和大氣關(guān)系時發(fā)現(xiàn),，在陰云密布,，海水退潮時是海藻最喜歡的天氣,，海水的漲落可以保持藻類的濕潤。但是在陽光直射時,，一旦海水退潮,，藻類就會暴露在陽光底下，這時褐藻會釋放出一種無機(jī)碘,。這種碘化物可以中和大氣中的臭氧,，但是隨著碘化物的增多，這些化學(xué)物質(zhì)就變成大氣凝結(jié)核,，云層開始在其周圍聚集,，為褐藻遮住陽光，從而影響氣候,，同時為褐藻提供一個更舒適的環(huán)境,。釋放碘化物是海藻在壓力狀態(tài)下的一種自我防御機(jī)制，在遭受微生物襲擊時,，海藻組織也會釋放大量碘化物到海水中,。（生物谷www.bioon.com）
生物谷推薦原始出處：
PNAS published May 5, 2008, 10.1073/pnas.0709959105
Iodide accumulation provides kelp with an inorganic antioxidant impacting atmospheric chemistry
Frithjof C. Küppera,b,c,d, Lucy J. Carpentere, Gordon B. McFiggansf, Carl J. Palmere,g, Tim J. Waiteh, Eva-Maria Bonebergb,i, Sonja Woitschb, Markus Weillerb, Rafael Abelaj, Daniel Grolimundj, Philippe Potink, Alison Butlerc, George W. Luther, IIIh, Peter M. H. Kroneckb, Wolfram Meyer-Klauckel, and Martin C. Feitersm
aScottish Association for Marine Science, Dunstaffnage Marine Laboratory, Oban, Argyll PA37 1QA, Scotland, United Kingdom; bFachbereich Biologie, Universität Konstanz, D-78457 Konstanz, Germany; cDepartment of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106; eDepartment of Chemistry, University of York, York YO10 5DD, United Kingdom; fSchool of Earth, Atmospheric, and Environmental Sciences, University of Manchester, Manchester M13 9PL, United Kingdom; hCollege of Marine Studies, University of Delaware, Lewes, DE 19958; iBiotechnologie Institut Thurgau, Unterseestrasse 47, CH-8280 Kreuzlingen, Switzerland; jSwiss Light Source, Paul Scherrer Institute, CH-5232 Villigen, Switzerland; kCentre National de la Recherche Scientifique and Université Pierre et Marie Curie Paris–VI, Station Biologique de Roscoff, Place Georges Teissier, BP 74, F-29682 Roscoff cedex, Bretagne, France; lEuropean Molecular Biology Laboratory, Hamburg Unit, Deutsches Elektronen Synchrotron, Notkestrasse 85, D-22607 Hamburg, Germany; and mDepartment of Organic Chemistry, Institute of Molecules and Materials, Radboud University Nijmegen, 1 Toernooiveld, NL-6525 ED, Nijmegen, The Netherlands
Edited by David M. Karl, University of Hawaii, Honolulu, HI, and approved March 11, 2008 (received for review October 18, 2007)
Abstract
Brown algae of the Laminariales (kelps) are the strongest accumulators of iodine among living organisms. They represent a major pump in the global biogeochemical cycle of iodine and, in particular, the major source of iodocarbons in the coastal atmosphere. Nevertheless, the chemical state and biological significance of accumulated iodine have remained unknown to this date. Using x-ray absorption spectroscopy, we show that the accumulated form is iodide, which readily scavenges a variety of reactive oxygen species (ROS). We propose here that its biological role is that of an inorganic antioxidant, the first to be described in a living system. Upon oxidative stress, iodide is effluxed. On the thallus surface and in the apoplast, iodide detoxifies both aqueous oxidants and ozone, the latter resulting in the release of high levels of molecular iodine and the consequent formation of hygroscopic iodine oxides leading to particles, which are precursors to cloud condensation nuclei. In a complementary set of experiments using a heterologous system, iodide was found to effectively scavenge ROS in human blood cells.
