tailieunhanh - Báo cáo lâm nghiệp: "Response to an ozone gradient of growth and enzymes implicated in tolerance to oxidative stress in Acer saccharum (Marsh.) seedlings"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: "Response to an ozone gradient of growth and enzymes implicated in tolerance to oxidative stress in Acer saccharum (Marsh.) seedlings" | Ann. For. Sci. 63 2006 387-397 INRA EDP Sciences 2006 DOI forest 2006019 387 Original article Response to an ozone gradient of growth and enzymes implicated in tolerance to oxidative stress in Acer saccharum Marsh. seedlings Catherine GAUCHERa b Nadine C0STANZ0c Paul WlDDENc Jean Pierre RENAUDd Pierre DlZENGREMELb Yves MAUFFETTEa Normand CHEVRIERa a GREFi Département des Sciences Biologiques Université du Québec à Montréal . 8888 Succ centre-ville Montréal Canada H3C 3P8 b Écologie et Écophysiologie Forestières UMR 1137 INRA-UHP Nancy 1 BP 239 54506 Vandoeuvre France c Department of Biology Concordia University 1455 West de Maisonneuve Montréal Canada H3G 1M8 d Centre de recherches Acéricoles-MAPAQ 1140 rue Taillon St Foy Canada G1N 3T9 Received 3 June 2005 accepted 12 October 2005 Abstract - Two-year-old sugar maple Acer saccharum Marsh. seedlings were exposed in open top chambers to an extensive gradient of O3 0 to 300 during 85 days under two light environments 20 and 80 of full sun at noon on a sunny day . The growth of truncated seedlings with one flush of leaves and episodic seedlings with two flushes was decreased as O3 increased especially the growth of the second flush which developed under the oxidative treatment. Visible leaf injuries developed during the season under high O3 concentrations. Survivalist growth strategy of sugar maple as seen by the root shoot ratio together with the enzymatic stimulations of glucose 6-phosphate dehydrogenase phosphoenolpyruvate carboxylase and glutathione reductase allowed the seedlings to tolerate the O3 doses. However at the end of the season the cumulative oxidative stress in the second flush of the episodic seedlings exposed to concentrations over 150 too large and exceeded the capacity of seedlings for detoxification and repair. carboxylation detoxification growth oxidative stress sugar maple seedlings Résumé - Réponse de la croissance et des enzymes impliquées dans la tolerance au .