title: Physiological responses and tolerance of kenaf (Hibiscus cannabinus L.) exposed to chromium.
abstract: Selection of kenaf species with chromium (Cr) tolerance and exploring the physiological mechanisms involved in Cr tolerance are crucial for application of these species to phyto-remediation. In the present study, a hydroponic experiment was conducted to investigate the variation in two kenaf cultivars, K39-2 and Zhe50-3 under Cr stress. At the same Cr concentration, the tolerance index (TI) of K39-2 was higher than that of Zhe50-3, indicating that K39-2 may be more tolerant to Cr than Zhe50-3. It was also observed that high concentration of chromium was accumulated both in the shoots and the roots of Hibiscus cannabinus L. The leaves of K39-2 accumulated 4760.28mgkg(-1) of dry weight under 1.50mM Cr stress, and the roots accumulated 11,958.33mgkg(-1). Physiological response shows that the antioxidant enzymes' superoxide dismutase (SOD), catalase activity (CAT) and peroxidase (POD) activities increased in the leaves and decreased in roots of the Cr-stressed plants nearly compared to the control. Moreover, the variation of antioxidant enzymes activities indicated Zhe50-3 was more vulnerable than K39-2, and the contents of the non-protein thiol pool (GSH, NPT and PCs) were higher in K39-2 than Zhe50-3 with the increased Cr concentration. Based on the observations above, it can be concluded that the well-coordinated physiological changes confer a greater Cr tolerance to K39-2 than Zhe50-3 under Cr exposure, and Hibiscus cannabinus L. has a great accumulation capacity for chromium.
authors.affiliation: College of Science, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Han
authors.initials: H
authors.lastname: Ding
authors.affiliation: College of Science, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Guodong
authors.initials: G
authors.lastname: Wang
authors.affiliation: College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Lili
authors.initials: L
authors.lastname: Lou
authors.affiliation: College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China. Electronic address: jinyinlv@nwsuaf.edu.cn.
authors.forename: Jinyin
authors.initials: J
authors.lastname: Lv
mesh_terms: D000222:Adaptation, Physiological; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D002857:Chromium / Q000378:metabolism* / Q000633:toxicity; D004781:Environmental Exposure / Q000009:adverse effects*; D031584:Hibiscus / Q000145:classification / Q000187:drug effects / Q000378:metabolism*; D018527:Hydroponics; D010084:Oxidation-Reduction; D009195:Peroxidase / Q000378:metabolism; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000378:metabolism; D012989:Soil Pollutants / Q000378:metabolism* / Q000633:toxicity; D013045:Species Specificity; D013312:Stress, Physiological; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D012989:Soil Pollutants; D002857:Chromium; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase
keywords: Antioxidants; Chromium stress; Kenaf; Tolerance