Sharma Indu, Pati Pratap Kumar, Bhardwaj Renu
Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar 143005, Punjab, India.
Indian J Biochem Biophys. 2010 Jun;47(3):172-7.
28-Homobrassinolide (28-HBL), a brassinosteroid is reported to play significant role in diverse physiological processes. It induces a range of cellular and adaptive responses to a range of environmental stresses. Cadmium (Cd) is a non-essential metal which alters various physiological processes and generates ROS, which can oxidize biological macromolecules and causes oxidative stress. This stress is generally overcome by the internal antioxidative defense system and stress shielding phytohormones. In this study, effect of 28-HBL was studied on growth and activities of antioxidant enzymes in known hyperaccumulator Raphanus sativus L. (radish) seedlings grown under cadmium (Cd) metal stress. To determine the influence of 28-HBL (0, 10-(11), 10-(9), 10-(7) M) in radish seedlings subjected to Cd (0, 0.5, 1.0, 1.5 mM) stress, the activities of antioxidant enzymes (APOX, CAT, GR, POD and SOD) were analyzed. In addition, length and biomass of radish seedlings was also recorded. Cd toxicity resulted in reduced length, biomass, protein content and activities of antioxidant enzymes. 28-HBL treatments lowered the Cd toxicity by enhancing the activities of antioxidant enzymes, biomass and seedling length. The present study thus suggests a possible role of 28-HBL in amelioration of metal stress by regulating the activities of antioxidant enzymes in radish.
28-高油菜素内酯（28-HBL）是一种油菜素甾醇，据报道在多种生理过程中发挥重要作用。它能诱导一系列细胞和适应性反应以应对多种环境胁迫。镉（Cd）是一种非必需金属，会改变各种生理过程并产生活性氧（ROS），活性氧可氧化生物大分子并导致氧化应激。这种胁迫通常由内部抗氧化防御系统和应激屏蔽植物激素来克服。在本研究中，研究了28-HBL对已知的镉（Cd）金属胁迫下生长的超积累植物萝卜（Raphanus sativus L.）幼苗抗氧化酶活性和生长的影响。为了确定28-HBL（0、10⁻¹¹、10⁻⁹、10⁻⁷ M）对遭受镉（0、0.5、1.0、1.5 mM）胁迫的萝卜幼苗的影响，分析了抗氧化酶（抗坏血酸过氧化物酶、过氧化氢酶、谷胱甘肽还原酶、过氧化物酶和超氧化物歧化酶）的活性。此外，还记录了萝卜幼苗的长度和生物量。镉毒性导致萝卜幼苗长度、生物量、蛋白质含量和抗氧化酶活性降低。28-HBL处理通过提高抗氧化酶活性、生物量和幼苗长度降低了镉毒性。因此，本研究表明28-HBL可能通过调节萝卜中抗氧化酶的活性在缓解金属胁迫方面发挥作用。
