Handique G K, Handique A K
Department of Botany, Nalbari College, Nalbari, India.
J Environ Biol. 2009 Mar;30(2):299-302.
Toxic heavy metals viz. lead, mercury and cadmium induced differential accumulation of proline in lemongrass (Cymbopogon flexuosus Stapf.) grown in soil amended with 50, 100, 200, 350 and 500 mg kg(-1) of the metals have been studied. Proline accumulation was found to be metal specific, organ specific and linear dose dependant. Further, proline accumulation following short term exposure (two months after transplantation) was higher than long term exposure (nine months after transplantation). Proline accumulation following short term exposure was 2.032 to 3.839 micro moles g(-1) for cadmium (50-200 mg kg(-1)); the corresponding range for mercury was 1.968 to 5.670 micro moles g(-1) and 0.830 to 4.567 micro moles g(-1) for lead (50-500 mg kg(-1) for mercury and lead). Proline accumulation was consistently higher in young tender leaf than old leaf, irrespective of the metal or duration of exposure. For cadmium treatment proline level was 2.032 to 3.839 micro moles g(-1) for young leaves while the corresponding value for old leaf was 1.728 to 2.396 micro moles g(-1) following short term exposure. The same trend was observed for the other two metals and duration of exposure. For control set proline accumulation in root was 0.425 micro moles g(-1) as against 0.805 and 0.533 micro moles g(-1) in young and old leaves respectively indicating that proline accumulation in root are lower than leaves, under both normal and stressed condition.
研究了有毒重金属铅、汞和镉对生长在添加了50、100、200、350和500毫克/千克这些金属的土壤中的柠檬草（Cymbopogon flexuosus Stapf.）脯氨酸差异积累的影响。发现脯氨酸积累具有金属特异性、器官特异性和线性剂量依赖性。此外，短期暴露（移植后两个月）后的脯氨酸积累高于长期暴露（移植后九个月）。短期暴露后，镉（50 - 200毫克/千克）的脯氨酸积累为2.032至3.839微摩尔/克；汞的相应范围为1.968至5.670微摩尔/克，铅（汞和铅为50 - 500毫克/千克）为0.830至4.567微摩尔/克。无论金属种类或暴露时间长短，幼嫩叶片中的脯氨酸积累始终高于老叶。镉处理时，短期暴露后幼叶的脯氨酸水平为2.032至3.839微摩尔/克，而老叶的相应值为1.728至2.396微摩尔/克。其他两种金属和暴露时间也观察到相同趋势。对照组中，根中的脯氨酸积累为0.425微摩尔/克，而幼叶和老叶分别为0.805和0.533微摩尔/克，这表明在正常和胁迫条件下，根中的脯氨酸积累均低于叶片。
