铅(Pb)胁迫对工业大麻苗期生理生化及富集特征的影响

摘要

Heavy metal Pb pollution seriously damage the ecological environment and impact human health, and the phytoremediation to Pb pollution is a hot topic in current research. Yunma 2, a variety of industrial hemp, was se-lected to study the effects of different lead (Pb) stress treatments on its physiological and biochemical mechanism and enrichment characteristics in seedling stage through pot experiment. The results showed that the dry biomass of roots, stems and leaves treated with all levels of Pb concentration (including 2 000mg/kg) were all increased com-pared with the control and respectively up to the maximum under the concentration of 800mg/kg, 400mg/kg and 800mg/kg. All tested physiological indicators, except the content of chlorophyll, were higher than the control. The contents of chlorophyll, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and peroxi-dase (POD) were no significant difference with the control under the concentration of 400 mg/kg. In hemp leaves, the contents of MDA and Pro were up to the maximum under the Pb concentration of 800mg/kg, while SOD, CAT and POD reached the maximum under 1 200-1 600mg/kg Pb.The maximum Pb absorption rates of roots, stems and leaves are separately 400-800mg/kg, 800-1 200mg/kg and 1 200-1 600 mg/kg. The accumulation of Pb in roots was much higher than that in shoots and leaves. The above results show that industrial hemp in the seedling stage has strong ability to adapt and accumulate Pb. It has the photosynthetic system and antioxidant capacity to al-leviate the high concentration of Pb stress by regulating its physiological indicators.%重金属铅 (Pb) 污染严重危害生态环境和人类健康,植物修复Pb污染是当今研究的热点课题.以云麻2号为研究材料,通过盆栽试验,设计7个Pb处理浓度研究工业大麻幼苗在Pb胁迫下的生理生化机制和富集特征.结果表明,在各个Pb处理浓度下 (包括2000mg/kg) 大麻根、茎、叶的干生物量均较之对照有所增加,生物量分别在Pb浓度800mg/kg、400mg/kg、800mg/kg时达最大值;叶片各生理指标除叶绿素外,各处理下各指标皆高于对照,其中叶绿素含量、丙二醛 (MDA)、超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT) 及过氧化物酶 (POD) 均在Pb 400mg/kg以下时与对照无显著差异,而至Pb 800mg/kg时,叶片中MDA和脯氨酸 (Pro) 则达到最大值,Pb 1200-1600mg/kg抗氧化酶SOD、CAT和POD达最大值;根、茎、叶中Pb吸收最大速度分别为Pb 400-800mg/kg、800-1200mg/kg、1200-1600mg/kg,根部Pb富集量远大于地上部茎、叶的富集量.各生理生化指标和富集特征均表明工业大麻苗期具有较强的适应和积累Pb能力,并具有稳定光合系统和抗氧化能力以此自我调节生理指标来缓解高Pb浓度胁迫.