CAJ | 학술논문

镉是植物非必需且生物毒性最强的重金属元素之一，然而镉富集植物能通过一定的响应机制来减少镉对自身产生的毒害，且不同植物之间镉的解毒机制存在差异。马缨丹（Lantana camara L.）是四川汉源铅锌矿区镉污染土壤的修复植物，但是关于其镉的分布特征和解毒机制并不明确。因此本文采用盆栽模拟试验，分别设置0（对照，不添加镉）、30、90、150、210 mg·kg-1镉5个处理，研究马缨丹对镉的富集、转运及其亚细胞分布特点，探讨马缨丹对镉的耐性和解毒机制，以期为植物耐镉的生理和分子生物学机制提供一定的理论依据。结果表明：镉质量分数低于90 mg·kg-1时对马缨丹生长没有影响，而镉质量分数高于150 mg·kg-1时对马缨丹生长有显著的抑制作用；随着镉质量分数的增加，马缨丹各器官中镉的质量分数逐渐增加，表现为根＞茎＞叶，且其转运系数小于1，表明马缨丹对镉有较强的根部滞留能力，可限制过量的镉向地上部器官的转运，减少镉对地上部的毒害，这可能是马缨丹耐受镉胁迫的机制之一；随着镉质量分数的增加，马缨丹地下部和地上部的镉富集量总体上均呈增加趋势，在210 mg·kg-1镉处理时，均达到最大值，分别为142.8和1031.6μg·plant-1，不同质量分数镉处理下，马缨丹地上部的镉富集量较大，占全株镉富集量的94.0%~88.3%；镉在马缨丹根和叶细胞可溶性组分中的分配比例最高，分别占62.1%~54.2%和59.8%~52.6%，其次在细胞壁中，分别占23.8%~34.4%和28.7%~39.5%，在细胞器和细胞膜中的较低，表明可溶性组分和细胞壁是镉在马缨丹根和叶细胞中的主要分布位点，液泡区隔化和细胞壁固持可能是马缨丹对镉的重要解毒和耐性机制之一。
력시식물비필수차생물독성최강적중금속원소지일，연이력부집식물능통과일정적향응궤제래감소력대자신산생적독해，차불동식물지간력적해독궤제존재차이。마영단（Lantana camara L.）시사천한원연자광구력오염토양적수복식물，단시관우기력적분포특정화해독궤제병불명학。인차본문채용분재모의시험，분별설치0（대조，불첨가력）、30、90、150、210 mg·kg-1력5개처리，연구마영단대력적부집、전운급기아세포분포특점，탐토마영단대력적내성화해독궤제，이기위식물내력적생리화분자생물학궤제제공일정적이론의거。결과표명：력질량분수저우90 mg·kg-1시대마영단생장몰유영향，이력질량분수고우150 mg·kg-1시대마영단생장유현저적억제작용；수착력질량분수적증가，마영단각기관중력적질량분수축점증가，표현위근＞경＞협，차기전운계수소우1，표명마영단대력유교강적근부체류능력，가한제과량적력향지상부기관적전운，감소력대지상부적독해，저가능시마영단내수력협박적궤제지일；수착력질량분수적증가，마영단지하부화지상부적력부집량총체상균정증가추세，재210 mg·kg-1력처리시，균체도최대치，분별위142.8화1031.6μg·plant-1，불동질량분수력처리하，마영단지상부적력부집량교대，점전주력부집량적94.0%~88.3%；력재마영단근화협세포가용성조분중적분배비례최고，분별점62.1%~54.2%화59.8%~52.6%，기차재세포벽중，분별점23.8%~34.4%화28.7%~39.5%，재세포기화세포막중적교저，표명가용성조분화세포벽시력재마영단근화협세포중적주요분포위점，액포구격화화세포벽고지가능시마영단대력적중요해독화내성궤제지일。
Cadmium (Cd) is one of the non-essentials of plant and the most toxic heavy metal elements in biological,however, Cd enrichment plant can reduce toxic of Cd via certain mechanisms, and there are some differences in detoxification mechanisms of Cd for different plant.Lantana camara L. is valuable in the phytoremediation of Cd-contaminated soil in Hanyuan mine area. However, distribution and detoxification mechanisms ofL.camara for cadmium remain poorly understood. In order to explore the tolerance and detoxification mechanisms of Cd ofL.camara, this study investigated the Cd accumulation, translocation and subcellular distribution inL.camara gorwn in pot which contain 0, 30, 90, 150 or 210 mg·kg-1Cd. The results showed that when the concentrations of application Cd were less than 90 mg·kg-1, the growth ofL. camara was not influenced, while the concentrations of application Cd were higher than 150 mg·kg-1, the growth ofL. camara was inhibited significantly. With the increasing of concentrations of application Cd, the concents of Cd in different organs ofL. camara increased gradually, and it’s in sequence as follows: roots> stems> leaves. Meanwhile, the translocation factor (TF) of Cd ofL. camara was less than 1 under different concentrations of Cd application. It suggested thatL. camara had a strong root retention capacity of Cd, which can reduce the toxicity of Cd to the organs of shoot. With the increasing of concentrations of application Cd, the Cd accumulation in roots and shoots increased gradually, and reached the maximum at 210 mg·kg-1 Cd, and was 142.8μg·plant-1and 1,031.6μg·plant-1, respectively. Cd accumulation in shoots was larger than roots, and accounting for 94.0%~88.3% in whole plant. The proportion of Cd in soluble fraction in roots and leaves were highest, followed by cell wall, organelles and membranes were lowest. The allocation proportion of Cd in soluble fraction in roots and leaves were 62.1%~54.2% and 59.8%~52.6% respectively, in cell wall were 23.8%~34.4% and 28.7%~39.5% respectively. It indicated that soluble fraction and cell wall were the main Cd-binding sites in roots and leaves ofL. camara, the vacuoles compartmentalization and cell wall precipitation may be an important detoxification mechanism ofL. camara of Cd.