CAJ | 학술논문

为探讨烟草根系镉液泡截留的基因型差异机理，采用苗期水培试验，研究了不同镉积累模式的两种基因型烟草[普通烟草品种 K326和黄花烟草（N.rustica）]根系镉螯合能力和相关基因的表达差异。结果表明：①镉处理前后还原型谷胱甘肽（GSH）和植物螯合肽（Phytochelatins，PCs）出现此消彼长的现象。与对照相比，1μmol/L 镉诱导处理导致K326和黄花烟草根系总非蛋白巯基（NPT）含量（质量分数）和PCs含量（质量分数）分别升高45.89%，57.75%和55.58%，84.00%，GSH含量（质量分数）降低10.70%和62.09%。镉处理前后黄花烟草GSH和PCs的变幅明显高于K326。②1μmol/L镉诱导处理促进烟草根系中的镉由交换态向螯合态转变，并且促使PCs向高分子量结合态转变。黄花烟草的转化能力高于K326。③对照处理中两基因型烟草根系螯合物中高分子量螯合物（High-molecular-weight chelation ，HMW）和低分子量螯合物（Low-molecular-weight chelation ，LMW）组分约各占一半。1μmol/L 镉诱导条件下，K326中HMW含量（体积分数）占总量的77.43%，黄花烟草中镉几乎全部以HMW形态存在。在镉诱导条件下黄花烟草根系镉向螯合态转化能力和结合能力均明显高于K326，说明根系镉螯合能力的差异是导致黄花烟草和普通烟草镉积累差异的原因之一。④黄花烟草根系植物螯合肽合成酶1基因（Phytochelatin synthase 1，PCS1）的表达对镉具有高度敏感性，与对照相比，1μmol/L镉处理下PCS1的表达量增加257.33%，而镉处理对K326中PCS1的表达影响不大。
위탐토연초근계력액포절류적기인형차이궤리，채용묘기수배시험，연구료불동력적루모식적량충기인형연초[보통연초품충 K326화황화연초（N.rustica）]근계력오합능력화상관기인적표체차이。결과표명：①력처리전후환원형곡광감태（GSH）화식물오합태（Phytochelatins，PCs）출현차소피장적현상。여대조상비，1μmol/L 력유도처리도치K326화황화연초근계총비단백구기（NPT）함량（질량분수）화PCs함량（질량분수）분별승고45.89%，57.75%화55.58%，84.00%，GSH함량（질량분수）강저10.70%화62.09%。력처리전후황화연초GSH화PCs적변폭명현고우K326。②1μmol/L력유도처리촉진연초근계중적력유교환태향오합태전변，병차촉사PCs향고분자량결합태전변。황화연초적전화능력고우K326。③대조처리중량기인형연초근계오합물중고분자량오합물（High-molecular-weight chelation ，HMW）화저분자량오합물（Low-molecular-weight chelation ，LMW）조분약각점일반。1μmol/L 력유도조건하，K326중HMW함량（체적분수）점총량적77.43%，황화연초중력궤호전부이HMW형태존재。재력유도조건하황화연초근계력향오합태전화능력화결합능력균명현고우K326，설명근계력오합능력적차이시도치황화연초화보통연초력적루차이적원인지일。④황화연초근계식물오합태합성매1기인（Phytochelatin synthase 1，PCS1）적표체대력구유고도민감성，여대조상비，1μmol/L력처리하PCS1적표체량증가257.33%，이력처리대K326중PCS1적표체영향불대。
In order to explore the genotype difference mechanism of Cd vacuole interception in tobacco root systems, hydroponic seedling experiments with different Cd treatments were carried out to study the differences of root system Cd chelating ability and related genes expression between two tobacco genotypes (K326 and N. rustica). The results showed that: 1) After Cd treatments, GSH decreased, while phytochelatins (PCs) increased. Comparing with the control, the contents of total non-protein thiol (NPT) and PCs in the roots of K326 and N. rustica in the treatment of 1 μmol/L Cd increased by 45.89%, 57.75% and 55.58%, 84.00%, while GSH content decreased by 10.70% and 62.09%, respectively. The change of GSH and PCs caused by Cd treatment was more significant in N.rustica than in K326. 2) Cd treatment promoted Cd in roots transforming from exchangeable state into chelated state, and promoted PCs transforming into high-molecular-weight bound state (HMW). Notably in N. rustica. 3) In the control, HMW and LMW each accounted roughly for half of the root system chelates in K326 or N. rustica. However, induced by the treatment of 1 μmol/L Cd, HMW accounted for 77.43%of root chelates in K326, and almost all Cd was in the form of HMW state in N.rustica. Under Cd inducing conditions, the transition ability of Cd to chelated state and the binding ability were significantly higher in N. rustica than in K326, it indicated that the difference of roots’Cd chelating ability was one of the reasons causing the difference of Cd accumulation between K326 and N. rustica. 4) PCS1 expression in the roots of N. rustica was highly sensitive to Cd, and increased by 257.33% in the treatment of 1 μmol/L Cd; while PCS1 expression in K326 was not affected significantly by Cd treatment.