基于红外光谱研究重离子辐射对牡丹幼苗生长的诱变效应

Mutagenic Effects of Heavy Ion Radiation on the Growth of Peony Seedlings Based on Infrared Spectroscopy

为理解重离子辐射对牡丹的诱变效应,采用不同剂量(0、10、20、40、60、80、100、120、150、200、300 Gy)的^(12)C^(6+)重离子束辐照凤丹牡丹种子,对各剂量辐照后牡丹表型进行分析,并借助傅里叶变换红外光谱(FTIR)研究不同辐射剂量下牡丹幼苗叶片中化学物质种类、结构和含量变化。结果表明,重离子辐射能显著降低出苗率,半致死剂量介于10~20 Gy之间。80~120 Gy能显著降低株高,并降低叶片长度和宽度,以及诱导叶片发生畸形。10~20 Gy能促进纤维素、半纤维素和木质素的形成,促进蛋白质二级结构α-螺旋和β-折叠的形成。20~150 Gy能抑制酯类、木质素、氨基Ⅱ和氨基A的合成,促进蛋白质甲基化、糖蛋白变异、脂类氧化和降解,抑制与果胶相连的β-折叠的形成,促进β-折叠、无规卷曲、α-螺旋、环与转角等蛋白质二级结构的形成。通过主成分、载荷图和聚类分析发现,10、20、40、60 Gy辐射剂量能显著改变凤丹牡丹叶片的化学成分,聚为一类;当辐射剂量为200 Gy时,牡丹叶片化学物质的变化较大,可单独聚为一类;其他剂量组与对照组差异不明显,聚为一类。本研究结果可为牡丹种子^(12)C^(6+)重离子辐射育种提供适宜诱变剂量区间(10~20 Gy)和理论基础。

In order to understand the mutagenic effect of heavy ion radiation on peony,the seeds of Fengdan peony were irradiated by ^(12)C^(6+)heavy ion beams under doses of 0,10,20,40,60,80,100,120,150,200,300 Gy,respectively,the phenotype of peony after irradiation were analyzed,and the changes of chemical compounds,structures and contents in the leaves of peony seedlings under different radiation doses were studied by Fourier transformation infrared spectroscopy(FTIR).The results showed that heavy ion radiation could significantly inhibit the emergence rate,and the half-lethal dose was between 10 and 20 Gy.80-120 Gy can significantly inhibit plant height,reduce leaf length and width,and induce leaf deformation.10-20 Gy can promote the formation of cellulose,hemicellulose and lignin,and promote the formation of protein secondary structureα-helix andβ-sheet.20-150 Gy can inhibit the synthesis of esters,lignin,amino II and amino A,promote protein methylation,glycoprotein mutation,lipid oxidation and degradation,inhibit the formation ofβ-sheets linked to pectin,and promote the formation of protein secondary structures such asβ-sheet,random coils,α-helices,loops and turns.Through principal component,loading diagram and cluster analysis,it was found that the radiation doses of 10,20,40 and 60 Gy could significantly change the chemical compositions in leaves of Fengdan peony,which were clustered into one category;when the radiation dose was 200 Gy,the chemical substances in the leaves of peony showed great differences,which could be clustered into one group;there was no significant difference between the other dose groups and the control group,which were clustered into one category.The results of this study will provide an appropriate mutagenic dose range(10-20 Gy)and theoretical basis for ^(12)C^(6+)heavy ion radiation breeding of peony seeds.