脲类细胞分裂素诱导尾叶桉愈伤组织分化过程中SOD活性及基因表达变化  

Changes of SOD Activity and Gene Expression during Callus Differentiation of Eucalyptus urophylla Induced by Urea Cytokinin

作　　者：李丽纯 许漫琪 黄惠紫 陈裕婷 李观玲 黄真池 Li Lichun;Xu Manqi;Huang Huizi;Chen Yuting;Li Guanling;Huang Zhenchi(Lingnan Normal University,Zhanjiang 524048,P.R.China)

机构地区：[1]岭南师范学院,湛江524048

出　　处：《东北林业大学学报》2023年第12期104-109,共6页Journal of Northeast Forestry University

基　　金：湛江市科技发展专项资金竞争性分配项目(2022A01055);海南省果蔬贮藏与加工重点实验室课题(HNGS202105);岭南师范学院大学生创新创业项目。

摘　　要：探讨3种脲类细胞分裂素(UCTK):N-苯基-N-噻唑基脲(PBU)、苯基噻二唑脲(TDZ)和氯吡苯脲(CPPU)诱导尾叶桉(Eucalyptus urophylla)愈伤组织分化的效果及作用机理。将下胚轴接种在含0.57μmol/L 6-BA+0.57μmol/L IAA的SPCa培养基,再添加4μmol/L的单种UCTK或浓度各为2μmol/L的UCTK间的两两组合。8周后,UCTK组合诱导所得再生型愈伤组织比例均高于49.27%,显著高于单种UCTK的不到29%。与单种UCTK处理相比,UCTK组合诱导的愈伤组织H 2O 2质量摩尔浓度降低、超氧阴离子清除速率下降、SOD活性则无规律性变化。与PBU处理相比,UCTK组合使6周龄愈伤组织的6个SOD基因的转录全部上调。设PBU+CPPU组合诱导所得2周龄愈伤组织中对应基因表达值为1,分析UCTK组合诱导愈伤组织膨大和分化过程中SOD基因的表达变化,发现SOD1和SOD3基因的转录变化最为显著。CPPU+TDZ处理2周后,SOD1和SOD3的转录达最大值,分别为762.53和1119.82;PBU+TDZ处理6周后,SOD1和SOD3的转录达最大值,分别为1501.81和7086.52;PBU+CPPU处理10周后,SOD1和SOD3的转录达最大值,分别为524.77和14789.44。分析结果可知:不同UCTK有协同效应,通过影响ROS代谢,减轻桉树愈伤组织褐化,促进分化;UCTK组合处理后,SOD1和SOD3的转录水平变化极为显著,预示其与愈伤组织分化密切相关。We explored the effect and mechanism of three urea cytokinins,PBU,TDZ or CPPU,on callus differentiation of Eucalyptus urophylla.The hypocotyl was inoculated in SPCa medium containing 0.57μmol/L 6-BA and 0.57μmol/L IAA,followed by the addition of 4μmol/L single urea CTK or two pairs of three urea CTKs at 2μmol/L.After 8 weeks,the proportion of regenerative callus induced by the UCTK combination was higher than 49.27%,which was significantly higher than that of less than 29%of the single urea CTK.Compared with single UCTK treatment,the H_(2)O_(2) content and superoxide anion scavenging rate of callus induced by UCTK combination decreased,and SOD activity changed irregularly.Compared with PBU treatment,the expressing of all six SOD genes up-regulated in 6-week callus induced by urea cytokinin combination.With the transcription level of the relative genes in 2-week callus induced by PBU normalized to one,the changes of SOD gene expression during callus expansion and differentiation induced by UCTK combination were analyzed.And the transcriptional changes of SOD1 and SOD3 genes were the most significant.The transcription levels of SOD1 and SOD3 arrived to the maximum values,762.53 and 1119.82,respectively,in 2-week callus induced by CPPU and TDZ.Those arrived to the maximum values,1501.81 and 7086.52,respectively,in 6-week callus induced by PBU and TDZ.Those arrived to the maximum values,524.77 and 14789.44,respectively,in 10-week callus induced by PBU and CPPU.The results implied that different UCTK had synergistic effect,which could reduce the browning and promote differentiation by affecting ROS metabolism.The significant changes of SOD1 and SOD3 transcription levels indicated a close correlation with callus differentiation.

关 键 词：尾叶桉 愈伤组织 脲类细胞分裂素 超氧化物歧化酶(SOD) 活性氧(ROS) 

分 类 号：Q945.78[生物学—植物学]