摘要
为系统研究东北红豆杉不同器官组织中紫杉醇含量的季节性变化规律及其环境响应机制,对东北红豆杉叶片、树皮、根系、木质部和果实进行季节性采样和HPLC定量分析,并检测紫杉醇合成关键酶基因及转录调控因子的表达水平。结果显示,紫杉醇含量在不同组织间存在显著差异(树皮>果实>叶片>根系>边材>心材),其中树皮含量全年最高,9月达峰值(1.391 mg/g);叶片和根系次之,9月峰值分别为0.776 mg/g和0.711 mg/g;果实在9月成熟期升至0.974 mg/g后迅速下降;边材和心材含量最低(0.05~0.30 mg/g)。紫杉醇合成关键酶基因TcTS和TcDBTNBT在树皮中表达量最高,9月达峰值,约为心材的3.27倍和2.94倍,果实在成熟期(9-10月)也表现出较高表达活性。转录调控方面,正向调控因子MYB3在生长旺盛期(5-9月)表达量逐渐升高,树皮中表达最强(9月为4.622);负调控因子MYC2在生长旺盛期叶片中达峰值(0.861),心材表达量最高,约为树皮的2倍,体现了器官间代谢平衡,两种调控因子在冬季休眠期均降至全年最低水平,导致紫杉醇含量随之降低。综上可见,东北红豆杉通过基因表达和转录调控在环境适应过程中实现生长与防御的平衡。
To systematically investigate the seasonal variation patterns of paclitaxel content in different organs and tissues of T.cuspidata and its environmental response mechanisms,this study conducted seasonal sampling and HPLC quantitative analysis of leaves,bark,roots,wood tissues,and fruits,and examined the expression levels of key enzyme genes and transcription factors involved in paclitaxel biosynthesis.Results showed significant differences in paclitaxel content among different tissues(bark>fruit>leaves>roots>sapwood>heartwood),with bark maintaining the highest content throughout the year and reaching a peak of 1.391 mg/g in September;leaves and roots followed,with September peaks of 0.776 mg/g and 0.711 mg/g,respectively;fruit content increased to 0.974 mg/g during September maturation before rapidly declining;sapwood and heartwood maintained the lowest contents(0.05-0.30 mg/g).Key enzyme genes TcTS and TcDBTNBT showed highest expression in bark,peaking in September at 3.27-fold and 2.94-fold higher than heartwood levels,respectively,while fruits also exhibited high expression activity during maturation(September-October).Regarding transcriptional regulation,the positive regulator MYB3 showed gradually increasing expression during the vigorous growth period(May-September),with strongest expression in bark(4.622 in September);the negative regulator MYC2 peaked in leaves during the growth period(0.861),with highest expression in heartwood at approximately twice that of bark,reflecting metabolic balance among organs.Both regulators decreased to their annual lowest levels during winter dormancy,leading to reduced paclitaxel content.In conclusion,T.cuspidata achieves a balance between growth and defense through gene expression and transcriptional regulation during environmental adaptation,providing scientific basis for optimizing collection strategies,improving paclitaxel yield,and promoting sustainable utilization of this rare species.
作者
王丹丹
陈佳欣
张彦文
李秋宏
WANG Dandan;CHEN Jiaxin;ZHANG Yanwen;LI Qiuhong(School of Science,Eastern Liaoning University,Dandong Liaoning 118003,China)
出处
《西北农业学报》
北大核心
2025年第7期1254-1262,共9页
Acta Agriculturae Boreali-occidentalis Sinica
基金
国家自然科学基金(32272757,31972363)
辽宁省科技计划联合计划(基金)(2023JH2/101700200)
辽宁省教育厅高校基本科研项目(JYTMS20230698)。
关键词
东北红豆杉
紫杉醇含量
季节性变化规律
转录因子
生理指标
Taxus cuspidata
Paclitaxel content
Seasonal variation pattern
Transcription factor
Physiological indicators
