目的 苯丙氨酸解氨酶（PAL）是植物次生代谢与抗逆反应的关键酶类之一，研究PAL基因的序列信息与逆境胁迫响应模式，揭示其蛋白结构与功能及抗逆信号网络。方法 采用RT-PCR、RACE技术获得白及PAL基因cDNA全长；Protparam、SOPMA、SWISS-MODEL等生物信息学软件分析其编码蛋白的理化特性、结构域等特征；DNAMAN、MEGA软件分别进行氨基酸多序列比对与系统进化分析；实时荧光定量PCR（qRT-PCR）技术进行PAL基因时空表达特异性与外源激素胁迫下响应检测。结果 克隆得到的BsPAL基因cDNA全长为2 708 bp，编码1条797个氨基酸组成的多肽，预测蛋白质相对分子质量为86 216.94，等电点6.24，具有植物PAL酶的典型结构域和活性中心，不具有跨膜结构域，与铁皮石斛、蝴蝶兰的PAL基因亲缘关系最近。qRT-PCR结果表明白及根中PAL表达量显著高于叶与茎。在MeJA处理下，PAL表达量呈逐渐上升再下降的趋势；SA处理下，则是先下降再上升的趋势。结论 白及PAL基因的克隆与序列特征分析、表达检测及响应MeJA和SA胁迫后的表达变化为阐明白及苯丙烷代谢途径与激素信号通路研究提供实验基础。

Objective Phenylalanine ammonia-lyase gene (PAL) is one of the key enzymes associated with stress resistance in secondary metabolism pathway of plants. Exploring its sequence information and expression profiling information in stress response could comprehensively peep at the protein structure, functions and signal network of plant stress resistance. Methods The full cDNA length of PAL from Bletilla striata was cloned by RT-PCR and RACE approaches. Physicochemical properties and conserved domain of BsPAL protein were determined by a series of bioinformatics tools as Protparam, SOPMA, SWISS-MODEL, etc. Multiple alignment and phylogenetic tree were achieved by DNAMAN and MEGA Software, respectively. The qPCR was employed to examine the expression profiles of BsPAL under exogenous hormone stress. Results The full cDNA of BsPAL was 2 708 bp, encoding a 797 amino-acid protein with a molecular weight of 86 216.94 and an isoelectric point (pI) of 6.24. The BsPAL protein included the typical structural domain and active site of PALs in other plants, and without transmembrane region, which was more homologous with PALs of Dendrobium officinale and Phalaenopsis aphrodita. The qPCR results revealed the expression level of BsPAL in roots was much higher than that in leaves and stems. Under MeJA treatment, the expression trend of BsPAL was first gradually ascending and then descending, while SA treatment had the reverse effect. Conclusion The BsPAL's sequence characterizing, expression profiling and responding patterns against SA and MEJA provided a research basis for elucidating the metabolic pathways of phenylpropanoid and hormone signaling research in B. striata.

国家自然科学基金资助项目（31560079）；国家自然科学基金资助项目（31560102）；贵州省科学技术基金项目（QKH-ZY[2013]3002）；贵州省科学技术基金项目（QKH-LH[2014]7549）；遵义市15851人才项目（201424）；贵州省科技厅人才成长项目（KY[2017]194；遵义医学院博士启动基金资助项目（F-809）