BACKGROUND Phenylalanine ammonia-lyase (PAL) catalyzes the first step in the biosynthetic phenylpropanoid pathway (PPP) via deamination of phenylalanine to trans-cinnamic acid, a precursor for the lignin and flavonoid biosynthetic pathways. Although its role is well-established in various plants, the functional significance of PAL genes in rice remains poorly understood. OBJECTIVE This study aims to find out the global feature of rice PAL genes associated with phosphate use efficiency. METHODS To identify the biological functions of individual rice PAL genes, we performed meta-expression profiling analysis based on phylogenomics of rice PAL genes and confirmed the expression patterns using Quantitative real-time PCR (qPCR). RESULTS We identified nine genes that were remarkably up-regulated during long-term phosphate (Pi) starvation and recovery processes through RNA-Seq data analysis. Expression patterns of the nine rice PAL genes under Pi starvation were further confirmed by qPCR, indicating that the function of PAL genes is strongly associated with Pi starvation response in rice. CONCLUSION Our study reports the functional significance of rice PAL genes involved in adaptation to low Pi growth conditions and provides useful information to improve Pi use efficiency in crop plant.

中文翻译：

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苯丙氨酸氨解酶家族与水稻对磷酸盐缺乏的反应密切相关。

背景技术苯丙氨酸氨裂合酶（PAL）通过将苯丙氨酸脱氨成反式肉桂酸（木质素和类黄酮生物合成途径的前体）催化生物合成苯丙氨酸途径（PPP）的第一步。尽管其作用已在多种植物中确立，但对水稻中PAL基因的功能意义仍知之甚少。目的本研究旨在发现与磷酸盐利用效率相关的水稻PAL基因的全球特征。方法为了鉴定单个水稻PAL基因的生物学功能，我们基于水稻PAL基因的系统组学进行了元表达谱分析，并使用定量实时PCR（qPCR）确认了表达模式。结果我们通过RNA-Seq数据分析确定了9个在长期磷酸盐（Pi）饥饿和恢复过程中显着上调的基因。qPCR进一步证实了9个水稻在Pi饥饿状态下的PAL基因表达模式，表明PAL基因的功能与水​​稻的Pi饥饿反应密切相关。结论我们的研究报告了水稻PAL基因参与低磷生长条件适应的功能意义，并为提高作物中磷的利用效率提供了有用的信息。