Tricholoma matsutake is a representative mushroom species with a characteristic pleasant aroma. The characteristic aroma component is methyl cinnamate, which is also produced in many plants. In basil, cinnamic acid is produced from l-phenylalanine (l-Phe) by phenylalanine ammonia-lyase (PAL) and converted to methyl cinnamate by a cinnamate/p-coumarate carboxyl methyltransferase. Two PAL genes, Tmpal1 and Tmpal2, have been isolated from T. matsutake. In this study, we aimed to clarify the relationships between l-Phe, methyl cinnamate production, and PAL expression in the mycelium of T. matsutake strain NBRC 30605. For this purpose, methyl cinnamate content, PAL activity, and transcript levels of Tmpal1 and Tmpal2 were examined in the mycelia of T. matsutake supplemented with l-Phe. The mycelia were cultured in 20 mL of a liquid medium (2% glucose, 0.15% yeast extract, and 0.15% Bacto Soytone) at 20 °C for 45 d, supplemented with 0.5-6 mM l-Phe, and then grown for a further 15 d. Mycelia cultured without l-Phe supplementation for 60 d in the medium were used as a control. Crude extracts were prepared from the mycelia harvested for enzymatic, protein, and methyl cinnamate assays. Methyl cinnamate was measured using gas chromatography. PAL activity was assayed by measuring the rate of trans-cinnamic acid formation as the absorbance at 290 nm (ɛ290 = 10,000 M−1 cm−1). The transcript levels of Tmpal1 and Tmpal2 were examined by performing real-time reverse transcriptase-quantitative PCR on the total RNA. Methyl cinnamate was detected in very low levels in cultures without l-Phe supplementation, but its content per mg of protein increased markedly with increasing concentrations of l-Phe, especially at 4-6 mM. When 6 mM l-Phe was added to the culture medium, the methyl cinnamate content was approximately 55-fold higher than that of the control sample. The specific activity of PAL also increased in cultures supplemented with l-Phe, especially at 4-6 mM. When l-Phe was added to the culture medium, the methyl cinnamate content in the mycelia was relatively well correlated with PAL activity. These results indicated that supplementation with l-Phe, a precursor of methyl cinnamate, increases the specific activity of PAL, leading to an increase in methyl cinnamate production in the mycelia of T. matsutake. The transcript level of Tmpal1 did not change markedly with l-Phe supplementation. In contrast, the transcript level of Tmpal2 increased greatly in cultures supplemented with 4-6 mM l-Phe. These results suggested that the expression of Tmpal1 and Tmpal2 was controlled by different regulatory mechanisms and that they may have different biological functions in T. matsutake. In addition, the pattern of PAL activity in the presence of l-Phe was similar to that of the transcript level of Tmpal2, but not Tmpal1, suggesting that the increase in PAL activity was dependent on the increased transcription of Tmpal2.

딸기의 2차대사에 관하여 phenylalanine ammonia-lyase는 풍미나 색소, 향기 등에 큰 영향을 미치며 숙도 측정지표로 여겨진다. phenylananine amonia-lyase는 숙성 전단계에 걸쳐 활성을 나타내기는 하나 완숙기와 과숙기에 그 활성이 뚜렷이 증가하였다. 이는 딸기의 숙성과 더불어 de novo 합성이 되기 때문으로 보인다. 분자량은 겔 크로마토그래피로 260, 000으로 나타났다.

Phenylalanine ammonia-lyase (PAL), a key enzyme of the phenylpropanoid biosynthesis pathway, is activated by a number of developmental and environmental cues. The coding region of the NtPAL4 gene was 2,154 bp in length, and its deduced protein was composed of 717 amino acids. Sequence analysis of NtPAL4 cDNA from tobacco (Nicotiana tabacum L.) revealed high structural similarity to PAL genes of other plant species. The NtPAL4 gene exists as a single copy in the tobacco plant, and its transcripts were strongly expressed in flowers and leaves. NtPAL4 expression was significantly induced in response to NaCl, mannitol, and cold treatments, but it was not induced by abscisic acid (ABA). NtPAL4 expression decreased gradually after treatment with ABA and H2O2; however, NtPAL4 transcripts accumulated after treatment with methyl viologen (MV). Our results suggest that the NtPAL4 gene may function in response to abiotic stresses.

Allium sativum, belongs to a member of the onion family (Alliaceae) are economically important vegetables because of the culinary value and medicinal purpose. Using PCR strategy with degenerated primers targeted to conserved regions of orthologous phenylalanine ammonia-lyase (PAL) and cinnamate 4-hydroxylase (C4H) sequences available, full-length PAL and C4H from A. sativum. The amino acid sequence of these genes is highly conserved, particularly AsPAL and AsC4H has greater than 70% amino acid identity to other plants. AsPAL and AgC4H were most highly expressed in roots of A. sativum, whereas lowest level of transcript was detected in flower. Phenolic compounds most highly produced in flowers of A. sativum. The presented sequences and expression an alysis of PAL and C4H will provide possible material to enhance the understading of phenolic compounds synthesis in A. sativum.