{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T19:47:57Z","timestamp":1790970477012,"version":"4.1.0"},"reference-count":44,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2025,12,22]],"date-time":"2025-12-22T00:00:00Z","timestamp":1766361600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"crossref","award":["32202327"],"award-info":[{"award-number":["32202327"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"crossref","award":["32472576"],"award-info":[{"award-number":["32472576"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Central Public-interest Scientific Institution Basal Research Fund","award":["1610212024008"],"award-info":[{"award-number":["1610212024008"]}]},{"name":"Chinese Academy of Agricultural Sciences for Agricultural Science and Technology Innovation Program of Tea Research Institute","award":["CAAS-ASTIP-2021-TRI"],"award-info":[{"award-number":["CAAS-ASTIP-2021-TRI"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>The tea plant (Camellia sinensis) employs inducible chemical defenses against insect herbivores, yet the role of phenylalanine ammonia-lyase (PAL) in this process remains inadequately characterized. This study demonstrates that PAL is essential for tea plant\u2019s direct resistance against the tea geometrid (Ectropis grisescens Warren). Inhibition of PAL activity using 2-Aminoindan-2-phosphonic acid significantly reduced catechins accumulation and promoted larval growth of E. grisescens. Compared to mechanical wounding alone, simulated herbivory feeding (mechanical wounding plus oral secretions) induced higher PAL activity and more pronounced upregulation of CsPAL genes. This response specifically highlighted CsPALb, CsPALd, and CsPALe as core, herbivore-responsive members. Transient silencing of CsPALb in tea leaves led to a significant reduction in the levels of catechin (-)-epigallocatechin and epigallocatechin gallate. Moreover, heterologous overexpression of CsPALb and CsPALd in tobacco (Nicotiana tabacum) enhances resistance to Spodoptera litura. Our results indicate that PAL-mediated phenylpropanoid metabolism is not only critical for herbivore resistance of tea plant, but can also provide valuable gene resources for improving herbivore resistance in other plants.<\/jats:p>","DOI":"10.3390\/ijms27010113","type":"journal-article","created":{"date-parts":[[2025,12,22]],"date-time":"2025-12-22T11:43:31Z","timestamp":1766403811000},"page":"113","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Phenylalanine Ammonia-Lyase as a Key Enzyme in Tea Plant Resistance to Herbivory"],"prefix":"10.3390","volume":"27","author":[{"given":"Ran","family":"Wang","sequence":"first","affiliation":[{"name":"Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China"},{"name":"State Key Laboratory of Tea Plant Germplasm Innovation and Resource Utilization, Hangzhou 310008, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhichao","family":"Chai","sequence":"additional","affiliation":[{"name":"Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China"},{"name":"State Key Laboratory of Tea Plant Germplasm Innovation and Resource Utilization, Hangzhou 310008, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yongchen","family":"Yu","sequence":"additional","affiliation":[{"name":"Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China"},{"name":"State Key Laboratory of Tea Plant Germplasm Innovation and Resource Utilization, Hangzhou 310008, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaona","family":"Qian","sequence":"additional","affiliation":[{"name":"Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China"},{"name":"State Key Laboratory of Tea Plant Germplasm Innovation and Resource Utilization, Hangzhou 310008, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jia","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China"},{"name":"State Key Laboratory of Tea Plant Germplasm Innovation and Resource Utilization, Hangzhou 310008, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7677-2718","authenticated-orcid":false,"given":"Xiaoling","family":"Sun","sequence":"additional","affiliation":[{"name":"Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China"},{"name":"State Key Laboratory of Tea Plant Germplasm Innovation and Resource Utilization, Hangzhou 310008, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xin","family":"Zhang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, National Center for Tea Plant Improvement, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China"},{"name":"State Key Laboratory of Tea Plant Germplasm Innovation and Resource Utilization, Hangzhou 310008, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1098\/rstb.1992.0016","article-title":"Interaction and Coevolution of Plants and Arthropods during the Palaeozoic and Mesozoic","volume":"335","author":"Scott","year":"1992","journal-title":"Philos. Trans. R. Soc. B"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3236","DOI":"10.1111\/pce.15324","article-title":"Transcriptional Reprogramming Deploys a Compartmentalized \u2018Timebomb\u2019 to Fend Off Chewing Herbivores","volume":"48","author":"Liu","year":"2025","journal-title":"Plant Cell Environ."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1007\/s11103-021-01159-3","article-title":"Genetic Divergence in Transcriptional Regulators of Defense Metabolism: Insight into Plant Domestication and Improvement","volume":"109","author":"Shoji","year":"2022","journal-title":"Plant Mol. Biol."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Jeong, H.J., Nam, B.E., Jeong, S.J., Lee, G., Kim, S.G., and Kim, J.G. (2024). Primary Metabolic Response of Aristolochia contorta to Simulated Specialist Herbivory under Elevated CO2 Conditions. Plants, 13.","DOI":"10.3390\/plants13111456"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2401","DOI":"10.1007\/s42976-025-00687-8","article-title":"Unveiling the Role of Phenol and Defense Related Enzymes in Host Resistance to Spot Blotch \u00d7 Wheat Pathosystem","volume":"53","author":"Chakraborty","year":"2025","journal-title":"Cereal Res. Commun."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"496","DOI":"10.1111\/pce.14216","article-title":"(+)-Catechin, Epicatechin and Epigallocatechin Gallate are Important Inducible Defensive Compounds against Ectropis grisescens in Tea Plants","volume":"45","author":"Li","year":"2021","journal-title":"Plant Cell Environ."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1007\/s44154-024-00201-w","article-title":"A Comprehensive Review of Transcription Factor-Mediated Regulation of Secondary Metabolites in Plants under Environmental Stress","volume":"5","author":"Rabeh","year":"2025","journal-title":"Stress Biol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"744","DOI":"10.1007\/s10886-013-0296-x","article-title":"Regurgitant Derived from the Tea Geometrid Ectropis obliqua Suppresses Wound-Induced Polyphenol Oxidases Activity in Tea Plants","volume":"39","author":"Yang","year":"2013","journal-title":"J. Chem. Ecol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1165","DOI":"10.1111\/pce.13897","article-title":"Indole Primes Defence Signalling and Increases Herbivore Resistance in Tea Plants","volume":"44","author":"Ye","year":"2021","journal-title":"Plant Cell Environ."},{"key":"ref_10","first-page":"5945","article-title":"Reactive Oxygen Species in Plants: An Invincible Fulcrum for Biotic Stress Mitigation","volume":"106","author":"Tyagi","year":"2022","journal-title":"Appl. Microbiol. Biotechnol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1164","DOI":"10.1111\/tpj.16180","article-title":"Non-Volatile Metabolites Mediate Plant Interactions with Insect Herbivores","volume":"114","author":"Luo","year":"2023","journal-title":"Plant J."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1063","DOI":"10.1007\/s00425-018-2965-z","article-title":"Structural, Functional and Evolutionary Diversity of 4-Coumarate-CoA Ligase in Plants","volume":"248","author":"Lavhale","year":"2018","journal-title":"Planta"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"110223","DOI":"10.1016\/j.plantsci.2019.110223","article-title":"Phenylalanine Roles in the Seed-to-Seedling Stage: Not Just an Amino Acid","volume":"289","author":"Perkowski","year":"2019","journal-title":"Plant Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"62587","DOI":"10.1039\/C5RA08196C","article-title":"Phenylalanine Ammonia-Lyase, a Key Component Used for Phenylpropanoids Production by Metabolic Engineering","volume":"5","author":"Kong","year":"2015","journal-title":"RSC Adv."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"180","DOI":"10.1111\/jipb.13054","article-title":"Contribution of Phenylpropanoid Metabolism to Plant Development and Plant-Environment Interactions","volume":"63","author":"Dong","year":"2021","journal-title":"J. Integr. Plant Biol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1038\/s41586-025-09280-9","article-title":"Deciphering Phenylalanine-Derived Salicylic Acid Biosynthesis in Plants","volume":"645","author":"Wang","year":"2025","journal-title":"Nature"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"e013","DOI":"10.48130\/bpr-0024-0006","article-title":"Accumulation Patterns of Flavonoids during Multiple Development Stages of Tea Seedlings","volume":"4","author":"Li","year":"2024","journal-title":"Beverage Plant Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"10714","DOI":"10.1038\/s41598-024-81968-w","article-title":"Genome-Wide Characterization of PAL, C4H, and 4CL Genes Regulating the Phenylpropanoid Pathway in Vanilla planifolia","volume":"15","author":"Kaur","year":"2025","journal-title":"Sci. Rep."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"e70047","DOI":"10.1111\/jph.70047","article-title":"Antioxidant Mechanisms, Phenylpropanoid Pathway and Photosynthetic Responses in Pepper Cultivars: Insights into Resistance to Xanthomonas euvesicatoria pv. euvesicatoria","volume":"173","author":"Fonseca","year":"2025","journal-title":"J. Phytopathol."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Timofeeva, T.A., Bubnova, A.N., Shagdarova, B.T., Varlamov, V.P., and Kamionskaya, A.M. (2024). Phenylalanine Ammonia-Lyase-Mediated Differential Response of Tomato (Solanum lycopersicum L.) Cultivars with Different Stress Tolerance to Treatment with Low-Molecular-Weight Chitosan. Agronomy, 14.","DOI":"10.3390\/agronomy14020386"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"218","DOI":"10.1038\/s41586-025-09175-9","article-title":"Complete Biosynthesis of Salicylic Acid from Phenylalanine in Plants","volume":"645","author":"Zhu","year":"2025","journal-title":"Nature"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1046\/j.1365-313X.1996.10020281.x","article-title":"Tobacco Plants Epigenetically Suppressed in Phenylalanine Ammonia-Lyase Expression Do Not Develop Systemic Acquired Resistance in Response to Infection by Tobacco Mosaic Virus","volume":"10","author":"Pallas","year":"1996","journal-title":"Plant J."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Jin, Q., Yao, Y., Cai, Y.P., and Lin, Y. (2013). Molecular Cloning and Sequence Analysis of a Phenylalanine Ammonia-Lyase Gene from dendrobium. PLoS ONE, 8.","DOI":"10.1371\/journal.pone.0062352"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"631.27","DOI":"10.1096\/fasebj.2019.33.1_supplement.631.27","article-title":"Probing the Effect of Pal-Peptidoglycan Interaction on Pal Release from Escherichia coli","volume":"33","author":"Liu","year":"2019","journal-title":"FASEB J."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1007\/s42161-019-00426-z","article-title":"Phenylalanine Ammonia Lyase (PAL) Contributes to the Resistance of Black Rice against Xanthomonas oryzae pv. oryzae","volume":"102","author":"Solekha","year":"2020","journal-title":"J. Plant Pathol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"996","DOI":"10.1016\/j.molcel.2019.03.013","article-title":"RRM Transcription Factors Interact with NLRs and Regulate Broad-Spectrum Blast Resistance in Rice","volume":"74","author":"Zhai","year":"2019","journal-title":"Mol. Cell"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Yao, X.W., Liang, X., Chen, Q., Liu, Y., Wu, C.L., Wu, M.F., Shui, J., Qiao, Y., Zhang, Y., and Geng, Y. (2023). MePAL6 Regulates Lignin Accumulation to Shape Cassava Resistance against Two-Spotted Spider Mite. Front. Plant Sci., 13.","DOI":"10.3389\/fpls.2022.1067695"},{"key":"ref_28","first-page":"678969","article-title":"Conservation, Divergence, and Genome-Wide Distribution of PAL and C4H Gene Families in Plants","volume":"2013","author":"Rawal","year":"2013","journal-title":"Int. J. Genom."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Yan, F., Li, H.Z., and Zhao, P. (2019). Genome-Wide Identification and Transcriptional Expression of the PAL Gene Family in Common Walnut (Juglans regia L.). Genes, 10.","DOI":"10.3390\/genes10010046"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Zhou, H.J., Liu, H.Z., Ma, J.Y., Yue, M., Wang, Y.L., Zhao, P., and Chen, Z.K. (2025). Genome-Wide Identification, Transcriptome Dynamics, and Expression Regulation of the Key Lignin Biosynthesis Gene Families PAL and CAD in Black Walnut Shell. BMC Plant Biol., 25.","DOI":"10.1186\/s12870-025-06884-1"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1016\/bs.afnr.2023.03.001","article-title":"Flavor Perception and Health Benefits of Tea","volume":"106","author":"Yu","year":"2023","journal-title":"Adv. Food Nutr. Res."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2364","DOI":"10.1093\/jee\/tox216","article-title":"Evidence of Premating Isolation Between Two Sibling Moths: Ectropis grisescens and Ectropis obliqua (Lepidoptera: Geometridae)","volume":"110","author":"Luo","year":"2017","journal-title":"J. Econ. Entomol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"e003","DOI":"10.48130\/bpr-0023-0036","article-title":"Emission pattern and anti-insect function of indole from tea plants (Camellia sinensis) attacked by tea geometrids","volume":"4","author":"Li","year":"2024","journal-title":"Beverage Plant Res."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Lin, S., Dong, Y., Li, X., Xing, Y., Liu, M., and Sun, X. (2020). JA-Ile-Macrolactone 5b Induces Tea Plant (Camellia sinensis) Resistance to Both Herbivore Ectropis obliqua and Pathogen Colletotrichum camelliae. Int. J. Mol. Sci., 21.","DOI":"10.3390\/ijms21051828"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Zhang, X., Ran, W., Li, X., Zhang, J., Ye, M., Lin, S., Liu, M., and Sun, X. (2022). Exogenous Application of Gallic Acid Induces the Direct Defense of Tea Plant Against Ectropis obliqua Caterpillars. Front. Plant Sci., 13.","DOI":"10.3389\/fpls.2022.833489"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"413","DOI":"10.1016\/j.plaphy.2017.06.030","article-title":"Six Phenylalanine Ammonia-Lyases from Camellia sinensis: Evolution, Expression, and Kinetics","volume":"118","author":"Wu","year":"2017","journal-title":"Plant Physiol. Biochem."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1606","DOI":"10.1002\/ps.5277","article-title":"Evolution and Functional Analysis of Odorant-Binding Proteins in Three Rice Planthoppers: Nilaparvata lugens, Sogatella furcifera, and Laodelphax striatellus","volume":"75","author":"He","year":"2019","journal-title":"Pest Manag. Sci."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"625","DOI":"10.1002\/jlac.1992199201107","article-title":"Inhibitors of Phenylalanine Ammonia-Lyase: 2-Aminoindan-2-phosphonic Acid and Related Compounds","volume":"1992","author":"Zon","year":"1992","journal-title":"Liebigs Ann. Chem."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1073\/pnas.1902771116","article-title":"An R2R3 MYB transcription factor confers brown planthopper resistance by regulating the phenylalanine ammonia-lyase pathway in rice","volume":"117","author":"He","year":"2020","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1016\/j.plantsci.2018.01.001","article-title":"Signaling Mechanisms Underlying Systemic Acquired Resistance to Microbial Pathogens","volume":"279","author":"Shine","year":"2019","journal-title":"Plant Sci."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"uhaf013","DOI":"10.1093\/hr\/uhaf013","article-title":"PhWRKY30 activates salicylic acid biosynthesis to positively regulate antiviral defense response in petunia","volume":"12","author":"Wang","year":"2025","journal-title":"Hortic. Res."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"163","DOI":"10.1111\/j.1432-1033.1986.tb09847.x","article-title":"Membrane-Bound Hydroxylases in Elicitor-Treated Bean Cells: Rapid Induction of the Synthesis of Prolyl Hydroxylase and a Putative Cytochrome P-450","volume":"159","author":"Bolwell","year":"1986","journal-title":"Eur. J. Biochem."},{"key":"ref_43","unstructured":"(2005). Determination of Substances Characteristic of Green and Black Tea\u2014Part 2: Content of Catechins in Green Tea\u2014Method Using High-Performance Liquid Chromatography (Standard No. ISO 14502-2:2005)."},{"key":"ref_44","first-page":"2814","article-title":"Transcriptional Mechanism of Jasmonate Receptor COI1-Mediated Delay of Flowering Time in Arabidopsis","volume":"27","author":"Zhai","year":"2015","journal-title":"Plant Cell"}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/1\/113\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,24]],"date-time":"2025-12-24T05:18:01Z","timestamp":1766553481000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/1\/113"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,22]]},"references-count":44,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,1]]}},"alternative-id":["ijms27010113"],"URL":"https:\/\/doi.org\/10.3390\/ijms27010113","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12,22]]}}}