{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T09:28:07Z","timestamp":1786958887905,"version":"build-2736575974"},"reference-count":58,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2026,8,16]],"date-time":"2026-08-16T00:00:00Z","timestamp":1786838400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004763","name":"Natural Science Foundation of Inner Mongolia Autonomous Region","doi-asserted-by":"publisher","award":["2026QC0549"],"award-info":[{"award-number":["2026QC0549"]}],"id":[{"id":"10.13039\/501100004763","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Plants"],"abstract":"<jats:p>Populus hopeiensis is an important native poplar species in northern China, but herbivorous insect damage seriously affects its growth and ecological function. WRKY transcription factors play important roles in plant stress responses; however, the function of WRKY23 homologs in woody plant resistance to chewing herbivores remains unclear. In this study, a herbivore-responsive WRKY transcription factor gene, PhWRKY23, was identified from P. hopeiensis. PhWRKY23 expression was significantly induced by Spodoptera litura feeding, with a maximum increase of approximately 69.71-fold the control level at the highest damage level, and the encoded protein was predominantly localized in the nucleus. To investigate its function, PhWRKY23-overexpressing and RNA interference transgenic lines were generated. In the choice feeding assay, the consumed leaf area of PhWRKY23-overexpressing plants was approximately 85.5% lower than that of WT plants after 8 h. In the no-choice feeding assay, the total larval mass after 6 d was approximately 38.8% lower in larvae fed on overexpression plants and 51.0% higher in larvae fed on RNAi plants than in those fed on WT plants. Physiological analysis showed that RNAi plants accumulated significantly more MDA than WT and overexpression plants, whereas overexpression plants had higher chlorophyll a, chlorophyll b, and carotenoid contents than the other genotypes. Phytohormone analysis further showed that PhWRKY23-overexpressing plants accumulated higher levels of jasmonic acid, jasmonoyl-L-isoleucine, and salicylic acid, whereas abscisic acid showed no significant difference among genotypes. Yeast two-hybrid screening identified several candidate PhWRKY23-interacting proteins, and pairwise validation confirmed that PhWRKY23 interacted with PhDOX1 in yeast. These results indicate that PhWRKY23 positively contributes to herbivore resistance in P. hopeiensis and that this resistance phenotype is associated with changes in JA, JA-Ile, and SA accumulation and defense-related physiological traits.<\/jats:p>","DOI":"10.3390\/plants15162483","type":"journal-article","created":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T08:05:41Z","timestamp":1786953941000},"page":"2483","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["PhWRKY23 Positively Contributes to Herbivore Resistance and Is Associated with Phytohormone and Defense-Related Responses in Populus hopeiensis"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-4748-9437","authenticated-orcid":false,"given":"Qi","family":"Zhang","sequence":"first","affiliation":[{"name":"College of Forestry, Inner Mongolia Agricultural University, Hohhot 010018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiaxin","family":"Liu","sequence":"additional","affiliation":[{"name":"College of Forestry, Inner Mongolia Agricultural University, Hohhot 010018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-9053-4641","authenticated-orcid":false,"given":"Yu-e","family":"Bai","sequence":"additional","affiliation":[{"name":"College of Forestry, Inner Mongolia Agricultural University, Hohhot 010018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Linlin","family":"Pang","sequence":"additional","affiliation":[{"name":"College of Forestry, Inner Mongolia Agricultural University, Hohhot 010018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shaobin","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Forestry, Inner Mongolia Agricultural University, Hohhot 010018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dongying","family":"Geng","sequence":"additional","affiliation":[{"name":"College of Forestry, Inner Mongolia Agricultural University, Hohhot 010018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jia","family":"Liu","sequence":"additional","affiliation":[{"name":"College of Forestry, Inner Mongolia Agricultural University, Hohhot 010018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aoga","family":"Li","sequence":"additional","affiliation":[{"name":"College of Forestry, Inner Mongolia Agricultural University, Hohhot 010018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1596","DOI":"10.1126\/science.1128691","article-title":"The genome of black cottonwood, Populus trichocarpa (Torr. & Gray)","volume":"313","author":"Tuskan","year":"2006","journal-title":"Science"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Prabhakaran Vasantha-Srinivasan, P.V., Noh, M.Y., Park, K.B., Kim, T.Y., Jung, W.J., Senthil-Nathan, S.S., and Han, Y.S. (2025). Plant immunity to insect herbivores: Mechanisms, interactions, and innovations for sustainable pest management. Front. Plant Sci., 16.","DOI":"10.3389\/fpls.2025.1599450"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1146\/annurev.arplant.59.032607.092825","article-title":"Plant immunity to insect herbivores","volume":"59","author":"Howe","year":"2008","journal-title":"Annu. Rev. Plant Biol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"527","DOI":"10.1146\/annurev-arplant-050718-095910","article-title":"Molecular interactions between plants and insect herbivores","volume":"70","author":"Erb","year":"2019","journal-title":"Annu. Rev. Plant Biol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1146\/annurev-genet-102209-163500","article-title":"New insights into plant responses to the attack from insect herbivores","volume":"44","author":"Wu","year":"2010","journal-title":"Annu. Rev. Genet."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1146\/annurev.arplant.53.100301.135207","article-title":"Plant responses to insect herbivory: The emerging molecular analysis","volume":"53","author":"Kessler","year":"2002","journal-title":"Annu. Rev. Plant Biol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"310","DOI":"10.1016\/j.tplants.2007.06.001","article-title":"Before gene expression: Early events in plant\u2013insect interaction","volume":"12","author":"Maffei","year":"2007","journal-title":"Trends Plant Sci."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"431","DOI":"10.1146\/annurev-arplant-042110-103854","article-title":"Plant defense against herbivores: Chemical aspects","volume":"63","author":"Boland","year":"2012","journal-title":"Annu. Rev. Plant Biol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"10242","DOI":"10.3390\/ijms140510242","article-title":"Plant defense against insect herbivores","volume":"14","author":"Zagrobelny","year":"2013","journal-title":"Int. J. Mol. Sci."},{"key":"ref_10","first-page":"e05765","article-title":"Pest categorisation of Spodoptera litura","volume":"17","author":"Bragard","year":"2019","journal-title":"EFSA J."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Pastierovi\u010d, F., Laff\u00e9rsov\u00e1, J., Kardo\u0161ov\u00e1, M., Rep\u00e1\u010d, I., and Giertych, M.J. (2024). Biochemical responses in Populus tremula: Defending against sucking and leaf-chewing insect herbivores. Plants, 13.","DOI":"10.3390\/plants13091243"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"9582","DOI":"10.1038\/s41598-022-13225-x","article-title":"Compensatory phenolic induction dynamics in aspen after aphid infestation","volume":"12","author":"Gaur","year":"2022","journal-title":"Sci. Rep."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Farhan, M., Ahmad, F., Ahmad, S., Khan, M.A., Khan, K.A., Al-Ghamdi, A.A., Ali, H., and Waseem, M. (2024). Aphid-resistant plant secondary metabolites: Types, insecticidal mechanisms and prospects for utilization. Plants, 13.","DOI":"10.3390\/plants13162332"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/S1360-1385(00)01600-9","article-title":"The WRKY superfamily of plant transcription factors","volume":"5","author":"Eulgem","year":"2000","journal-title":"Trends Plant Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1016\/j.tplants.2010.02.006","article-title":"WRKY transcription factors","volume":"15","author":"Rushton","year":"2010","journal-title":"Trends Plant Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1199","DOI":"10.1007\/s00299-012-1241-0","article-title":"Genome-wide survey and characterization of the WRKY gene family in Populus trichocarpa","volume":"31","author":"He","year":"2012","journal-title":"Plant Cell Rep."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"6629","DOI":"10.1093\/jxb\/eru381","article-title":"Genome-wide identification and characterization of the Populus WRKY transcription factor family and analysis of their expression in response to biotic and abiotic stresses","volume":"65","author":"Jiang","year":"2014","journal-title":"J. Exp. Bot."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1648","DOI":"10.1104\/pp.109.138990","article-title":"The role of WRKY transcription factors in plant immunity","volume":"150","author":"Pandey","year":"2009","journal-title":"Plant Physiol."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Wang, W., Cao, H., Wang, J., and Zhang, H. (2025). Recent advances in functional assays of WRKY transcription factors in plant immunity against pathogens. Front. Plant Sci., 15.","DOI":"10.3389\/fpls.2024.1517595"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1186\/s42483-025-00349-x","article-title":"Transcription factor WRKY complexes in plant signaling pathways","volume":"7","author":"Chen","year":"2025","journal-title":"Phytopathol. Res."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1984","DOI":"10.1105\/tpc.108.058594","article-title":"Induced plant defenses in the natural environment: Nicotiana attenuata WRKY3 and WRKY6 coordinate responses to herbivory","volume":"20","author":"Skibbe","year":"2008","journal-title":"Plant Cell"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"e04805","DOI":"10.7554\/eLife.04805","article-title":"Prioritizing plant defence over growth through WRKY regulation facilitates infestation by non-target herbivores","volume":"4","author":"Li","year":"2015","journal-title":"eLife"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3682","DOI":"10.1111\/pbi.70169","article-title":"BpWRKY6 regulates insect resistance by affecting jasmonic acid and terpenoid synthesis in Betula platyphylla","volume":"23","author":"Xie","year":"2025","journal-title":"Plant Biotechnol. J."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"358","DOI":"10.1104\/pp.108.119131","article-title":"A role for AtWRKY23 in feeding site establishment of plant-parasitic nematodes","volume":"148","author":"Grunewald","year":"2008","journal-title":"Plant Physiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1554","DOI":"10.1073\/pnas.1121134109","article-title":"Transcription factor WRKY23 assists auxin distribution patterns during Arabidopsis root development through local control on flavonol biosynthesis","volume":"109","author":"Grunewald","year":"2012","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Pr\u00e1t, T., Hajn\u00fd, J., Grunewald, W., Vasileva, M., Moln\u00e1r, G., Tejos, R., Schmid, M., Sauer, M., and Friml, J. (2018). WRKY23 is a component of the transcriptional network mediating auxin feedback on PIN polarity. PLoS Genet., 14.","DOI":"10.1371\/journal.pgen.1007177"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"48","DOI":"10.1111\/j.1469-8137.2009.02955.x","article-title":"Expression profiling and functional analysis of Populus WRKY23 reveals a regulatory role in defense","volume":"184","author":"Major","year":"2009","journal-title":"New Phytol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1016\/j.tplants.2012.01.003","article-title":"Role of phytohormones in insect-specific plant reactions","volume":"17","author":"Erb","year":"2012","journal-title":"Trends Plant Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1021","DOI":"10.1093\/aob\/mct067","article-title":"Jasmonates: Biosynthesis, perception, signal transduction and action in plant stress response, growth and development","volume":"111","author":"Wasternack","year":"2013","journal-title":"Ann. Bot."},{"key":"ref_30","first-page":"257","article-title":"Jasmonates: News on occurrence, biosynthesis, metabolism and action of an ancient group of signaling compounds","volume":"247","author":"Wasternack","year":"2018","journal-title":"Planta"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1146\/annurev.arplant.043008.092007","article-title":"Jasmonate passes muster: A receptor and targets for the defense hormone","volume":"60","author":"Browse","year":"2009","journal-title":"Annu. Rev. Plant Biol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"400","DOI":"10.1038\/nature09430","article-title":"Jasmonate perception by inositol-phosphate-potentiated COI1\u2013JAZ co-receptor","volume":"468","author":"Sheard","year":"2010","journal-title":"Nature"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1016\/j.pbi.2016.07.005","article-title":"Redundancy and specificity in jasmonate signalling","volume":"33","author":"Chini","year":"2016","journal-title":"Curr. Opin. Plant Biol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1233","DOI":"10.1111\/pbi.12417","article-title":"Jasmonate in plant defence: Sentinel or double agent?","volume":"13","author":"Yan","year":"2015","journal-title":"Plant Biotechnol. J."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"uhaf082","DOI":"10.1093\/hr\/uhaf082","article-title":"Salicylic acid and jasmonic acid in plant immunity","volume":"12","author":"Zhang","year":"2025","journal-title":"Hortic. Res."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"773","DOI":"10.1111\/jipb.13820","article-title":"Salicylic acid: The roles in plant immunity and crosstalk with other hormones","volume":"67","author":"Tian","year":"2025","journal-title":"J. Integr. Plant Biol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1146\/annurev-cellbio-092910-154055","article-title":"Hormonal modulation of plant immunity","volume":"28","author":"Pieterse","year":"2012","journal-title":"Annu. Rev. Cell Dev. Biol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"473","DOI":"10.1007\/s11103-008-9435-0","article-title":"Role of plant hormones in plant defence responses","volume":"69","author":"Bari","year":"2009","journal-title":"Plant Mol. Biol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"839","DOI":"10.1104\/pp.107.112029","article-title":"Cross talk in defense signaling","volume":"146","author":"Koornneef","year":"2008","journal-title":"Plant Physiol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1146\/annurev-phyto-073009-114447","article-title":"Hormone crosstalk in plant disease and defense: More than just jasmonate\u2013salicylate antagonism","volume":"49","author":"Grant","year":"2011","journal-title":"Annu. Rev. Phytopathol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1267","DOI":"10.1093\/mp\/ssu049","article-title":"Growth\u2013defense tradeoffs in plants: A balancing act to optimize fitness","volume":"7","author":"Huot","year":"2014","journal-title":"Mol. Plant"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1146\/annurev-arplant-042817-040322","article-title":"Reactive oxygen species in plant signaling","volume":"69","author":"Waszczak","year":"2018","journal-title":"Annu. Rev. Plant Biol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"373","DOI":"10.1146\/annurev.arplant.55.031903.141701","article-title":"Reactive oxygen species: Metabolism, oxidative stress, and signal transduction","volume":"55","author":"Apel","year":"2004","journal-title":"Annu. Rev. Plant Biol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"909","DOI":"10.1016\/j.plaphy.2010.08.016","article-title":"Reactive oxygen species and antioxidant machinery in abiotic stress tolerance in crop plants","volume":"48","author":"Gill","year":"2010","journal-title":"Plant Physiol. Biochem."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"58","DOI":"10.1016\/j.molp.2017.09.010","article-title":"Carotenoid metabolism in plants: The role of plastids","volume":"11","author":"Sun","year":"2018","journal-title":"Mol. Plant"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1186\/s43897-022-00023-2","article-title":"Plant carotenoids: Recent advances and future perspectives","volume":"2","author":"Sun","year":"2022","journal-title":"Mol. Hortic."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"597","DOI":"10.1111\/tpj.12386","article-title":"Carotenoid oxidation products as stress signals in plants","volume":"79","author":"Havaux","year":"2014","journal-title":"Plant J."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"112588","DOI":"10.1016\/j.phytochem.2020.112588","article-title":"Recent advances in polyphenol oxidase-mediated plant stress responses","volume":"181","author":"Zhang","year":"2021","journal-title":"Phytochemistry"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"507","DOI":"10.1016\/S0031-9422(97)00539-6","article-title":"A survey of wound- and methyl jasmonate-induced leaf polyphenol oxidase in crop plants","volume":"47","author":"Constabel","year":"1998","journal-title":"Phytochemistry"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1306","DOI":"10.4161\/psb.21663","article-title":"Mechanisms of plant defense against insect herbivores","volume":"7","author":"War","year":"2012","journal-title":"Plant Signal. Behav."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1046\/j.1365-313x.2002.01195.x","article-title":"Involvement of the Arabidopsis \u03b1-DOX1 fatty acid dioxygenase in protection against oxidative stress and cell death","volume":"29","author":"Sanz","year":"2002","journal-title":"Plant J."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"914","DOI":"10.1093\/mp\/ssr105","article-title":"Role of 9-lipoxygenase and \u03b1-dioxygenase oxylipin pathways as modulators of local and systemic defense","volume":"5","author":"Vicente","year":"2012","journal-title":"Mol. Plant"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"977","DOI":"10.1094\/MPMI-01-13-0031-R","article-title":"Expression of \u03b1-DIOXYGENASE 1 in tomato and Arabidopsis contributes to plant defenses against aphids","volume":"26","author":"Avila","year":"2013","journal-title":"Mol. Plant-Microbe Interact."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"315","DOI":"10.1016\/S1360-1385(02)02290-2","article-title":"Impact of phyto-oxylipins in plant defense","volume":"7","year":"2002","journal-title":"Trends Plant Sci."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"511","DOI":"10.1016\/j.plaphy.2008.12.011","article-title":"Oxylipins: Structurally diverse metabolites from fatty acid oxidation","volume":"47","author":"Mosblech","year":"2009","journal-title":"Plant Physiol. Biochem."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/j.plaphy.2014.07.012","article-title":"Characterization of two highly similar CBF\/DREB1-like genes, PhCBF4a and PhCBF4b, in Populus hopeiensis","volume":"83","author":"Wang","year":"2014","journal-title":"Plant Physiol. Biochem."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"319","DOI":"10.1105\/tpc.016980","article-title":"The WRKY70 transcription factor: A node of convergence for jasmonate-mediated and salicylate-mediated signals in plant defense","volume":"16","author":"Li","year":"2004","journal-title":"Plant Cell"},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"849","DOI":"10.1139\/X09-015","article-title":"Development of a standardized methodology for quantifying total chlorophyll and carotenoids from foliage of hardwood and conifer tree species","volume":"39","author":"Minocha","year":"2009","journal-title":"Can. J. For. Res."}],"container-title":["Plants"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2223-7747\/15\/16\/2483\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T08:58:55Z","timestamp":1786957135000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2223-7747\/15\/16\/2483"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,16]]},"references-count":58,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["plants15162483"],"URL":"https:\/\/doi.org\/10.3390\/plants15162483","relation":{},"ISSN":["2223-7747"],"issn-type":[{"value":"2223-7747","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,16]]}}}