Poplar Gene PtoJAZ10 Boosts Insect Resistance in Tobacco

Researchers have mapped the jasmonate ZIM-domain (JAZ) gene family in poplar 741 and shown that one member, PtoJAZ10, can strengthen defence against a major agricultural pest when transferred into tobacco. The study, published as an open-access research article in BMC Plant Biology, addresses a gap in knowledge about how poplar JAZ proteins contribute to herbivore resistance.

JAZ proteins are core components of jasmonic acid signalling, a hormonal pathway with critical roles in plant growth, development and stress defence. In poplar 741, the team identified 39 JAZ family members, designated PtoJAZ1 through PtoJAZ39 according to their chromosomal positions. Phylogenetic analysis sorted the family into six subclades, and most of the encoded proteins contained conserved C-terminal motifs 1 to 3. Collinearity and promoter analyses revealed close evolutionary relationships with JAZ homologs in Eucalyptus grandis, along with abundant hormone- and stress-responsive cis-elements in the promoters of these genes.

Expression testing pointed to PtoJAZ10 as a standout candidate. Its activity was strongly induced by methyl jasmonate, abscisic acid and feeding by the cotton bollworm Helicoverpa armigera, with a 17.5-fold increase recorded after 24 hours of herbivory. Subcellular localization experiments confirmed that PtoJAZ10 encodes a nuclear protein, consistent with a regulatory function.

To test its function directly, the researchers overexpressed PtoJAZ10 heterologously in tobacco. The transgenic plants showed markedly reduced leaf consumption and suppressed larval growth of H. armigera compared with wild-type plants. Upon insect attack, the engineered tobacco accumulated higher levels of jasmonic acid, abscisic acid and lignin, together with elevated antioxidant and phenylpropanoid biosynthetic enzyme activities and lower malondialdehyde content, a marker of oxidative damage.

Transcriptome profiling offered a possible mechanistic explanation: PtoJAZ10 appears to coordinately enhance insect resistance and stress tolerance by regulating core genes of the mitogen-activated protein kinase signalling pathway, such as MPK3 and MPK6, and the phenylpropanoid biosynthesis pathway, including CCoAOMT1 and CCoAOMT2. Several defence-related genes, among them MPK3/6, WRKY33 and CCoAOMT1, showed increased expression in the PtoJAZ10-overexpressing tobacco plants. The authors note that this work systematically characterizes the JAZ gene family in poplar 741 and verifies that heterologous overexpression of PtoJAZ10 in tobacco improves insect resistance, laying a foundation for exploring the molecular mechanisms of poplar insect defence. Because the results come from tobacco rather than poplar itself, the findings represent a proof of principle for the gene’s defensive role rather than a demonstrated field application in forest trees.

Subject of Research: The JAZ gene family in poplar and the role of PtoJAZ10 in plant defence against insect herbivores

Article Title: Identification of the PtoJAZ gene family and functional validation of PtoJAZ10 in enhancing insect resistance in tobacco

Article References: Sun, M., Gu, L., Long, L., Chen, X., Wang, S., Wang, C., Jiang, M., Zhang, J., & Yang, M. (2026). Identification of the PtoJAZ gene family and functional validation of PtoJAZ10 in enhancing insect resistance in tobacco. BMC Plant Biology. https://doi.org/10.1186/s12870-026-10170-z

Image Credits: AI Generated

DOI: 10.1186/s12870-026-10170-z

Keywords: poplar, JAZ proteins, jasmonic acid, PtoJAZ10, tobacco, Helicoverpa armigera, insect resistance, phenylpropanoid biosynthesis, MAPK signalling, plant defence, gene family, transgenic plants