Expression Patterns of the Poplar Gene Family in Response to and Hormone Treatment and the Role of in Disease Resistance

Plant nuclear factor-Y (NF-Y) transcription factors (TFs) are key regulators of growth and stress resistance. However, the role of NF-Y TFs in poplar in response to biotic stress is still unclear. In this study, we cloned 26 encoding genes in the hybrid poplar × , including 12 s, six s, and eight s. Their physical and chemical parameters, conserved domains, and phylogeny were subsequently analyzed. The protein-protein interaction (PPI) network showed that the three PdbNF-Y subunits may interact with NF-Y proteins belonging to two other subfamilies and other TFs. Tissue expression analysis revealed that s exhibited three distinct expression patterns in three tissues. Cis-elements related to stress-responsiveness were found in the promoters of s, and most s were shown to be differentially expressed under and hormone treatments. Compared with the and subfamilies, more s were significantly induced under the two treatments. Moreover, loss- and gain-of-function analyses showed that plays a positive role in poplar resistance to . Additionally, RT‒qPCR analyses showed that overexpression and silencing altered the transcript levels of JA-related genes, including , , , , , , and , suggesting that -mediated disease resistance is related to activation of the JA pathway. Our findings will contribute to functional analysis of genes in woody plants, especially their roles in response to biotic stress.