Abstract

Being an invasive plant,Polygonum cuspidatumis highly resilient and can survive in unfavorable environments for long periods; however, its molecular mechanisms associated with such environmental resistance are largely unknown. In this study, a WRKY transcription factor (TF) gene,PcWRKY11, was identified fromP. cuspidatumby analyzing methyl jasmonate (MeJA)-treated transcriptome data. It showed a high degree of homology with WRKY11 fromArabidopsis thaliana, containing a WRKY domain and a zinc finger structure and II-d WRKY characteristic domains of HARF, a calmodulin-binding domain (C-motif), and a putative nuclear localization signal (NLS) through sequence alignment and functional element mining. qPCR analysis showed that the expression of PcWRKY11 can be induced by NaCl, osmotic stress, and UV-C. In this study, we also found that overexpression ofPcWRKY11inA. thalianacould significantly increase salt tolerance. To explore its possible molecular mechanism, further investigations showed that compared with the wild type (WT), under salt stress, the transgenic plants showed a lower malondialdehyde (MDA) content, higher expression ofascorbate peroxidase (APX) andsuperoxide dismutase(SOD), and higher enzyme activity of peroxidase(POD), superoxide dismutase (SOD), and catalase (CAT). Moreover, the transgenic plants also showed higher expression of Δ1-pyrroline-5-carboxylate synthase (AtP5CS), and higher contents of proline and soluble sugar. Taken together, these results indicate thatPcWRKY11may have a positive role in plants’ adaptation to salinity conditions by reducing reactive oxygen species (ROS) levels and increasing osmosis substance synthesis.Keywords:Polygonum cuspidatum;PcWRKY11;salt stress;ROS;transgenicArabidopsis thaliana