Expression patterns of WRKY genes in di-haploid Populus simonii × P. nigra in response to osmotic stress and ABA treatment

Abstract

In this study, 108 WRKY genes with complete conserved WRKY domain and zinc-finger motif were identified from poplar in silico, and they were classified into three subfamilies named I, II, and III. The WRKY members in group II were further clustered into five subgroups (IIa-e), where members in group I and III formed a single cluster. Thirteen highly expressed genes were employed to profile their spatio-temporal expression patterns in response to osmotic stress and ABA treatment by qRT-PCR. Under both osmotic stress and ABA treatment, overall gene expression displayed a dynamic pattern of ''induced amplification-recover'' in leaves, but not in roots and stems. Regarding individual gene expression across the seven time points and the three tissues, five genes (PthWRKY28, 56, 62, 88, and 106) were involved in regulation of both osmotic stress tolerance and ABA signaling transduction pathways. Meanwhile, four genes (PthWRKY41, 44, 51, and 116) played distinct roles in either osmotic stress or ABA treatment condition. These suggested that WRKY genes and corresponding pathways may play a critical role in regulating poplar responses to osmotic stress and ABA treatment in a dynamic and tissuespecific manner.

Cloning and overexpression of PeWRKY31 from Populus × euramericana enhances salt and biological tolerance in transgenic Nicotiana

“…The latest release of the PlantTFDB (http://planttfdb.cbi.pku.edu.cn/)transcription factor database contains a total of 185 Populus tomentosa WRKYs. Over a dozen related transcription factors have been isolated, their functions have been verified [25], and the WRKY family genes in many poplar trees have been shown to respond to abiotic stress and play important roles in salt resistance [26][27][28]. Preliminary laboratory research revealed that PeWRKY31 of Populus × euramericana responded to biological stress, but the underlying mechanism was not clear.…”