Genome-Wide Identification and Analysis of the WRKY Gene Family in the Xerophytic Evergreen <i>Ammopiptanthus nanus</i>

• Main Authors: Xin Hao, Shuyao Wang, Yingying Chen, Yue Qu, Hongjun Yao, Yingbai Shen
• Format: Article
• Language: English
• Published: MDPI AG 2020-10-01
• Series: Agronomy
• Subjects: <i>Ammopiptanth</i>us <i>nanus</i>; biotic and abiotic stresses; expression analysis; gene structure; WRKY
• Online Access: https://www.mdpi.com/2073-4395/10/11/1634

The WRKY family of transcription factors plays important roles in plant growth and responses to biotic and abiotic stresses. <i>Ammopiptanthus nanus</i>, the only evergreen broadleaf shrub endemic to the desert and semi-desert regions of northwestern China, is highly tolerant to various stresses. However, a systematic study of WRKY proteins in <i>A. nanus</i> has not been reported. In the present study, we identified 63 WRKY genes in the <i>A. nanus</i> genome. Based on the conserved WRKY domains, zinc finger structures, and phylogenetic relationships in their encoded proteins, we classified these genes into four groups (group I–IV) and several subgroups (subgroup IIa–IIe). Conserved motif analysis showed that all motifs except those within the WRKY domains had a subfamily-specific distribution. Expression analysis revealed that the <i>AnWRKY</i> genes had distinct expression patterns, with some being more responsive to herbivory and drought stresses than others. Based on the results of our current study, we speculate that <i>AnWRKY40</i> and <i>AnWRKY48</i> are positive regulators of the plant’s response to drought and herbivory stresses, respectively. Our results indicate that <i>AnWRKY</i> genes contribute to the ability of <i>A. nanus</i> plants to withstand harsh, dry conditions.