A Comprehensive Identification and Expression Analysis of the WUSCHEL Homeobox-Containing Protein Family Reveals Their Special Role in Development and Abiotic Stress Response in <i>Zea mays</i> L.

oleh: Xuanxuan Chen, Yunyan Hou, Yongyan Cao, Bo Wei, Lei Gu

Format: Article
Diterbitkan: MDPI AG 2023-12-01

Deskripsi

Maize is an important food and cash crop worldwide. The WUSCHEL (WUS)-related homeobox (WOX) transcription factor (TF) family plays a significant role in the development process and the response to abiotic stress of plants. However, few studies have been reported on the function of <i>WOX</i> genes in maize. This work, utilizing the latest maize B73 reference genome, results in the identification of 22 putative <i>ZmWOX</i> gene family members. Except for chromosome 5, the 22 <i>ZmWOX</i> genes were homogeneously distributed on the other nine chromosomes and showed three tandem duplication and 10 segmental duplication events. Based on phylogenetic characteristics, ZmWOXs are divided into three clades (e.g., WUS, intermediate, and ancient groups), and the majority of ZmWOXs in same group display similar gene and protein structures. Cross-species collinearity results indicated that some <i>WOX</i> genes might be evolutionarily conservative. The promoter region of <i>ZmWOX</i> family members is enriched in light, plant growth/hormone, and abiotic stress-responsive elements. Tissue-specific expression evaluation showed that <i>ZmWOX</i> genes might play a significant role in the occurrence of maize reproductive organs. Transcriptome data and RT-qPCR analysis further showed that six <i>ZmWOX</i> genes (e.g., <i>ZmWOX1</i>, <i>4</i>, <i>6</i>, <i>13</i>, <i>16</i>, and <i>18</i>) were positively or negatively modulated by temperature, salt, and waterlogging stresses. Moreover, two <i>ZmWOXs</i>, <i>ZmWOX1</i> and <i>ZmWOX18</i>, both were upregulated by abiotic stress. ZmWOX18 was localized in the nucleus and had transactivation activities, while ZmWOX1 was localized in both the cytoplasm and nucleus, without transactivation activity. Overall, this work offers new perspectives on the evolutionary relationships of <i>ZmWOX</i> genes and might provide a resource for further detecting the biological functions of <i>ZmWOXs</i>.