Table_5_Genome-Wide Identification and Low Temperature Responsive Pattern of Actin Depolymerizing Factor (ADF) Gene Family in Wheat (Triticum aestivum L.).XLSX

The actin depolymerizing factor (ADF) gene family, which is conserved in eukaryotes, is important for plant development, growth, and stress responses. Cold stress restricts wheat growth, development, and distribution. However, genome-wide identification and functional analysis of the ADF family in wheat is limited. Further, because of the promising role of ADF genes in cold response, there is need for an understanding of the function of this family on wheat under cold stress. In this study, 25 ADF genes (TaADFs) were identified in the wheat genome and they are distributed on 15 chromosomes. The TaADF gene structures, duplication events, encoded conversed motifs, and cis-acting elements were investigated. Expression profiles derived from RNA-seq data and real-time quantitative PCR analysis revealed the tissue- and temporal-specific TaADF expression patterns. In addition, the expression levels of TaADF13/16/17/18/20/21/22 were significantly affected by cold acclimation or freezing conditions. Overexpression of TaADF16 increased the freezing tolerance of transgenic Arabidopsis, possibly because of enhanced ROS scavenging and changes to the osmotic regulation in cells. The expression levels of seven cold-responsive genes were up-regulated in the transgenic Arabidopsis plants, regardless of whether the plants were exposed to low temperature. These findings provide fundamental information about the wheat ADF genes and may help to elucidate the regulatory effects of the encoded proteins on plant development and responses to low-temperature stress.

肌动蛋白解聚因子（actin depolymerizing factor，ADF）基因家族在真核生物中高度保守，对植物的生长发育、形态建成及胁迫响应具有重要调控作用。低温胁迫会限制小麦的生长、发育与分布，但目前针对小麦全基因组范围内ADF基因家族的鉴定与功能分析仍较为匮乏。此外，由于ADF基因在低温响应中展现出良好的应用前景，亟需解析该家族在小麦应对低温胁迫过程中的具体功能。本研究从小麦基因组中鉴定得到25个ADF基因（TaADFs），它们分布于15条染色体上。研究人员对TaADF基因的结构、复制事件、编码蛋白的保守基序及顺式作用元件开展了系统研究。通过RNA测序（RNA-seq）数据与实时定量聚合酶链反应（real-time quantitative PCR, qPCR）的表达谱分析，揭示了TaADF基因的组织特异性与时间特异性表达模式。此外，TaADF13/16/17/18/20/21/22的表达水平在低温驯化或冰冻处理条件下发生显著改变。过表达TaADF16可提升转基因拟南芥的冰冻耐受能力，这可能与其增强活性氧（reactive oxygen species, ROS）清除能力及调节细胞渗透稳态有关。在转基因拟南芥植株中，无论是否经过低温处理，7个低温响应基因的表达水平均显著上调。本研究结果为小麦ADF基因家族提供了基础研究数据，可为阐明其编码蛋白在植物发育及低温胁迫响应中的调控机制提供参考。