He Zihang, Tian Zengzhi, Zhang Qun, Wang Zhibo, Huang Ruikun, Xu Xin, Wang Yucheng, Ji Xiaoyu
College of Forestry, Shenyang Agricultural University, Shenyang, Liaoning, China.
The Key Laboratory of Forest Tree Genetics, Breeding and Cultivation of Liaoning Province, Shenyang Agricultural University, Shenyang, Liaoning, China.
Front Plant Sci. 2022 Oct 24;13:1022076. doi: 10.3389/fpls.2022.1022076. eCollection 2022.
The gene family is a plant-specific family of transcription factors and play a vital role in many plant growth processes and abiotic stress responses. Nevertheless, the functions of the gene family in woody plants, especially in (birch), are hardly known. In this study, we performed a genome-wide analysis of 40 genes () and identified typical GRAS domains of most . The were unevenly distributed on 14 chromosomes of birch and the phylogenetic analysis of six species facilitated the clustering of 265 GRAS proteins into 17 subfamilies. We observed that closely related GRAS homologs had similar conserved motifs according to motif analysis. Besides, an analysis of the expression patterns of 26 showed that most were highly expressed in the leaves and responded to salt stress. Six were selected for -acting element analysis because of their significant upregulation under salt treatment, indicating that many elements were involved in the response to abiotic stress. This result further confirmed that these might participate in response to abiotic stress. Transiently transfected birch plants with transiently overexpressed 6 and RNAi-silenced 6 were generated for gain- and loss-of-function analysis, respectively. In addition, overexpression of showed phenotype resistant to salt stress, decreased the cell death and enhanced the reactive oxygen species (ROS) scavenging capabilities and proline content under salt treatment, consistent with the results in transiently transformed birch plants. This study is a systematic analysis of the gene family in birch plants, and the results provide insight into the molecular mechanism of the gene family responding to abiotic stress in birch plants.
该基因家族是植物特有的转录因子家族，在许多植物生长过程和非生物胁迫响应中发挥着至关重要的作用。然而，该基因家族在木本植物，尤其是在白桦中的功能却鲜为人知。在本研究中，我们对40个该基因（）进行了全基因组分析，并鉴定了大多数基因的典型GRAS结构域。这些基因在白桦的14条染色体上分布不均，对六个物种的系统发育分析有助于将265个GRAS蛋白聚类为17个亚家族。根据基序分析，我们观察到亲缘关系较近的GRAS同源物具有相似的保守基序。此外，对26个基因表达模式的分析表明，大多数基因在叶片中高表达并对盐胁迫有响应。由于其中6个基因在盐处理下显著上调，因此选择它们进行顺式作用元件分析，表明许多元件参与了对非生物胁迫的响应。这一结果进一步证实了这些基因可能参与非生物胁迫响应。分别构建了瞬时过表达6个基因和RNAi沉默6个基因的白桦植株，用于功能获得和功能缺失分析。此外，过表达该基因表现出对盐胁迫的抗性表型，减少了细胞死亡，并增强了盐处理下的活性氧（ROS）清除能力和脯氨酸含量，这与瞬时转化白桦植株的结果一致。本研究对白桦植株中的该基因家族进行了系统分析，结果为深入了解白桦植株中该基因家族响应非生物胁迫的分子机制提供了依据。
