Yan Wei, Wang Runze, Zhang Yutong, Zhang Xiuxiu, Wang Qin
Institute of Biotechnology, Inner Mongolia Academy of Science and Technology, Hohhot, China.
Department of Biochemistry and Molecular Biology, Binzhou Medical University, Yantai, China.
Front Plant Sci. 2024 Sep 19;15:1466431. doi: 10.3389/fpls.2024.1466431. eCollection 2024.
HD-Zip proteins are plant-specific transcription factors known for their diverse functions in regulating plant growth, development, and responses to environmental stresses. Among the HD-Zip II genes, has been previously linked to abiotic stress responses. In this study, we conducted a functional characterization of in the regulation of root growth and development. Upon auxin stimulation, expression of was promptly up-regulated. Overexpression of in led to reduced primary root growth and inhibited lateral root formation. Interestingly, the transgenic plants expressing exhibited differential responses to three types of auxins (IAA, NAA, and 2,4-D) in terms of root growth and development compared to the wild-type plants. Specifically, primary root growth was less affected, and lateral root formation was enhanced in the transgenic plants when exposed to auxins. This differential response suggests a potential role for in modulating auxin transport and accumulation, as evidenced by the reduced sensitivity of the transgenic plants to the auxin transport inhibitor NPA and lower expression levels of auxin-related reporters such as - ()::PIN1-GFP, ::PIN3-GFP, ::PIN7-GFP, and ::GFP compared to wild-type plants. Additionally, microarray analysis of the root tissues revealed down-regulation of several auxin-responsive genes in transgenic seedlings compared to wild-type plants. These findings collectively indicate that plays a critical regulatory role in root growth and development by modulating auxin accumulation and response in the roots.
HD-Zip蛋白是植物特有的转录因子，以其在调节植物生长、发育和对环境胁迫的反应中的多种功能而闻名。在HD-Zip II基因中，先前已与非生物胁迫反应相关联。在本研究中，我们对其在根生长和发育调控中的功能进行了表征。在生长素刺激下，其表达迅速上调。在中过表达导致主根生长减少并抑制侧根形成。有趣的是，与野生型植物相比，表达的转基因植物在根生长和发育方面对三种生长素（IAA、NAA和2,4-D）表现出不同的反应。具体而言，当暴露于生长素时，转基因植物的主根生长受影响较小，侧根形成增强。这种差异反应表明在调节生长素运输和积累方面具有潜在作用，这一点通过转基因植物对生长素运输抑制剂NPA的敏感性降低以及与野生型植物相比生长素相关报告基因如-（）::PIN1-GFP、::PIN3-GFP、::PIN7-GFP和::GFP的表达水平较低得到证明。此外，对根组织的微阵列分析显示，与野生型植物相比，转基因幼苗中几个生长素响应基因的表达下调。这些发现共同表明，通过调节根中生长素的积累和反应，在根生长和发育中起关键的调节作用。
