Elucidating the function of the CYBDOM protein HYP1 in phosphorus deficiency-dependent primary root growth

阐明 CYBDOM 蛋白 HYP1 在磷缺乏依赖性初生根生长中的功能

• 批准号: 437991832
• 负责人: Professor Dr. Nicolaus von Wirén
• 金额: --
• 依托单位: Abteilung Physiologie und Zellbiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/437991832?language=en
• 关键词: Elucidating; function; CYBDOM; protein; HYP1

The availability of nutrients in soils has a strong impact on root growth and development. Apart from effects triggered by single nutrients, also the interaction of different elements can act as a cue to modify root developmental processes. Recent studies have shown that the transition metal iron (Fe) can inhibit root elongation in response to low phosphorus (P) by initiating a complex interplay of redox reactions and signaling events in the root apical zone of P-deprived plants. However, still little is known about the mechanism underlying Fe-dependent redox activity in P-deficient roots. By combining transcriptomics with bioinformatics and reverse genetics in Arabidopsis thaliana we identified a novel cytochrome b561/dopamine beta-monooxygenase N-terminal (CYBDOM) protein, which is predicted to drive apoplastic redox reactions by using cytosolic ascorbate as an electron donor. Our preliminary work demonstrated that the identified protein, which we named HYPERSENSITIVE TO LOW P 1 (HYP1), is crucial for maintaining root growth on low P availability. Thus, the main objectives of this project are: i) to determine the genetic link between HYP1 and other molecular players that adjust root growth under low P and to assess how HYP1 localization in specific roots zones affects cell biological responses in zones where this protein is not expressed; ii) to characterize HYP1- and ascorbate-dependent redox changes in P-deprived roots and to investigate the role of HYP1 in ferric Fe reduction or ascorbate regeneration in the apoplast; and iii) to determine the biochemical function of HYP1 and the functional interplay between the protein’s cytochrome b561 core and the DOMON domain. To achieve these goals, we will combine genetic tools with histochemical, cell biological, biochemical and pharmacological methods. The findings of this research will shed light on the physiological function of yet poorly characterized ascorbate-dependent trans-membrane electron transport via CYBDOMs. Furthermore, the characterization of HYP1 will provide a means to improve root stress tolerance by manipulating root apoplastic redox activity.

土壤中养分的有效性对根系的生长和发育有很大的影响。除了单一营养素引发的影响外，不同元素的相互作用也可以作为改变根系发育过程的线索。近年来的研究表明，过渡金属铁（Fe）通过在缺磷植物根尖区引发氧化还原反应和信号传导等复杂的相互作用，抑制根伸长。然而，仍然知之甚少的机制，铁依赖的氧化还原活性在缺磷的根。通过将转录组学与生物信息学和反向遗传学相结合，我们在拟南芥中鉴定了一种新的细胞色素b561/多巴胺β-单加氧酶N-末端（CYBDOM）蛋白，该蛋白被预测通过使用胞质抗坏血酸作为电子供体来驱动质外体氧化还原反应。我们的初步工作表明，所鉴定的蛋白质，我们命名为低磷超敏感1（HYP 1），是维持低磷供应的根生长至关重要。因此，本项目的主要目标是：i）确定HYP 1和在低P下调节根生长的其他分子参与者之间的遗传联系，并评估HYP 1在特定根区域中的定位如何影响该蛋白不表达的区域中的细胞生物学反应; ii）表征缺磷根中HYP 1和抗坏血酸依赖的氧化还原变化，并研究HYP 1在质外体中铁还原或抗坏血酸再生中的作用;和iii）确定HYP 1的生物化学功能和蛋白质的细胞色素b561核心与DOMON结构域之间的功能相互作用。为了实现这些目标，我们将联合收割机遗传工具与组织化学，细胞生物学，生物化学和药理学方法相结合。这项研究的结果将揭示尚未充分表征的抗坏血酸依赖性跨膜电子传递通过CYBDOMs的生理功能。此外，HYP 1的表征将提供一种手段，以提高根胁迫耐受性，通过操纵根质外体氧化还原活性。