Freed Catherine, Craige Branch, Donahue Janet, Cridland Caitlin, Williams Sarah Phoebe, Pereira Chris, Kim Jiwoo, Blice Hannah, Owen James, Gillaspy Glenda
Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA.
Plant Physiol. 2024 Dec 23;197(1). doi: 10.1093/plphys/kiae582.
Inositol pyrophosphates are eukaryotic signaling molecules that have been recently identified as key regulators of plant phosphate sensing and homeostasis. Given the importance of phosphate to current and future agronomic practices, we sought to design plants, which could be used to sequester phosphate, as a step in a phytoremediation strategy. To achieve this, we expressed diadenosine and diphosphoinositol polyphosphate phosphohydrolase (DDP1), a yeast (Saccharomyces cerevisiae) enzyme demonstrated to hydrolyze inositol pyrophosphates, in Arabidopsis thaliana and pennycress (Thlaspi arvense), a spring annual cover crop with emerging importance as a biofuel crop. DDP1 expression in Arabidopsis decreased inositol pyrophosphates, activated phosphate starvation response marker genes, and increased phosphate accumulation. These changes corresponded with alterations in plant growth and sensitivity to exogenously applied phosphate. Pennycress plants expressing DDP1 displayed increases in phosphate accumulation, suggesting that these plants could potentially serve to reclaim phosphate from phosphate-polluted soils. We also identified a native Arabidopsis gene, Nucleoside diphosphate-linked moiety X 13 (NUDIX13), which we show encodes an enzyme homologous to DDP1 with similar substrate specificity. Arabidopsis transgenics overexpressing NUDIX13 had lower inositol pyrophosphate levels and displayed phenotypes similar to DDP1-overexpressing transgenics, while nudix13-1 mutants had increased levels of inositol pyrophosphates. Taken together, our data demonstrate that DDP1 and NUDIX13 can be used in strategies to regulate plant inositol pyrophosphates and could serve as potential targets for engineering plants to reclaim phosphate from polluted environments.
肌醇焦磷酸是真核生物信号分子，最近被确定为植物磷感知和稳态的关键调节因子。鉴于磷对当前和未来农艺实践的重要性，我们试图设计可用于螯合磷的植物，作为植物修复策略的一个步骤。为实现这一目标，我们在拟南芥和遏蓝菜（一种作为生物燃料作物正变得日益重要的春季一年生覆盖作物）中表达了二腺苷和二磷酸肌醇多磷酸磷酸水解酶（DDP1），该酶是一种酵母（酿酒酵母）酶，已证明可水解肌醇焦磷酸。拟南芥中DDP1的表达降低了肌醇焦磷酸水平，激活了磷饥饿反应标记基因，并增加了磷积累。这些变化与植物生长的改变以及对外源施加磷的敏感性相对应。表达DDP1的遏蓝菜植株的磷积累增加，表明这些植物可能有助于从磷污染土壤中回收磷。我们还鉴定出一个拟南芥天然基因，核苷二磷酸连接的部分X 13（NUDIX13），我们发现它编码一种与DDP1同源且底物特异性相似的酶。过表达NUDIX13的拟南芥转基因植株的肌醇焦磷酸水平较低，并且表现出与过表达DDP1的转基因植株相似的表型，而nudix13 - 1突变体的肌醇焦磷酸水平升高。综上所述，我们的数据表明DDP1和NUDIX13可用于调节植物肌醇焦磷酸的策略中，并可作为工程改造植物以从污染环境中回收磷的潜在靶点。
