Pyrophosphate-fructose 6-phosphate 1-phosphotransferase (PFP1) regulates starch biosynthesis and seed development via heterotetramer formation in rice (Oryza sativa L.)
Pyrophosphate-fructose 6-phosphate 1-phosphotransferase (PFP1) regulates starch biosynthesis and seed development via heterotetramer formation in rice (Oryza sativa L.)
复制标题
焦磷酸果糖 6-磷酸 1-磷酸转移酶 (PFP1) 通过水稻 (Oryza sativa L.) 中异四聚体的形成来调节淀粉生物合成和种子发育。
DOI：
10.1111/pbi.13173
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发表时间：
2020-01-01
影响因子：
13.8
通讯作者：
Qiao, Yongli
中科院分区：
文献类型：
--
作者：
Chen, Chen;He, Bingshu;Qiao, Yongli
焦磷酸-果糖6-磷酸1-磷酸转移酶（Pyrophosphate-fructose 6-phosphate 1-phosphotransferase，PFP 1）在糖酵解过程中可逆地将果糖6-磷酸和焦磷酸转化为果糖1，6-二磷酸和正磷酸，在植物中具有多种功能。然而，PFP 1调节淀粉代谢的机制仍然难以捉摸。本研究探讨了PFP 1在水稻粉质胚乳和灌浆缺陷中的作用。与野生型相比，pfp 1 -3的粒重和淀粉含量显著降低，蛋白质和脂肪含量显著增加，淀粉的理化性质和胚发育过程中的变化发生了改变。图位克隆显示pfp 1 -3是一个新的等位基因，编码PFP 1的调节β亚基（PFP 1 β）。烟酰胺腺嘌呤二核苷酸（NAD+）的测量表明，PFP 1 β的突变显着降低其酶活性。PFP 1 β和PFP 1的四个推定催化α亚基中的三个，PFP 1 α 1、PFP 1 α 2和PFP 1 α 4，彼此相互作用形成异源四聚体。此外，PFP 1 β、PFP 1 α 1和PFP 1 α 2也形成同源二聚体。此外，转录组分析显示，PFP 1 β的突变显着改变了淀粉生物合成途径中许多必需酶的表达。多种脂质和糖酵解中间体和海藻糖代谢产物的浓度升高，在pFP 1 -3胚乳，表明PFP 1调节胚乳代谢，可能通过可逆的调节代谢通量。这些研究结果为水稻种子胚乳发育和淀粉合成提供了新的认识，有助于选育高产优质水稻品种。
Pyrophosphate-fructose 6-phosphate 1-phosphotransferase (PFP1) reversibly converts fructose 6-phosphate and pyrophosphate to fructose 1, 6-bisphosphate and orthophosphate during glycolysis, and has diverse functions in plants. However, mechanisms underlying the regulation of starch metabolism by PFP1 remain elusive. This study addressed the function of PFP1 in rice floury endosperm and defective grain filling. Compared with the wild type, pfp1-3 exhibited remarkably low grain weight and starch content, significantly increased protein and lipid content, and altered starch physicochemical properties and changes in embryo development. Map-based cloning revealed that pfp1-3 is a novel allele and encodes the regulatory beta-subunit of PFP1 (PFP1 beta). Measurement of nicotinamide adenine dinucleotide (NAD+) showed that mutation of PFP1 beta markedly decreased its enzyme activity. PFP1 beta and three of four putative catalytic alpha-subunits of PFP1, PFP1 alpha 1, PFP1 alpha 2, and PFP1 alpha 4, interacted with each other to form a heterotetramer. Additionally, PFP1 beta, PFP1 alpha 1 and PFP1 alpha 2 also formed homodimers. Furthermore, transcriptome analysis revealed that mutation of PFP1 beta significantly altered expression of many essential enzymes in starch biosynthesis pathways. Concentrations of multiple lipid and glycolytic intermediates and trehalose metabolites were elevated in pfp1-3 endosperm, indicating that PFP1 modulates endosperm metabolism, potentially through reversible adjustments to metabolic fluxes. Taken together, these findings provide new insights into seed endosperm development and starch biosynthesis and will help in the breeding of rice cultivars with higher grain yield and quality.