title: The high-affinity phosphate transporter GmPT5 regulates phosphate transport to nodules and nodulation in soybean.
abstract: Legume biological nitrogen (N) fixation is the most important N source in agroecosystems, but it is also a process requiring a considerable amount of phosphorus (P). Therefore, developing legume varieties with effective N(2) fixation under P-limited conditions could have profound significance for improving agricultural sustainability. We show here that inoculation with effective rhizobial strains enhanced soybean (Glycine max) N(2) fixation and P nutrition in the field as well as in hydroponics. Furthermore, we identified and characterized a nodule high-affinity phosphate (Pi) transporter gene, GmPT5, whose expression was elevated in response to low P. Yeast heterologous expression verified that GmPT5 was indeed a high-affinity Pi transporter. Localization of GmPT5 expression based on β-glucuronidase staining in soybean composite plants with transgenic roots and nodules showed that GmPT5 expression occurred principally in the junction area between roots and young nodules and in the nodule vascular bundles for juvenile and mature nodules, implying that GmPT5 might function in transporting Pi from the root vascular system into nodules. Overexpression or knockdown of GmPT5 in transgenic composite soybean plants altered nodulation and plant growth performance, which was partially dependent on P supply. Through both in situ and in vitro (33)P uptake assays using transgenic soybean roots and nodules, we demonstrated that GmPT5 mainly functions in transporting Pi from roots to nodules, especially under P-limited conditions. We conclude that the high-affinity Pi transporter, GmPT5, controls Pi entry from roots to nodules, is critical for maintaining Pi homeostasis in nodules, and subsequently regulates soybean nodulation and growth performance.
authors: State Key Laboratory for Conservation and Utilization of Subtropical Agrobioresources, Root Biology Center, South China Agricultural University, Guangzhou 510642, China.
authors: Lu
authors: L
authors: Qin
authors: Jing
authors: J
authors: Zhao
authors: Jiang
authors: J
authors: Tian
authors: Liyu
authors: L
authors: Chen
authors: Zhaoan
authors: Z
authors: Sun
authors: Yongxiang
authors: Y
authors: Guo
authors: Xing
authors: X
authors: Lu
authors: Mian
authors: M
authors: Gu
authors: Guohua
authors: G
authors: Xu
authors: Hong
authors: H
authors: Liao
mesh_terms: D001681:Biological Assay; D001692:Biological Transport; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D005966:Glucuronidase / Q000378:metabolism; D018527:Hydroponics; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism; D028061:Phosphate Transport Proteins / Q000235:genetics / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D055170:Plant Root Nodulation / Q000235:genetics / Q000502:physiology*; D030821:Plants, Genetically Modified; D034622:RNA Interference; D012231:Rhizobium / Q000502:physiology; D053204:Root Nodules, Plant / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D012995:Solubility; D013025:Glycine max / Q000235:genetics / Q000254:growth & development / Q000382:microbiology / Q000502:physiology*; D013489:Suppression, Genetic
chemical_list: D028061:Phosphate Transport Proteins; D010710:Phosphates; D010940:Plant Proteins; D010758:Phosphorus; D005966:Glucuronidase; D009584:Nitrogen