Root Biology Center, South China Agricultural University, Guangzhou 510642, China; Institute of Maize and Featured Upland Crops, Zhejiang Academy of Agricultural Sciences, Hangzhou 310004, China.
Root Biology Center, South China Agricultural University, Guangzhou 510642, China; College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
Plant Sci. 2024 Nov;348:112211. doi: 10.1016/j.plantsci.2024.112211. Epub 2024 Aug 8.
Phosphorus (P) is an essential macronutrient for plant growth and development. Rapid alkalisation factors (RALFs) play crucial roles in plant responses to nutrient stress. However, the functions of Glycine max RALFs (GmRALFs) under low P (LP) stress remain elusive. In this study, we first identified 27 GmRALFs in soybean and then revealed that, under LP conditions, GmRALF10, GmRALF11, and GmRALF22 were induced in both roots and leaves, whereas GmRALF5, GmRALF6, and GmRALF25 were upregulated in leaves. Furthermore, GmRALF22 was found to be the target gene of the transcription factor GmPHR1, which binds to the P1BS cis-element in the promoter of GmRALF22 via electrophoretic mobility shift assay and dual-luciferase experiments. Colonisation with Bacillus subtilis which delivers GmRALF22, increases the expression of the high-affinity phosphate (Pi) transporter genes GmPT2, GmPT11, GmPT13, and GmPT14, thus increasing the total amount of dry matter and soluble Pi in soybeans. RNA sequencing revealed that GmRALF22 alleviates LP stress by regulating the expression of jasmonic acid- (JA-), salicylic acid- (SA-), and immune-related genes. Finally, we verified that GmRALF22 was dependent on FERONIA (FER) to promote Arabidopsis primary root growth under LP conditions. In summary, the GmPHR1-GmRALF22 module positively regulates soybean tolerance to LP.
磷（P）是植物生长和发育所必需的大量营养素。快速碱化因子（RALFs）在植物对养分胁迫的反应中起着至关重要的作用。然而，大豆 Glycine max RALFs（GmRALFs）在低磷（LP）胁迫下的功能仍不清楚。在本研究中，我们首先在大豆中鉴定了 27 个 GmRALFs，然后揭示了在 LP 条件下，GmRALF10、GmRALF11 和 GmRALF22 在根和叶中均被诱导，而 GmRALF5、GmRALF6 和 GmRALF25 在叶中上调。此外，发现 GmRALF22 是转录因子 GmPHR1 的靶基因，GmPHR1 通过电泳迁移率变动分析和双荧光素酶实验与 GmRALF22 启动子中的 P1BS 顺式元件结合。定殖表达 GmRALF22 的枯草芽孢杆菌会增加高亲和力磷酸盐（Pi）转运基因 GmPT2、GmPT11、GmPT13 和 GmPT14 的表达，从而增加大豆的干物质总量和可溶性 Pi。RNA 测序显示，GmRALF22 通过调节茉莉酸（JA）-、水杨酸（SA）-和免疫相关基因的表达来缓解 LP 胁迫。最后，我们验证了 GmRALF22 依赖于 FERONIA（FER）在 LP 条件下促进拟南芥主根生长。总之，GmPHR1-GmRALF22 模块正向调节大豆对 LP 的耐受性。
