Jiao Honghong, Hua Zhongyi, Zhou Junhui, Hu Jin, Zhao Yuyang, Wang Yingping, Yuan Yuan, Huang Luqi
State Key Laboratory of Grassland Agro-ecosystems, Engineering Research Center of Grassland Industry, Ministry of Education, Gansu Tech Innovation Centre of Western China Grassland Industry, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China.
State Key Laboratory of Dao-di Herbs, National Resource Center for Chinese Materia Medica, Chinese Academy of Chinese Medical Sciences, Beijing 100700, China.
Int J Biol Macromol. 2023 Apr 1;233:123648. doi: 10.1016/j.ijbiomac.2023.123648. Epub 2023 Feb 11.
Panax root is an important material used in food and medicine. Its cultivation and production usually depend on root shape and ginsenoside content. There is limited understanding about the synergistic regulatory mechanisms underlying root development and ginsenoside accumulation in Panax. MADS-box transcription factors possibly play a significant role in regulation of root growth and secondary metabolites. In this study, we identified MADS-box transcription factors of Panax, and found high expression levels of SVP, ANR1 and SOC1-like clade genes in its roots. We confirmed that two SOC1-like genes, PgMADS41 and PgMADS44, bind to expansion gene promoters (PgEXLB5 and PgEXPA13), which contribute to root growth, and to SE-4, CYP716A52v2-4, and β-AS-13 promoters, which participate in ginsenoside Ro biosynthesis. These two genes were found to increase lateral root number and main root length in transgenic Arabidopsis thaliana by improving AtEXLA1, AtEXLA3, AtEXPA5, and AtEXPA6 gene expression. As a non-phytohormone regulatory tool, Ro can stimulate adventitious root growth by influencing their expression and ginsenoside accumulation. Our study provides new insights into the coordinated regulatory function of SOC1-like clade genes in Panax root development and triterpenoid accumulation, paving the way towards understanding root formation and genetic improvement in Panax.
人参根是食品和医药领域的重要原料。其种植和生产通常取决于根的形状和人参皂苷含量。目前对人参根发育和人参皂苷积累的协同调控机制了解有限。MADS-box转录因子可能在根生长和次生代谢产物的调控中发挥重要作用。在本研究中，我们鉴定了人参的MADS-box转录因子，并发现其根中SVP、ANR1和SOC1-like进化枝基因的高表达水平。我们证实，两个SOC1-like基因PgMADS41和PgMADS44与促进根生长的扩张基因启动子（PgEXLB5和PgEXPA13）以及参与人参皂苷Ro生物合成的SE-4、CYP716A52v2-4和β-AS-13启动子结合。通过提高AtEXLA1、AtEXLA3、AtEXPA5和AtEXPA6基因的表达，发现这两个基因可增加转基因拟南芥的侧根数和主根长度。作为一种非植物激素调控工具，Ro可通过影响不定根的表达和人参皂苷积累来刺激其生长。我们的研究为SOC1-like进化枝基因在人参根发育和三萜积累中的协同调控功能提供了新的见解，为理解人参根的形成和遗传改良铺平了道路。
