Mechanism and function of root circumnutation

Proc Natl Acad Sci U S A. 2021 Feb 23;118(8):e2018940118. doi: 10.1073/pnas.2018940118.

Abstract

Early root growth is critical for plant establishment and survival. We have identified a molecular pathway required for helical root tip movement known as circumnutation. Here, we report a multiscale investigation of the regulation and function of this phenomenon. We identify key cell signaling events comprising interaction of the ethylene, cytokinin, and auxin hormone signaling pathways. We identify the gene Oryza sativa histidine kinase-1 (HK1) as well as the auxin influx carrier gene OsAUX1 as essential regulators of this process in rice. Robophysical modeling and growth challenge experiments indicate circumnutation is critical for seedling establishment in rocky soil, consistent with the long-standing hypothesis that root circumnutation facilitates growth past obstacles. Thus, the integration of robotics, physics, and biology has elucidated the functional importance of root circumnutation and uncovered the molecular mechanisms underlying its regulation.

Keywords: circumnutation; histidine kinase-1; rice roots.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biological Transport
  • Cytokinins / metabolism
  • Gene Expression Regulation, Plant*
  • Histidine Kinase / genetics
  • Histidine Kinase / metabolism*
  • Indoleacetic Acids / pharmacology*
  • Oryza / drug effects
  • Oryza / genetics
  • Oryza / growth & development*
  • Oryza / metabolism
  • Plant Growth Regulators / pharmacology
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plant Roots / drug effects
  • Plant Roots / genetics
  • Plant Roots / growth & development*
  • Plant Roots / metabolism
  • Soil / chemistry*

Substances

  • Cytokinins
  • Indoleacetic Acids
  • Plant Growth Regulators
  • Plant Proteins
  • Soil
  • Histidine Kinase