Role of heterotrimeric Gα proteins in maize development and enhancement of agronomic traits

PLoS Genet. 2018 Apr 30;14(4):e1007374. doi: 10.1371/journal.pgen.1007374. eCollection 2018 Apr.

Abstract

Plant shoot systems derive from the shoot apical meristems (SAMs), pools of stems cells that are regulated by a feedback between the WUSCHEL (WUS) homeobox protein and CLAVATA (CLV) peptides and receptors. The maize heterotrimeric G protein α subunit COMPACT PLANT2 (CT2) functions with CLV receptors to regulate meristem development. In addition to the sole canonical Gα CT2, maize also contains three eXtra Large GTP-binding proteins (XLGs), which have a domain with homology to Gα as well as additional domains. By either forcing CT2 to be constitutively active, or by depleting XLGs using CRISPR-Cas9, here we show that both CT2 and XLGs play important roles in maize meristem regulation, and their manipulation improved agronomic traits. For example, we show that expression of a constitutively active CT2 resulted in higher spikelet density and kernel row number, larger ear inflorescence meristems (IMs) and more upright leaves, all beneficial traits selected during maize improvement. Our findings suggest that both the canonical Gα, CT2 and the non-canonical XLGs play important roles in maize meristem regulation and further demonstrate that weak alleles of plant stem cell regulatory genes have the capacity to improve agronomic traits.

Publication types

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

MeSH terms

  • Agriculture
  • GTP-Binding Protein alpha Subunits / genetics
  • GTP-Binding Protein alpha Subunits / metabolism*
  • Gene Expression Regulation, Developmental
  • Gene Expression Regulation, Plant
  • Gene Knockout Techniques
  • Genes, Plant
  • Meristem / genetics
  • Meristem / growth & development
  • Meristem / metabolism
  • Mutation
  • Phylogeny
  • Plant Leaves / genetics
  • Plant Leaves / growth & development
  • Plant Leaves / metabolism
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Plants, Genetically Modified
  • Zea mays / genetics
  • Zea mays / growth & development*
  • Zea mays / metabolism*

Substances

  • GTP-Binding Protein alpha Subunits
  • Plant Proteins

Grants and funding

This work was supported by funding from the Agriculture and Food Research Initiative competitive grants 2013-02198 and 2017-06299 of the USDA National Institute of Food and Agriculture. The funder had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.