Low-glutathione mutants are impaired in growth but do not show an increased sensitivity to moderate water deficit

PLoS One. 2019 Oct 18;14(10):e0220589. doi: 10.1371/journal.pone.0220589. eCollection 2019.

Abstract

Glutathione is considered a key metabolite for stress defense and elevated levels have frequently been proposed to positively influence stress tolerance. To investigate whether glutathione affects plant performance and the drought tolerance of plants, wild-type Arabidopsis plants and an allelic series of five mutants (rax1, pad2, cad2, nrc1, and zir1) with reduced glutathione contents between 21 and 63% compared to wild-type glutathione content were phenotypically characterized for their shoot growth under control and water-limiting conditions using a shoot phenotyping platform. Under non-stress conditions the zir1 mutant with only 21% glutathione showed a pronounced dwarf phenotype. All other mutants with intermediate glutathione contents up to 62% in contrast showed consistently slightly smaller shoots than the wild-type. Moderate drought stress imposed through water withdrawal until shoot growth ceased showed that wild-type plants and all mutants responded similarly in terms of chlorophyll fluorescence and growth retardation. These results lead to the conclusion that glutathione is important for general plant performance but that the glutathione content does not affect tolerance to moderate drought conditions typically experienced by crops in the field.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis Proteins* / genetics
  • Arabidopsis Proteins* / metabolism
  • Arabidopsis* / genetics
  • Arabidopsis* / growth & development
  • Glutathione* / genetics
  • Glutathione* / metabolism
  • Mutation*
  • Plant Shoots* / genetics
  • Plant Shoots* / growth & development
  • Water / metabolism*

Substances

  • Arabidopsis Proteins
  • Water
  • Glutathione

Grants and funding

This work was supported by Deutsche Forschungsgemeinschaft (DFG) within the Research Training Group GRK 2064 (AM; MS; SJM-S), grant ME1567/9-1/2 within the Priority Program SPP1710 (AM), the Emmy-Noether programme (SCHW1719/1-1; MS), and Excellence Initiative (EXC 1028; SK). The Seed Fund grant CoSens from the Bioeconomy Science Center, NRW (AM; MS) is gratefully acknowledged. The scientific activities of the Bioeconomy Science Center are financially supported by the Ministry of Innovation, Science and Research within the framework of the NRW Strategieprojekt BioSC (No. 313/323-400-002 13). SB received financial support through a fellowship from the Higher Education Commission, Pakistan.