Mutations in Plastidial 5-Aminolevulinic Acid Biosynthesis Genes Suppress a Pleiotropic Defect in Shoot Development of a Mitochondrial GABA Shunt Mutant in Arabidopsis

Plant Cell Physiol. 2015 Jun;56(6):1229-38. doi: 10.1093/pcp/pcv050. Epub 2015 Apr 2.

Abstract

Plant developmental processes are co-ordinated with the status of cell metabolism, not only in mitochondria but also in plastids. In Arabidopsis thaliana, succinic semialdehyde (SSA), a GABA shunt metabolite, links the specific mitochondrial metabolic pathway to shoot development. To understand the mechanism of SSA-mediated development, we isolated a succinic semialdehyde dehydrogenase (ssadh) suppressor mutant, affected in its ability to catalyze SSA to succinic acid. We found that pleiotropic developmental phenotypes of ssadh are suppressed by a mutation in GLUTAMATE-1-SEMIALDEHYDE 2, 1-AMINOMUTASE 2 (GSA2), which encodes a plastidial enzyme converting glutatamate-1-semialdehyde to 5-aminolevulinic acid (5-ALA). In addition, a mutation in either HEMA1 or GSA1, two other enzymes for 5-ALA synthesis, also suppressed ssadh fully and partially, respectively. Furthermore, exogenous application of 5-ALA and SSA disturbed leaf development. These results suggest that metabolism in both mitochondria and plastids affect shoot development.

Keywords: GABA shunt; GSA; Leaf development; SSADH; Tetrapyrrole biosynthetic pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Aminolevulinic Acid / metabolism*
  • Aminolevulinic Acid / pharmacology
  • Arabidopsis / genetics*
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / metabolism
  • Biosynthetic Pathways / drug effects
  • Biosynthetic Pathways / genetics
  • Down-Regulation / drug effects
  • Down-Regulation / genetics
  • Gene Expression Regulation, Plant / drug effects
  • Genes, Chloroplast*
  • Genes, Suppressor
  • Genetic Pleiotropy* / drug effects
  • Meristem / genetics
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Molecular Sequence Data
  • Mutation / genetics*
  • Phenotype
  • Plant Leaves / genetics
  • Plant Shoots / drug effects
  • Plant Shoots / genetics
  • Plant Shoots / growth & development*
  • Plastids / drug effects
  • Plastids / genetics*
  • Plastids / metabolism
  • Suppression, Genetic
  • gamma-Aminobutyric Acid / metabolism*

Substances

  • Arabidopsis Proteins
  • gamma-Aminobutyric Acid
  • Aminolevulinic Acid