Regulation of ATG6/Beclin-1 homologs by abiotic stresses and hormones in rice (Oryza sativa L.)

Genet Mol Res. 2012 Oct 11;11(4):3676-87. doi: 10.4238/2012.August.17.3.

Abstract

Autophagy, a complex and conserved mechanism, serving as a defense response in all eukaryotic organisms, is regulated by several proteins, among which ATG proteins are the most important due to their involvement in autophagosome formation. ATG6/Beclin-1 proteins, reported to be essential for autophagosome formation and assigned as a conserved domain, were subjected to database searches. We found three homologs in the rice (Oryza sativa) genome. A phylogeny tree was constructed to establish their across species relationship, which divided them into three distinct groups; two for plants, i.e., monocots and dicots, and one for animals. Evolutionary study of this family by critical amino acid conservation analysis revealed significant functional divergence. The finding of important stress-related cis-acting elements in the promoter region of rice ATG6 genes demonstrated their involvement in abiotic stress responses. Furthermore, expression profiling of rice ATG6 genes based on microarray data, as well as by semi-quantitative RT-PCR showed differential expression when subjected to different stresses suggesting the involvement of OsATG6 genes in abiotic stresses (heat, cold and drought) and hormone (abscisic acid) responses. Analysis of co-expressed genes showed that most of them annotated to DNA repair pathways and proteolysis, etc. Collectively, these results suggest the involvement of OsATG6 genes in different stresses, and provide a basis for further functional studies to investigate the biological mechanism of action of these genes under abiotic stresses.

MeSH terms

  • Adaptor Proteins, Vesicular Transport / chemistry*
  • Amino Acid Sequence
  • Arabidopsis Proteins / chemistry*
  • Beclin-1
  • Evolution, Molecular
  • Gene Expression Profiling
  • Gene Expression Regulation, Plant / drug effects
  • Genes, Plant / genetics
  • Molecular Sequence Data
  • Oligonucleotide Array Sequence Analysis
  • Oryza / drug effects*
  • Oryza / genetics
  • Oryza / physiology*
  • Phylogeny
  • Plant Growth Regulators / pharmacology*
  • Plant Proteins / chemistry
  • Plant Proteins / genetics
  • Plant Proteins / metabolism*
  • Protein Structure, Tertiary
  • Protein Transport / drug effects
  • Regulatory Sequences, Nucleic Acid / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Alignment
  • Sequence Homology, Amino Acid*
  • Stress, Physiological / drug effects*
  • Stress, Physiological / genetics
  • Subcellular Fractions / drug effects
  • Subcellular Fractions / metabolism

Substances

  • Adaptor Proteins, Vesicular Transport
  • Arabidopsis Proteins
  • Beclin-1
  • Plant Growth Regulators
  • Plant Proteins
  • beclin 1 protein, Arabidopsis