Table 1

Major functional categories of senescence-associated genes*

Functional category
Associated processes
Abundant genes

Macromolecule degradation
Breakdown of proteins, nucleic acids, lipids and polysaccharides
Cysteine proteases, ubiquitin-related genes, RING finger proteins, nucleases, lipases/acylhydrolases, phospholipases, glucanases, β-glucosidase, pectinesterases, and polygalacturonase
Nutrient recycling
Transport of peptides, amino acids, sugars, purines, pyrimidines and ions
Oligopeptide transporters, ammonium transporter purine and pyrimidine transporters, glutamine synthetase and glutamate synthase, sugar transporters (MFSs), and ABC transporters
Defense and cell rescue mechanisms
Abiotic and biotic stress, and oxidative stress
Metallothionein, glutathione S-transferase, protein similar to jasmonate-inducible protein, glutathione peroxidase, and cold-regulated protein COR6.6
Transcriptional regulation
Transcription factors
Zinc finger proteins, basic helix-loop-helix proteins, bZIP proteins, HMG-box proteins and transcription factors of the WRKY, NAC, AP2, MYB, HB, TCP and GRAS families
Signal transduction
Protein phosphorylation and dephosphorylation
Receptor-like kinases, components of MAP kinase signal cascades, phosphatases and phospholipases, calcium-binding EF-hand protein RD20, calcium-dependent protein kinases, and cytoskeleton-associated proteins

*Determined by the abundance of senescence-associated ESTs, as described by Guo et al. [4]. bZIP, basic leucine zipper; HB, homeobox protein; HMG, high mobility group; MAP, mitogen-activated kinase; MSF, major facilitator superfamily; NAC, no apical meristem (NAM) proteins.

Gepstein Genome Biology 2004 5:212