Table 1.

Some commonly up and down-regulated processes, as identified by gene expression studies, when a range of higher plant species were exposed to low O₂ conditions.

Species	Treatment	Genes up-regulated	Genes down-regulated	Reference
Cotton (Gossypium hirsutum L.)	Soil waterlogging	Glycolysis, fermentation and mitochondrial electron transport pathways, ethylene synthesis, alanine synthesis	Cell wall synthesis, flavonoid production and synthesis of amino acids	Christianson et al. (2010b)
Arabidopsis	Hypoxia (3 % oxygen)	Glycolysis, fermentation amino acid metabolism, ethylene synthesis, protein kinase activity, and auxin responses	Cell wall synthesis, nucleosome structures, water channels and ion transporters	Liu et al. (2005)
Poplar	Soil waterlogging	Glycolysis, fermentation, trehalose synthesis, proline synthesis	Signalling, phenylalanine synthesis	Christianson et al. (2010a)
Rice	Anoxia	Glycolysis, ethylene response factors, ethanolic fermentation, pyruvate metabolism, heat shock proteins, starch synthesis	PEP carboxylase, sugar transporters, catalase, signal transduction	Lasanthi-Kudahettige et al. (2007)
Sugar beet	Waterlogging	Glycolysis/pentose phosphate cycle, carbohydrate metabolism, seed specific proteins, transport, transcription, signal transduction, lipid metabolism, protein biosynthesis, protein folding, metabolism and cell division cycle	Cytoplasmic ribosomal proteins, translation initiation factors, seed storage proteins, late embryogenesis, seed maturation and dehydration proteins	Pestsova et al. (2008)
Maize	Submergence	Glycolysis, and ethanolic fermentation, auxin response factor, carbohydrate and energy metabolism	Starch synthase aminotransferase, homeostasis and signal cascades of hormone	Zhang et al. (2008)
Soybean	Submergence	Photosynthesis, glycolysis, Ser-Gly-Cys group amino acid synthesis, regulation of transcription, ubiquitin-mediated protein degradation and cell death	Synthesis of phosphofructokinase glucosyl and glucuronyl transferase, secondary metabolism, transport, cell wall synthesis, amino acid metabolism	Nanjo et al. (2011)