The metabolic effects of native and transgenic hemoglobins on plants

Increased level of hemoglobin 1 enhances survival of hypoxic stress and promotes early growth in Arabidopsis thaliana

“…These plants have increased growth, speed of germination, and production of secondary metabolites (reviewed in ref. 29). Our results show that GLB1 reproduces some of the effects of VITaq GLB; however, the two proteins have quite different biochemical properties.…”

Expression of Alcaligenes eutrophus Flavohemoprotein and Engineered Vitreoscilla Hemoglobin-Reductase Fusion Protein for Improved Hypoxic Growth of Escherichia coli

“…One of the foremost examples of inverse metabolic engineering (the genetic transfer of useful phenotypes to heterologous organisms) is expression of Vitreoscilla hemoglobin (VHb) in aerobic bacteria, yeast, fungi, and plants to enhance their growth and productivity (2,6,14,25). Although the exact mechanism by which VHb causes these effects is unknown, it has been hypothesized that due to its unusual kinetic parameters for oxygen binding and release (K D ϭ 72 M) (45), VHb is able to scavenge oxygen molecules from solution and provide them for cellular activities in heterologous organisms (18,45,49).…”

Vitreoscilla Hemoglobin (VHb) Overexpression Increases Hypoxia Tolerance in Zebrafish (Danio rerio)

“…Some studies suggested that VHb could protect cells from nitrosative and oxidative stress both in bacteria and plants (Kaur et al 2002;Wang et al 2009). Therefore, VHb may function to scavenge oxygen radicals, reducing peroxidases under hypoxia (Bülow et al 1999). We suggest that VHb can alleviate oxidative stress by the relatively higher mRNA expression levels of antioxidant enzymes in zebrafish, which could help to reduce damage by the reactive oxygen species to the tissue cells.…”

“…In hypoxic conditions, VHb is proposed to enhance respiration and energy metabolism by promoting oxygen delivery with a high oxygen dissociation rate constant (Bülow et al 1999;Frey and Kallio 2003). VHb has also been shown to improve growth, protein secretion, and metabolite productivity when the vhb gene is expressed in various organisms including microorganisms, plants, and mammalian cells (Khosla et al 1990;DeModena et al 1993;Pendse and Bailey 1994;Holmberg et al 1997;Wilhelmson et al 2006).…”