Phytoremediation of arsenate contaminated soil by transgenic canola and the plant growth-promoting bacterium Enterobacter cloacae CAL2

New advances in plant growth-promoting rhizobacteria for bioremediation

“…A number of plants which can tolerate and accumulate high concentration of metals were discovered recently and were defined as hyperaccumulators. Ideal hyperaccumulators for bioremediation require the characteristics of rapid growth and a high amount of biomass (Nie et al, 2002). But in fact, many hyperaccumulators are slow in growth and inhibited in the presence of high concentration of heavy metals.…”

“…Besides transition of gene between bacteria, transgenic plants have been constructed for higher remediation efficiency (Grckho et al, 2000;Nie et al, 2002;Stearns et al, 2005). The expression of ACC deaminase in the plant exhibits several advantages against in the bacteria: (1) during the initial stages of seed germination, the bacterial ACC deaminase activity is likely to be much lower than the activity in transgenic plants (Nie et al, 2002); (2) it can constantly stimulate plant growth, which leads to a higher metal accumulation; (3) in some cases an increase in the shoot/root ratio (Grckho et al, 2000); (4) prompting metal uptake of certain fast-growing plants for the substitution of slow-growing hyperaccumulators (Stearns et al, 2005).…”

Role of soil rhizobacteria in phytoremediation of heavy metal contaminated soils

“…In recent years, the use of PGPR as an inducer of systemic resistance in crop plants against different pathogens has been demonstrated under field conditions (Wei et al, 1991;1996;Vidhyasekaran and Muthamilan, 1999;Viswanathan and Samiyappan, 1999). Nie et al(2002) reported that antibiotic-secreting plant growth-promoting bacterial strains can inhibit the proliferation and subsequent invasion of phytopathogens, hence protecting plants from further damage in the presence of arsenate. Experiments showed that seed treated with P. fluorescens strain 97 protected beans against halo blight disease caused by Pseudomonas syringae pv.…”

Exploring the Potential of Bacteria-Assisted Phytoremediation of Arsenic-Contaminated Soils

“…Transgenic canola expressing a bacterial ACC deaminase have increased germination rate compared to non-transformed canola when grown in the presence of arsenate. The mechanism implicated here was the reduction of stress-induced ethylene by the action of the ACC deaminase (Nie et al, 2002). Furthermore, biomass of canola was highest in transgenic canola inoculated with the PGPR Enterobacter cloacae CAL2 thus having highest arsenate accumulated.…”