Release of Volatile Selenium Compounds by Plants. Collection Procedures and Preliminary Observations

Abstract

was highest in sheaths and lowest in developing heads. Ash content of all plant parts except stems was higher in spring than in fall. Stems were only slightly lower in the spring. Percentage of silica in the ash was highest in the roots in spring, averaging 43.3%, and was lowest in developing heads (average of 9.80%).Spodograms representative of the silica deposition in various parts of the barley plants are shown in Figure 1. Considerable difference existed between the depositional pattern occurring in leaves and in sheaths. Rows of crenate edged silica particles, like those observed in barley sheaths, also, occurred in wheat sheaths (6, 8). The results showed no direct relationship between silica content and resistance to greenbugs, cold, or diseases. Both resistant and nonresistant varieties had high silica SELENIUM contents.There may be a relationship between early depositions and type of deposition to such resistance, as has been indicated by other workers.

Overexpression of Selenocysteine Methyltransferase in Arabidopsis and Indian Mustard Increases Selenium Tolerance and Accumulation

“…Selenium is unusual among trace elements because it can also be removed from the ground ecosystem by phytovolatilization, i.e. plants metabolize inorganic Se to relatively nontoxic, volatile forms (dimethyl selenide [DMSe] and dimethyl diselenide [DMDSe]), which escape to the atmosphere (Lewis et al, 1966;Terry et al, 2000). Selenium phytoremediation has been achieved under field conditions using fast-growing plant species, such as Indian mustard (Brassica juncea;Bañ uelos et al, 1997), which accumulates Se to hundreds of parts per million (Bañ uelos and Schrale, 1989).…”

Rhizosphere Bacteria Enhance Selenium Accumulation and Volatilization by Indian Mustard1

“…A large proportion of the Se removed by the wetland was accumulated in plant tissues and sediments, and it was estimated that 10% to 30% of the removed Se was volatilized. Se volatilization is the process by which inorganic Se is converted to volatile forms (Lewis et al, 1966;Evans et al, 1968;Lewis, 1971;Frankenberger and Karlson, 1994;Terry and Zayed, 1994). Dimethylselenide, the predominant form of volatile Se, is 500 to 700 times less toxic than inorganic forms of Se (McConnell and Portman, 1952;Ganther et al, 1966;Wilber, 1980).…”

Phytoremediation: A novel green technology to restore soil health

“…This process is called phytovolatilization, the most controversial of all phytoremediation technologies. According to Brooks (1998), the release of volatile Se compounds from higher plants was first reported by Lewis et al (1966). Terry et al (1992) reported that members of the Brassicaceae are capable of releasing up to 40 g Se ha -1 day -1 as various gaseous compounds.…”