Cp. Witte et al., Addition of nickel to Murashige and Skoog medium in plant tissue culture activates urease and may reduce metabolic stress, PL CELL TIS, 68(1), 2002, pp. 103-104
Nickel has been identified as an essential element for plant growth. The la
ck of nickel and the inclusion of cobalt leads to absence of urease activit
y in plants grown on MS medium in tissue culture. To avoid leaf damage and
metabolic stress, nickel should be included in tissue culture growth media.