Trehalose changes hydraulic conductance of tissue-cultured soybean embryos

The hydraulic properties of tissue-cultured soybean (Glycine max [L.] Merr.) embryos grown on trehalose - containing culture media were investigated. Water potentials of culture media ranged from -0.13 to -0.65 MPa when sucrose and/or trehalose concentrations were altered. The wall extensibility was greatly larger than hydraulic conductance, and the size of the effective turgor was much smaller than that of the growth - induced water potential, indicating that hydraulic conductance and the growth induced water potential were predominantly regulating growth of soybean embryos under tissue culture conditions. The hydraulic conductance of soybean embryos grown on trehalose-containing media became smaller than that in sucrose-containing media. When both sucrose and trehalose were added to the culture media, the hydraulic conductance became an intermediate between only sucrose - containing and only trehalose - containing treatments. It is suggested that trehalose might reduce hydraulic conductance in soybean embryos, resulting in growth retardation of soybean embryos.