Blue light stimulation of cell proliferation and glyoxalase I activity in callus cultures of Amaranthus paniculatus

Light grown callus cultures of Amaranthus paniculatus showed faster cell proliferation compared to those grown in darkness. When these callus cultures were transferred from light to darkness, the rate of cell proliferation decreased. However, during the dark period if a short irradiation (5 min) of blue light was given once everyday, the rate of cell proliferation was similar or even higher to light grown cultures. This effect was noticed both on fresh weight and on cell number basis. Blue light also increased the activity of glyoxalase-I, an enzyme correlated with cell proliferation. The requirement of light was overcome if the dark grown callus was incubated in the presence of A23187, suggesting a role of calcium in cell proliferation and glyoxalase-I activation. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.