Effects of CeCl3 and LaCl3 on callus and root induction and the physical response of tobacco tissue culture

Laand Cehave positive effects on plant growth and production. Although it is well known that rare earth elements promote cell growth. the biological effects of Laand Ceon callus, shoot and root induction in tobacco are still unclear. The relationships among callus induction, rooting, enzyme activities and stomatal characteristics in tobacco are unknown. The objectives of this study were to identify the relationships between the induction of calluses, shoots, roots, stomata and enzyme activities. The induction percentages of calluses, buds, roots were recorded at 5,10,15, 20 and 25 days after Laand Cetreatments. Peroxidase isoenzyme activity was determined by electrophoresis. The characteristics of the stomata were observed under an optical microscope. Our results show that low concentrations of Ce(<15 mg/L) result in increases in the induction percentages of calluses,buds and roots, but La(>5 mg/L) inhibits the induction of calluses, buds and roots. There are more peroxidase isoenzyme bands in Cetreatments than in Latreatments. This is consistent with the induction percentages of calluses,buds and roots in Ceand Latreatments. High enzyme activities may promote the induction of calluses, buds and roots. The stomata area and stomata number of leaves are significantly different between Latreatments and Cetreatments. Laimproves the stomata area and number. Based on these results, we speculate that Lamay promote the development of the photosynthetic system. Cemay promote tobacco growth and rooting by improving enzyme activities.