Abstract
The enzymatic activity and the gene expression of pectin methylesterase (PME) in Populus 0-B cells which can grow in the medium without boron were examined. The activity of PME was higher than that of 1/1-B cells which required enough boron (100 μM), as well as 1/20-B cells tolerant to low boron condition (5 μM). However changes in the activity were different from 1/20-B. The activity decreased until 6 days after subculture and then increased. The gene expression of PME was similar to 1/20-B. Namely a large amount of PME mRNA was accumulated in 8-10 days and gene expression was observed until the later stage of culture period in which no gene expression was observed in 1/1-B. From these results, it was indicated that the induction mechanism of PME as the adaptation to the boron deficiency was present in 0-B as well as 1/20-B.
