抄録
We determined the role of phenolic metabolism in promoting shoot regeneration in vivo by shading cut surfaces of tomato stems. The number of regenerated shoots from shaded stems was significantly increased (36.2) compared with unshaded stems (18.2). The concentration of phenols in shaded stems during 7–28 days after cutting was lower than that in unshaded stems, and decreased to concentrations lower than initial levels during the experimental period. The activity of phenylalanine ammonia-lyase (PAL) in unshaded stems was higher than that in shaded stems and fluctuated, whereas PAL activity in shaded stems stably remained at a lower level than the initial level. Neither polyphenol oxidase activity nor peroxidase activity were affected by shading. As the result, shading induced suppressed PAL activity and a lower concentration of phenols in the cut stems of tomato plants, and increased the number of regenerated shoots.
