EFFECTS OF METHYL JASMONATE AND ELICITOR ON THE ACTIVATION OF PHENYLALANINE AMMONIA-LYASE AND THE ACCUMULATION OF SCOPOLETIN AND SCOPOLIN IN TOBACCO CELL-CULTURES
M. Sharan et al., EFFECTS OF METHYL JASMONATE AND ELICITOR ON THE ACTIVATION OF PHENYLALANINE AMMONIA-LYASE AND THE ACCUMULATION OF SCOPOLETIN AND SCOPOLIN IN TOBACCO CELL-CULTURES, PLANT SCI, 132(1), 1998, pp. 13-19
The effects of methyl jasmonate (MJ) and elicitor on the phenylpropano
id metabolism in tobacco was studied. It was found that suspended cell
s of tobacco, responded to MJ and elicitor from the plant pathogenic f
ungus Fusarium solani with differential formation of phenolic compound
s. Both MJ and elicitor induced phenylalanine ammonia-lyase (PAL, EC 4
.3.1.5) activity to comparable levels. Northern hybridization showed t
hat the increase in PAL activity was preceded by PAL mRNA accumulation
, PAL was induced transcriptionally and enzymatically faster in elicit
or-treated cells as compared to MJ-treated cells. HPLC of extracts fro
m tobacco cells and their culture filtrate treated with MJ, showed an
induction of the syntheses of coumarin-scopoletin and scopolin. This e
ffect was not seen in elicitor-treated or control cell cultures. Scopo
lin was mainly found within the cell (99%), whereas scopoletin accumul
ated in the culture filtrate (90%). We conclude that though MJ mimics
stress, indicating its possible role in the plant defense metabolism,
responses of tobacco cells to MJ and elicitor are distinct. (C) 1998 E
lsevier Science Ireland Ltd. All rights reserved.