A transient increase in rosmarinic acid (RA) content in cultured cells of Lithospermum erythrorhizon was observed after addition of yeast extract (YE) to the suspension cultures, reaching a maximum at 24 hr. The highest increase of the RA content (2.5-fold) was obtained when 6-day-old cells in the exponential growth phase were treated with YE. Preceding the induced RA accumulation, phenylalanine ammonia-lyase (PAL) activity increased rapidly, whereas tyrosine aminotransferase (TAT) activity was largely unaffected by the treatment. The incorporation of both (14)C-phenylalanine and (14)C-tyrosine into RA was enhanced in the YE-treated cells, consistent with increased synthesis of the ester.

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Callus tissues derived from seedlings of roselle (Hibiscus sabdariffa L.) were shown to produce two cyanidin glycosides as major anthocyanin pigments. Both callus growth and anthocyanin synthesis were remarkably stimulated by 2,4-dichlorophenoxyacetic acid. The highest anthocyanin yield was observed when 1 μM 2,4-D in combination with 0.1-1 μM kinetin was supplemented to the culture medium. In contrast, gibberellic acid showed inhibitory effect on anthocyanin production.

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The genetic nature of low capsaicin content in variant strains induced by grafting was elucidated by crossing the G 5 S23 strain with the two cultivars, 'Yatsubusa' (Capsicum annuum L. var . fasciculatum Ilish) andSpanish Paprika' (C. annuum L. grossum Sendt) originally used for grafting . Decreased capsaicin synthesis was a stable characteristic for at least several generations from G 5S 16 to G5S 23 and was transmitted to the progenies of crosses . This fact shows that the decreased capsaicin synthesis is a genetic trait in the graft-induced variant strains . The genetically dependent characteristic of pungency of the G 5 S23 , ' Yatsubusa'and `Spanish Paprika' were analysed by High Perfomance Liquid Chromatography measurement and tasting assay .Cross experiment between the G5 S 23 strain, hot parent 'Yatsubusa' and sweet parent `Spanish Paprika' showed that `pungent' and `sweet' for pungency chracteristics are generally controlled by at least two pairs of genes . Although segregation of capsaicin content and pungency was clearly demonstrated in F 2 progenies from reciprocal crosses between the G 5 S23 strain and `Spanish Paprika', F 2 progenies from reciprocal crosses between G5 S 23 and 'Yatsubusa' were all hot and did not develop low capsaicin plants .