Strong Allelopathic Activities of Leaves and Cultured Cells of <i>Spiraea thunbergii</i> Assayed by the Protoplast Co-Culture Method with Digital Image Analysis: Evaluation of <i>Cis</i>- and <i>Trans</i>-Cinnamic Acid as Allelochemicals

In vitro Bioassay of Allelopathic Activities of Soybean, and Three Isoflavones, Using Protoplast Co-culture Method with Digital Image Analysis

“…The four isoflavones, daidzein (Kobayashi et al, daidzin, genistein, genistin, which inhibited lettuce protoplast division 100% at 100 µM belong to the group of chemicals with strong allelopathic activity studied using the protoplast co-culture method. Similar inhibitory activity has been reported, e.g., canavanine in Vicia villosa (Sasamoto et al, 2019); L-DOPA in Mucuna pruriens (Sasamoto et al, 2013); isoflavonoid, rotenone in Derris indica (Inoue et al, 2015); cinnamic acid and tulipalin A (Mardani-Korrani et al, 2020) in Spiraea thunbergii (Suzuki et al, 2021). Rapid uptake of isoflavones by lettuce protoplasts occurred after 1 day of culture (Figure 10), and showed some damage on spherical enlargement of protoplast.…”

“…The pattern of inhibition was similar to that of soybean protoplasts, Kudzu (Kobayashi et al, 2021) and many plant protoplasts and their putative allelochemicals studied. Several putative allelochemicals, e.g., trans-and cis-cinnamic acid (Suzuki et al, 2021) and volatile compounds, tulipalin A and safranal showed the strongest inhibition at the cell wall formation stage (Mardani-Korrani et al, 2020).…”

“…Analysis by the sandwich method, revealed higher activity in young leaves of potted plants (Mori et al, 2015) than in leaves of field-grown mature plant of leguminous Mucuna gigantea (Fujii & Hiradate, 2003). Differences in the allelopathic activities with the in vitro bioassay methods, i.e., the sandwich method and protoplast co-culture method, have been reported using several plants and putative allelochemicals, e.g., four bamboo species (Ogita & Sasamoto, 2017), poplar, birch and abscisic acid (Sasamoto & Yokota, 2021), and Spiraea thunbergii and trans-cinnamic acid (Suzuki et al, 2021).…”

Strong Allelopathic Activity in Purple Leaves of Transgenic Spiraea cantoniensis Containing Cyanidin 3-Glucoside Assayed by the Protoplast Co-culture Method with Digital Image Analysis

“…Medium was MS basal medium containing 1 µM 2,4-D and 0.1 µM BA, 3% sucrose and 0.8 M mannitol As shown in Figure 4, protoplasts of purple leaves of transgenic Spiraea cantoniensis at high protoplast densities inhibited the cell division of lettuce (100% by 80 × 10 3 mL -1 ) while those of green leaves of non-transgenic S. cantoniensis showed only 20% inhibitory activity (Figure 3). The purple leaf protoplasts showed strong inhibition like the green leaf protoplasts of Spiraea thunbergii, though the latter showed 90% inhibition at 40 × 10 3 mL -1 (Suzuki et al, 2021). Spiraea thunbergii showed strong inhibitory allelopathic activity and S. cantoniensis showed weak activity in the lettuce seedlings growth test for in vitro bioassay of allelopathic activities (Takemura et al, 2013).…”

“…The difference in inhibition with the growth stages of recipient lettuce protoplasts was compared with the results obtained by the DIA-PP method in non-transgenic Spiraea thunbergii and cis-and trans-cinnamic acids (Suzuki et al, 2021), and another anthocyanin, cyanidin 3,5-di-glucoside (cyanin), which was evaluated as an allelochemical of red callus of a mangrove Sonneratia ovata, (Sasamoto et al, 2018), in comparison with that of carotenoid pigments, which showed strong inhibition at the yellow pigment accumulation stage (Sasamoto et al, 2021).…”