Continuous UV-B Irradiation Induces Morphological Changes and the Accumulation of Polyphenolic Compounds on the Surface of Cucumber Cotyledons

• DOI: 10.1269/jrr.07046
• Publication Date: 2007-11-21T05:50:39Z
• Authors: Seiji YAMASAKI; Naoto NOGUCHI; Kotaro MIMAKI
• Keywords: Trichome; Cucumis; Toluidine

Sharp-headed and globular-headed trichomes are found on the surface of cucumber (Cucumis sativus L.) cotyledons. Most sharp-headed consist three cells. Toluidine blue O stains but not trichomes. The effect continuous ultraviolet-B (UV-B; 290-320 nm) irradiation cotyledons was examined with respect to two trichome types. Continuous UV-B induced cell division at or under basal part trichomes, resulting in an increase number layers from six. In parallel, area stained by toluidine expanded include epidermal cells surrounding Regions alkali-induced fluorescence due presence polyphenolic compounds coincided areas O. contrast, did cause morphological changes Thus, causes accumulation induces specific around exposure also increases lignin content this tissue. Therefore, may induce compounds, especially stress lignins, near