Action of ultraviolet radiation (UV-B) upon cuticular waxes in some crop plants

Abstract

The surface structure and composition of surface lipids were examined in leaves of barley, bean, and cucumber seedlings grown in a growth chamber under white light and low levels of ultraviolet (UV-B; 280-320 nm) radiation. The cuticular wax of cucumber cotyledons and bean leaves appeared as a thin homogeneous layer, whereas on barley leaves crystal-like structures could be observed under these irradiation conditions. Principally, the amount of cuticular wax found in barley leaves was five times greater than in bean or cucumber leaves. The prediominant wax components were primary alcohols in barley, primary alcohols and monoesters in bean, and alkanes in cucumber cotyledons. Irradiation with enhanced UV-B levels caused an increase of total wax by about 25% in all plant species investigated. Aldehydes, detected as a minor constituent of cucumber and barley wax, increased twofold. Distribution patterns of the homologs within some wax classes were different at low and enhanced UV-B levels. In general, the distribution of the homologs was shifted to shorter acyl chain lengths in wax of leaves exposed to enhanced UV-B levels. This was most apparent in cucumber wax, less in bean or barley wax. The UV-B-caused effects upon cucumber wax were mainly due to a response by the adaxial surface of the leaf.

Symbiotic fungi alter plant chemistry that discourages leaf‐cutting ants

“…Most compounds found in our leaf surface chloroform extracts had been reported as cuticular waxes or components of the cell membrane of leaves, fruits and seeds of cucumber (Steinm€ uller & Tevini , 1985;Akihisa et al, 1986Akihisa et al, , 1988Hartmann, 1998;Chun et al, 2006). Our results showed that high levels of C. tropicale colonization did not cause significant changes in the composition of cuticular waxes of leaves.…”

Effects of u.v.‐B radiation on epicuticular wax production and chemical composition of four Picea species

“…1), early shoot development (Cape & Percy, 1993) and lower shade tolerance relative to other species (Farrar, 1995). Steinmuller & Tevini (1985), Tevini & Steinmuller (1987), with soybean and Barnes et al (1994Barnes et al ( , 1996 with tobacco, observed a shift toward shorter chain lengths with increased u.v.-B. No effect of u.v.-B on short-to long-chain length homologue ratios was recorded in this study.…”

“…Wax composition in conifers is product of genetic make up (Percy, McQuattie & Rebbeck, 1994) and environmental factors (Gunthardt-Goerg, 1987 ;Cape & Percy, 1993) such as light quality and quantity, temperature and relative humidity. Although it is unresolved whether the cuticle plays any significant role in protecting the plant against u.v.-B, wax chemical composition has been shown to be altered by elevated u.v.-B in a range of crop species such as tobacco (Barnes et al, 1994(Barnes et al, , 1996, pea (Gonzalez et al, 1997), cucumber, bean, and barley (Steinmuller & Tevini, 1985). Recent evidence suggests that there is a critical level for u.v.-B effects on wax biosynthesis in at least one broadleaf tree species, sugar maple (Acer saccharum) (Gordon, Percy & Riding, 1998).…”

“…Following exposure of a sensitive tobacco genotype to elevated levels of u.v.-B, Barnes et al (1996) observed reduced amounts of wax on the adaxial leaf surface, whereas Steinmuller & Tevini (1985) observed an increase in wax production of up to 23 % on bean leaves. Wax amounts recorded in this study were not affected by increasing u.v.-B.…”

Wax Layers onCosmos bipinnatusPetals Contribute Unequally to Total Petal Water Resistance

“…V. faba flower wax was characterized by high levels of C 22 alcohol (Griffiths et al, 1999), in contrast to either C 26 or C 30 alcohols in leaf waxes of the closely related Fabaceae spp. Phaseolus vulgaris (Steinmüller and Tevini, 1985), Medicago truncatula (Zhang et al, 2005), and Pisum sativum (Gniwotta et al, 2005; the composition of V. faba leaf wax has not been reported yet). Arabidopsis flower wax is dominated by C 29 alkane (Shi et al, 2011), shorter than the prevalent C 31 homolog in leaves (Jenks et al, 1995) but similar to inflorescence stems and siliques (Todd et al, 1999).…”