The plant cuticle is a continuous extracellular protective layer covering the outermost surfaces of higher plants that are in contact with the surrounding atmosphere. These findings provide further insights to support the exploration of potential techniques for extending the shelf life of cut flowers based on cuticular transpiration barrier properties. This suggests that the less effective transpiration barrier provided by the tepal waxes may result from the shorter C-chain aliphatics in the tepal cuticle, compared to those in the leaf cuticle. In addition, the chain-length distributions were similar between compound classes within cultivars, whereas the predominant C-chain lengths were substantially different between organs. Primary alcohols and fatty acids as well as small amounts of alkyl esters, ketones, and branched or unsaturated n -alkanes were also detected in both tepal and leaf waxes, depending on the cultivar and organ. Very-long-chain aliphatics were the main wax constituents and were dominated by n -alkanes with carbon (C) chain lengths of C 27 and C 29, and C 29 and C 31 in the tepal and leaf waxes, respectively. The overall wax coverage of the tepals was higher compared to that of the leaves. Lily cuticular transpiration exhibited cultivar- and organ-specific differences, where transpiration from the tepals was higher than leaves and was higher in the ‘Huang Tianba’ than ‘Tiber’ cultivar. The minimum water conductance of tepal cuticles was higher at the green bud than open flower stage. Here, the cuticular transpiration rate and wax composition of three lily cultivars were determined. Studies on leaf cuticular transpiration have been widely conducted however, little is known about cuticular transpiration in flowers. Cuticular wax is the primary barrier to uncontrolled water loss for aerial plant organs. The vase life of cut flowers is largely affected by post-harvest water loss. All taken together, the flower waxes of this species had properties greatly differing from those on vegetative organs.Ĭopyright © 2014, American Society of Plant Biologists. Approximately two-thirds of the abaxial surface water barrier was found to reside in the epicuticular wax layer of the petal, and only one-third in the intracuticular wax.
bipinnatus thus impose relatively weak water transport barriers, compared with typical leaf cuticles.
Transpiration resistances equaled 3.0 x 104 s m-1 and 1.5 x 104 s m-1 for the adaxial and abaxial surfaces, respectively. Detailed analyses revealed distinct differences between waxes on the adaxial and abaxial petal sides, and between the epi- and intracuticular waxes. The petal wax was found to contain unusually high concentrations of C22 and C24 fatty acids and primary alcohols, much shorter than those in leaf and stem waxes. 3.8 times larger than the projected petal area. The abaxial petal surface is relatively flat, whereas the adaxial side consists of conical epidermis cells rendering it ca. This present work provides a detailed characterization of the petal waxes, using Cosmos bipinnatus as a model, and compares them with leaf and stem waxes. Flowers have life histories and functions largely different from other organs, and it remains to be seen whether flower waxes have compositions and physiological properties differing from those on other organs. Accordingly, the properties of waxes have been studied in much detail, albeit with a strong focus on leaf and fruit waxes.
Cuticular waxes coat all primary above-ground plant organs as a crucial adaptation to life on land.