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Postharvest treatment with nano-silver (NS) extends the longevity of many cut flowers, including carnation ( Dianthus caryophyllus L.). Its beneficial effects are generally attributed to the inhibition of bacterial growth in basal stem-ends. However, Ag + ions released from NS are also potential blockers of ethylene action. In the present study, we investigated the efficacy of NS pulse treatment, compared with conventional silver thiosulfate (STS) treatment, for alleviation the effects of exogenous ethylene on cut standard ‘Master’ carnation flowers. Cut carnations exposed to 5 or 10 μL L −1 ethylene for 12 h showed reduced vase life, inhibited flower opening, premature wilting, and petal discoloration, which markedly diminished their ornamental quality. A NS pulse treatment of 250 mg L −1 (2.3 mmol L −1 ) for 1 h prior to ethylene exposure reduced the inhibited flower opening and, thereby, prolonged the vase life. These effects were comparatively inferior in terms of flower opening and vase life extension to those obtained with a 1.0 mmol L −1 STS pulse for 1 h. However, without exogenous ethylene NS treatment was nearly as effective as STS treatment for enhancing flower opening and extending vase life. NS treated cut carnation stems (exposed to exogenous ethylene or not) also maintained higher relative fresh weight during the vase period than those treated with STS. The Ag concentration in the stem-ends of the NS-treated cut carnations was higher than that in those of STS-treated stems, and was also higher than that in other tissues. Moreover, Ag provided by NS also reached the receptacles, calyxes, and petals. Overall, NS pulse treatments enhanced the ornamental quality and extending the vase life of cut ‘Master’ carnation flowers by antagonizing the deleterious effects of ethylene and probably inhibiting the proliferation of bacteria at the cut stem-ends. [ABSTRACT FROM AUTHOR]

Stomata present on leaves are the main channels for water vapor exchange between the plant and atmosphere, and contribute to water loss of cut flowers. Although cut gerberas ( Gerbera jamesonii Bolus) are commonly composed of a terminal composite floral head and a scape, and have no leaves, they are also prone to severe water deficits, presumably resulting from water loss exceeding water uptake. We have investigated the distribution and characteristics of stomata of cut ‘Real’ gerberas, and their response to light and abscisic acid (ABA) treatments, to increase understanding of their functionality in postharvest water loss. Stomata were widely distributed on various parts of floral organs and the scape in cut gerberas, including the lower epidermis of the ray floret petals, trans florets, disc florets, lower epidermis of sepals, and the uppermost and middle parts of scape surfaces. The highest stomatal density was observed on the lower epidermis of sepals. Cut gerberas had the largest stomata on the middle scape surface and the smallest on the surface of the uppermost scape. Nonetheless, the lower epidermis of sepals had the highest relative stomatal area, which was higher than that of the other parts. Additionally, the lower sepal epidermis had the highest maximum stomatal conductance of water vapor (g wmax ), and which was higher than that of the lower and upper leaf epidermis. The opening of stomata on various parts of cut gerberas differed in their response to light, and the highest percentage of open stomata and largest aperture were found in the stomata on the lower epidermis of sepals. Changes in water loss in cut gerberas exhibited a distinct circadian rhythm over a four-day vase period with an alternating 12-h light/dark cycle. In the lower epidermis of sepals, ABA painting treatment significantly inhibited stomatal opening and reduced water loss in cut gerberas over a 6 h light period. These findings imply the critical involvement of stomata on the lower epidermis of sepals in water loss of cut gerberas, and improve our understanding of the mechanism underlying their water deficit symptoms. [ABSTRACT FROM AUTHOR]

• Transcriptomic profiling of cut wounded lily stems was performed. • Temporal molecular events involved in cut-wounding response were characterized. • ROS and JA biosynthesis genes were up-regulated within 1–6 h after cut-wounding. • Lignin biosynthesis genes were up-regulated between 6 and 48 h after cut-wounding. • Potential molecular mechanism of cut-wounding response in lily stems were proposed. Plants are prone to wounding by various means, which mainly occur with exposure to environmental mechanical stimuli or via herbivory. The plant wounding response is believed to be mediated by potential molecular mechanisms. However, the wounding response and its molecular mechanism in cut flowers, which are severely wounded plant tissues, have been poorly studied. To gain insight into the molecular mechanisms in response to cut-wounding, this work presents the transcriptional characterization of the temporal molecular events triggered by cut-wounding in the stem-ends of cut 'Tiber' lily flowers. RNA-Seq analysis detected 11887 differentially expressed genes, which could be categorized into four clusters based on response time and expression patterns. The fast response typically includes the up-regulation of reactive oxygen species (ROS) and jasmonic acid (JA) biosynthesis genes within 1–6 h after cut-wounding, followed by the up-regulation of lignin biosynthesis genes. Further analysis revealed complex signal cascades in lily stems following cut-wounding. In the early stage (1–6 h), Ca2+ promotes ROS and JA biosynthesis gene expression through calcium signal transmission. In the late stage (6–48 h), the expression of lignin biosynthesis genes was up-regulated by ROS and JA signal transduction. These results provide insight into the temporal molecular events in lily stems triggered by cut-wounding and their potential molecular mechanisms. [ABSTRACT FROM AUTHOR]