Search Results
Volatile chemicals emitted from the flowers of globe amaranth (Gomphrena globosa) were collected using a dynamic headspace technique and analyzed using gas chromatography–mass spectrometry. Among the four globe amaranth cultivars analyzed, Fireworks was the highest producer of floral volatiles. The flowers of the other three cultivars, Las Vegas White, Las Vegas Pink, and Las Vegas Purple, emit less volatiles, both qualitatively and quantitatively, than ‘Fireworks’. ‘Fireworks’ was chosen for detailed characterization of regulation of floral volatile emission. A diurnal pattern of emission of floral volatiles was observed from the flowers of ‘Fireworks’. In addition, the emission pattern was not significantly affected by light, suggesting that the circadian clock plays a major role in the regulation of volatile emission. The emission of floral volatiles from ‘Fireworks’ flowers that were treated with several chemicals was also analyzed. The treatment with silver thiosulphate, an ethylene inhibitor, led to enhanced emission of total volatiles. In contrast, the treatments with salicylic acid and jasmonic acid led to enhanced emission of total floral volatiles at 4 h but reduced emission at 24 h after the treatment. Biochemical pathways leading to the production of the major floral volatiles of globe amaranth are proposed and partly validated by cluster analysis of floral volatiles emitted from ‘Fireworks’ flowers under various conditions. The implications of the results of this study to the understanding of the reproductive biology of globe amaranth and the breeding of novel globe amaranth cultivars are discussed.
Volatile chemicals emitted from the flowers of chinese wisteria (Wisteria sinenesis) and japanese wisteria (W. floribunda) were collected using a dynamic headspace technique and identified using gas chromatography–mass spectrometry; 28 and 22 compounds were detected from chinese wisteria and japanese wisteria flowers, respectively. These chemicals can be classified into four major classes, including fatty acid derivatives, benzenoids/phenylpropanoids, terpenoids, and nitrogen-containing compounds. Two monoterpenes, (E)-β-ocimene and linalool, belonging to the class of terpenoids, were the most abundant compounds emitted from both species. Despite strong similarity, the floral volatile profiles of the two species displayed variations in both quality and quantity. Chinese wisteria was selected as a model for further study of volatile emission from different parts of flowers, emission dynamics, and regulation of floral scent production. Although floral volatiles were detected from all flower parts, petals emitted the most. The emission of floral volatiles displayed a diurnal pattern with the maximal emissions occurring during the daytime. This rhythmic pattern was determined to be light-dependent. Regulation of floral volatile emission by exogenous chemicals, including silver thiosulphate (an ethylene inhibitor), salicylic acid, and jasmonic acid, also was analyzed. Generally, jasmonic acid promoted the emission of floral volatiles. In contrast, neither silver thiosulphate nor salicylic acid showed a significant effect on floral volatile emission. The results presented in this article suggest that wisteria can serve as a useful system for exploring novel biochemistry of floral scent biosynthesis. They also build a foundation for the study of the biological/ecological significance of floral volatiles on the reproductive biology of wisteria species.
Camellia sinensis cultivars were treated with 5 mm putrescine (Put) under a range of sodium chloride (NaCl) concentrations. Plant performance, as indicated by various indicators associated with plant growing condition such as photosynthetic parameters and polyamine (PA) contents, especially the content of Put, was improved by the treatment. The extent of both Na+ accumulation and K+ loss increased. The activity levels of the antioxidant enzymes related to salt stress, such as superoxide dismutase (SOD), peroxidase (POD), and catalase, were significantly altered with different salt stress levels and showed a decrease in the general trend. Besides, tea polyphenols, the tea quality indicator, increased during the salinity treatment but decreased when we applied Put. These findings suggest that treatment with Put might constitute an effective means for alleviating salinity stress–induced injury through its positive effect on photosynthetic efficiency and for controlling reactive oxygen species (ROS) scavenging ability under appropriate salt stress levels.
As one of the most important fruit tree crops, apple (Malus ×domestica), is faced with the serious impact of soil salinization. However, the underlying genetic and regulatory network remains elusive. Here, we adopted time-course RNA sequencing to decipher the genetic basis and regulatory module of apple in response to salt stress. Among a series of intense changes in genes at each time point, the critical genes in the mitogen-activated protein kinase signaling pathway were highly consistent with the duration of the stress treatment. Moreover, Salt Overly Sensitive 1 (SOS1) genes were identified and predicted to play important roles in the response process. We constructed coexpression modules and explored modules significantly associated with stress. SOS genes were identified in the hub genes, suggesting a critical role. Interestingly, transcription factors were also identified and predicted to cointeract with SOS genes in the hub genes of the coexpression module [e.g., HB7 (MD01G1226600), WRKY33 (MD12G1181000), and ERF106 (MD07G1248700)]. Collectively, our exploration and findings provide a reference and data resource for the study of genetic and salt regulatory networks in apple.
Shennongjia mountain region is famous for its various kinds of species. Through one year's deep-going expedition in the area, lots of valuable plant species were collected, among them many are very useful and had not been used in landscape. Such as Arisaema lobatum var. variegatum nv. LuDiFei, Cremastra appendiculata var. fulva LuDiFei, Stylophorum lasiocarpum (Oliv.) Fedde, Sedum filipes Hems., Iris wilsonii C. H. Wright, Amaranthus caudatus L., Cotoneaster dammeri Schneid, Meconopsis quintupineria Regel., Lysimachia paridiformis Franch., Dysoma versipellis (Hance) M. Cheng, Adiantum pedatum L. and so on. Some genera are quite rich in this region, especially in Rosa, Sorbus, Cotoneaster, Lonicera, Impatiens, Aconitum, Gentiana, Adiantum etc. All these are marvelous material for direct appliance in garden and for breeding. There are many rare plants in the area, large communities of Davidia involucrata Baillon and Chimonanthus praecox (L.) Link were found during the expedition, and what interesting more is that various natural variations do exist in the communities. Detail description and evaluation were given to the important species, and some suggestions of protection and utilization were offered in the paper.
Fresh fruit of longan (Dimocarpus longan Lour.) are susceptible to pericarp browning and aril breakdown. Aril breakdown in longan fruit is regarded as one of the most important factors reducing quality and shortening storage life of the fruit. To better understand the molecular mechanism of aril breakdown, the expression patterns of three expansin (EXP) and three xyloglucan endotransglucosylase (XET) genes in relation to the aril breakdown of longan fruit stored at room temperature (25 °C) or low temperature (4 °C) were investigated. The results showed that aril breakdown index increased progressively during storage at 25 and at 4 °C. Northern blotting analysis revealed that the accumulations of three EXP and three XET genes exhibited differential characteristics with the occurrence of aril breakdown. During storage at 25 °C, the accumulations of Dl-XET3 increased after 1 day, suggesting that Dl-XET3 correlated well with the early aril breakdown, while Dl-EXP3 together with Dl-XET1 and Dl-XET2 was involved in later aril breakdown. However, expression of Dl-XET1 and Dl-XET2 could be mainly involved in aril breakdown of longan fruit stored at 4 °C. In addition, Dl-EXP2, whose accumulation increased sharply when longan fruit were transferred from low temperature to room temperature within 12 hours, was related to the aril breakdown in this storage period. These data indicated that Dl-EXPs and Dl-XETs were closely related to aril breakdown in longan fruit.