Although nectar is crucial for most pollinators, its evolutionary origin has received scant attention. Nectar is derived from the phloem solution. Both have high sugar concentrations (usually 10-30% solutes by fresh mass); the main solute in the phloem is sucrose, whereas nectar can also contain considerable amounts of fructose and glucose. The phloem, not the xylem, is the supplier of water to flowers and certain other organs. Therefore, a 'leaky phloem' hypothesis for the origin of nectar is presented based on the elevated hydrostatic pressure that can occur within the phloem and the structural weakness of developing phloem tissues. A 'sugar excretion' hypothesis is also presented that considers the solute accumulation resulting from the relatively high transpiration rates of flowers.
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http://dx.doi.org/10.1016/j.tplants.2003.12.003 | DOI Listing |
Food Chem
December 2024
Key Laboratory of Dairy Science, Ministry of Education, Department of Food Science, Northeast Agricultural University, Harbin 150030, PR China. Electronic address:
The volatile markers and aroma properties of unifloral safflower honey in Xinjiang, China were identified for the authentication. An untargeted metabolomics analysis was performed to compare the volatile components in safflower honey with those in four other unifloral honey and the nectar plants of safflower honey through headspace solid-phase microextraction-chromatography-mass spectrometry. Tentative markers, including benzaldehyde, longifolene, and cedrol, were comprehensively screened through variable importance in projection based on orthogonal partial least-squares discrimination analysis, nectar origin volatile components analysis, and odor characteristics analysis.
View Article and Find Full Text PDFmSphere
December 2024
Department of Microbiology, Cornell University, Ithaca, New York, USA.
Unlabelled: The bacterial genus includes species found in environmental habitats like soil and water, as well as taxa adapted to be host-associated or pathogenic. High genetic diversity may allow for this habitat flexibility, but the specific genes underlying switches between habitats are poorly understood. One lineage of has undergone a substantial habitat change by evolving from a presumed soil-dwelling ancestral state to thrive in floral nectar.
View Article and Find Full Text PDFNew Phytol
December 2024
Department of Animal Health, Complutense University of Madrid, 28040, Madrid, Spain.
An emerging focus of research at the intersection of botany, zoology, and microbiology is the study of floral nectar as a microbial habitat, referred to as the nectar microbiome, which can alter plant-pollinator interactions. Studies on these microbial communities have primarily focused on yeasts, and it was only about a decade ago that bacteria began to be studied as widespread inhabitants of floral nectar. This review aims to give an overview of the current knowledge on nectar bacteria, with emphasis on evolutionary origin, dispersal mode, effects on nectar chemistry and plant-animal interactions, community assembly, agricultural applications, and their use as model systems in ecological research.
View Article and Find Full Text PDFPlants (Basel)
November 2024
Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago 8380000, Chile.
Honey is a natural sweet element that bees make with flower nectar, revered for its distinct flavor, nutritional value, and potential health benefits. Chilean beekeeping has a diverse range of honey varieties, many of which are unique. The quillay ( Molina, soapbark tree) is a Chilean endemic tree whose honey has not been studied in depth.
View Article and Find Full Text PDFAntioxidants (Basel)
October 2024
Department of Food Science and Technology, School of Agricultural Sciences, University of Patras, G. Seferi 2, 30100 Agrinio, Greece.
Numerous health benefits have been attributed in the last decades to the regular consumption of fruits, vegetables, herbs and spices, along with honey, in a balanced diet. In this context, the aim of the present review was to provide the literature with the most relevant studies focusing on the determination protocols of these polyphenols and other reducing agents in selected fruits (orange, lemon, grapefruit, prunus, apricot, peach, plum, sweet cherry), spices (oregano, cinnamon, clove, saffron, turmeric) and honey of different botanical origin (nectar or honeydew). In addition, the content and the extraction methods of these compounds, along with their metabolic pathway, have been critically evaluated and discussed.
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