Comparing the contents, functions and neonicotinoid take-up between floral and extrafloral nectar within a single species (Hemerocallis citrina Baroni)

Author:

Zhou Hong-Xia1,Milne Richard I2,Cui Peng3,Gu Wen-Jing1,Hu Meng-Fang1,Liu Xin-Yue1,Song Yue-Qin1,Cao Jun4,Zha Hong-Guang1ORCID

Affiliation:

1. College of Life and Environment Sciences, Huangshan University, Huangshan 245041, China

2. Institute of Molecular Plant Sciences, University of Edinburgh, Edinburgh EH9 3JH, UK

3. Instrumental Analysis Centre, Huangshan University, Huangshan 245041, China

4. Yunnan Key Laboratory of Plant Reproductive Adaption and Evolutionary Ecology and School of Ecology and Environmental Science, Yunnan University, Kunming 650500, China

Abstract

Abstract Background and Aims Many angiosperms can secrete both floral (FN) and extrafloral (EFN) nectar. However, much remains unclear about how EFN and FN differ in secretion, composition and ecological function, especially when both FN and EFN are secreted on flowers of the same species. Methods Hemerocallis citrina flowers secrete both FN and EFN. The FN and EFN traits including volume, presentation pattern and temporal rhythms of secretion were compared by field observation. Sugar and amino acid contents were analysed using regular biochemical methods, whereas the proteome was investigated by combined gel-based and gel-free approaches. Animal feeders on FN and EFN were investigated by field observation. Hemerocallis citrina plants were exposed by soil drenching to two systemic insecticides, acetamiprid and imidacloprid, and the concentration of these in FN and EFN was measured by ultra-high performance liquid chromatography coupled with mass spectrometry. Key Results Hemerocallis citrina FN was concentrated and sucrose dominant, secreted in the mature flower tube and served as a reward for pollinators. Conversely, EFN was hexose rich, more dilute and less rich in sugar and amino acids. EFN was secreted on the outside of developing floral buds, and was likely to attract predatory animals for defence. EFN had fewer phenolics, but more pathogenesis-related components, such as chitinase and glucanase. A significantly different proteomic profile and enzymatic activities between FN and EFN suggest that they had different biosynthesis mechanisms. Both neonicotinoid insecticides examined became present in both nectar types soon after application, but in greater concentration within EFN; EFN also attracted a wider range of insect species than FN. Conclusions Hemerocallis citrina FN and EFN differed in production, composition and ecological function. The EFN pathway could be a significant way for neonicotinoids to enter the wild food chain, and must be considered when evaluating the risks to the environment of other systemic insecticides.

Funder

National Natural Science Foundation of China

Key Research Projects of Natural Science in Universities in Anhui Province

National College Students’ Innovation and Entrepreneurship Training Program

Science and Technology program of Yunnan province

Publisher

Oxford University Press (OUP)

Subject

Plant Science

Reference52 articles.

1. The evolution of sexual fluids in gymnosperms from pollination drops to nectar;von Aderkas;Frontiers in Plant Science,2018

2. The role of thrips in pollination;Ananthakrishnan;Current Science,1993

3. Floral nectar sugar constituents in relation to pollinator type.;Baker,1983

4. The protective function of ants visiting the extrafloral nectaries of Bixa orellana (Bixaceae);Bentley;Journal of Ecology,1977

5. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein–dye binding;Bradford;Analytical Biochemistry,1976

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