Effects of amino acids in Camellia oleifera nectar on survival of Apis mellifera workers

<bold>Objective</bold> The amino acid content of plant nectar affects the collecting preference of bees.Previous research found that nectar-rich <italic>Camellia oleifera</italic> flowers were unattractive to foragers，leading to low efficiency of bees pollinating <italic>C. oleifera</italic> to increase yields.This experiment aims to compare the types and contents of amino acids in the nectar of three different species to investigate the effects of the amino acid composition of <italic>C. oleifera</italic>.nectar on <italic>Apis mellifera</italic>，thus providing new ideas for improving the pollination efficiency of honey bees on <italic>C. oleifera</italic>. <bold>Method</bold> Three types of <italic>C. oleifera</italic> nectar were used for the study，and the amino acid types and absolute contents of different varieties of <italic>Camellia oleifera</italic> nectar were detected by liquid chromatography-tandem mass spectrometry（LC/MS）.The effects of the highest levels of amino acids（L-Glutamine）in <italic>C. oleifera</italic> nectar on the expression of genes related to longevity，immunity and detoxification in western honey bees were also assessed. <bold>Result</bold> （1）Gan 447，Changlin 18 and Gan 68 <italic>C. oleifera</italic> nectar all contained 19 of the 21 amino acids，but there were differences in the fractions and concentrations，among which，glycine and cysteine were not detected in Gan 447 and Changlin 18 <italic>C. oleifera</italic> nectar，while asparagine and cysteine were not detected in Gan 68 <italic>C. oleifera</italic> nectar.（2）The content of L-glutamine was the highest in the three oil tea nectars，including Gan 447 oil tea nectar，which was as high as（1 612.63±17.85）mg/kg，and the content of proline（Pro）and γ-aminobutyric acid（GABA）in the three <italic>C. oleifera</italic> nectars were low（&lt;100 mg/kg）.（3）The addition of L-glutamine at the same dose as that in the nectar of Gan 447（1 610 mg/kg）to the diet had no significant effect on the lifespan of Western honeybee（Apis mellifera）workers（<italic>P</italic>&gt;0.05），Nor does it induce the upregulated expression of the worker bees’ detoxification genes ［defensin 1（Defensin1）and abaecin（Abaecin）］as well as immune genes ［cytochrome P450（Cytochrome P450，CYP450），glutathione S-transferase 3（GSTS3），and catalase（Catalase）］. <bold>Conclusion</bold> High levels of L-glutamine in <italic>C. oleifera</italic> nectar do not threaten the survival of <italic>A. mellifera</italic> workers.Lower levels of proline and GABA in <italic>C. oleifera</italic> nectar may contribute to the weaker attractiveness of <italic>C. oleifera</italic> flowers to <italic>A. mellifera</italic>.