Dietary Supplementation of Honey Bee Larvae with Arginine and Abscisic Acid Enhances Nitric Oxide and Granulocyte Immune Responses after Trauma

Abstract

Many biotic and abiotic stressors impact bees’ health, acting as immunosupressors and contribute to colony losses. Thus, the importance of studying the immune response of honey bees is central to develop new strategies aiming to enhance bees’ fitness to confront the threats affecting them. If a pathogen breaches the physical and chemical barriers, honey bees can protect themselves from infection with cellular and humoral immune responses which represent a second line of defense. Through a series of correlative studies we have previously reported that abscisic acid (ABA) and nitric oxide (NO) share roles in the same immune defenses of Apis mellifera (A. mellifera). Here we show results supporting that the supplementation of bee larvae’s diet reared in vitro with l-Arginine (precursor of NO) or ABA enhanced the immune activation of the granulocytes in response to wounding and lipopolysaccharide (LPS) injection.

Effect of Abscisic Acid (ABA) Combined with Two Different Beekeeping Nutritional Strategies to Confront Overwintering: Studies on Honey Bees’ Population Dynamics and Nosemosis

“…The results obtained in this work suggest that ABA enhanced Langstroth-size honey bee colonies’ strengths associated with differences in population dynamics (stable levels of adults and brood) and the changes levels of prevalence of Nosema obtained overwintering. These results support all previous reports of the effects of ABA in honey bees [17,41,51] adding new evidence to suggest that this phytochemical is a natural alternative to be used in environmentally friendly strategies associated with the integrated management of bee colonies.…”

“…We applied a standard ABA concentration of 50 µM because: (a) it is within the range of previously reported ABA concentrations found in nectar, pollen [40], honey and bees [17,41] and (b) this concentration has been shown to have positive effects on the immunity of bee larvae reared in the laboratory in response to various stress conditions [17,51]. Further, the concentration of ABA found in local honey are very low (around 0.0008·μmol/g, data obtained by our group) in comparison with the concentration found in other honeys, like for example the monofloral honey of strawberry tree ( Arbutus unedo L., around 1.5 μmol/g) [40].…”

Foraging behaviour and preference of pollen sources by honey bee (Apis mellifera) relative to protein contents

“…The next amino acid predominated was arginine. Honey bee larvae fed with Larginine-and abscisic acid-supplemented diet was found to enhance the fitness via nitric oxide and granulocyte immune response (Negri et al, 2017). On the other hand, non-essential amino acids are also worthy.…”

Physiological Effects of Some Pollen Substitutes Diets on Caged Honey Bee Workers (Apis mellifera L.)

“…So, providing colonies with protein source all over the year, especially during dearth periods of pollen is a critical matter. Recently, several studies have given more attention to formulate supplementary diets or substitutes to compensate the lack of the natural protein source (pollen) (Zheng et al, 2014;Amro et al, 2016;Negri et al, 2017;Gamal Eldin et al, 2018;Gregorc et al, 2019;Younis, 2019). Moreover, different pollen types from different plant origin differently effects on the physiological conditions of worker honey bee (Amro et al, 2015).…”