Characterization of the Geranylgeranyl Diphosphate Synthase Gene in Acyrthosiphon pisum (Hemiptera: Aphididae) and Its Association With Carotenoid Biosynthesis

Abstract

Carotenoids play many crucial roles in organisms. Recently, the de novo synthesis of carotenoids has been reported in pea aphid (Acyrthosiphon pisum) through horizontally transferred genes. However, their upstream pathway in the pea aphid is poorly understood. Geranylgeranyl diphosphate synthase (GGPPS) is the functional enzyme in the synthesis of geranylgeranyl diphosphate (GGPP) which is a precursor for the biosynthesis of many biological metabolites, including carotenoid synthesis. In this study, we performed a series of experiments to characterize GGPPS gene and its association with carotenoid biosynthesis. (1) determining the transcript abundance and carotenoid content in two geographical strain with red and green morphs, and (2) examining the abundance of carotenoid related genes and carotenoid levels after silencing of GGPPS in both red and green morphs. We observed that GGPPS was more highly expressed in the green morph than in the red morph of two strains of the pea aphid. The total level of carotenoids was also higher in green morphs than in red morphs in both strains. In addition to the total carotenoid difference, the carotenoids found in the two morphs also differed. There were α-carotene, β-carotene, and γ-carotene in the green morphs, but three additional carotenoids, including cis-torulene∗, trans-torulene∗, and 3,4-didehydrolycopene∗, were present in the red morphs. Silencing the GGPPS by RNAi in both the red and green morphs decreased the expression of some carotenoid biosynthesis-related genes, including carotenoid synthase/cyclase genes and carotenoid desaturase genes in green morphs. Carotenoid levels were decreased in both green and red morphs. However, the specific carotenoids present were not changed after silencing GGPPS. These results demonstrated that GGPPS may act as the upstream enzyme to influence the synthesis of the total amount of carotenoids. The present study provided important molecular evidence for the conserved roles of GGPPS associated with carotenoids biosynthesis and will enhance further investigation on the mechanisms of carotenoid biosynthesis in pea aphid.

Cecal microbiome composition and metabolic function in probiotic treated broilers

“…The association between improved weight gain and LAB has also been observed by Yan et al [39] and De Cesare et al [40]. Hence, LAB may be able to enhance the energy and mineral recovery from nutrients; its higher intestinal colonization results in a better digestive efficiency [37,41]. Based on this correlative evidence, it is tempting to speculate that the supplementation of SYNBIO may have optimized a metabolic resource allocation to emerge a LAB population at 21 days of age, influencing the elevated survival of broilers found in this treatment.…”

“…In fact, some Lactobacillus strains have been reported by their capacity to produce B group vitamins [36]. The vitamins are acquired by the host through the diet and from gut microbial de novo synthesis [37], suggesting that supplementation of SYNBIO might perform a function on vitamin producingmicroorganisms. Furthermore, the addition of SYNBIO in the feed resulted in an overabundance of lactic acid hetero-and homo-fermentative pathways.…”

Fine Mapping and Candidate Gene Identification of a White Flower Gene BrWF3 in Chinese Cabbage (Brassica rapa L. ssp. pekinensis)

“…Carotenoids, flavonoids and betalains are three main classes of natural pigments contributing to different flower colors, among which the accumulation of carotenoids can cause yellow, orange and red colorations (DellaPenna and Pogson, 2006;Grotewold, 2006). In nature, greater than 800 structurally different carotenoid compounds have been identified (Nisar et al, 2015;Ding et al, 2019), which are further divided into two main groups, carotenes and xanthophylls (Nisar et al, 2015;Ding et al, 2019). In many cases, xanthophylls (i.e., letein, zeaxanthin, and violaxanthin) are the most prevalent carotenoids in yellow flowers (Ohmiya, 2011).…”

Parental silencing of a horizontally transferred carotenoid desaturase gene causes a reduction of red pigment and fitness in the pea aphid

“…Carotenoids were analyzed by HPLC according to previously published methods . Carotenoids were separated in a C30 column (250 × 4.6 mm, 5 μm particle size) (YMC, Kyoto, Japan).…”