Identification of a gustatory receptor tuned to sinigrin in the cabbage butterfly Pieris rapae

Abstract

Glucosinolates are token stimuli in host selection of many crucifer specialist insects, but the underlying molecular basis for host selection in these insects remains enigmatic. Using a combination of behavioral, electrophysiological, and molecular methods, we investigate glucosinolate receptors in the cabbage butterfly Pieris rapae. Sinigrin, as a potent feeding stimulant, elicited activity in larval maxillary lateral sensilla styloconica, as well as in adult medial tarsal sensilla. Two P. rapae gustatory receptor genes PrapGr28 and PrapGr15 were identified with high expression in female tarsi, and the subsequent functional analyses showed that Xenopus oocytes only expressing PrapGr28 had specific responses to sinigrin; when ectopically expressed in Drosophila sugar sensing neurons, PrapGr28 conferred sinigrin sensitivity to these neurons. RNA interference experiments further showed that knockdown of PrapGr28 reduced the sensitivity of adult medial tarsal sensilla to sinigrin. Taken together, we conclude that PrapGr28 is a gustatory receptor tuned to sinigrin in P. rapae, which paves the way for revealing the molecular basis of the relationships between crucifer plants and their specialist insects.

Characterization of Antennal Chemosensilla and Associated Chemosensory Genes in the Orange Spiny Whitefly, Aleurocanthus spiniferus (Quaintanca)

“…Recently, more research has been focused on the function of three chemosensory receptor types: ORs, GRs, and IRs ( Zhang R.B. et al, 2017 ; Yang et al, 2020 , 2021 ). In this study, we identified six ORs in the A. spiniferus transcriptome.…”

“…In M. persicae , the high glutamine concentration stimulated the feeding behavior ( Cao et al, 2017 ). Overexpressing PrapGR28 from Pieris rapae in Drosophila files resulted in a strong preference to the food with sinigrin whereas the wild-type (WT) files showed avoidance ( Yang et al, 2021 ). In B. mori , BmorGR66 mutant showed no significant feeding preference for both mulberry leaves and Mongolian oak leaves, while WT B. mori did not eat Mongolian oak leaves ( Zhang Z.J.…”

Oxalic acid binds to gustatory receptor Gr23a and inhibits feeding in the brown planthopper

“…Grs in insects are known to form heterodimers with co-receptors to recognize the tastant (Dahanukar et al ., 2007; Lee et al ., 2009). Nevertheless, there are several instances of the expression of a single insect Gr in a heterologous expression system sufficient to confer tastant responses, including Gr5a, Gr43a and Gr64e from Drosophila , BmGr8 and BmGr9 from the silkworm Bombyx mori , PxutGr1 from the swallowtail butterfly Papilio xuthus , HarmGR35, HarmGR50 and HarmGR195 from the polyphagous pest Helicoverpa armigera , AgGr25 from the malaria mosquito Anopheles gambiae (Chyb et al ., 2003; Freeman et al ., 2014; Sato et al , 2011; Zhang et al ., 2011; Ozaki et al ., 2011; Xu et al ., 2016), and PrapGr28 from the cabbage butterfly Pieris rapae (Yang et al ., 2021). In this study, the HEK293T cells expressing NlGr23a caused responses to OA (Figure 1F).…”

Two gustatory receptors involved in host plant recognition of silkworm larvae

“…The lepidopteran Gr phylogeny was generated using full-length amino acid sequences of Grs from Bombyx mori [30], P. xylostella [38], H. melpomene [39], PxutGr1 [23], and PrapGr28 [24]. The sequences were aligned with MAFFT v.7 (http://mafft.cbrc.jp/alignment/server/).…”

“…PxutGr1 from the swallowtail butterfly, Papilio xuthus , is responsible for the sensitivity of tarsal taste sensilla to synephrine, which acts as an ovipositioning stimulant [23]. PrapGr28 from the cabbage butterfly, Pieris rapae , contributes to sinigrin sensitivity in adult tarsal taste sensilla [24], although sinigrin is a feeding stimulant for their larvae [25]. PxylGr34 from the diamondback moth, Plutella xylostella , is involved in response to canonical plant hormones, brassinolide, and 24-epibrassinolide, a feeding and oviposition deterrent, in MG of larvae [26].…”