In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 113, No. 11 ( 2016-03-15), p. 2922-2927
Abstract:
Sesquiterpenes play important roles in insect communication, for example as pheromones. However, no sesquiterpene synthases, the enzymes involved in construction of the basic carbon skeleton, have been identified in insects to date. We investigated the biosynthesis of the sesquiterpene (6 R ,7 S )-himachala-9,11-diene in the crucifer flea beetle Phyllotreta striolata , a compound previously identified as a male-produced aggregation pheromone in several Phyllotreta species. A (6 R ,7 S )-himachala-9,11-diene–producing sesquiterpene synthase activity was detected in crude beetle protein extracts, but only when ( Z , E )-farnesyl diphosphate [( Z , E )-FPP] was offered as a substrate. No sequences resembling sesquiterpene synthases from plants, fungi, or bacteria were found in the P. striolata transcriptome, but we identified nine divergent putative trans -isoprenyl diphosphate synthase ( trans -IDS) transcripts. Four of these putative trans -IDSs exhibited terpene synthase (TPS) activity when heterologously expressed. Recombinant Ps TPS1 converted ( Z , E )-FPP to (6 R ,7 S )-himachala-9,11-diene and other sesquiterpenes observed in beetle extracts. RNAi-mediated knockdown of Ps TPS1 mRNA in P. striolata males led to reduced emission of aggregation pheromone, confirming a significant role of Ps TPS1 in pheromone biosynthesis. Two expressed enzymes showed genuine IDS activity, with Ps IDS1 synthesizing ( E , E )-FPP, whereas Ps IDS3 produced neryl diphosphate, ( Z , Z )-FPP, and ( Z , E )-FPP. In a phylogenetic analysis, the Ps TPS enzymes and Ps IDS3 were clearly separated from a clade of known coleopteran trans -IDS enzymes including Ps IDS1 and Ps IDS2. However, the exon–intron structures of IDS and TPS genes in P. striolata are conserved, suggesting that this TPS gene family evolved from trans-IDS ancestors.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.1523468113
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2016
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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