Knocking down a putative Δ(1) -pyrroline-5-carboxylate dehydrogenase gene by RNA interference inhibits flight and causes adult lethality in the Colorado potato beetle Leptinotarsa decemlineata (Say).
BACKGROUND
Leptinotarsa decemlineata is an able disperser by flight. Novel control strategies must be explored to control the damage and inhibit the dispersal efficiently. Proline is a major energy substrate during flight. Δ-Pyrroline-5-carboxylate dehydrogenase (P5CDh) catalyses the second step of proline degradation for the production of ATP.


RESULTS
A full-length Ldp5cdh cDNA was cloned. Ldp5cdh was ubiquitously expressed in the eggs, the first through fourth larval instars, wandering larvae, pupae and adults. In the adults, Ldp5cdh mRNA was widely distributed in thorax muscles, midgut, foregut, hindgut, Malpighian tubules, ventral ganglion, fat body and epidermis, with the expression levels from the highest to the lowest. Two double-stranded RNAs (dsRNAs) (dsLdp5cdh1 and dsLdp5cdh2) targeting Ldp5cdh were constructed and bacterially expressed. Ingestion of dsLdp5cdh1 and dsLdp5cdh2 successfully silenced Ldp5cdh, significantly increased the contents of proline, arginine and alanine, but strongly decreased the contents of asparate, asparagine, glutamate and glutamine in the haemolymph. Moreover, knocking down Ldp5cdh significantly reduced ATP content, decreased flight speed, shortened flight distance and increased adult mortality.


CONCLUSIONS
It seems that identified Ldp5cdh encodes a functional P5CDh enzyme, and Ldp5cdh may serve as a potential target for dsRNA-based pesticide for controlling the damage and dispersal of L. decemlineata adults. © 2014 Society of Chemical Industry.
Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China.|State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, China.
Pin-Jun
PJ
Wan
Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
Kai-Yun
KY
Fu
Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
Feng-Gong
FG
Lü
Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
Xin-Xin
XX
Wang
Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi, China.
Wen-Chao
WC
Guo
Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
Guo-Qing
GQ
Li
D050842:1-Pyrroline-5-Carboxylate Dehydrogenase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001517:Coleoptera / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D005260:Female; D055785:Gene Knockdown Techniques; D007300:Insect Control; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000469:parasitology; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D011198:Solanum tuberosum / Q000469:parasitology*
D019476:Insect Proteins; D012330:RNA, Double-Stranded; D050842:1-Pyrroline-5-Carboxylate Dehydrogenase
Leptinotarsa decemlineata; RNA interference; amino acid; flight; mortality; pyrroline-5-carboxylate dehydrogenase