title: Knockdown of a nutrient amino acid transporter gene LdNAT1 reduces free neutral amino acid contents and impairs Leptinotarsa decemlineata pupation.
abstract: A Leptinotarsa decemlineata SLC6 NAT gene (LdNAT1) was cloned. LdNAT1 was highly expressed in the larval alimentary canal especially midgut. LdNAT1 mRNA levels were high right after the molt and low just before the molt. JH and a JH analog pyriproxyfen activated LdNAT1 expression. RNAi of an allatostatin gene LdAS-C increased JH and upregulated LdNAT1 transcription. Conversely, silencing of a JH biosynthesis gene LdJHAMT decreased JH and reduced LdNAT1 expression. Moreover, 20E and an ecdysteroid agonist halofenozide repressed LdNAT1 expression, whereas a decrease in 20E by RNAi of an ecdysteroidogenesis gene LdSHD and disruption of 20E signaling by knockdown of LdE75 and LdFTZ-F1 activated LdNAT1 expression. Thus, LdNAT1 responded to both 20E and JH. Moreover, knockdown of LdNAT1 reduced the contents of cysteine, histidine, isoleucine, leucine, methionine, phenylalanine and serine in the larval bodies and increased the contents of these amino acids in the larval feces. Furthermore, RNAi of LdNAT1 inhibited insulin/target of rapamycin pathway, lowered 20E and JH titers, reduced 20E and JH signaling, retarded larval growth and impaired pupation. These data showed that LdNAT1 was involved in the absorption of several neutral amino acids critical for larval growth and metamorphosis.
authors.affiliation: Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Kai-Yun
authors.initials: KY
authors.lastname: Fu
authors.affiliation: Department of Plant Protection, Xinjiang Academy of Agricultural Sciences; Urumqi 830091, China.
authors.forename: Wen-Chao
authors.initials: WC
authors.lastname: Guo
authors.affiliation: Department of Plant Protection, Xinjiang Academy of Agricultural Sciences; Urumqi 830091, China.
authors.forename: Tursun
authors.initials: T
authors.lastname: Ahmat
authors.affiliation: Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Guo-Qing
authors.initials: GQ
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D026905:Amino Acid Transport Systems / Q000145:classification / Q000235:genetics*; D021542:Amino Acids, Neutral / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001517:Coleoptera / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D004441:Ecdysterone / Q000494:pharmacology; D005243:Feces / Q000737:chemistry; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D019476:Insect Proteins / Q000145:classification / Q000235:genetics*; D007605:Juvenile Hormones / Q000494:pharmacology; D008969:Molecular Sequence Data; D010802:Phylogeny; D011679:Pupa / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
chemical_list: D026905:Amino Acid Transport Systems; D021542:Amino Acids, Neutral; D019476:Insect Proteins; D007605:Juvenile Hormones; D011725:Pyridines; C055613:pyriproxyfen; D004441:Ecdysterone