title: Optimized scorpion polypeptide LMX: a pest control protein effective against rice leaf folder.
abstract: Lepidopteran insect pests are the main class of pests causing significant damage to crop plant yields. Insecticidal scorpion peptides exhibit toxicity specific for insects. Here, we report that a peptide LMX, optimized from the insect-specific scorpion neurotoxin LqhIT2, showed high levels of activity against rice leaf folder in vitro and in planta. Oral ingestion of LMX protein led to a significant decrease in feeding on rice leaves, repression of larval growth and development, delay in molting, and increase in larval lethality. Compared with LqhIT2 protein, the stability and insecticidal efficacy of LMX was better. Meanwhile, biochemical analysis showed that LMX protein ingestion dramatically decreased ecdysone content in rice leaf folder larvae, and down-regulated enzymatic activities of the detoxification system (α-naphthyl acetate esterase and glutathione S-transferase), the digestive system (tryptase and chymotrypsin), and the antioxidant system (catalase). These changes were tightly correlated with the dosage of LMX protein. Transgene analysis showed that the rate of leaf damage, and the number of damaged tillers and leaves in the transgenic line were greatly reduced relative to wild type plants and empty vector plants. Based on these observations, we propose that the insect-specific scorpion neurotoxin peptide LMX is an attractive and effective alternative molecule for the protection of rice from rice leaf folder.
authors: State Key Laboratory of Hybrid Rice; Key Laboratory for Research and Utilization of Heterosis in Indica Rice of Ministry of Agriculture; Engineering Research Center for Plant Biotechology and Germplasm Utilization of Ministry of Education; College of Life Sciences, Wuhan University, Wuhan, China.
authors: Xiuzi
authors: X
authors: Tianpei
authors: State Key Laboratory of Hybrid Rice; Key Laboratory for Research and Utilization of Heterosis in Indica Rice of Ministry of Agriculture; Engineering Research Center for Plant Biotechology and Germplasm Utilization of Ministry of Education; College of Life Sciences, Wuhan University, Wuhan, China.
authors: Yingguo
authors: Y
authors: Zhu
authors: State Key Laboratory of Hybrid Rice; Key Laboratory for Research and Utilization of Heterosis in Indica Rice of Ministry of Agriculture; Engineering Research Center for Plant Biotechology and Germplasm Utilization of Ministry of Education; College of Life Sciences, Wuhan University, Wuhan, China.
authors: Shaoqing
authors: S
authors: Li
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D060829:Arthropod Proteins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D003062:Codon / Q000235:genetics; D004063:Digestion / Q000187:drug effects; D004440:Ecdysone / Q000378:metabolism; D005247:Feeding Behavior; D007814:Larva / Q000187:drug effects / Q000378:metabolism; D007915:Lepidoptera / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D008958:Models, Molecular; D009498:Neurotoxins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D012275:Oryza / Q000235:genetics / Q000502:physiology; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D010572:Pest Control, Biological / Q000379:methods*; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology; D011487:Protein Conformation; D012605:Scorpions / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D060829:Arthropod Proteins; D003062:Codon; D009498:Neurotoxins; D010455:Peptides; D004440:Ecdysone