Terpenoids are important compounds associated with the pest and herbivore resistance mechanisms of plants; consequently, it is essential to identify and explore terpene synthase (TPS) genes in maize. In the present study, we identified 31 TPS genes based on a pan-genome of 26 high-quality maize genomes containing 20 core genes (present in all 26 lines), seven dispensable genes (present in 2 to 23 lines), three near-core genes (present in 24 to 25 lines), and one private gene (present in only 1 line). Evaluation of ka/ks values of TPS in 26 varieties revealed that TPS25 was subjected to positive selection in some varieties. Six ZmTPS had ka/ks values less than 1, indicating that they were subjected to purifying selection. In 26 genomes, significant differences were observed in ZmTPS25 expression between genes affected by structural variation (SV) and those not affected by SV. In some varieties, SV altered the conserved structural domains resulting in a considerable number of atypical genes. The analysis of RNA-seq data of maize Ostrinia furnacalis feeding revealed 10 differentially expressed ZmTPS, 9 of which were core genes. However, many atypical genes for these responsive genes were identified in several genomes. These findings provide a novel resource for functional studies of ZmTPS.

A series of complex processes regulate muscle development, and lncRNAs play essential roles in the regulation of skeletal myogenesis. Using RNA sequencing, we profiled the lncRNA expression during goat (Capra hircus) skeletal muscle development, which included seven stages across fetal 45 (F45), 65 (F65), 90 (F90), 120 (F120), 135 (F135) days, born for 24 h (B1) and 90 (B90) days. A total of 15,079 lncRNAs were identified in the seven stages, and they were less conservative with other species (human, cow, and mouse). Among them, 547 were differentially expressed, and they divided the seven stages into three functional transition periods. Following weighted gene co-expression network analysis (WGCNA), five lncRNA modules specific for developmental stages were defined as three types: ‘Early modules’, ‘late modules’, and ‘individual-stage-specific modules’. The enrichment content showed that ‘early modules’ were related to muscle structure formation, ‘late modules’ participated in the ‘p53 signaling pathway’ and other pathways, the F90-highly related module was involved in the ‘MAPK signaling pathway’, and other pathways. Furthermore, we identified hub-lncRNA in three types of modules, and LNC_011371, LNC_ 007561, and LNC_001728 may play important roles in goat skeletal muscle. These data will facilitate further exploration of skeletal muscle lncRNA functions at different developmental stages in goats.

Bacillus thuringiensis is an effective entomopathogen, and its crystal toxin expressed in transgenic crops has been widely used for pest control. However, insect resistance risk is the main threat to the continued successful utility of Bt crops. Several studies reported the role of midgut microbiota in Bt resistance, but the mechanism remains controversial. In the present study, using high-throughput sequencing of the bacterial 16S ribosomal RNA gene, we surveyed the midgut bacterial flora of Ostrinia furnacalis from one Bt-susceptible (ACB-BtS) and two Bt-resistant (ACB-AbR and ACB-FR) strains and explored the mortality of O. furnacalis after eliminating the gut bacteria. Gut bacterial diversity in Bt-resistant strains was significantly lower in Bt-resistant than in Bt-susceptible strains. Ordination analyses and statistical tests showed that the bacterial community of ACB-AbR was distinguishable from ACB-BtS. The genus Halomonas was dominated in ACB-BtS, but the unclassified_Enterobacteriaceae was the most enriched genus in ACB-AbR and ACB-FR. Furthermore, interactions of the bacterial community are more complex in Bt-resistant strains than in Bt-susceptible strains. Moreover, the mortalities of ACB-AbR and ACB-BtS strains treated by the Cry1Ab toxin were significantly reduced after eliminating the gut bacteria. Our findings suggest that Bt stressors structured in the midgut bacterial community and the microbiota have the potential to regulate the Bt-induced killing mechanism.

Asian corn borer (ACB), Ostrinia furnacalis, is a predominant pest species that is widely distributed across major corn-growing regions in China. Tetraniliprole, a novel diamid insecticide, exhibited good efficacy on lepidopteran insect pests and was officially sanctioned for controlling ACB in China. In this study, a tetraniliprole-resistant strain called ACB-TLR was obtained from a susceptible strain, ACB-SS, after 10 continuous generation selections with tetraniliprole. Additionally, the fitness cost of the ACB-TLR strain was assessed. The results showed that ACB developed 11.58-fold resistance to tetraniliprole and the realized heritability was estimated as 0.213. The ACB-TLR strain displayed 2.10 times cross-resistance to chlorantraniliprole, but we found no cross-resistance to emamectin benzoate and deltamethrin. The development time of larvae and pupae was significantly prolonged, the adult longevity was significantly shorter, and the pupation and emergence rates were significantly reduced in the ACB-TLR strain than in the ACB-SS strain, with a relative fitness of 0.39. The current study indicated that ACB has the potential to develop resistance to tetraniliprole in the field. However, the decreased fitness may allow insecticide resistance to be managed.