Genetic Architecture and Candidate Genes for Pubescence Length and Density and Its Relationship With Resistance to Common Cutworm in Soybean

Soybean pubescence plays an important role in insect resistance, drought tolerance, and other stresses. Hence, a deep understanding of the molecular mechanism underlying pubescence is a prerequisite to a deeper understanding of insect resistance and drought tolerance. In the present study, quantitative trait loci (QTL) mapping of pubescence traits was performed using a high-density inter-specific linkage map of one recombinant inbred line (RIL) population, designated NJRINP. It was observed that pubescence length (PL) was negatively correlated with pubescence density (PD). A total of 10 and 9 QTLs distributed on six and five chromosomes were identified with phenotypic variance (PV) of 3.0–9.9% and 0.8–15.8% for PL and PD, respectively, out of which, eight and five were novel. Most decreased PL (8 of 10) and increased PD (8 of 9) alleles were from the wild soybean PI 342618B. Based on gene annotation, Protein ANalysis THrough Evolutionary Relationships and literature search, 21 and 12 candidate genes were identified related to PL and PD, respectively. In addition, Glyma.12G187200 from major QTLs qPL-12-1 and qPD-12-2, was identified as Ps (sparse pubescence) before, having an expression level of fivefold greater in NN 86-4 than in PI 342618B, hence it might be the candidate gene that is conferring both PL and PD. Based on gene expression and cluster analysis, three and four genes were considered as the important candidate genes of PL and PD, respectively. Besides, leaves with short and dense (SD) pubescence, which are similar to the wild soybean pubescence morphology, had the highest resistance to common cutworm (CCW) in soybean. In conclusion, the findings in the present study provide a better understanding of genetic basis and candidate genes information of PL and PD and the relationship with resistance to CCW in soybean.

Transcriptomics and Metagenomics of Common Cutworm (Spodoptera Litura) and Fall Armyworm (Spodoptera Frugiperda) Reveal Their Differences on Detoxification and Development

BackgroundSpodoptera litura is an important polyphagous pest that causes great damage to agriculture. We performed RNA-seq from 15 individuals of S. litura, including different larval (fifth and sixth instar larvae), chrysalis, and adult developmental stages. We also sequenced the Spodoptera frugiperda to compared with the S. litura. ResultsA total of 101,885 differentially expressed transcripts (DETs) were identified in the S. litura. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses indicated that the S. litura may undergo active development and basic metabolism, such as xenobiotic and detoxifying metabolism, during its larvae and adult stages, which explains the difficulty to control it. We also found that DETs of single-copy orthologous genes between S. litura and S. frugiperda were involved in basic metabolism and developmental, but S. litura were highly enriched in energy and metabolic processes, whereas S. frugiperda had stronger nervous and olfactory functions. Metagenomics analysis in larval S. litura and S. frugiperda revealed that microbiota can both participate in the detoxification and metabolism processes in them, but the relative abundance of detoxification-related microbiota was more abundant in S. frugiperda. Transcriptome results also confirmed the detoxification-related pathway of S. frugiperda was more abundant than that of S. litura. ConclusionsTherefore, we can conclude that the detoxification ability of S. frugiperda is stronger than that of in S. litura, which is related to the wide adaptation and strong resistance of S. frugiperda. Our study might provide clues to the development of novel pest control strategies.

An insight into black cutworm (Agrotis ipsilon): A glimpse on globally important crop pest

Many agricultural pests create problems for farmers leading to production loss. Since agriculture plays an important role in the economy of a nation, controlling and management of such pests is of great importance. Cutworms are notorious agricultural pests infesting a wide variety of crops leading to production loss. Cutworms are distributed worldwide and many species of cutworms have also been reported feeding on all kinds of crops. Agrotis ipsilon is one of the most common cutworm species prevailing in different continents. Understanding the biology and management of these pests will be of great use for farmers. In this article, brief information on cutworms; specifically A. ipsilon species is highlighted. A brief description of host, migration, control and management of A. ipsilon are also highlighted.

Bacterial-mediated RNAi and functional analysis of Natalisin in a moth

The neuropeptide natalisin (NTL) has been determined to play essential roles in reproduction in two Diptera and one Coleoptera species. Whether NTL has similar or even different functions in Lepidoptera remains to be determined. Here, we cloned the NTL transcript in the common cutworm moth Spodoptera litura. This transcript encodes a 438-amino acid protein. Twelve putative Sl-NTL neuropeptides were defined by cleavage sites. These NTL peptides share a DDPFWxxRamide C-terminal motif. The expressions of Sl-NTL is low during the egg and larval stages, which increased to a higher level during the pupal stage, and then reached the maximum during the adult stage. Moreover, the expression pattern during the pupal stage is similar between sexes while during the adult stage, it is dimorphic. To explore the function of Sl-NTL and assess its potential as a target for pest control, we knocked down the expression of Sl-NTL in both sexes by using bacteria-mediated RNAi. This technique significantly down regulated (reduced up to 83%) the expression of Sl-NTL in both sexes. Knocking down Sl-NTL expression did not significantly affect its development, survival and morphology but significantly reduced adults’ reproductive behavior (including female calling, male courtship, mating and remating patterns and rates) and reproductive output (offspring gain reduced more than 70%).