Abstract Diamondback moth, Plutella xylostella (L.), is a specialist pest on cruciferous crops of economic importance. The large‐scale use of chemical insecticides for the control of this insect pest has caused a number of challenges to agro‐ecosystems. With the advent of the omics era, genetic pest management strategies are becoming increasingly feasible and show a powerful potential for pest control. Here, we review strategies for using transgenic plants and sterile insect techniques for genetic pest management and introduce the major advances in the control of P. xylostella using a female‐specific RIDL (release of insects carrying a dominant lethal gene) strategy. Further, the advantages of gene drive developed in combination with sex determination and CRISPR/Cas9 systems are addressed, and the corresponding prospects and implementation issues are discussed. It is predictable that under the policy and regulation of professional committees, the genetic pest control strategy, especially for gene drive, will open a new avenue to sustainable pest management not only for P. xylostella but also for other insect pests.
The soil microbiome is crucial for improving the services and functioning of agroecosystems. Numerous studies have demonstrated the potential of soil physical-chemical properties in driving the belowground microbial assemblages in different agroecosystems. However, not much is known about the assemblage of bacteria and fungi in response to soil physical-chemical properties and the surrounding landscape composition in different vegetable fields of a highly intensive agricultural system. Here, we investigated the effects of soil physical-chemical properties and landscape composition on the community trends of bacteria and fungi in two different soil compartments (bulk and rhizospheric soils) of two different brassica crop types (Chinese cabbage and flower cabbage). The results revealed that bulk soil had a higher alpha diversity of both bacteria and fungi than rhizospheric soil. Each of the soil physical-chemical properties and landscape compositions contributed differently to driving the community structure of distinct bacterial and fungal taxa in both soil compartments and crop types. The higher proportions of forest, grassland, and cultivated land, along with the higher amount of soil calcium in flower cabbage fields, promote the assemblage of Gammaproteobacteria, Actinobacteria, Oxyophotobacteria, Agaricomycetes, and Eurotiomycetes. On the other hand, in Chinese cabbage fields, the increased amounts of iron, zinc, and manganese in the soil together with higher proportions of non-brassica crops in the surrounding landscape strongly support the assemblage of Deltaproteobacteria, Gemmatimonadetes, Bacilli, Clostridia, Alphaproteobacteria, an unknown bacterial species Subgroup-6, Mortierellomycetes, Rhizophlyctidomycetes, and Chytridiomycetes. The findings of this study provide the most comprehensive, comparative, and novel insights related to the bacterial and fungal responses in a highly intensive vegetable growing system for the improvement of the soil fertility and structure. These are important clues for the identification of key bacteria and fungi contributing to the plant-environment interactions and are of a practical significance for landscape-based ecological pest management.
Brassica plants have glucosinolate (GLs)-myrosinase defense mechanisms to deter herbivores. However, Plutella xylostella specifically feeds on Brassica vegetables. The larvae possess three glucosinolate sulfatases (PxGSS1–3) that compete with plant myrosinase for shared GLs substrates and produce nontoxic desulfo-GLs (deGLs). Although PxGSSs are considered potential targets for pest control, the lack of a comprehensive review has hindered the development of PxGSSs-targeted pest control methods. Recent advances in integrative multi-omics analysis, substrate-enzyme kinetics, and molecular biological techniques have elucidated the evolutionary origin and functional diversity of these three PxGSSs. This review summarizes research progress on PxGSSs over the past 20 years, covering sequence properties, evolution, protein modification, enzyme activity, structural variation, substrate specificity, and interaction scenarios based on functional diversity. Finally, we discussed the potential applications of PxGSSs-targeted pest control technologies driven by artificial intelligence, including CRISPR/Cas9-mediated gene drive, transgenic plant-mediated RNAi, small-molecule inhibitors, and peptide inhibitors. These technologies have the potential to overcome current management challenges and promote the development and field application of PxGSSs-targeted pest control.
The diamondback moth, Plutella xylostella is a cosmopolitan pest that has evolved resistance to all classes of insecticide, and costs the world economy an estimated US $4-5 billion annually. We analyse patterns of variation among 532 P. xylostella genomes, representing a worldwide sample of 114 populations. We find evidence that suggests South America is the geographical area of origin of this species, challenging earlier hypotheses of an Old-World origin. Our analysis indicates that Plutella xylostella has experienced three major expansions across the world, mainly facilitated by European colonization and global trade. We identify genomic signatures of selection in genes related to metabolic and signaling pathways that could be evidence of environmental adaptation. This evolutionary history of P. xylostella provides insights into transoceanic movements that have enabled it to become a worldwide pest.
Glycoside hydrolase family 1 (GH1) members exhibit a broad substrate spectrum and play important roles in insect-plant interactions, such as the defensive β-glucosidase and β-thioglucosidase (so-called myrosinase). However, knowledge about the expression profiling and function of glycoside hydrolase family 1 members in a specialist pest of crucifers Plutella xylostella is still limited. In this study, 13 putative glycoside hydrolase family 1 members of P. xylostella were identified based on the sequence characteristics, while no myrosinase activity was detectable in P. xylostella using gas chromatography-mass spectrometry (GC-MS). Expression profiling of these glycoside hydrolase family 1 members identified the midgut-specific gene Px008848 that is induced by host plant. Further experiments revealed that the in vitro expressed Px008848 protein had β-glucosidase activity and the survival rate of the larvae feeding on wounded Arabidopsis thaliana leaves declined when leaves were treated with purified Px008848 protein. When CRISPR/Cas9-based homozygous mutant larvae of Px008848 and wild-type larvae were respectively transferred onto the A. thaliana, the larval survival rate of the mutant larvae was significantly higher than that of the wild-type individuals. Our work showed that certain insect glycoside hydrolase family 1 gene may have negative effect on the development of larvae feeding on the host plant, which broadened our understandings on the evolutionary function of this gene family in the insect-plant interaction.