, a well-documented and endemic pest throughout most of the Americas, affecting more than 100 species of host plants. It is a quarantine pest according to the Asia and Pacific Plant Protection ...Commission (APPPC) and the catalog of quarantine pests for plants imported to the People's Republic of China. Based on 1781 global distribution records of
and eight bioclimatic variables, the potential geographical distributions (PGDs) of
were predicted by using a calibrated MaxEnt model. The contribution rate of bioclimatic variables and the jackknife method were integrated to assess the significant variables governing the PGDs. The response curves of bioclimatic variables were quantitatively determined to predict the PGDs of
under climate change. The results showed that: (1) four out of the eight variables contributed the most to the model performance, namely, mean diurnal range (bio2), precipitation seasonality (bio15), precipitation of the driest quarter (bio17) and precipitation of the warmest quarter (bio18); (2) PGDs of
under the current climate covered 418.15 × 10
km
, and were large in China; and (3) future climate change will facilitate the expansion of PGDs for
under shared socioeconomic pathways (SSP) 1-2.6, SSP2-4.5, and SSP5-8.5 in both the 2030s and 2050s. The conversion of unsuitable to low suitability habitat and moderately to high suitability habitat increased by 8.43% and 2.35%, respectively. From the present day to the 2030s, under SSP1-2.6, SSP2-4.5 and SSP5-8.5, the centroid of the suitable habitats of
showed a general tendency to move eastward; from 2030s to the 2050s, under SSP1-2.6 and SSP5-8.5, it moved southward, and it moved slightly northward under SSP2-4.5. According to bioclimatic conditions,
has a high capacity for colonization by introduced individuals in China. Customs ports should pay attention to host plants and containers of
and should exchange information to strengthen plant quarantine and pest monitoring, thus enhancing target management.
Heat shock proteins are molecular chaperones that are involved in numerous normal cellular processes and stress responses, and heat shock factors are transcriptional activators of heat shock ...proteins. Heat shock factors and heat shock proteins are coordinated in various biological processes. The regulatory function of heat shock factors in the expression of genes encoding heat shock proteins (Hsps) has been documented in some model insects, however, the role of transcription factors in modulating Hsps in other insects is still limited. In this study, one heat shock factor gene (
AhHsf
) was isolated and its two potential target genes (
AhHsp70
and
AhsHsp21
) were confirmed from
Agasicles hygrophila
.
AhHsf
sequence analysis indicated that it belongs to the Hsfs gene family. RT-qPCR showed that expression levels of heat shock factors and of two heat shock proteins significantly increased under heat stress. Injection with double-stranded
Hsf
RNA in freshly emerged adult beetles significantly inhibited expression of
AhHsp70
and
AhsHsp21
, shortened the adult survival, drastically reduced egg production, and ultimately led to a decrease in fecundity. RNA interference (RNAi)-mediated suppression of
AhHsp70
or
AhsHsp21
expression also significantly affected expression of
AhHsf
. Our findings revealed a potential transcriptional function of AhHsf to regulate expression of
AhHsp70
and
AhsHsp21
, which may play a key role in
A. hygrophila
thermotolerance. Our results improve our understanding of the molecular mechanisms of the AhHsf - AhHsps signaling pathway in
A. hygrophila.
In Hymenoptera species, the reproductive mode is usually arrhenotoky, where haploid males arise from unfertilized eggs and diploid females from fertilized eggs. In addition, a few species reproduce ...by thelytoky, where diploid females arise from unfertilized eggs. Diploid females can be derived through various cytological mechanisms in thelytokous Hymenoptera species. Hitherto, these mechanisms were revealed mainly in endosymbiont-induced thelytokous Hymenoptera species. In contrast, thelytokous Hymenoptera species in which a reproductive manipulator has not been verified or several common endosymbionts have been excluded were paid less attention in their cytological mechanisms, for instance,
(Hymenoptera: Eulophidae). Here, we investigated the cytological mechanism of
.
using cytological methods and genetic markers. Our observations indicated that the diploid karyotypes of two strains of
.
consist of four pairs of relatively large metacentric chromosomes and one pair of short submetacentric chromosomes (2
= 10). The arrhenotokous strains could complete normal meiosis, whereas the thelytokous strain lacked meiosis and did not expulse any polar bodies. This reproductive type of lacking meiosis is classified as apomictic thelytoky. Moreover, a total of 636 microsatellite sequences were obtained from thelytokous
.
, dominated by dinucleotide repeats. Genetic markers results showed all three generations of offspring from thelytokous strain maintained the same genotype as their parents. Our results revealed that
.
is the first eulophid parasitoid wasp in Hymenoptera whose thelytoky was not induced by bacteria to form an apomictic thelytoky. These findings provide a baseline for future inner molecular genetic studies of ameiotic thelytoky.
Two new clerodane-type diterpenes, tinosporins C (
) and tinosporins D (
) were isolated from the stems of
(Oliv.), together with three known ones, columbin (
), tinophylloloside (
), and ...tinospinoside D (
). The structures of these compounds were determined on the basis of spectroscopic data interpretation, with that of the absolute configuration of compound
was assigned by experimental and calculated ECD spectra. The cytotoxicity and α-glucosidase inhibitory activities of isolated compounds were evaluated in vitro.
Abstract
When female host feeding parasitoids encounter a potential host, they face a complicated trade-off between either laying an egg for investing in current reproduction or feeding on or killing ...the host for future reproduction. Few studies have measured these behavioral shift patterns in a given host-parasitoid association thus far. We systematically assessed the behavioral shifts and life history traits of a host feeding parasitoid,
Necremnus tutae,
on different instars of its host
Tuta absoluta. N. tutae
females, as idiobiont host feeding parasitoids, can act on the 1st–4th instar larvae of
T. absoluta
by either host feeding, parasitizing or host killing. Moreover, a significant behavioral shift was observed on different instar hosts.
N. tutae
preferred to feed on the young hosts (1st and 2nd instars), lay eggs on middle-aged hosts (3rd instars) and kill old hosts (4th instars) by ovipositor-mediated stinging. The offspring of
N. tutae
showed a significant female-biased sex ratio, with the number of instars of
T. absoluta
larvae that were parasitized increasing. Specifically, nonreproductive host mortality induced by host feeding and host killing accounted for high percentages of the total mortality (ranging from 70% on 3rd instar hosts to 88% on 1st instar and 4th instar hosts). We hypothesize that
N. tutae
could be not merely a parasitoid but also a predator. Our results shed light on the nonreproductive abilities of a host feeding parasitoid that should be given further attention, especially when evaluating the efficacy of parasitoids.
The position of the chromatin opening of
undergoes significant changes under different temperature stresses, and numerous regulatory factors have been found. In this study, we verified two key ...factors, cytochrome P450 4C1 and carbonic anhydrase 3. The results showed that invasive whiteflies had a significantly lower heat resistance after silencing
and
. In addition, whiteflies had a higher cold tolerance after silencing
. These results indicate that
and
are key regulators in the temperature adaptation of
. Moreover, they may be key factors in influencing the geographical distribution and dispersal of
as an invasive species in China.
Mikania micrantha is a fast-growing global invasive weed species that causes severe damage to natural ecosystems and very large economic losses of forest and crop production. It has advantages in ...photosynthesis, including a similar net photosynthetic rate as C4 plants and a higher carbon fixation capacity. We used a combination of genomics and transcriptomics approaches to study the evolutionary mechanisms and circadian expression patterns of M. micrantha. In M. micrantha, 16 positive selection genes focused on photoreaction and utilization of photoassimilates. In different tissues, 98.1% of the genes associated with photoresponse had high expression in stems, and more than half of the genes of the C4 cycle had higher expression in stems than in leaves. In stomatal opening and closing, 2 genes of carbonic anhydrase (CAs) had higher expression at 18:00 than at 8:00, and the slow anion channel 1 (SLAC1) and high-leaf-temperature 1 kinase (HT1) genes were expressed at low levels at 18:00. In addition, genes associated with photosynthesis had higher expression levels at 7:00 and 17:00. We hypothesized that M. micrantha may undergo photosynthesis in the stem and flower organs and that some stomata of the leaves were opening at night by CO2 signals. In addition, its evolution may attenuate photoinhibition at high light intensities, and enhance more efficient of photosynthesis during low light intensity. And the tissue-specific photosynthetic types and different diurnal pattern of photosynthetic-related genes may contribute to its rapid colonization of new habitats of M. micrantha.
Biological invasions are responsible for substantial environmental and economic losses. The red turpentine beetle (RTB), Dendroctonus valens LeConte, is an important invasive bark beetle from North ...America that has caused substantial tree mortality in China. The lack of a high-quality reference genome seriously limits deciphering the extent to which genetic adaptions resulted in a secondary pest becoming so destructive in its invaded area. Here, we present a 322.41 Mb chromosome-scale reference genome of RTB, of which 98% of assembled sequences are anchored onto fourteen linkage groups including the X chromosome with a N50 size of 24.36 Mb, which is significantly greater than other Coleoptera species. Repetitive sequences make up 45.22% of the genome, which is higher than four other Coleoptera species, i.e., Mountain pine beetle Dendroctonus ponderosae, red flour beetle Tribolium castaneum, blister beetle Hycleus cichorii, and Colorado potato beetle Leptinotarsa decemlineata. We identify rapidly expanded gene families and positively selected genes in RTB, which may be responsible for its rapid environmental adaptation. Population genetic structure of RTB was revealed by genome resequencing of geographic populations in native and invaded regions, suggesting substantial divergence of the North American population and illustrates the possible invasion and spread route in China. Selective sweep analysis highlighted the enhanced ability of Chinese populations in environmental adaptation. Overall, our high-quality reference genome represents an important resource for genomics study of invasive bark beetles, which will facilitate the functional study and decipher mechanism underlying invasion success of RTB by integrating the Pinus tabuliformis genome.
Long noncoding RNAs (lncRNAs) have emerged as an important class of transcriptional regulators in cellular processes. The past decades have witnessed great progress in lncRNA studies in a variety of ...organisms. The codling moth (Cydia pomonella L.) is an important invasive insect in China. However, the functional impact of lncRNAs in this insect remains unclear. In this study, an atlas of codling moth lncRNAs was constructed based on publicly available RNA-seq datasets.
In total, 9875 lncRNA transcripts encoded by 9161 loci were identified in the codling moth. As expected, the lncRNAs exhibited shorter transcript lengths, lower GC contents, and lower expression levels than protein-coding genes (PCGs). Additionally, the lncRNAs were more likely to show tissue-specific expression patterns than PCGs. Interestingly, a substantial fraction of the lncRNAs showed a testis-biased expression pattern. Additionally, conservation analysis indicated that lncRNA sequences were weakly conserved across insect species, though additional lncRNAs with homologous relationships could be identified based on synteny, suggesting that synteny could be a more reliable approach for the cross-species comparison of lncRNAs. Furthermore, the correlation analysis of lncRNAs with neighbouring PCGs indicated a stronger correlation between them, suggesting potential cis-acting roles of these lncRNAs in the regulation of gene expression.
Taken together, our work provides a valuable resource for the comparative and functional study of lncRNAs, which will facilitate the understanding of their mechanistic roles in transcriptional regulation.
Mikania micrantha
is a noxious invasive plant causing enormous economic losses and ecological damage. Soil microbiome plays an important role in the invasion process of
M. micrantha
, while little is ...known about its rhizosphere microbiome composition and function. In this study, we identified the distinct rhizosphere microbial communities of
M. micrantha
, by comparing them with those of two coexisting native plants (
Polygonum chinense
and
Paederia scandens
) and the bulk soils, using metagenomics data from field sampling and pot experiment. As a result, the enrichment of phosphorus-solubilizing bacteria
Pseudomonas
and
Enterobacter
was consistent with the increased soil available phosphorus in
M. micrantha
rhizosphere. Furthermore, the pathogens of
Fusarium oxysporum
and
Ralstonia solanacearum
and pathogenic genes of type III secretion system (T3SS) were observed to be less abundant in
M. micrantha
rhizosphere, which might be attributed to the enrichment of biocontrol bacteria
Catenulispora
,
Pseudomonas
, and
Candidatus Entotheonella
and polyketide synthase (PKS) genes involved in synthesizing antibiotics and polyketides to inhibit pathogens. These findings collectively suggested that the enrichment of microbes involved in nutrient acquisition and pathogen suppression in the rhizosphere of
M. micrantha
largely enhances its adaptation and invasion to various environments.
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