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1.
BMC Plant Biol ; 21(1): 358, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34348650

RESUMO

BACKGROUND: The South America pinworm, Tuta absoluta, is a destructive pest of tomato that causes important losses worldwide. Breeding of resistant/tolerant tomato cultivars could be an effective strategy for T. absoluta management but, despite the economic importance of tomato, very limited information is available about its response to this treat. To elucidate the defense mechanisms to herbivore feeding a comparative analysis was performed between a tolerant and susceptible cultivated tomato at both morphological and transcriptome level to highlight constitutive leaf barriers, molecular and biochemical mechanisms to counter the effect of T. absoluta attack. RESULTS: The tolerant genotype showed an enhanced constitutive barrier possibly as result of the higher density of trichomes and increased inducible reactions upon mild infestation thanks to the activation/repression of key transcription factors regulating genes involved in cuticle formation and cell wall strength as well as of antinutritive enzymes, and genes involved in the production of chemical toxins and bioactive secondary metabolites. CONCLUSIONS: Overall, our findings suggest that tomato resilience to the South America pinworm is achieved by a combined strategy between constitutive and induced defense system. A well-orchestrated modulation of plant transcription regulation could ensure a trade-off between defense needs and fitness costs. Our finding can be further exploited for developing T. absoluta tolerant cultivars, acting as important component of integrated pest management strategy for more sustainable production.


Assuntos
Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Doenças das Plantas/genética , Folhas de Planta/genética , Transcriptoma , Animais , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Interações Hospedeiro-Parasita , Larva/fisiologia , Lycopersicon esculentum/metabolismo , Lycopersicon esculentum/parasitologia , Mariposas/fisiologia , Doenças das Plantas/parasitologia , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA-Seq/métodos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tricomas/genética , Tricomas/metabolismo , Tricomas/parasitologia
2.
Genes (Basel) ; 11(4)2020 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-32231109

RESUMO

Cotton possesses certain physical features, including leaf and stem trichomes that help plants deter damage caused by insect pests, and to some extent, from abiotic factors as well. Among those features, trichomes (pubescence) hold a special place as a first line of defense and a managemental tool against sucking insect pests of cotton. Different insect pests of cotton (whiteflies, aphids, jassids, and boll weevil) severely damage the yield and quality of the crop. Likewise, whiteflies, aphids, jassids, and other insect pests are considered as potential carriers for cotton leaf curl viruses and other diseases. Genotyping by sequencing (GBS) study was conducted to understand and explore the genomic regions governing hairy (Pubescence) leaves and stem phenotypes. A total of 224 individuals developed from an intraspecific cross (densely haired cotton (Liaoyang duomao mian) × hairless cotton (Zong 128)) and characterized phenotypically for leaf and stem pubescence in different environments. Here we identify and report significant QTLs (quantitative trait loci) associated with leaf and stem pubescence, and the response of plant under pest (aphid) infestation. Further, we identified putative genes colocalized on chromosome A06 governing mechanism for trichome development and host-pest interaction. Our study provides a comprehensive insight into genetic architecture that can be employed to improve molecular marker-assisted breeding programs aimed at developing biotic (insect pests) resilient cotton cultivars.


Assuntos
Afídeos/fisiologia , Cromossomos de Plantas/genética , Resistência à Doença/genética , Gossypium/genética , Doenças das Plantas/genética , Locos de Características Quantitativas , Tricomas/genética , Animais , Mapeamento Cromossômico , Resistência à Doença/imunologia , Ligação Genética , Genótipo , Gossypium/crescimento & desenvolvimento , Gossypium/parasitologia , Fenótipo , Doenças das Plantas/imunologia , Doenças das Plantas/parasitologia , Tricomas/crescimento & desenvolvimento , Tricomas/parasitologia
3.
BMC Plant Biol ; 18(1): 64, 2018 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-29661140

RESUMO

BACKGROUND: Previously, transgenic trichome-bearing (hairy leaf) Brassica napus lines expressing either the Arabidopsis thaliana GL3 gene (line AtGL3+) [1] or the AtGL3 gene in combination with an RNAi construct to down-regulate TTG1 (line K-5-8) [2] were developed. The leaves of these lines exhibited altered insect feeding (flea beetle) and oviposition (diamondback moth) behaviour compared to the non-transgenic semi-glabrous leaves of B. napus cv. Westar. Interestingly, the cotyledons of these lines remained glabrous, but also showed reduced feeding by flea beetles. Here we examine the composition and global transcriptome of the glabrous cotyledons from these transgenic lines to ascertain the mechanism(s) underlying this unexpected phenomenon. RESULTS: Approximately, 7500 genes were up-regulated in cotyledons of each hairy line, compared with < 30 that were down-regulated. The up-regulated genes included those involved in cell wall synthesis, secondary metabolite production, redox, stress and hormone-related responses that have the potential to impact host plant cues required to elicit defense responses toward insect pests. In particular, the expression of glucosinolate biosynthetic and degradation genes were substantially altered in the glabrous cotyledons of the two hairy leaf lines. The transcriptomic data was supported by glucosinolate and cell wall composition profiles of the cotyledons. Changes in gene expression were much more extreme in the AtGL3+ line compared with the K-5-8 line in terms of diversity and intensity. CONCLUSIONS: The study provides a roadmap for the isolation and identification of insect resistance compounds and proteins in the glabrous cotyledons of these hairy leaf lines. It also confirms the impact of mis-expression of GL3 and TTG1 on types of metabolism other than those associated with trichomes. Finally, the large number of up-regulated genes encoding heat shock proteins, PR proteins, protease inhibitors, glucosinolate synthesis/breakdown factors, abiotic stress factors, redox proteins, transcription factors, and proteins required for auxin metabolism also suggest that these cotyledons are now primed for resistance to other forms of biotic and abiotic stress.


Assuntos
Brassica napus/metabolismo , Brassica napus/parasitologia , Besouros/patogenicidade , Cotilédone/metabolismo , Cotilédone/parasitologia , Fatores de Transcrição/metabolismo , Transcriptoma/genética , Animais , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Brassica napus/genética , Cotilédone/genética , Regulação da Expressão Gênica de Plantas , Glucosinolatos/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/genética , Tricomas/genética , Tricomas/metabolismo , Tricomas/parasitologia
4.
Sci Rep ; 7(1): 12052, 2017 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-28935893

RESUMO

Bladderworts (Utricularia, Lentibulariaceae, Lamiales) constitute the largest genus of carnivorous plants but only aquatic species (about one fifth of the genus) have so far been thoroughly studied as to their suction trap functioning. In this study, we comparatively investigated trap biomechanics in 19 Utricularia species to examine correlations between life-forms, trapping mechanisms, and functional-morphological traits. Our investigations show the existence of two functional trap principles (passive trap in U. multifida vs. active suction traps), and - in active suction traps - three main trapdoor movement types (with several subtypes). The trapdoor movement types and their corresponding functional-morphological features most presumably represent adaptations to the respective habitat. We furthermore give insights into fluid dynamics during suction in three representatives of the main types of trapdoor movement. The results on functional morphology and trapdoor movement were mapped onto a new phylogenetic reconstruction of the genus, derived from the rapidly evolving chloroplast regions trnK, rps16 and trnQ-rps16 and a sampling of 105 Utricularia species in total. We discuss potential scenarios of trap character evolution and species radiation, highlighting possible key innovations that enable such a unique carnivorous lifestyle in different habitats.


Assuntos
Ecossistema , Evolução Molecular , Variação Genética , Lamiales/genética , Endorribonucleases/genética , Lamiales/classificação , Lamiales/parasitologia , Microscopia Eletrônica de Varredura , Nucleotidiltransferases/genética , Filogenia , RNA de Transferência de Lisina/genética , Especificidade da Espécie , Tricomas/parasitologia , Tricomas/ultraestrutura
5.
Sci Rep ; 7(1): 12102, 2017 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-28935950

RESUMO

The adaptation of herbivorous insects to various host plants facilitates the spread and outbreak of many important invasive pests, however, the molecular mechanisms that underneath this process are poorly understood. In the past three decades, two species of the whitefly Bemisia tabaci complex, Middle East-Asia Minor 1 and Mediterranean, have invaded many countries. Their rapid and widespread invasions are partially due to their ability to infest a wide range of host plants. In this study, we determined the transcriptome and phenotypic changes of one Mediterranean whitefly population during its adaptation to tobacco, an unsuitable host plant. After several generations on tobacco, whiteflies showed increased survival and fecundity. High-throughput RNA sequencing showed that genes involved in muscle contraction and carbohydrate metabolism were significantly up-regulated after adaptation. Whiteflies reared on tobacco were further found to have increased body volume and muscle content and be trapped by tobacco trichomes in a lower frequency. On the other hand, gene expression in endosymbionts of whitefly did not change significantly after adaptation, which is consistent with the lack of cis-regulatory element on endosymbiont genomes. Over all, our data suggested that higher body volume and strengthened muscle might help whiteflies overcome physical barriers and survive on tobacco.


Assuntos
Adaptação Fisiológica/genética , Perfilação da Expressão Gênica , Hemípteros/genética , Proteínas de Insetos/genética , Animais , Peso Corporal/genética , Fertilidade/genética , Ontologia Genética , Hemípteros/fisiologia , Sequenciamento de Nucleotídeos em Larga Escala , Interações Hospedeiro-Parasita , Região do Mediterrâneo , Proteínas Musculares/genética , Tabaco/parasitologia , Tricomas/parasitologia
6.
Plant Sci ; 262: 103-114, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28716406

RESUMO

Cyclins exist extensively in various plant species. Among them, B-type cyclins play important roles in the transition of G2-to-M. However, few B-type cyclins have been reported to participate in reproductive organ development and trichome formation. In this study, transgene analysis showed that SlCycB2 overexpression caused abnormal flower with the unclosed stamen, shortened style and aberrant pollen. In addition, nearly all non-glandular trichomes, as well as the glandular ones were disappeared. On the contrary, suppression of SlCycB2 could promote type III and type V trichomes formation. Detection of secondary metabolites indicated that the production of monoterpene and sesquiterpene were significantly decreased in SlCycB2-OE plants, which thus resulted in the reduction of the defense against Prodenia litura. Transcriptome profile demonstrated that the differentially expressed genes mainly participate in the biosynthesis of terpenes, cutin, suberine and wax. Furthermore, we identified several homologs of SlCycB2, SlCycB3, NtCycB2, AtCycB2, which have similar regulatory functions in trichome formation. These results indicate that SlCycB2 plays a critical role in reproductive organ development, multicellular trichome initiation, secondary metabolite biosynthesis and Prodenia litura defense in tomato. The similar roles of its homologs in multicellular trichome formation suggest that Solanaceous species may share common regulatory pathway.


Assuntos
Ciclina B/metabolismo , Lepidópteros/patogenicidade , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Terpenos/metabolismo , Animais , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Flores/parasitologia , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Lycopersicon esculentum/genética , Lycopersicon esculentum/parasitologia , Monoterpenos/metabolismo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/parasitologia , Sesquiterpenos/metabolismo , Tricomas/genética , Tricomas/crescimento & desenvolvimento , Tricomas/metabolismo , Tricomas/parasitologia
7.
Plant Physiol ; 174(1): 370-386, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28275149

RESUMO

O-Acyl sugars (O-AS) are abundant trichome-specific metabolites that function as indirect defenses against herbivores of the wild tobacco Nicotiana attenuata; whether they also function as generalized direct defenses against herbivores and pathogens remains unknown. We characterized natural variation in O-AS among 26 accessions and examined their influence on two native fungal pathogens, Fusarium brachygibbosum U4 and Alternaria sp. U10, and the specialist herbivore Manduca sexta At least 15 different O-AS structures belonging to three classes were found in N. attenuata leaves. A 3-fold quantitative variation in total leaf O-AS was found among the natural accessions. Experiments with natural accessions and crosses between high- and low-O-AS accessions revealed that total O-AS levels were associated with resistance against herbivores and pathogens. Removing O-AS from the leaf surface increased M. sexta growth rate and plant fungal susceptibility. O-AS supplementation in artificial diets and germination medium reduced M. sexta growth and fungal spore germination, respectively. Finally, silencing the expression of a putative branched-chain α-ketoacid dehydrogenase E1 ß-subunit-encoding gene (NaBCKDE1B) in the trichomes reduced total leaf O-AS by 20% to 30% and increased susceptibility to Fusarium pathogens. We conclude that O-AS function as direct defenses to protect plants from attack by both native pathogenic fungi and a specialist herbivore and infer that their diversification is likely shaped by the functional interactions among these biotic stresses.


Assuntos
Resistência à Doença , Folhas de Planta/química , Açúcares/química , Tabaco/química , 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/genética , 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/metabolismo , Acilação , Alternaria/fisiologia , Animais , Fusarium/fisiologia , Inativação Gênica , Herbivoria/fisiologia , Manduca/fisiologia , Estrutura Molecular , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Folhas de Planta/microbiologia , Folhas de Planta/parasitologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Tabaco/microbiologia , Tabaco/parasitologia , Tricomas/genética , Tricomas/microbiologia , Tricomas/parasitologia
8.
Ecotoxicol Environ Saf ; 120: 449-56, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26150137

RESUMO

Rough rice grains are often stored for extended periods before they are used or consumed. However, during storage, the rough rice is vulnerable to insect infestation, resulting in significant economic loss. Previous studies have shown that volatiles cues, physical characteristics, and taste chemicals on the grains could be the important key behavior factors for storage insect pests to locate the hosts and select oviposition sites. It is also well known that the transgenic Bt rough rice line T1C-19, which expresses a cry1C(⁎) gene has a high resistance to Lepidoptera pests. However, there were no evidences to show the consequences of host preference for non-target insect pests after growing Bt transgenic rice. In this study, the potential key factors of Bt rough rice were investigated for their impacts on the behaviors of non-target pest lesser grain borer Rhyzopertha dominica, the main weevil pest of grain and its parasitic wasps Anisopteromalus calandrae, the natural enemy of the beetle. Both electronic nose and electronic tongue analyses showed that the parameters of Bt rough rice were analogous to those of the non-Bt rough rice. The volatile profiles of Bt and non-Bt rough rice examined by gas chromatographic mass spectrometry (GC-MS) were similar. For most volatile compounds, there were no significantly quantitative differences in compound quantities between Bt and non-Bt rough rice. The densities of sclereids and trichomes on the rough rice husk surface were statistically equal in Bt and non-Bt rough rice. The non-target pest, R. dominica, and its parasitoid wasp, A. calandrae, were attracted to both rough rice and could not distinguish the transgenic T1C-19 from the isogenic rough rice. These results demonstrated that Bt rough rice has no negative impacts on the host preference behaviors of non-target stored product pest R. dominica and its parasitoid A. calandrae.


Assuntos
Besouros/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/parasitologia , Proteínas de Plantas/genética , Vespas/metabolismo , Animais , Bioensaio , Contaminação de Alimentos/análise , Parasitologia de Alimentos , Armazenamento de Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Olfatometria , Oviposição/fisiologia , Controle Biológico de Vetores/métodos , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Análise de Componente Principal , Tricomas/parasitologia , Compostos Orgânicos Voláteis/análise
9.
Exp Appl Acarol ; 60(2): 127-38, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23238958

RESUMO

Tomato plants have their leaves, petioles and stems covered with glandular trichomes that protect the plant against two-spotted spider mites and many other herbivorous arthropods, but also hinder searching by phytoseiid mites and other natural enemies of these herbivores. This trichome cover creates competitor-free and enemy-free space for the tomato russet mite (TRM) Aculops lycopersici (Acari: Eriophyidae), being so minute that it can seek refuge and feed inbetween the glandular trichomes on tomato cultivars currently used in practice. Indeed, several species of predatory mites tested for biological control of TRM have been reported to feed and reproduce when offered TRM as prey in laboratory experiments, yet in practice these predator species appeared to be unable to prevent TRM outbreaks. Using the phytoseiid mite, Amblydromalus limonicus, we found exactly the same, but also obtained evidence for successful establishment of a population of this predatory mite on whole plants that had been previously infested with TRM. This successful establishment may be explained by our observation that the defensive barrier of glandular plant trichomes is literally dropped some time after TRM infestation of the tomato plants: the glandular trichome heads first rapidly develop a brownish discoloration after which they dry out and fall over onto the plant surface. Wherever TRM triggered this response, predatory mites were able to successfully establish a population. Nevertheless, biological control was still unsuccessful because trichome deterioration in TRM-infested areas takes a couple of days to take effect and because it is not a systemic response in the plant, thereby enabling TRM to seek temporary refuge from predation in pest-free trichome-dense areas which continue to be formed while the plant grows. We formulate a hypothesis unifying these observations into one framework with an explicit set of assumptions and predictions to be tested in future experiments.


Assuntos
Lycopersicon esculentum/parasitologia , Ácaros/fisiologia , Folhas de Planta/anatomia & histologia , Folhas de Planta/parasitologia , Tricomas/parasitologia , Animais , Feminino , Herbivoria , Oviposição , Comportamento Predatório
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