The dynamics of molecular components that regulate aphid-plant interactions

Aphids are economically important insect pests, which feed on phloem sap using stylets. Aphids cause significant losses of crop yield, through draining plant resources and vectoring over 275 plant viruses. In plant-pathogen interactions, basal plant defense involving pathogen associated molecular pattern (PAMP) triggered immunity (PTI) and effector triggered immunity (ETI) effectively fends off the majority of plant pathogens. I aimed to discover whether these mechanisms are also involved in the plant response to aphids. I found that elicitors present within aphids can evoke PTI/ETI defense responses. In Arabidopsis thaliana, perception of aphid elicitors requires the Leucine-Rich Repeat Receptor- Like Kinase (LRR-RLK) BAK1, which is required for multiple PTI responses via interaction with other RLKs. I identified two RLKs which may detect aphid elicitors and provide specificity to aphid detection. Successful aphid colonization of plants is thought to involve the suppression of PTI and ETI via effectors, leading to effector-triggered susceptibility (ETS). I investigated a Myzus persicae effector, Mp10, and found that it was required for success on Arabidopsis and could block immune signalling. A plant target for Mp10 was identified via a yeast twohybrid screen. Further investigations suggest that the Mp10 target has previously unknown roles in immune receptor trafficking. Mp10 induces ETI-like responses when expressed in plants, which I found were not dependent upon Mp10 effector action or salicylic acid. A yeast two-hybrid screen of candidate aphid effectors revealed interactions with plant resistance proteins, which may play a role in the aphid-plant interaction. Aphid effector proteins were also found to interact with each other, suggesting a role in the regulation of effector action and delivery into plants. Taken together, the research described in this thesis has elucidated the roles of PTI, ETS and ETI in insect-plant interactions and identified specific plant and aphid proteins that are involved in these

Helminth extracellular vesicles: interactions with the host immune system

As long-lived parasites, helminths depend upon immunomodulation of their hosts for survival. The release of excretory-secretory (ES) products, including proteins, lipids and RNAs is how successful host manipulation is achieved. It has recently been discovered that the ES products of helminths contain extracellular vesicles (EVs), with every species investigated found to secrete these lipid-bound structures. EVs are perfect for packaging and delivering immune modulators to target cell types. This review outlines the research carried out on helminth EVs and their constituents thus far, as well as their interaction with components of the mammalian immune system. We discuss how targeting EVs will aid treatment of helminth infection and consider how EVs and their immunomodulatory cargo could be used as therapeutics as we progress through this exciting era

The Leucine-Rich Repeat Receptor-Like Kinase BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 and the Cytochrome P450 PHYTOALEXIN DEFICIENT3 Contribute to Innate Immunity to Aphids in Arabidopsis

The importance of pathogen-associated molecular pattern-triggered immunity (PTI) against microbial pathogens has been recently demonstrated. However, it is currently unclear if this layer of immunity mediated by surface-localized pattern recognition receptors (PRRs) also plays a role in basal resistance to insects, such as aphids. Here, we show that PTI is an important component of plant innate immunity to insects. Extract of the green peach aphid (GPA; Myzus persicae) triggers responses characteristic of PTI in Arabidopsis (Arabidopsis thaliana). Two separate eliciting GPA-derived fractions trigger induced resistance to GPA that is dependent on the leucine-rich repeat receptor-like kinase BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1)/SOMATIC-EMBRYOGENESIS RECEPTOR-LIKE KINASE3, which is a key regulator of several leucine-rich repeat-containing PRRs. BAK1 is required for GPA elicitor-mediated induction of reactive oxygen species and callose deposition. Arabidopsis bak1 mutant plants are also compromised in immunity to the pea aphid (Acyrthosiphon pisum), for which Arabidopsis is normally a nonhost. Aphid-derived elicitors induce expression of PHYTOALEXIN DEFICIENT3 (PAD3), a key cytochrome P450 involved in the biosynthesis of camalexin, which is a major Arabidopsis phytoalexin that is toxic to GPA. PAD3 is also required for induced resistance to GPA, independently of BAK1 and reactive oxygen species production. Our results reveal that plant innate immunity to insects may involve early perception of elicitors by cell surface-localized PRRs, leading to subsequent downstream immune signaling

Extracellular vesicles: new targets for vaccines against helminth parasites

The hunt for effective vaccines against the major helminth diseases of humans has yet to bear fruit despite much effort over several decades. No individual parasite antigen has proved to elicit full protective immunity, suggesting that combinatorial strategies may be required. Recently it has been discovered that extracellular vesicles released by parasitic helminths contain multiple potential immune modulators, which could together be targeted by a future vaccine. Increasing knowledge of helminth extracellular vesicle components, both enclosed by and exposed on the membrane, will open up a new field of targets for an effective vaccine. This review discusses the interactions between helminth extracellular vesicles and the immune system discovered thus far, and the advantages of targeting these lipid-bound packages with a vaccine. In addition, we also comment upon specific antigens that may be the best targets for an anti-helminth vaccine. In the future, extensive knowledge of the parasites' full arsenal in controlling their host may finally provide us with the ideal target for a fully effective vaccine

DETEKSI GLUKOSA DALAM URIN ORANGUTAN SUMATERA (PONGO ABELII) MENGGUNAKAN STRIPTEST SEMIKUANTITATIF DI TAMAN HEWAN PEMATANG SIANTAR

Penelitian ini bertujuan mengetahui ada tidaknya glukosa dalam uron orangutan sumatera (Pongo abelii) sebagai penunjang diagnosa di Taman Hewan Pematang Siantar, Sumatera Utara. Pengoleksian urin terhadap 4 ekor orangutan sumatera di dalam kandang yang dilakukan pada pagi hari yaitu saat orangutan bangun tidur atau sebelum pemberian pakan orangutan. Pengulangan uji dilakukan 3 kali selama 10 hari pada bulan Januari 2015. Setelah pengoleksian urin kemudian dilakukan pemeriksaan dengan cara mencelupkan stripstest pada 5-10 ml urin selama 30 detik. Analisis data menggunakan metode deskriptif kualitatif dengan hasil bersifat semikuantitatif melalui pembacaan nilai glukosa pada stripstest yang memiliki skala perubahan warna yaitu : negatif, positif 1 (100 mg/dL), positif 2 (250 mg/dL), positif 3 (500 mg/dL), dan positif 4 (1000 mg/dL). Hasil penelitian menunjukkan bahwa dari 4 sampel urin orangutan sumatera tidak terdeteksi adanya glukosa dalam urin

Generation, culture, and stimulation of small intestinal murine organoids in parasitology research

Summary: Parasitic helminth worms frequently infect the gastrointestinal tract and interact with the intestinal epithelium and specialized cell types within it. Intestinal organoids derived from stem cells that line the intestine represent a transformational technology in the study of epithelial-parasite dialogue. Here, we present a protocol for establishing small intestine organoid cultures and administering parasite products of interest to these cultures. We then describe steps for evaluating their impact by microscopy, flow cytometry, immunohistology, and mRNA gene expression.For complete details on the use and execution of this protocol, please refer to Drurey et al. (2022).1 : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics

The leucine-rich repeat receptor-like kinase BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 and the cytochrome P450 PHYTOALEXIN DEFICIENT3 contribute to innate immunity to aphids in Arabidopsis

The importance of pathogen-associated molecular pattern-triggered immunity (PTI) against microbial pathogens has been recently demonstrated. However, it is currently unclear if this layer of immunity mediated by surface-localized pattern recognition receptors (PRRs) also plays a role in basal resistance to insects, such as aphids. Here, we show that PTI is an important component of plant innate immunity to insects. Extract of the green peach aphid (GPA; Myzus persicae) triggers responses characteristic of PTI in Arabidopsis (Arabidopsis thaliana). Two separate eliciting GPA-derived fractions trigger induced resistance to GPA that is dependent on the leucine-rich repeat receptor-like kinase BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1)/SOMATIC-EMBRYOGENESIS RECEPTOR-LIKE KINASE3, which is a key regulator of several leucine-rich repeat-containing PRRs. BAK1 is required for GPA elicitor-mediated induction of reactive oxygen species and callose deposition. Arabidopsis bak1 mutant plants are also compromised in immunity to the pea aphid (Acyrthosiphon pisum), for which Arabidopsis is normally a nonhost. Aphid-derived elicitors induce expression of PHYTOALEXIN DEFICIENT3 (PAD3), a key cytochrome P450 involved in the biosynthesis of camalexin, which is a major Arabidopsis phytoalexin that is toxic to GPA. PAD3 is also required for induced resistance to GPA, independently of BAK1 and reactive oxygen species production. Our results reveal that plant innate immunity to insects may involve early perception of elicitors by cell surface-localized PRRs, leading to subsequent downstream immune signaling

An immuno-suppressive aphid saliva protein is delivered into the cytosol of plant mesophyll cells during feeding

Herbivore selection of plant hosts and plant responses to insect colonization have been subjects of intense investigations. A growing body of evidence suggests that, for successful colonization to occur, (effector/virulence) proteins in insect saliva must modulate plant defense responses to the benefit of the insect. A range of insect saliva proteins that modulate plant defense responses have been identified, but there is no direct evidence that these proteins are delivered into specific plant tissues and enter plant cells. Aphids and other sap-sucking insects of the order Hemiptera use their specialized mouthparts (stylets) to probe plant mesophyll cells until they reach the phloem cells for long-term feeding. Here, we show, by immunogold-labeling of ultrathin sections of aphid feeding sites, that an immuno-suppressive aphid effector localizes in the cytoplasm of mesophyll cells near aphid stylets but not in cells further away from aphid feeding sites. In contrast, another aphid effector protein localizes in the sheaths composed of gelling saliva that surround the aphid stylets. Thus, insects deliver effectors directly into plant tissue. Moreover, different aphid effectors locate extracellularly in the sheath saliva or are introduced into the cytoplasm of plant cells

The phosphorylation state of chloroplast transit peptides regulates preprotein import

Import of nuclear encoded proteins into chloroplast is an essential and well-regulated mechanism. The cytosolic kinases STY8, STY17 and STY46 have been shown to phosphorylate chloroplast preprotein transit peptides advantaging the binding of a 14-3-3 dimer. Analyses of sty8 sty17 sty46 mutant plants revealed a role for the kinases in chloroplast differentiation, possibly due to lack of transit peptide phosphorylation. Moreover we could show that not only phosphorylation but also transit peptide dephosphorylation appears to be required for the fine regulation of the back-transport of nuclear encoded proteins to the chloroplast