scholarly journals An aphid effector promotes barley susceptibility through suppression of defence gene expression

2020 ◽  
Vol 71 (9) ◽  
pp. 2796-2807 ◽  
Author(s):  
Carmen Escudero-Martinez ◽  
Patricia A Rodriguez ◽  
Shan Liu ◽  
Pablo A Santos ◽  
Jennifer Stephens ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sequence Similarity ◽  
Rhopalosiphum Padi ◽  
Functional Characterization ◽  
Aphid Species ◽  
Transgenic Barley ◽  
Defence Gene Expression ◽  
Hormone Signalling ◽  
Plant Susceptibility

Abstract Aphids secrete diverse repertoires of effectors into their hosts to promote the infestation process. While ‘omics’ approaches facilitated the identification and comparison of effector repertoires from a number of aphid species, the functional characterization of these proteins has been limited to dicot (model) plants. The bird cherry-oat aphid Rhopalosiphum padi is a pest of cereal crops, including barley. Here, we extend efforts to characterize aphid effectors with regard to their role in promoting susceptibility to the R. padi–barley interaction. We selected three R. padi effectors based on sequence similarity to previously characterized Myzus persicae effectors and assessed their subcellular localization, expression, and role in promoting plant susceptibility. Expression of R. padi effectors RpC002 and Rp1 in transgenic barley lines enhanced plant susceptibility to R. padi but not M. persicae, for which barley is a poor host. Characterization of Rp1 transgenic barley lines revealed reduced gene expression of plant hormone signalling genes relevant to plant–aphid interactions, indicating that this effector enhances susceptibility by suppressing plant defences in barley. Our data suggest that some aphid effectors specifically function when expressed in host species, and feature activities that benefit their corresponding aphid species.

scholarly journals An aphid effector promotes barley susceptibility through suppression of defence gene expression

2019 ◽  
Author(s):  
Carmen Escudero-Martinez ◽  
Patricia A. Rodriguez ◽  
Pablo A. Santos ◽  
Jennifer Stephens ◽  
Jorunn I.B. Bos
Keyword(s):  
Gene Expression ◽  
Rhopalosiphum Padi ◽  
Functional Characterization ◽  
Aphid Species ◽  
Subcellular Localisation ◽  
Transgenic Barley ◽  
Defence Gene Expression ◽  
Hormone Signalling ◽  
Plant Susceptibility

AbstractAphids secrete diverse repertoires of effectors into their hosts to promote the infestation process. While “omics”-approaches facilitated the identification and comparison of effector repertoires from a number of aphid species, the functional characterization of these proteins has been limited to dicot (model) plants. The bird cherry-oat aphid Rhopalosiphum padi is a pest of cereal crops, including barley. Here, we extended efforts to characterize aphid effectors with regards to their role in promoting susceptibility to the R. padi-barley interaction. We selected 3 R. padi effectors based on sequences similarity to previously characterized M. persicae effectors and assessed their subcellular localisation, expression, and role in promoting plant susceptibility. Expression of R. padi effectors RpC002 and Rp1 in transgenic barley lines enhanced plant susceptibility to R. padi but not M. persicae, for which barley is a poor host. Characterization of Rp1 transgenic barley lines revealed reduced gene expression of plant hormone signalling genes relevant to plant-aphid interactions, indicating this effector enhances susceptibility by suppressing plant defences in barley. Our data suggests that some aphid effectors specifically function when expressed in host species, and feature activities that benefit their corresponding aphid species.

scholarly journals HDAC4, a Human Histone Deacetylase Related to Yeast HDA1, Is a Transcriptional Corepressor

1999 ◽  
Vol 19 (11) ◽  
pp. 7816-7827 ◽  
Author(s):  
Audrey H. Wang ◽  
Nicholas R. Bertos ◽  
Marko Vezmar ◽  
Nadine Pelletier ◽  
Milena Crosato ◽  
...  
Keyword(s):  
Gene Expression ◽  
Histone Deacetylase ◽  
Sequence Similarity ◽  
Functional Characterization ◽  
Small Region ◽  
Chromosome Band ◽  
Terminal Domain ◽  
Its Gene ◽  
Repression Domain

ABSTRACT Histone acetylation plays an important role in regulating chromatin structure and thus gene expression. Here we describe the functional characterization of HDAC4, a human histone deacetylase whose C-terminal part displays significant sequence similarity to the deacetylase domain of yeast HDA1. HDAC4 is expressed in various adult human tissues, and its gene is located at chromosome band 2q37. HDAC4 possesses histone deacetylase activity intrinsic to its C-terminal domain. When tethered to a promoter, HDAC4 represses transcription through two independent repression domains, with repression domain 1 consisting of the N-terminal 208 residues and repression domain 2 containing the deacetylase domain. Through a small region located at its N-terminal domain, HDAC4 interacts with the MADS-box transcription factor MEF2C. Furthermore, HDAC4 and MEF2C individually upregulate but together downmodulate c-jun promoter activity. These results suggest that HDAC4 interacts with transcription factors such as MEF2C to negatively regulate gene expression.

scholarly journals Harnessing a Transient Gene Expression System in Nicotiana benthamiana to Explore Plant Agrochemical Transporters

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 524
Author(s):  
Bingqi Wu ◽  
Zhiting Chen ◽  
Xiaohui Xu ◽  
Ronghua Chen ◽  
Siwei Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transient Expression ◽  
Nicotiana Benthamiana ◽  
Heterologous Gene Expression ◽  
Expression System ◽  
Functional Characterization ◽  
Transient Gene Expression ◽  
High Mobility ◽  
Gene Expression System

Functional characterization of plant agrichemical transporters provided an opportunity to discover molecules that have a high mobility in plants and have the potential to increase the amount of pesticides reaching damage sites. Agrobacterium-mediated transient expression in tobacco is simple and fast, and its protein expression efficiency is high; this system is generally used to mediate heterologous gene expression. In this article, transient expression of tobacco nicotine uptake permease (NtNUP1) and rice polyamine uptake transporter 1 (OsPUT1) in Nicotiana benthamiana was performed to investigate whether this system is useful as a platform for studying the interactions between plant transporters and pesticides. The results showed that NtNUP1 increases nicotine uptake in N. benthamiana foliar discs and protoplasts, indicating that this transient gene expression system is feasible for studying gene function. Moreover, yeast expression of OsPUT1 apparently increases methomyl uptake. Overall, this method of constructing a transient gene expression system is useful for improving the efficiency of analyzing the functions of plant heterologous transporter-encoding genes and revealed that this system can be further used to study the functions of transporters and pesticides, especially their interactions.

scholarly journals Functional Characterization of a Novel Promoter Element Required for an Innate Immune Response in Drosophila

2003 ◽  
Vol 23 (22) ◽  
pp. 8272-8281 ◽  
Author(s):  
Hanna Uvell ◽  
Ylva Engström
Keyword(s):  
Gene Expression ◽  
Antimicrobial Peptide ◽  
Functional Characterization ◽  
Binding Activity ◽  
Innate Immune ◽  
Site Directed Mutagenesis ◽  
Promoter Element ◽  
Peptide Gene ◽  
Inducible Genes

ABSTRACT Innate immune reactions are crucial processes of metazoans to protect the organism against overgrowth of faster replicating microorganisms. Drosophila melanogaster is a precious model for genetic and molecular studies of the innate immune system. In response to infection, the concerted action of a battery of antimicrobial peptides ensures efficient killing of the microbes. The induced gene expression relies on translocation of the Drosophila Rel transcription factors Relish, Dif, and Dorsal to the nucleus where they bind to κB-like motifs in the promoters of the inducible genes. We have identified another putative promoter element, called region 1 (R1), in a number of antimicrobial peptide genes. Site-directed mutagenesis of the R1 site diminished Cecropin A1 (CecA1) expression in transgenic Drosophila larvae and flies. Infection of flies induced a nuclear R1-binding activity that was unrelated to the κB-binding activity in the same extracts. Although the R1 motif was required for Rel protein-mediated CecA1 expression in cotransfection experiments, our data argue against it being a direct target for the Drosophila Rel proteins. We propose that the R1 and κB motifs are targets for distinct regulatory complexes that act in concert to promote high levels of antimicrobial peptide gene expression in response to infection.

Novel biochemical and functional insights into nuclear Ca2+ transport through IP3Rs and RyRs in osteoblasts

2000 ◽  
Vol 278 (5) ◽  
pp. F784-F791 ◽  
Author(s):  
Olugbenga A. Adebanjo ◽  
Gopa Biswas ◽  
Baljit S. Moonga ◽  
Hindupur K. Anandatheerthavarada ◽  
Li Sun ◽  
...  
Keyword(s):  
Gene Expression ◽  
Nuclear Envelope ◽  
Nuclear Membrane ◽  
Ryanodine Receptors ◽  
Functional Characterization ◽  
Inositol Trisphosphate Receptors ◽  
Nuclear Membranes ◽  
Sds Page ◽  
Direct Regulation

We report the first biochemical and functional characterization of inositol trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs) in the nuclear membrane of bone-forming (MC3T3-E1) osteoblasts. Intact nuclei fluoresced intensely with anti-RyR (Ab34) and anti-IP3R (Ab40) antisera in a typically peripheral nuclear membrane pattern. Isolated nuclear membranes were next subjected to SDS-PAGE and blotted with isoform-specific anti-receptor antisera, notably Ab40, anti-RyR-1, anti-RyR-2 (Ab129), and anti-RyR-3 (Ab180). Only anti-RyR-1 and Ab40 showed bands corresponding, respectively, to full-length RyR-1 (∼500 kDa) and IP3R-1 (∼250 kDa). Band intensity was reduced by just ∼20% after brief tryptic proteolysis of intact nuclei; this confirmed that isolated nuclear membranes were mostly free of endoplasmic reticular contaminants. Finally, the nucleoplasmic Ca2+ concentration ([Ca2+]np) was measured in single nuclei by using fura-dextran. The nuclear envelope was initially loaded with Ca2+ via Ca2+-ATPase activation (1 mM ATP and ∼100 nM Ca2+). Adequate Ca2+ loading was next confirmed by imaging the nuclear envelope (and nucleoplasm). Exposure of Ca2+-loaded nuclei to IP3 or cADP ribose resulted in a rapid and sustained [Ca2+]np elevation. Taken together, the results provide complementary evidence for nucleoplasmic Ca2+ influx in osteoblasts through nuclear membrane-resident IP3Rs and RyRs. Our findings may conceivably explain the direct regulation of osteoblastic gene expression by hormones that use the IP3-Ca2+pathway.

Sign in / Sign up

Export Citation Format

Share Document