scholarly journals Allelic variants of the NLR protein Rpi-chc1 differentially recognise members of the Phytophthora infestans PexRD12/31 effector superfamily through the leucine-rich repeat domain

2020 ◽  
Author(s):  
Daniel Monino-Lopez ◽  
Maarten Nijenhuis ◽  
Linda Kodde ◽  
Sophien Kamoun ◽  
Hamed Salehian ◽  
...  
Keyword(s):  
Phytophthora Infestans ◽  
Coiled Coil ◽  
Effector Proteins ◽  
Solanum Chacoense ◽  
List Type ◽  
Leucine Rich Repeat ◽  
Allelic Variants ◽  
Rxlr Effectors ◽  
The Difference ◽  
Effector Recognition

SummaryPhytophthora infestans is a pathogenic oomycete that causes the infamous potato late blight disease. Resistance (R) genes from diverse Solanum species encode intracellular receptors that recognize P. infestans RXLR effector proteins and provide effective defence responses. To deploy these R genes in a durable fashion in agriculture, we need to understand the mechanism of effector recognition and the way the pathogen evades recognition.We cloned sixteen allelic variants of the Rpi-chc1 gene from Solanum chacoense and other Solanum species, and identified the cognate P. infestans RXLR effectors. These tools were used to study receptor-ligand interactions and co-evolution.Functional and non-functional alleles of Rpi-chc1 encode Coiled-Coil-Nucleotide Binding-Leucine-Rich-Repeat (CNL) proteins. Rpi-chc1.1 recognised multiple PexRD12 (AVRchc1.1) proteins while Rpi-chc1.2 recognised multiple PexRD31 (AVRchc1.2) proteins, both from the PexRD12/31 superfamily. Domain swaps between Rpi-chc1.1 and Rpi-chc1.2 revealed that overlapping subdomains in the LRR were responsible for the difference in effector recognition.This study showed that Rpi-chc1.1 and Rpi-chc1.2, evolved to recognize distinct members of the same PexRD12/31 effector family via the LRR domain. The biased distribution of polymorphisms suggests that exchange of LRRs during host-pathogen co-evolution can lead to novel recognition specificities. These insights will help future strategies to breed for durable resistant varieties.

scholarly journals Rpi-amr3 confers resistance to multiple Phytophthora species by recognizing a conserved RXLR effector

2021 ◽  
Author(s):  
Xiao Lin ◽  
Andrea Olave-Achury ◽  
Robert Heal ◽  
Kamil Witek ◽  
Hari S. Karki ◽  
...  
Keyword(s):  
Late Blight ◽  
Phytophthora Infestans ◽  
Plant Pathogens ◽  
Nucleotide Binding ◽  
Phytophthora Species ◽  
Crop Plants ◽  
Leucine Rich Repeat ◽  
Nucleotide Binding Domain ◽  
Rxlr Effectors ◽  
Rxlr Effector

Diverse pathogens from the genus Phytophthora cause disease and reduce yields in many crop plants. Although many Resistance to Phytophthora infestans (Rpi) genes effective against potato late blight have been cloned, few have been cloned against other Phytophthora species. Most Rpi genes encode nucleotide-binding domain, leucine-rich repeat- containing (NLR) proteins, that recognize RXLR effectors. However, whether NLR proteins can recognize RXLR effectors from multiple different Phytophthora pathogens has rarely been investigated. Here, we report the effector AVRamr3 from P. infestans that is recognized by Rpi-amr3 from S. americanum. We show here that AVRamr3 is broadly conserved in many different Phytophthora species, and that recognition of AVRamr3 homologs enables resistance against multiple Phytophthora pathogens, including P. parasitica and P. palmivora. Our findings suggest a novel path to identifying R genes against important plant pathogens.

scholarly journals NADase and now Ca2+ channel, what else to learn about plant NLRs?

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Li Wan ◽  
Zuhua He
Keyword(s):  
Cell Death ◽  
Interleukin 1 ◽  
Coiled Coil ◽  
Defense Responses ◽  
Effector Proteins ◽  
Leucine Rich Repeat ◽  
Downstream Signaling ◽  
Pathogen Effectors ◽  
Activate Cell ◽  
Insight Into

AbstractPlant intracellular immune receptors known as NLR (Nucleotide-binding Leucine-rich repeat, NB-LRR) proteins confer resistance and cause cell death upon recognition of cognate effector proteins from pathogens. Plant NLRs contain a variable N-terminal domain: a Toll/interleukin-1 receptor (TIR) domain or a coiled-coil (CC) domain or an RPW8 (Resistance to Powdery Mildew 8)-like CC (CCR) domain. TIR-NLR, CC-NLR and CCR-NLR are known as TNL, CNL and RNL, respectively. TNLs and CNLs recognize pathogen effectors to activate cell death and defense responses, thus are regarded as sensor NLRs. RNLs are required downstream of TNLs to activate cell death and defense responses, thus are regarded as helper NLRs. Previous studies show that some TNLs form tetrameric resistosome as NAD+ cleaving enzymes to transduce signal, while some CNLs form pentameric resistosome with undefined biochemical function. Two recent breakthrough studies show that activated CNL and RNL function as Ca2+ channel to cause cell death and defense responses and provide a completely new insight into the downstream signaling events of CNL and TNL pathways.

scholarly journals Phytophthora infestans Sporangia Produced in Culture and on Tomato Leaflet Lesions Show Marked Differences in Indirect Germination Rates, Aggressiveness, and Global Transcription Profiles

2019 ◽  
Vol 32 (5) ◽  
pp. 515-526 ◽  
Author(s):  
William E. Fry ◽  
Sean P. Patev ◽  
Kevin L. Myers ◽  
Kan Bao ◽  
Zhangjun Fei
Keyword(s):  
Phytophthora Infestans ◽  
Differentially Expressed Genes ◽  
Differentially Expressed ◽  
Rna Seq ◽  
Moist Chamber ◽  
Field Isolates ◽  
Rxlr Effectors ◽  
Transcription Profiles ◽  
Independent Field ◽  
Pure Cultures

Sporangia of Phytophthora infestans from pure cultures on agar plates are typically used in lab studies, whereas sporangia from leaflet lesions drive natural infections and epidemics. Multiple assays were performed to determine if sporangia from these two sources are equivalent. Sporangia from plate cultures showed much lower rates of indirect germination and produced much less disease in field and moist-chamber tests. This difference in aggressiveness was observed whether the sporangia had been previously incubated at 4°C (to induce indirect germination) or at 21°C (to prevent indirect germination). Furthermore, lesions caused by sporangia from plates produced much less sporulation. RNA-Seq analysis revealed that thousands of the >17,000 P. infestans genes with a RPKM (reads per kilobase of exon model per million mapped reads) >1 were differentially expressed in sporangia obtained from plate cultures of two independent field isolates compared with sporangia of those isolates from leaflet lesions. Among the significant differentially expressed genes (DEGs), putative RxLR effectors were overrepresented, with almost half of the 355 effectors with RPKM >1 being up- or downregulated. DEGs of both isolates include nine flagellar-associated genes, and all were down-regulated in plate sporangia. Ten elicitin genes were also detected as DEGs in both isolates, and nine (including INF1) were up-regulated in plate sporangia. These results corroborate previous observations that sporangia produced from plates and leaflets sometimes yield different experimental results and suggest hypotheses for potential mechanisms. We caution that use of plate sporangia in assays may not always produce results reflective of natural infections and epidemics.

scholarly journals Characterisation of an antimicrobial and phytotoxic ribonuclease secreted by the fungal wheat pathogen Zymoseptoria tritici

2017 ◽  
Author(s):  
Graeme J. Kettles ◽  
Carlos Bayon ◽  
Caroline A. Sparks ◽  
Gail Canning ◽  
Kostya Kanyuka ◽  
...  
Keyword(s):  
Expression Pattern ◽  
Effector Proteins ◽  
Yeast Cells ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
List Type ◽  
Expression Systems ◽  
Zymoseptoria Tritici ◽  
Loop Region

Abstract-The fungus Zymoseptoria tritici is the causal agent of Septoria Tritici Blotch (STB) disease of wheat leaves. Z. tritici secretes many functionally uncharacterised effector proteins during infection. Here we characterised a secreted ribonuclease (Zt6) with an unusual biphasic expression pattern.-Transient expression systems were used to characterise Zt6, and mutants thereof, in both host and non-host plants. Cell-free protein expression systems monitored impact of Zt6 protein on functional ribosomes, and in vitro assays of cells treated with recombinant Zt6 determined toxicity against bacteria, yeasts and filamentous fungi.-We demonstrated that Zt6 is a functional ribonuclease and that phytotoxicity is dependent on both the presence of a 22-amino acid N-terminal “loop” region and its catalytic activity. Zt6 selectively cleaves both plant and animal rRNA species, and is toxic to wheat, tobacco, bacterial and yeast cells but not to Z. tritici itself.-Zt6 is the first Z. tritici effector demonstrated to have a likely dual functionality. The expression pattern of Zt6 and potent toxicity towards microorganisms suggests that whilst it may contribute to the execution of wheat cell death, it is also likely to have an important secondary function in antimicrobial competition and niche protection.

scholarly journals The association of neurofibromatosis and autism symptomatology is confounded by behavioral problems

2019 ◽  
Author(s):  
Hadley Morotti ◽  
Sarah Mastel ◽  
Kory Keller ◽  
Rebecca A. Barnard ◽  
Trevor Hall ◽  
...  
Keyword(s):  
Adaptive Behavior ◽  
Behavioral Problems ◽  
Neurofibromatosis Type ◽  
Social Responsiveness ◽  
List Type ◽  
Autism Symptoms ◽  
Simons Simplex Collection ◽  
Autism Symptomatology ◽  
The Difference ◽  
Clinically Significant

AbstractAimto evaluate if autism symptoms and diagnoses are raised in children with neurofibromatosis type 1 (NF1), to which levels, and to determine if co-occurring symptomatology accounts for this elevation.MethodWe interrogated our hospital electronic medical records. We collected parental reports of autism symptomatology, adaptive behavior, and co-occurring behavioral and emotional problems on a subsample of 45 children (9 years 2 months, 49% male). Age- and sex-matched controls with (N=180) or without ASD (N=180) were drawn from the Simons Simplex Collection and compared cross-sectionally to participants with NF1.ResultsDiagnoses of ADHD (8.8%), not of ASD (2.1%), were raised among 968 children with NF1 identified through electronic search. Mean Social Responsiveness Score (55.9) was below the cut-off of 60 for significant autism symptoms. Participants with NF1 had significantly more autism and behavioral symptoms than typically developing (TD) controls, and significantly less than controls with autism, with one exception: ADHD symptom levels were similar to those of autistic controls. When emotional, ADHD, and communication scores were covaried, the difference between participants with NF1 and TD controls disappeared almost entirely.InterpretationOur results do not support an association between NF1 and autism, both at the symptom and disorder levels.What this paper addsDiagnoses of ADHD, not of ASD, were raised among children with NF1.Increases in autism symptoms did not reach clinically significant thresholds.Co-occurring ADHD symptoms accounted for increased autism questionnaire scores.Adaptive behavior in NF1 participants showed normal socialization but lower communication proficiency.

scholarly journals Effects of long-term closed environment on human saliva microbiota and salivary cytokines

2020 ◽  
Author(s):  
Yinzhen Zhu ◽  
Zikai Hao ◽  
Yuming Fu ◽  
Jianlou Yang ◽  
Chen Dong ◽  
...  
Keyword(s):  
Human Saliva ◽  
Mucosal Barrier ◽  
Future Research ◽  
Controlled Environment ◽  
List Type ◽  
Tnf Α ◽  
Normal Environment ◽  
The Difference ◽  
Sharing Space ◽  
The Impact

AbstractCompared with the normal environment, the microbiota in controlled closed cabins such as space capsules, Lunar/Mars bases have changed. To ensure the health of crewmembers, it’s necessary to understand the effects of these changes on human symbiotic microorganisms and immunity. In this study, the experimental platform “Lunar Palace 1” with a similar closed and controlled environment was used to research the effects of changed microbial exposure on human saliva microbiota and salivary cytokines. This paper studied on four crewmembers who participated in the third phase of the “Lunar Palace 365” experiment, analyzing the dynamic changes of saliva microbiota and salivary cytokines, and further studying the correlation between salivary cytokines and highly abundant genera. According to our data, the crewmembers’ saliva microbiota and salivary cytokines fluctuated smoothly throughout the whole experiment. Although a part of microbes increased or decreased some times, they recovered quickly after leaving the controlled environment. The level of IL-6, IL-10 and TNF-α in crewmembers’ saliva decreased from normal environment to the controlled environment, showing reduced levels of oral inflammatory response in crewmembers. In addition, although there were significant individual differences in crewmembers’ saliva microbiota, sharing living space reduced the difference. Furthermore, the level of TNF-α showed a consistent positive correlation with the abundance of Actinomyces and Rothia in the controlled environment, indicating healthy individuals’ oral mucosal barrier may be sensitive to changes in saliva microbiota. According to the result, semi-sterile environments in controlled closed cabins didn’t cause persistent changes in human saliva microbiota and oral immunity. Besides, it provides a new idea for future research on the impact of the controlled environment on crewmembers health, and provides guidance for studying the effect of semi-sterile environments on human immunity based on saliva microbiota.Key pointsSaliva microbes kept stable for individual but got convergent when sharing space;The level of salivary cytokines reduced after entering the controlled environment;There were complex correlations between salivary cytokines and saliva microbes;The crewmembers adapt well to the controlled environment.

scholarly journals Recognition of Phytophthora infestans in potato (Solanum tuberosum L.): Scr74 gene as an example

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Mulusew Kassa Bitew ◽  
Emmanouil Domazakis
Keyword(s):  
Amino Acid ◽  
Phytophthora Infestans ◽  
Solanum Tuberosum L ◽  
Effector Proteins ◽  
Wild Potato ◽  
Detached Leaf ◽  
Polymorphic Genes ◽  
Cysteine Rich Protein ◽  
In The Wild ◽  
Polymorphic Gene

AbstractPhytophthora infestans is the causal agent of late blight, the most devastating disease of potato worldwide. The P. infestans genome encodes potentially polymorphic genes that evolve continually to evade the recognition of plant R genes, though it has hundreds of predicted and conserved effector proteins recognised by the plant. The gene Scr74 encodes a predicted 74-amino acid secreted cysteine-rich protein belonging to a highly polymorphic gene family within P. infestans. This study screened the recognition of Scr74 genes in wild potato genotypes from August 2013 to January 2014 in the Plant Breeding Laboratory of Wageningen University, the Netherlands. To identify the recognition of the Scr74 gene, we grew potato genotypes in the green house for PVX assays, detached leaf assays and molecular work. Twenty-seven good-quality sequences of the Scr74 gene variant with a length of 74 amino acids were found and more frequent amino acid variation was detected on the mature protein. Seventeen Scr74 constructs were identified as diversified and two effectors were strongly recognised by wild S. verrucosum genotypes via effectoromics from the PVX assay. A strong plant cell death hypersensitive response (HR) was recorded on wild S. verrucosum and S. tuberosum genotypes from the detached leaf assay. This recognition seems to be a useful indicator for the presence of a resistance gene (s) to the polymorphic effectors of P. infestans (as it has seen on Scr74 gene) in the wild potato genotypes.

Czech and Slovak Society

1993 ◽  
Vol 28 (4) ◽  
pp. 479-495 ◽  
Author(s):  
Jiří Musil
Keyword(s):  
Structural Analysis ◽  
List Type ◽  
Cultural Institutions ◽  
Definition Of The Situation ◽  
Czechoslovak Society ◽  
Slovak Society ◽  
The Difference ◽  
Definition Of ◽  
Czech Lands ◽  
Political Economic

THIS STUDY IS ONE OF COMPARATIVE STRUCTURAL ANALYSIS deliberately avoiding a sociological definition of the situation. It is assumed that two societies had existed in Czechoslovakia for some time and the difference between them, and possible analogies, are examined. There is also an assumption that the division of Czechoslovakia occurred especially because ‘Czechoslovak society’ as such had not yet been established; this was in spite of the fact that the two societies, at the time of the split, had substantially more in common than they had had at the time of Czechoslovakia's formation. There exists the view, which we want to verify, that during the decline of the federation the following factors were significant:1. The differences in economic, social, cultural and dispositional structures;2. The asynchronous and differing processes of modernization in both societies;3. The different consequences of the formation of societies of Soviet type in the Czech Lands in Slovakia;4. The differing processes for rectification of political, economic and cultural institutions in both republics after November 1989.

Modeling the Effects of Crop Rotation and Tillage on Sugarbeet Yield and Soil Nitrate Using RZWQM2

2021 ◽  
Vol 64 (2) ◽  
pp. 461-474
Author(s):  
Mohammad J. Anar ◽  
Zhulu Lin ◽  
Liwang Ma ◽  
Amitava Chatterjee
Keyword(s):  
Soil Water ◽  
Crop Rotation ◽  
Crop Yield ◽  
Crop Rotations ◽  
Biofuel Production ◽  
List Type ◽  
Soil Nitrate ◽  
N Losses ◽  
The Difference ◽  
Tillage Operations

HighlightsFour crop growth modules in RZWQM2 were calibrated for four sugarbeet rotation sequences.Sugarbeet following wheat had a slightly higher yield (3% to 6.5%).Moldboard plow increased sugarbeet yield by 1% to 2%.The difference in N losses under different crop rotations and tillage operations was negligible.Abstract. Sugarbeet (Beta vulgaris) is considered to be one of the most viable alternatives to corn for biofuel production as it may be qualified as the feedstock for advanced biofuels (reducing greenhouse gas emission by 50%) under the Energy Independence and Security Act (EISA) of 2007. Because sugarbeet production is affected by crop rotation and tillage through optimal use of soil water and nutrients, simulation of these effects will help in making proper management decisions. In this study, the CSM-CERES-Beet, CSM-CERES-Maize, CROPSIM-Wheat, and CROPGRO-Soybean models included in the RZWQM2 were calibrated against experimental field data of crop yield, soil water, and soil nitrate from the North Dakota State University Carrington Research Extension Center from 2014 to 2016. The models performed reasonably well in simulating crop yield, soil water, and nitrate (rRMSE = 0.055 to 2.773, d = 0.541 to 0.997). Simulation results identified a non-significant effect of crop rotation on sugarbeet yield, although sugarbeets following wheat resulted in 3% to 6.5% higher yields compared to other crops. Net mineralization and N uptake rates were slightly higher when sugarbeets followed wheat compared to the other crops. Seasonal N and water mass balances also showed lower N and water stresses when sugarbeets followed wheat. The effects of tillage operations on sugarbeet yield were also non-significant. The difference in the N losses to runoff and drainage from the sugarbeet fields under different crop rotations and tillage operations was negligible. As sugarbeet production may be expanded into nontraditional planting areas in the Red River Valley due to potential demand for biofuel production, our findings will help to assess the associated environmental impacts and identify suitable crop rotations and management scenarios in the region. Keywords: Biofuel, Crop rotation, RZWQM2, Sugarbeet, Tillage.

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