Secretory Peptides as Bullets: Effector Peptides from Pathogens against Antimicrobial Peptides from Soybean

Ku, Yee-Shan; Cheng, Sau‐Shan; Gerhardt, Aisha; Cheung, Ming-Yan; Contador, Carolina A.; Poon, Lok-Yiu Winnie; Lam, Hon‐Ming

doi:10.3390/ijms21239294

Cited by 14 publications

(11 citation statements)

References 161 publications

(290 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Neither of the two effectors have any known enzyme-like domains. T2REP is predicted to have a positive charge with an even number of cysteines at the C-terminus (https:// aps.unmc.edu/predi ction), like many antimicrobial peptides and peptide effectors (Ku et al, 2020;Lazzaro et al, 2020). Thus, T2REP could potentially interfere with the host membranes.…”

Section: Effectors T1rep and T2rep Are Regulated Explicitly By The Ea...mentioning

confidence: 99%

Characterization of two infection‐induced transcription factors of Magnaporthe oryzae reveals their roles in regulating early infection and effector expression

Cao

Chen

Xie

et al. 2022

Molecular Plant Pathology

View full text Add to dashboard Cite

The initial stage of rice blast fungus, Magnaporthe oryzae, infection, before 36 h postinoculation, is a critical timespan for deploying pathogen effectors to overcome the host's defences and ultimately cause the disease. However, how this process is regulated at the transcription level remains largely unknown. This study functionally characterized two M. oryzae Early Infection-induced Transcription Factor genes (MOEITF1 and MOEITF2) and analysed their roles in this process. Target gene deletion and mutant phenotype analysis showed that the mutants Δmoeitf1 and Δmoeitf2 were only defective for infection growth but not for vegetative growth, asexual/sexual sporulation, conidial germination, and appressoria formation. Gene expression analysis of 30 putative effectors revealed that most effector genes were down-regulated in mutants, implying a potential regulation by the transcription factors. Artificial overexpression of two severely down-regulated effectors, T1REP and T2REP, in the mutants partially restored the pathogenicity of Δmoeitf1 and Δmoeitf2, respectively, indicating that these are directly regulated. Yeast one-hybrid assay and electrophoretic mobility shift assay indicated that Moeitf1 specifically bound the T1REP promoter and Moeitf2 specifically bound the T2REP promoter. Both T1REP and T2REP were predicted to be secreted during infection, and the mutants of T2REP were severely reduced in pathogenicity.Our results indicate crucial roles for the fungal-specific Moeitf1 and Moeitf2 transcription factors in regulating an essential step in M. oryzae early establishment after penetrating rice epidermal cells, highlighting these as possible targets for disease control.

show abstract

Section: Effectors T1rep and T2rep Are Regulated Explicitly By The Ea...mentioning

confidence: 99%

Characterization of two infection‐induced transcription factors of Magnaporthe oryzae reveals their roles in regulating early infection and effector expression

Cao

Chen

Xie

et al. 2022

Molecular Plant Pathology

View full text Add to dashboard Cite

show abstract

“…Another example of a bacterial protein C-terminal fragment (~7 fold more abundant in the mutant sample in LCMS TDP, adjusted p-value 5E-5) is included in Supplementary Figure S20. Given the potential role of secreted peptides in signaling in rhizosphere and root development, (Matsuzaki et al, 2010;Ku et al, 2020;Xiang et al, 2021), some of these proteoforms may have biological implications in symbiosis and/or immune response.…”

Section: Msi Maps Spatial Distribution Of Proteoforms In Tissue Sectionsmentioning

confidence: 99%

Discovery top-down proteomics in symbiotic soybean root nodules

Zhou

Fulcher²,

Zemaitis³

et al. 2022

Front. Anal. Sci.

View full text Add to dashboard Cite

Proteomic methods have been widely used to study proteins in complex biological samples to understand biological molecular mechanisms. Most well-established methods (known as bottom-up proteomics, BUP) employ an enzymatic digestion step to cleave intact proteins into smaller peptides for liquid chromatography (LC) mass spectrometry (MS) detection. In contrast, top-down proteomics (TDP) directly characterizes intact proteins including all possible post-translational modifications (PTMs), thus offering unique insights into proteoform biology where combinations of individual PTMs may play important roles. We performed TDP on soybean root nodules infected by the symbiotic Bradyrhizobium japonicum in both the wildtype bacterium and a nifH- mutant, which lacks the ability to fix nitrogen in the soybean root nodule. TDP captured 1648 proteoforms derived from 313 bacterial genes and 178 soybean genes. Leghemoglobin, the most abundant protein in the sample, existed in many truncated proteoforms. Interestingly, these truncated proteoforms were considerably more abundant in the wildtype relative to the nifH- mutant, implicating protease activity as an important factor in nitrogen fixation. Proteoforms with various PTMs and combinations thereof were identified using an unrestricted open modification search. This included less common PTMs such as myristoylation, palmitoylation, cyanylation, and sulfation. In parallel, we collected high resolution MS imaging (MSI) data of intact proteins and biopolymers (<20 kDa due to current technical limitations) from sections of the soybean root nodules using matrix-assisted laser desorption/ionization (MALDI) coupled to high resolution Orbitrap. Several detected proteoforms exhibited unique spatial distributions inside the infection zone and cortex, suggesting functional compartmentalization in these regions. A subset of peaks from the MALDI-MSI were assigned to proteoforms detected in TDP LCMS data based on matching accurate masses. Many of the proteins detected in both LCMS and MALDI-MSI are currently uncharacterized in UniProt: the PTM and spatial information presented here will be valuable in understanding their biological functions. Taken together, our study demonstrates how untargeted TDP approach can provide unique insights into plant proteoform biology. On-going technology developments are expected to further improve TDP coverage for more comprehensive high-throughput analysis of proteoforms.

show abstract

“…Upon pathogen infection, plants perceive the signal elicited by the secretions from the pathogens known as pathogen-associated molecular patterns (PAMPs) or microbe-associated molecular patterns (MAMPs; Medzhitov and Janeway, 1997 ), through pattern recognition receptors (PRRs). The signal perception triggers a series of defense responses including the generation of reactive oxygen species (ROS), fluctuations in the cellular calcium level, activation of proteins, such as mitogen-activated protein kinases (MAPKs), and GTP-binding proteins (G-proteins), and synthesis of stress hormones such as jasmonic acid (JA), salicylic acid (SA), and ethylene ( Zhang and Zhou, 2010 ; Li et al, 2016b ; Ku et al, 2020 ). These signaling events regulate the expressions of defense-related genes such as Pathogenesis-Related ( PR ) genes ( Zhang and Zhou, 2010 ; Li et al, 2016b ; Ku et al, 2020 ).…”

Section: Introductionmentioning

confidence: 99%

Identification of stably expressed reference genes for expression studies in Arabidopsis thaliana using mass spectrometry-based label-free quantification

Cheng

Ku²,

Cheung³

et al. 2022

Front. Plant Sci.

Self Cite

View full text Add to dashboard Cite

Arabidopsis thaliana has been used regularly as a model plant in gene expression studies on transcriptional reprogramming upon pathogen infection, such as that by Pseudomonas syringae pv. tomato DC3000 (Pst DC3000), or when subjected to stress hormone treatments including jasmonic acid (JA), salicylic acid (SA), and abscisic acid (ABA). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) has been extensively employed to quantitate these gene expression changes. However, the accuracy of the quantitation is largely dependent on the stability of the expressions of reference genes used for normalization. Recently, RNA sequencing (RNA-seq) has been widely used to mine stably expressed genes for use as references in RT-qPCR. However, the amplification step in RNA-seq creates an intrinsic bias against those genes with relatively low expression levels, and therefore does not provide an accurate quantification of all expressed genes. In this study, we employed mass spectrometry-based label-free quantification (LFQ) in proteomic analyses to identify those proteins with abundances unaffected by Pst DC3000 infection. We verified, using RT-qPCR, that the levels of their corresponding mRNAs were also unaffected by Pst DC3000 infection. Compared to commonly used reference genes for expression studies in A. thaliana upon Pst DC3000 infection, the candidate reference genes reported in this study generally have a higher expression stability. In addition, using RT-qPCR, we verified that the mRNAs of the candidate reference genes were stably expressed upon stress hormone treatments including JA, SA, and ABA. Results indicated that the candidate genes identified here had stable expressions upon these stresses and are suitable to be used as reference genes for RT-qPCR. Among the 18 candidate reference genes reported in this study, many of them had greater expression stability than the commonly used reference genes, such as ACT7, in previous studies. Here, besides proposing more appropriate reference genes for Arabidopsis expression studies, we also demonstrated the capacity of mass spectrometry-based LFQ to quantify protein abundance and the possibility to extend protein expression studies to the transcript level.

show abstract

Secretory Peptides as Bullets: Effector Peptides from Pathogens against Antimicrobial Peptides from Soybean

Cited by 14 publications

References 161 publications

Characterization of two infection‐induced transcription factors of Magnaporthe oryzae reveals their roles in regulating early infection and effector expression

Characterization of two infection‐induced transcription factors of Magnaporthe oryzae reveals their roles in regulating early infection and effector expression

Discovery top-down proteomics in symbiotic soybean root nodules

Identification of stably expressed reference genes for expression studies in Arabidopsis thaliana using mass spectrometry-based label-free quantification

Contact Info

Product

Resources

About