Faculty Opinions recommendation of Integration of danger peptide signals with herbivore-associated molecular pattern signaling amplifies anti-herbivore defense responses in rice.

Abstract Background Avr-Pita was the first effector identified in the blast fungus (Magnaporthe oryzae)–rice (Oryza sativa) pathosystem. However, the molecular mechanism underlying its effects on the host plant has remained a long-standing mystery. Results Here, we report that ectopically expressing Avr-Pita in rice enhances susceptibility to M. oryzae and suppresses pathogen-associated molecular pattern (PAMP)-triggered defense responses. Avr-Pita targets the host mitochondria and interacts with the cytochrome c oxidase (COX) assembly protein OsCOX11, a key regulator of mitochondrial reactive oxygen species (ROS) metabolism in rice. Overexpressing Avr-Pita or OsCOX11 increased COX activity and decreased ROS accumulation triggered by the fungal PAMP chitin. OsCOX11-overexpressing plants showed increased susceptibility to M. oryzae, whereas OsCOX11-knockdown plants showed resistance to M. oryzae. Conclusions Taken together, these findings suggest that the fungal pathogen M. oryzae delivers the effector Avr-Pita to the host plant, where it enhances COX activity thus decreasing ROS accumulation. Therefore, this effector suppresses host innate immunity by perturbing ROS metabolism in the mitochondria.

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The Effect of Transcription Factor MYB14 on Defense Mechanisms in Vitis quinquangularis-Pingyi

International Journal of Molecular Sciences ◽

10.3390/ijms21030706 ◽

2020 ◽

Vol 21 (3) ◽

pp. 706 ◽

Cited By ~ 5

Author(s):

Yangyang Luo ◽

Qingyang Wang ◽

Ru Bai ◽

Ruixiang Li ◽

Lu Chen ◽

...

Keyword(s):

Transcription Factor ◽

Nicotiana Benthamiana ◽

Defense Mechanisms ◽

Qualitative Difference ◽

Defense Responses ◽

Molecular Pattern ◽

Effector Triggered Immunity ◽

Pathogen Associated Molecular Pattern ◽

Basal Immunity ◽

Stilbene Biosynthesis

In the current study, we identified a transcription factor, MYB14, from Chinese wild grape, Vitis quinquangularis-Pingyi (V. quinquangularis-PY), which could enhance the main stilbene contents and expression of stilbene biosynthesis genes (StSy/RS) by overexpression of VqMYB14. The promoter of VqMYB14 (pVqMYB14) was shown to be induced as part of both basal immunity (also called pathogen-associated molecular pattern (PAMP)-triggered immunity, PTI) and effector-triggered immunity (ETI), triggered by the elicitors flg22 and harpin, respectively. This was demonstrated by expression of pVqMYB14 in Nicotiana benthamiana and Vitis. We identified sequence differences, notably an 11 bp segment in pVqMYB14 that is important for the PTI/ETI, and particularly for the harpin-induced ETI response. In addition, we showed that activation of the MYB14 promoter correlates with differences in the expression of MYB14 and stilbene pattern induced by flg22 and harpin. An experimental model of upstream signaling in V. quinquangularis-PY is presented, where early defense responses triggered by flg22 and harpin partially overlap, but where the timing and levels differ. This translates into a qualitative difference with respect to patterns of stilbene accumulation.

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The Role of Peptide Signals Hidden in the Structure of Functional Proteins in Plant Immune Responses

International Journal of Molecular Sciences ◽

10.3390/ijms20184343 ◽

2019 ◽

Vol 20 (18) ◽

pp. 4343 ◽

Cited By ~ 3

Author(s):

Irina Lyapina ◽

Anna Filippova ◽

Igor Fesenko

Keyword(s):

Immune Responses ◽

Defense Responses ◽

Innate Immune ◽

Functional Protein ◽

Diverse Range ◽

Peptide Signals ◽

Plant Pathogen Interactions ◽

Molecular Patterns ◽

Damage Associated Molecular Patterns

Plants have evolved a sophisticated innate immune system to cope with a diverse range of phytopathogens and insect herbivores. Plasma-membrane-localized pattern recognition receptors (PRRs), such as receptor-like kinases (RLK), recognize special signals, pathogen- or damage-associated molecular patterns (PAMPs or DAMPs), and trigger immune responses. A growing body of evidence shows that many peptides hidden in both plant and pathogen functional protein sequences belong to the group of such immune signals. However, the origin, evolution, and release mechanisms of peptide sequences from functional and nonfunctional protein precursors, known as cryptic peptides, are largely unknown. Various special proteases, such as metacaspase or subtilisin-like proteases, are involved in the release of such peptides upon activation during defense responses. In this review, we discuss the roles of cryptic peptide sequences hidden in the structure of functional proteins in plant defense and plant-pathogen interactions.

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Crosstalk between Calcium and ROS Signaling during Flg22-Triggered Immune Response in Arabidopsis Leaves

Plants ◽

10.3390/plants11010014 ◽

2021 ◽

Vol 11 (1) ◽

pp. 14

Author(s):

Matthew J. Marcec ◽

Kiwamu Tanaka

Keyword(s):

Second Messengers ◽

Cytosolic Calcium ◽

Defense Responses ◽

Calcium Signal ◽

Pharmacological Agents ◽

Ros Signaling ◽

Molecular Pattern ◽

Respiratory Burst Oxidase ◽

Insight Into ◽

Calcium Elevation

Calcium and reactive oxygen species (ROS) are two of the earliest second messengers in response to environmental stresses in plants. The rise and sequestration of these messengers in the cytosol and apoplast are formed by various channels, transporters, and enzymes that are required for proper defense responses. It remains unclear how calcium and ROS signals regulate each other during pattern-triggered immunity (PTI). In the present study, we examined the effects of perturbing one signal on the other in Arabidopsis leaves upon the addition of flg22, a well-studied microbe-associated molecular pattern (MAMP). To this end, a variety of pharmacological agents were used to suppress either calcium or ROS signaling. Our data suggest that cytosolic calcium elevation is required to initiate and regulate apoplastic ROS production generated by respiratory burst oxidase homologs (RBOHs). In contrast, ROS has no effect on the initiation of the calcium signal, but is required for forming a sufficient amplitude of the calcium signal. This finding using pharmacological agents is corroborated by the result of using a genetic double mutant, rbohd rbohf. Our study provides an insight into the mutual interplay of calcium and ROS signals during the MAMP-induced PTI response in plants.

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Identification of Msp1-Induced Signaling Components in Rice Leaves by Integrated Proteomic and Phosphoproteomic Analysis

International Journal of Molecular Sciences ◽

10.3390/ijms20174135 ◽

2019 ◽

Vol 20 (17) ◽

pp. 4135 ◽

Cited By ~ 9

Author(s):

Ravi Gupta ◽

Cheol Woo Min ◽

Yu-Jin Kim ◽

Sun Tae Kim

Keyword(s):

Plasma Membrane ◽

Protein Kinase ◽

Defense Responses ◽

Mitogen Activated Protein Kinase ◽

Calcium Dependent ◽

Molecular Pattern ◽

Mitogen Activated Protein ◽

Dependent Protein ◽

Rice Leaves ◽

Respiratory Burst Oxidase

MSP1 is a Magnaporthe oryzae secreted protein that elicits defense responses in rice. However, the molecular mechanism of MSP1 action is largely elusive. Moreover, it is yet to be established whether MSP1 functions as a pathogen-associated molecular pattern (PAMP) or an effector. Here, we employed a TMT-based quantitative proteomic analysis of cytosolic as well as plasma membrane proteins to decipher the MSP1 induced signaling in rice. This approach led to the identification of 6691 proteins, of which 3049 were identified in the plasma membrane (PM), while 3642 were identified in the cytosolic fraction. A parallel phosphoproteome analysis led to the identification of 1906 phosphopeptides, while the integration of proteome and phosphoproteome data showed activation of proteins related to the proteolysis, jasmonic acid biosynthesis, redox metabolism, and MAP kinase signaling pathways in response to MSP1 treatment. Further, MSP1 induced phosphorylation of some of the key proteins including respiratory burst oxidase homologue-D (RBOHD), mitogen-activated protein kinase kinase kinase-1 (MEKK1), mitogen-activated protein kinase-3/6 (MPK3/6), calcium-dependent protein kinase (CDPK) and calmodulin (CaM) suggest activation of PAMP-triggered immunity (PTI) in response to MSP1 treatment. In essence, our results further support the functioning of MSP1 as a PAMP and provide an overview of the MSP1 induced signaling in rice leaves.

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The tomato receptor CuRe1 senses a cell wall protein to identify Cuscuta as a pathogen

Nature Communications ◽

10.1038/s41467-020-19147-4 ◽

2020 ◽

Vol 11 (1) ◽

Cited By ~ 2

Author(s):

Volker Hegenauer ◽

Peter Slaby ◽

Max Körner ◽

Julien-Alexander Bruckmüller ◽

Ronja Burggraf ◽

...

Keyword(s):

Cell Wall ◽

Host Plants ◽

Parasitic Plants ◽

Defense Responses ◽

Resistance Mechanisms ◽

Peptide Epitope ◽

Molecular Pattern ◽

A Cell ◽

Membrane Bound ◽

Glycine Rich Protein

Abstract Parasitic plants of the genus Cuscuta penetrate shoots of host plants with haustoria and build a connection to the host vasculature to exhaust water, solutes and carbohydrates. Such infections usually stay unrecognized by the host and lead to harmful host plant damage. Here, we show a molecular mechanism of how plants can sense parasitic Cuscuta. We isolated an 11 kDa protein of the parasite cell wall and identified it as a glycine-rich protein (GRP). This GRP, as well as its minimal peptide epitope Crip21, serve as a pathogen-associated molecular pattern and specifically bind and activate a membrane-bound immune receptor of tomato, the Cuscuta Receptor 1 (CuRe1), leading to defense responses in resistant hosts. These findings provide the initial steps to understand the resistance mechanisms against parasitic plants and further offer great potential for protecting crops by engineering resistance against parasitic plants.

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The Aquaporin TaPIP2;10 Confers Resistance to Two Fungal Diseases in Wheat

Phytopathology ◽

10.1094/phyto-02-21-0048-r ◽

2021 ◽

Author(s):

Xiaobing Wang ◽

Kai Lu ◽

Xiaohui Yao ◽

Liyuan Zhang ◽

Fubin Wang ◽

...

Keyword(s):

Powdery Mildew ◽

Fusarium Head Blight ◽

Plant Immunity ◽

Defense Responses ◽

Crop Productivity ◽

Fungal Diseases ◽

Head Blight ◽

Plasma Membrane Intrinsic Protein ◽

Molecular Pattern ◽

Source Plant

Plants employ aquaporins of the plasma membrane intrinsic protein (PIP) family to import environmental substrates, thereby affecting various processes, such as the cellular responses regulated by the signaling molecule hydrogen peroxide (H2O2). Common wheat (Triticum aestivum) contains 24 candidate members of the PIP family, designated as TaPIP1;1 to TaPIP1;12 and TaPIP2;1 to TaPIP2;12. To date, none of these TaPIP candidates has been characterized for substrate selectivity or defense responses in their source plant. Here, we report that T. aestivum aquaporin TaPIP2;10 facilitates the cellular uptake of H2O2 to confer resistance against powdery mildew and Fusarium head blight, two devastating fungal diseases in wheat throughout the world. In wheat, the apoplastic H2O2 signal is induced by fungal attack, while TaPIP2;10 is stimulated to translocate this H2O2 into the cytoplasm, where it activates defense responses to restrict further attack. TaPIP2;10-mediated transport of H2O2 is essential for pathogen-associated molecular pattern triggered plant immunity (PTI). Typical PTI responses are induced by the fungal infection and intensified by overexpression of the TaPIP2;10 gene. TaPIP2;10 overexpression causes a 70% enhancement in wheat resistance to powdery mildew and an 86% enhancement in resistance to Fusarium head blight. By reducing the disease severities, TaPIP2;10 overexpression brings about more than 37% increase in wheat grain yield. These results verify the feasibility of using an immunity-relevant aquaporin to concomitantly improve crop productivity and immunity.

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The hydroxyproline-rich glycopeptide systemin precursor NapreproHypSys does not play a central role in Nicotiana attenuata's anti-herbivore defense responses

Plant Cell & Environment ◽

10.1111/j.1365-3040.2007.01719.x ◽

2007 ◽

Vol 30 (11) ◽

pp. 1450-1464 ◽

Cited By ~ 4

Author(s):

BEATRICE BERGER ◽

IAN T. BALDWIN

Keyword(s):

Defense Responses ◽

Herbivore Defense

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Tomato SOBIR1/EVR Homologs Are Involved in Elicitin Perception and Plant Defense Against the Oomycete Pathogen Phytophthora parasitica

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-12-14-0405-r ◽

2015 ◽

Vol 28 (8) ◽

pp. 913-926 ◽

Cited By ~ 19

Author(s):

Ke-Chun Peng ◽

Chao-Wen Wang ◽

Chih-Hang Wu ◽

Chun-Tzu Huang ◽

Ruey-Fen Liou

Keyword(s):

Cell Death ◽

Plant Defense ◽

Marker Gene ◽

Defense Responses ◽

Kinase Domain ◽

Phytophthora Parasitica ◽

Callose Deposition ◽

Molecular Pattern ◽

Molecular Events ◽

Species Production

During host-pathogen interactions, pattern recognition receptors form complexes with proteins, such as receptor-like kinases, to elicit pathogen-associated molecular pattern-triggered immunity (PTI), an evolutionarily conserved plant defense program. However, little is known about the components of the receptor complex, as are the molecular events leading to PTI induced by the oomycete Phytophthora pathogen. Here, we demonstrate that tomato (Solanum lycopersicum) SlSOBIR1 and SlSOBIR1-like genes are involved in defense responses to Phytophthora parasitica. Silencing of SlSOBIR1 and SlSOBIR1-like enhanced susceptibility to P. parasitica in tomato. Callose deposition, reactive oxygen species production, and PTI marker gene expression were compromised in SlSOBIR1- and SlSOBIR1-like–silenced plants. Interestingly, P. parasitica infection and elicitin (ParA1) treatment induced the relocalization of SlSOBIR1 from the plasma membrane to endosomal compartments and silencing of NbSOBIR1 compromised ParA1-mediated cell death on Nicotiana benthamiana. Moreover, the SlSOBIR1 kinase domain is indispensable for ParA1 to trigger SlSOBIR1 internalization and plant cell death. Taken together, these results support the idea of participation of solanaceous SOBIR1/EVR homologs in the perception of elicitins and indicate their important roles in plant basal defense against oomycete pathogens.

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