Greg Martin

Boyce Schulze Downey Professor
Greg Martin
gbm7@cornell.edu
Office/Lab: 327/326
Phone: 607-254-1208
Office/Lab: 327/326
Email: gbm7@cornell.edu
Office Phone: 607-254-1208
Lab Phone: 607-220-9610
Graduate Fields: Plant Pathology & Plant-Microbe Biology; Plant Biology
Research Overview

How do bacteria infect plants and how do plants defend themselves from such attacks?

The long-term goal of research in the Martin laboratory is to use knowledge gained about the molecular basis of plant-pathogen interactions to develop plants with increased natural resistance to diseases. Such plants would require fewer applications of pesticides producing economic and environmental benefits while providing food for consumers with less pesticide residue.

The Martin laboratory studies the molecular basis of bacterial infection processes and the plant immune system. The research focuses on speck disease which is caused by the infection of tomato leaves with the bacterial pathogen Pseudomonas syringae pv. tomato. This is an economically important disease that can decrease both the yield and quality of tomato fruits. It also serves as an excellent experimental system for studying the molecular mechanisms that underlie plant-pathogen interactions and how they have evolved. Many experimental resources, including an increasing number of genome sequences, are available for both tomato and P. s. pv. tomato. Current work relies on diverse experimental approaches involving methods derived from the fields of biochemistry, bioinformatics, cell biology, forward and reverse genetics, genomics, molecular biology, plant breeding, plant pathology and structural biology.

Research in the Martin lab is supported, in part, by: USDA-BARD IS-4931-16C, NSF IOS-1451754 and NSF-IOS-1546625

See more...

In the interaction of Pseudomonas with tomato, the plant responds rapidly to a potential infection by detecting certain conserved molecules expressed by the pathogen. At this stage, the pathogen uses a specialized secretion system to deliver virulence proteins, such as AvrPto and AvrPtoB, into the plant cell. These pathogen proteins suppress early host defenses and thereby promote disease susceptibility. Some tomato varieties express a resistance gene, Pto, which encodes a protein that detects the presence of AvrPto or AvrPtoB and activates a second strong immune system that halts the progression of bacterial speck disease.

The Martin lab is currently studying many aspects of the molecular mechanisms that underlie the bacterial infection process and the plant response to infection. One project takes advantage of the genetic natural variation present in wild relatives of tomato to identify new genes that contribute to plant immunity. These genes provide insights into the plant immune system and also can be bred into new tomato varieties to enhance disease resistance. A second project relies on next-generation sequencing methods to identify tomato genes whose expression increases during the interaction with P. s. pv. tomato. The expression of these genes is then reduced by using virus-induced gene silencing or the genes are mutated using CRISPR/Cas9 to test whether they make a demonstrable contribution to immunity.

Links

.

Martin Lab Pedigree

Evolution of immunity

Evolution of pathogen recognition and defense responses in wild species of tomato and tomato heirloom varieties.

Pattern-triggered immunity

The plant immune system 1: Mechanisms underlying recognition and response to microbe-associated molecular patterns.

Effector-triggered immunity

The plant immune system II: Mechanisms underlying recognition and response to pathogen effector proteins.

AvrPto virulence mechanisms

Virtulence mechanisms of the AvrPto effector protein from Pseudomonas syringae pv. tomato.

Methods to study plant immunity

Development of methods and resources to study the plant immune system.

Nicotiana benthamiana genome project

Nicotiana benthamiana genome project.

Intern Projects

Identifying natural variation in the plant immune system using cultivated and wild species of tomato and investigating the underlying mechanisms through gene mapping-by-sequencing and CRISPR/Cas9 genome editing methods.

The Martin laboratory studies the molecular basis of plant immunity and bacterial pathogenesis. Our focus is on the infection of tomato by Pseudomonas syringae pv. tomato as this interaction results in bacterial speck, an economically important disease, and also serves as a powerful model system for understanding fundamental mechanisms involved in plant-pathogen biology. On the bacterial side, we study virulence proteins and associated mechanisms that the pathogen uses to interfere with the plant immune response. On the plant side, we identify and characterize genes, proteins and molecular mechanisms that play a role in host immunity and susceptibility. Our work relies on natural variation for these traits that is present in cultivated tomato and in the 12 wild relatives of tomato that originated in South America. For the characterization of both plant and bacterial genes and proteins, we use a variety of experimental approaches including biochemistry, bioinformatics, genetics, genomics, molecular biology, and structural biology.

Examples of research projects in my laboratory include: 1) Using tomato varieties that have natural variation in their immune system to clone and characterize the genes responsible; 2) Using CRISPR/Cas9 genome-editing methods to mutate immunity-associated genes and investigate alterations in the plant defense system; and 3) Investigating bacterial proteins that play a key role in promoting pathogenesis and virulence.

Representative publication: https://nph.onlinelibrary.wiley.com/doi/abs/10.1111/nph.15788

Interns in the Martin Lab are funded by NSF IOS-1451754 and REU-1358843.

Internship Program | Projects & FacultyApply for an Internship

PP2C phosphatase Pic1 negatively regulates phosphorylation status of Pti1b kinase, a regulator of flagellin-triggered immunity in tomato
2019.
Giska, F., Martin, Gregory B.
Biochemical Journal.
BCJ20190299
:
Natural variation for unusual host responses and flagellin‐mediated immunity against Pseudomonas syringae in genetically diverse tomato accessions
2019.
Roberts, R., Mainiero, S., Powell, A., Liu, A., Shi, K., Hind, S., Strickler, S., Collmer, A., Mart…
New Phytologist.
:
Transcriptome-based identification and validation of reference genes for plant-bacteria interaction studies using Nicotiana benthamiana
2019.
Pombo, M.A., Ramos, R.N., Zheng, Y., Fei, Zhangjun, Martin, Gregory B., Rosli, H.G.
Scientific Reports.
9
:
Plant Genome Editing Database (PGED): A Call for Submission of Information about Genome-Edited Plant Mutants
2019.
Zheng,Y., Zhang, N., Martin, Gregory B., Fei, Zhangjun
Molecular Plant.
12
:
127–129
The Ptr1 locus of Solanum lycopersicoides confers resistance to race 1 strains of Pseudomonas syringae pv. tomato and to Ralstonia pseudosolanacearum by recognizing the type III effectors AvrRpt2/RipBN
2019.
Mazo-Molina, C., Mainiero, S., Hind, S.R., Kraus, C.M., Vachev, M., Maviane-Macia, F., Lindeberg, M…
Molecular Plant-Microbe Interactions.
:
The tomato Pto gene confers resistance to Pseudomonas floridensis, an emergent plant pathogen with just nine type III effectors
2019.
Eckshtain-Levi, N., Lindeberg, M., Vallad, G.E., Martin, Gregory B.
Plant Pathology.
:
Virus-induced gene silencing database for phenomics and functional genomics in Nicotiana benthamiana
2018.
Senthil-Kumar, M., Wang, Chang, J., Ramegowda, V., del Pozo, O., Liu, Y., Doraiswamy, V., Lee, H.-K.…
Plant Direct.
2
:
e00055
Detecting the interaction of peptide ligands with plant membrane receptors
2017.
Hind, S. R., Hoki, J. S., Baccile, J. A., Boyle, P. C., Schroeder, Frank, Martin, Gregory B.
Current protocols in plant biology.
2
:
240–269
Generation of a Collection of Mutant Tomato Lines Using Pooled CRISPR Libraries
2017.
Jacobs, T. B., Zhang, N., Patel, D., Martin, Gregory B.
Plant Physiology.
174
:
2023–2037
A Subset of Ubiquitin-Conjugating Enzymes Is Essential for Plant Immunity
2017.
Zhou, B., Mural, R. V., Chen, X., Oates, M. E., Connor, R. A., Martin, Gregory B., Gough, J., Zeng, …
Plant Physiology.
173
:
1371–1390
The Bacterial Effector AvrPto Targets the Regulatory Coreceptor SOBIR1 and Suppresses Defense Signaling Mediated by the Receptor-Like Protein Cf-4
2017.
Wu, J., van der Burgh, A. M., Bi, G., Zhang, L., Alfano, J. R., Martin, Gregory B., Joosten, M. HAJ
Molecular Plant-Microbe Interactions.
31
:
MPMI08170203FI–MPMI-08-17-0203
Pseudomonas syringae – tomato interactions: an unfolding New York story
2017.
Lindeberg, M., Collmer, A., Martin, Gregory B., Smart, C.
PHYTOPATHOLOGY.
107
:
10–10
Ser 360 and Ser 364 in the Kinase Domain of Tomato SIMAPKKKα are Critical for Programmed Cell Death Associated with Plant Immunity
2017.
Hwang, I. S., Brady, J., Martin, Gregory B., Oh, C. S.
The plant pathology journal.
33
:
163–169
Use of RNA-seq data to identify and validate RT-qPCR reference genes for studying the tomato-Pseudomonas pathosystem
2017.
Pombo, M. A., Zheng, Y., Fei, Zhangjun, Martin, Gregory B., Rosli, H. G.
Nature Scientific Reports.
7
:
44905–44905
The Tomato Kinase Pti1 Contributes to Production of Reactive Oxygen Species in Response to Two Flagellin-Derived Peptides and Promotes Resistance to Pseudomonas syringae Infection
2017.
Schwizer, S., Kraus, C. M., Dunham, D. M., Zheng, Y., Fernandez-Pozo, N., Pombo, M. A., Fei, Zhangju…
Molecular Plant-Microbe Interactions.
30
:
725–738
Natural Variation in Tomato Reveals Differences in the Recognition of AvrPto and AvrPtoB Effectors from Pseudomonas syringae
2016.
Kraus, C. M., Munkvold, K. R., Martin, Gregory B.
Molecular Plant.
9
:
639–649
Detecting N-myristoylation and S-acylation of host and pathogen proteins in plants using click chemistry
2016.
Boyle, P. C., Schwizer, S., Hind, S. R., Kraus, C. M., Torre Diaz, S., He, B., Martin, Gregory B.
Plant Methods.
12
:
High-throughput CRISPR Vector Construction and Characterization of DNA Modifications by Generation of Tomato Hairy Roots
2016.
Jacobs, T. B., Martin, Gregory B.
Journal of visualized experiments : JoVE.
:
Tomato receptor FLAGELLIN-SENSING 3 binds flgII-28 and activates the plant immune system
2016.
Hind, S. R., Strickler, S. R., Boyle, P. C., Dunham, D. M., Bao, Z., O'Doherty, I. M., Baccile, J. A…
Nature Plants.
2
:
16128–16128
iTAK: A Program for Genome-wide Prediction and Classification of Plant Transcription Factors, Transcriptional Regulators, and Protein Kinases
2016.
Zheng, Y., Jiao, C., Sun, H., Rosli, H. G., Pombo, M. A., Zhang, P., Banf, M., Dai, X., Martin, Greg…
Molecular Plant.
9
:
1667–1670

Nucleic acids encoding proteins with pathogen resistance activity and plants transformed therewith
Greg Martin
Technology Area:Biotic Stress - Disease
US Patent/Application(s): 7,138,569
Publication: EMBO 2003
Nucleic acids encoding proteins with pathogen resistance activity and plants transformed therewith
Greg Martin
Technology Area:Biotic Stress - Disease
US Patent/Application(s): 6,653,533
Publication: EMBO 1997
Flagellin-sensing 3 (‘fls3’) protein and methods of use
Greg Martin
Technology Area:Biotic Stress - Disease
US Patent/Application(s): PCT/US2015/039520
Publication: Science 2016
Gene conferring disease resistance to plants by responding to an avirulence gene in plant pathogens
Greg Martin
Technology Area:Biotic Stress - Disease
US Patent/Application(s): 5,648,599
Publication: Science 1993
Increased Resistance to Race 1 Pseudomonas via Modulation of the Rph1
Greg Martin
Technology Area:Biotic Stress - Disease
US Patent/Application(s): 15/254,370
Bacterial effector proteins which inhibit programmed cell death
Greg Martin
Technology Area:Biotic Stress - Disease
US Patent/Application(s): 7,888,467
Publication: PNAS 2002

Contact:

Boyce Thompson Institute
533 Tower Rd.
Ithaca, NY 14853
607.254.1234
contact@btiscience.org