Georg Jander

Professor
Georg Jander
gj32@cornell.edu
Office/Lab: 127/116
Phone: 607-216-8129
Office/Lab: 127/116
Email: gj32@cornell.edu
Office Phone: 607-254-1365
Affiliations: Adjunct Professor, Section of Plant Biology / School of Integrative Plant Science / Cornell University
Graduate Fields: Plant Biology; Entomology
Research Overview

 

Introduction

 

Plants in nature are faced with attack by potentially several hundred thousand species of herbivorous insects. Nevertheless, the world is still green, and any given plant species is resistant to attack by most insects. To a large extent, resistance to herbivory is mediated by a wide array of toxic and deterrent plant metabolites. Between- and within-species variation in the production of defensive chemicals often determines which plants a particular insect species is able to consume. Some economically important plant toxins, e.g. nicotine in tobacco and glucosinolates in cruciferous vegetables, have been studied extensively. However, the great majority of plant defensive metabolites remain completely unknown. A typical leaf contains a few thousand different small molecules that can be detected by mass spectrometry, but only a few hundred of these have identified structures. Many, perhaps most of these completely unknown plant metabolites function in defense against herbivores and/or pathogens.

 

The Jander lab studies the genetic and biochemical mechanisms that mediate plant interactions with insect herbivores. This includes not only the identification of novel defense-related plant metabolites, but also characterization of the genes and enzymes that are involved in their biosynthesis. Plant species that are currently being investigated include Zea mays (maize), Arabidopsis thaliana (mouse-ear cress), Asclepias syriaca (common milkweed), Asclepias syriaca (tropical milkweed), Erysimum cheiranthoides (wormseed wallflower), and Nicotiana benthamiana (an Australian tobacco species). Genetic mapping of natural variation in insect resistance, mass spectrometry-based screens to identify previously unknown plant defensive metabolites, and characterization of biosynthetic enzymes through knockout mutations and in vitro enzyme assays have led to the discovery of novel plant defense mechanisms. On the insect side of the interaction, a major research focus is the investigation of strategies that herbivores use to avoid plant defenses or suppress them in a targeted manner.

 

Examples of current research projects in the Jander lab are:

 

Maize-insect interactions

Aphids on Maize

Thirteen corn leaf aphids (Rhopalosiphum maidis) and one green peach aphid (Myzus persicae) on the stem of a maize plant.

Benzoxazinoids, a group indole-derived metabolites, have a prominent role in the herbivore defenses of maize, wheat, rye, and other grasses. Research in the Jander lab has included the discovery of previously unknown genes involved in maize benzoxazinoid biosynthesis, isolation of mutations that affect defense-induced benzoxazinoid production, and investigation of defensive trade-offs in the production of different types of benzoxazinoids. A current research focus is the regulation of other maize defenses by benzoxazinoids and their breakdown products.

 

Among insects that feed on maize, Rhopalosiphum maidis (corn leaf aphids) have been a longer-term research interest in the lab. Cultivated maize varieties show wide variation in their resistance to aphid feeding. Specific genes that mediate aphid resistance have been identified by quantitative trait locus (QTL) mapping of aphid progeny production on different maize inbred lines. To investigate the insect side of the interaction, Sugarcane mosaic virus, which infects maize and is transmitted by aphids, has been engineered for virus-induced silencing of aphid transcription. By reducing aphid gene expression in a targeted manner, it is possible to study the function of specific genes in plant-aphid interactions.

 

Arabidopsis-aphid interactions

A fourth-instar green peach aphid (Myzus persicae) on an Arabidopsis leaf

A fourth-instar green peach aphid (Myzus persicae) on an Arabidopsis leaf

The green peach aphid (Myzus persicae) feeds readily on hundreds of plant species, including the genetic model plants Arabidopsis thaliana (Arabidopsis) and Nicotiana benthamiana (an Australian tobacco species). As broad generalist herbivores, green peach aphids are exposed to a wide variety of toxic metabolites in the plants from which they are feeding. Thus, green peach aphids must have broadly effective mechanisms to avoid or inactivate plant toxins and other defenses.

 

Analysis of salivary proteins, which are injected into the plant phloem when aphids are feeding, has demonstrated that some act as effectors that suppress plant defenses, whereas others are recognized by plants as signals to initiate defense responses. Silencing the expression of aphid salivary genes by RNA interference, in combination with Arabidopsis and N. benthamiana mutant lines, can demonstrate the specificity of such interactions. Ongoing research in the Jander lab is directed at identifying the functions of individual aphid salivary proteins, as well as their targeted interactions with defense signaling and metabolic pathways in plants.

 

Biosynthesis of cardiac glycosides in wallflowers and milkweeds

Wormseed wallflower (Erysimum cheiranthoides) in a growth chamber at the Boyce Thompson Institute.

Wormseed wallflower (Erysimum cheiranthoides) in a growth chamber at the Boyce Thompson Institute.

Production of cardiac glycosides, plant defensive metabolites that are toxic to most animal species, has evolved several times in different plant families. However, despite hundreds of publications on the ecological functions and medical uses of cardiac glycosides, the complete biosynthetic pathway has not been identified any plant species. Working together with Tobias Züst at the University of Bern and other collaborators, the Jander lab has established Erysimum cheiranthoides (wormseed wallflower) as a new genetic and genomic model system for studying cardiac glycoside biosynthesis. Isolation of mutant lines, co-expression analysis, and comparative genomics have identified numerous candidate genes involved in cardiac glycoside biosynthesis by wallflowers. In addition to investigating the defensive functions of the different cardiac glycosides in wallflowers, a major goal of this research is to identify the complete biosynthetic pathway and thereby enable the production of cardiac glycosides in heterologous systems.

 

Like wallflowers, Asclepias syriaca (common milkweed) and Asclepias curassavica (tropical milkweed) produce cardiac glycosides as a defense against insect herbivory. Correlation of cardiac glycoside content and gene expression in different milkweed tissues has identified candidate genes for cardiac glycoside biosynthesis in milkweeds. The role of these genes in cardiac glycoside biosynthesis will be tested by expression silencing in common milkweed and/or tropical milkweed. Since wallflowers and milkweeds evolved cardiac glycoside biosynthesis independently, it is likely that they use similar but not identical biosynthetic pathways for the production of these important defensive metabolites.

 

  • BTI Awarded Numerous Grants

  • BTI Graduate Students Receive Schmittau-Novak Grants

    We would like to congratulate five BTI graduate students who are Spring 2020 Schmittau-Novak Grants Program recipients. Supported by a bequest from the estate of Jean Schmittau in honor of Joseph Novak, Cornell University Plant Biology Professor Emeritus, the Schmittau-Novak Small Grants Program is designed to provide graduate students in Cornell’s School of Integrative Plant […] Read more »
  • Wallflowers Could Lead to New Drugs

    Plant-derived chemicals called cardenolides have long been used to treat heart disease, and have shown potential as cancer therapies. But the compounds are very toxic, making it difficult for doctors to prescribe a dose that works without harming the patient. For decades, researchers have longed to figure out how plants biosynthesize cardenolides, knowledge that could […] Read more »
  • BTI Celebrates Another Successful Summer Internship Program

    Boyce Thompson Institute celebrated its 19th annual Plant Genome Research Program (PGRP) summer internship program with an award ceremony at the George and Helen Kohut Symposium, which was held at the Institute on August 8. The PGRP focuses on training and inspiring the next generation of scientists to help feed a growing population, while protecting […] Read more »
  • BTI Welcomes Summer Student Interns

Intern Projects

Genetic and biochemical mechanisms of plant defense against insects.

Plants in nature are subject to attack by wide variety of caterpillars, beetles, aphids, and other insect herbivores. Although there are a million or more species of herbivorous insects, any individual plant species is resistant to the vast majority of these. Insect feeding is inhibited by an array of chemical defenses that exhibits great variability both within and among different plant species. However, although it is known that any plant leaf contains several thousand different metabolites, most of these remain unidentified. In the Jander lab we are investigating natural variation in the herbivore resistance of maize, tomato, and potato to elucidate the molecular basis of plant defense traits. Through a combination of genetic crosses, gene expression assays, metabolite profiling, and insect growth experiments, we are able to identify specific plant genes, biosynthetic pathways, and metabolites that are required to mount an effective anti-herbivore defense.

Internship Program | Projects & FacultyApply for an Internship

Engineering insect resistance using plant specialized metabolites.
2021.
Zhou, S., Jander, Georg
Curr Opin Biotechnol..
70
:
115–121
Phenolic sucrose esters: evolution, regulation, biosynthesis, and biological functions
2021.
Deng, R., Li, W., Berhow, M.A., Jander, Georg, Zhou, S.
Plant Molecular Biology.
:
Genetic mapping identifies a rice naringenin O-glucosyltransferase that influences insect resistance
2021.
Yang, Z., Li, N., Kitano, T., Li, P., Spindel, J.E., Wang, L., Bai, G., Xiao, Y., McCouch, S.R., Ish…
Plant J..
:
A sugarcane mosaic virus vector for rapid in planta screening of proteins that inhibit the growth of insect herbivores
2021.
Chung, S.H., Bigham, M., Lappe, R.R., Chan, B., Nagalakshmi, U., Whitham, S.A., Dinesh-Kumar, S.P., …
Plant Biotechnol J..
:
Engineering pest tolerance through plant-mediated RNA interference.
2021.
Chung, S.H., Feng, H., Jander, Georg
Curr Opin Plant Biol..
60
:
Interaction of eukaryotic proliferating cell nuclear antigen (PCNA) with the replication-associated protein (Rep) of cotton leaf curl Multan virus and pedilanthus leaf curl virus.
2021.
Shakir, S., Jander, Georg, Nahid, N., Mubin, M., Younus, A., Nawaz-Ul-Rehman, M.S.
3 Biotech.
11
:
14
Comparison of in Vitro and in Planta Toxicity of Vip3A for Lepidopteran Herbivores
2020.
Khan, M.H., Jander, Georg, Mukhtar, Z., Arshad, M., Sarwar, M., Asad, S.
J Econ Entomol..
113
:
2959–2971
Arabidopsis ADC1 functions as an Nδ -acetylornithine decarboxylase.
2020.
Lou, Y.R., Ahmed, S., Yan, J., Adio, A.M., Powell, H.M., Morris, P.F., Jander, Georg
J Integr Plant Biol..
62
:
601–613
Independent evolution of ancestral and novel defenses in a genus of toxic plants (Erysimum, Brassicaceae)
2020.
Züst, T, Strickler, S.R., Powell, A.F., Mabry, M.E., An, H., Mirzaei, M., York, T., Holland, C.K., …
Elife.
9
:
e51712
Metabolome-Scale Genome-Wide Association Studies Reveal Chemical Diversity and Genetic Control of Maize Specialized Metabolites.
2020.
Zhou, S., Kremling, K.A., Bandillo, N., Richter, A., Zhang, Y.K., Ahern, K.R., Artyukin, A.B., Hui, …
Plant Cell.
31
:
Silencing cathepsin L expression reduces Myzus persicae protein content and the nutritional value as prey for Coccinella septempunctata.
2019.
Rauf, I., Asif, M., Amin, I., Naqvi, R.Z., Umer, N., Mansoor, S., Jander, Georg
Insect Mol Biol..
28
:
785–797
Natural variation in the expression and catalytic activity of a naringenin 7-O-methyltransferase influences antifungal defenses in diverse rice cultivars.
2019.
Murata, K., Kitano, T., Yoshimoto, R., Takata, R., Ube, N., Ueno, K., Ueno, M., Yabuta, Y., Teraishi…
Plant J..
8
:
pii: e40260
Systemic disruption of the homeostasis of transfer RNA isopentenyltransferase causes growth and development abnormalities in Bombyx mori
2019.
Chen, Y., Bai, B., Yan, H., Wen, F., Qin, D., Jander, Georg, Xia, Q., Wang, G.,
Insect Molecular Biology.
28
:
380–391
Ethylene signaling regulates natural variation in the abundance of antifungal acetylated diferuloylsucroses and Fusarium graminearum resistance in maize seedling roots
2019.
Zhou, S., Zhang, Y.K., Kremling, K.A., Ding, Y., Bennett, J.S., Bae, J.S., Kim, D.K., Ackerman, H.H.…
New Phytologist.
221
:
2096–2111
12-Oxo-Phytodienoic Acid Acts as a Regulator of Maize Defense against Corn Leaf Aphid
2019.
Varsani, S., Grover, S., Zhou, S., Koch, K.G., Huang, P.C., Kolomiets, M.V., Williams, W.P., Heng-Mo…
Plant Physiology.
179
:
1402–1415
Genome sequence of the corn leaf aphid (Rhopalosiphum maidis Fitch)
2019.
Chen, W., Shakir, S., Bigham, M., Richter, A., Fei, Zhangjun, Jander, Georg
GigaScience.
8
:
giz033
Metabolome-Scale Genome-Wide Association Studies Reveal Chemical Diversity and Genetic Control of Maize Specialized Metabolites
2019.
Zhou, S., Kremling, K.A., Bandillo, N., Richter, A., Zhang, Y.K., Ahern, K.R., Artyukhin, A.B., Hui,…
The Plant Cell.
31
:
937–955
In-planta expression of insecticidal proteins provides protection against lepidopteran insects
2019.
Rauf, I., Javaid, S., Naqvi, R.Z., Mustafa, R., Amin, I., Mukhtar, A., Jander, Georg, Mansoor, S.
Scientific Reports.
9
:
6745
Arabidopsis ADC1 functions as an Nδ‐acetylornithine decarboxylase
2019.
Lou, Y.R., Ahmed, S., Yan, J., Adio, A.M., Powell, H.M., Morris, P.F., Jander, Georg
Journal of Integrative Plant Biology.
:
Revisiting Plant‐Herbivore Co‐Evolution in the Molecular Biology Era
2018.
Jander, Georg
Annual Plant Reviews.
:
361–384

Compositions and methods for increasing methionine content in plants
Georg Jander
US Patent: US9879273B2
Methods of screening compounds useful for prevention of infection or pathogenicity
Georg Jander
US Patent: 7,166,270
 

Contact:

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