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 feed from. Some economically important plant toxins, e.g. nicotine in tobacco, have been studied extensively. However, the great majority of the defensive metabolites found in plants 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. It is likely that many of the as yet 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 maize, Arabidopsis, and potato. 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.

The long-term goal of research on the chemical ecology of plant-insect interactions is to use the discoveries that are made in the laboratory to increase the natural resistance of crop plants to herbivore attack. Plants that are bred to have enhanced herbivore resistance would require fewer applications of potentially harmful pesticides, thereby providing benefits to the environment and reducing the input costs for farmers.

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.

The Jander lab is collaborating with groups at the University of Bern, the Max Planck Institute for Chemical Ecology and Tel Aviv University to study the biosynthesis and function of benzoxazinoids. These indole-derived metabolites have a prominent role in the herbivore defenses of maize, wheat, rye and other grasses. Recent findings have included the discovery of previously unknown genes involved in maize benzoxazinoid biosynthesis, isolation of mutations that affect defense-induced benzoxazinoid production and evidence that there are defensive trade-offs in the production of different types of benzoxazinoids.

Although other insect herbivores are also being studied, maize-aphid interactions are a particular research emphasis of the Jander lab. Cultivated maize shows wide variation in its resistance to feeding by corn leaf aphids (Rhopalosiphum maidis). Whereas these aphids produce several progeny per day on some maize varieties, others are almost completely resistant to aphid attack. Genetic mapping of aphid progeny production on different maize inbred lines identified specific regions of the maize genome that influence this trait. In some cases, this genetic mapping approach has led to the discovery of specific maize genes and metabolites that provide aphid resistance.

Arabidopsis-aphid interactions

Green Peach Aphid

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

The green peach aphid (Myzus persicae) is a focus of ongoing research in the Jander lab. As broad generalist herbivores, green peach aphids are exposed to a wide variety of defensive metabolites in the plant species from which they feed. Similar to the corn leaf aphid, the utilization of different host plants by the green peach aphid is often determined by the abundance of specific plant defensive metabolites. Analysis of aphid salivary proteins, which are injected into the plant as the insects are feeding, has demonstrated that some of these proteins are involved in suppressing plant defenses, whereas others are recognized by plants as signals to mount defense responses.

Plant-mediated RNA interference (RNAi), whereby double-stranded RNA targeting insect genes is produced in the plant, has potential applications as an aphid control method. Research conducted in collaboration with Angela Douglas’ lab at Cornell University showed that growth and reproduction of green peach aphids is reduced on Arabidopsis plants transformed with RNAi constructs that limited the expression of aphid osmoregulatory genes. Current research efforts are directed at identifying aphid-specific genes that can be used for RNAi-mediated control of green peach aphids, without affecting the growth and survival of beneficial insect species that might consume these aphids.

Potato metabolic changes induced by tuber moth feeding

When certain potato varieties are subjected to low-level infestation with the Guatemalan tuber moth (Tecia solanivora), there is a two-fold increase in the marketable yield of uninfested tubers on the same plants. Tuber growth changes are associated with increased dry mass of uninfested tubers on infested plants, rather than merely higher water content. Current research, in collaboration with Katja Poveda’s lab at Cornell University is focused on identifying alterations in potato photosynthesis, sugar transport and other aspects of primary metabolism that lead to increased starch deposition in the tubers of potato plants infested with the Guatemalan tuber moth.

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
Tecia solanivora infestation increases tuber starch accumulation inPastusa Suprema potatoes
2018.
Kumar, P., Garrido, E., Zhao, K., Zheng, Y., Alseekh, S., Vargas-Ortiz, E., Fernie, A. R., Fei, Zhan…
Journal of Integrative Plant Biology.
:
Maize carbohydrate partitioning defective1 Impacts Carbohydrate Distribution, Callose Accumulation, and Phloem Function
2018.
Julius, B. T., Slewinski, T. L., Frank Baker, R., Tzin, V., Zhou, S., Bihmidine, S., Jander, Georg, …
Journal of Experimental Botany.
:
Changes in the free amino acid composition of Capsicum annuum (pepper) leaves in response to Myzus persicae (green peach aphid) infestation. A comparison with water stress
2018.
Florencio-Ortiz, V., Sellés-Marchart, S., Zubcoff-Vallejo, J., Jander, Georg, Casas, J. L.
PLOS One.
13
:
Erysimum cheiranthoides, an ecological research system with potential as a genetic and genomic model for studying cardiac glycoside biosynthesis
2018.
Züst, T., Mirzaei, M., Jander, Georg
Phytochemistry Reviews.
:
1–13
Beyond defense: Multiple functions of benzoxazinoids in maize metabolism
2018.
Zhou, S., Richter, A., Jander, Georg
Plant and Cell Physiology.
:
Genetic mapping identifies loci that influence tomato resistance against Colorado potato beetles
2018.
Vargas-Ortiz, E., Gonda, I., Smeda, J. R., Mutschler, M. A., Giovannoni, James J., Jander, Georg
Nature Scientific Reports.
8
:
RNAi-mediated silencing of endogenous Vlnv gene confers stable reduction of cold-induced sweetening in potato (Solanum tuberosum L. cv. Désirée)
2018.
Hameed, A., Bilal, R., Latif, F., Van Eck, Joyce, Jander, Georg, Mansoor, S.
Plant Biotechnology Reporter.
12
:
1–11
A role for 9-lipoxygenases in maize defense against insect herbivory
2018.
Woldemariam, M. G., Ahern, K., Jander, Georg, Tzin, V.
Plant Signaling and Behavior.
13
:
e1422462–e1422462
Computational and biological characterization of fusion proteins of two insecticidal proteins for control of insect pests
2018.
Javaid, S., Naz, S., Amin, I., Jander, Georg, Ul-Haq, Z., Mansoor, S.
Nature Scientific Reports.
8
:
Transcriptomics reveals multiple resistance mechanisms against cotton leaf curl disease in a naturally immune cotton species, Gossypium arboreum
2017.
Naqvi, R. Z., Zaidi, S. SEA, Akhtar, K. P., Strickler, S., Woldemariam, M., Mishra, B., Shahid Mukht…
Nature Scientific Reports.
7
:
Rapid transcriptional plasticity of duplicated gene clusters enables a clonally reproducing aphid to colonise diverse plant species
2017.
Mathers, T. C., Chen, Y., Kaithakottil, G., Legeai, F., Mugford, S. T., Baa-Puyoulet, P., Bretaudeau…
Genome Biology.
18
:
Concurrent Overexpression of Arabidopsis thaliana Cystathionine γ-Synthase and Silencing of Endogenous Methionine γ-Lyase Enhance Tuber Methionine Content in Solanum tuberosum
2017.
Kumar, P., Jander, Georg
Journal of Agricultural and Food Chemistry.
65
:
2737–2742
Abscisic acid-regulated protein degradation causes osmotic stress-induced accumulation of branched-chain amino acids in Arabidopsis thaliana
2017.
Huang, T., Jander, Georg
Planta.
246
:
737–747
A Global Coexpression Network Approach for Connecting Genes to Specialized Metabolic Pathways in Plants
2017.
Wisecaver, J. H., Borowsky, A. T., Tzin, V., Jander, Georg, Kliebenstein, D. J., Rokas, A.
The Plant Cell.
29
:
944–959
Metabolic engineering of Rhodopseudomonas palustris for the obligate reduction of n-butyrate to n-butanol
2017.
Doud, D. FR, Holmes, E. C., Richter, H., Molitor, B., Jander, Georg, Angenent, L. T.
Biotechnology for Biofuels.
10
:
RNAi-Mediated Simultaneous Resistance Against Three RNA Viruses in Potato
2017.
Hameed, A., Tahir, M. N., Asad, S., Bilal, R., Van Eck, Joyce, Jander, Georg, Mansoor, S.
Molecular Biotechnology.
59
:
73–83
Costs and Tradeoffs of Resistance and Tolerance to Belowground Herbivory in Potato
2017.
Garrido, E., Díaz, M. F., Bernal, H., Ñustez, C. E., Thaler, J., Jander, Georg, Poveda, K.
PLOS One.
12
:
e0169083–e0169083
Rapid defense responses in maize leaves induced by Spodoptera exigua caterpillar feeding
2017.
Tzin, V., Hojo, Y., Strickler, S. R., Bartsch, L. J., Archer, C. M., Ahern, K. R., Zhou, S., Christe…
Journal of Experimental Botany.
68
:
4709–4723
Rewiring of jasmonate and phytochrome B signalling uncouples plant growth-defense tradeoffs
2016.
Campos, M. L., Yoshida, Y., Major, I. T., De Oliveira Ferreira, D., Weraduwage, S. M., Froehlich, J.…
Nature Communications.
7
:
12570–12570
Abscisic acid deficiency increases defence responses against Myzus persicae in Arabidopsis
2016.
Hillwig, M. S., Chiozza, M., Casteel, C. L., Lau, S. T., Hohenstein, J., Hernández, E., Jander, Geo…
Molecular Plant Pathology.
17
:
225–235
Methods of screening compounds useful for prevention of infection or pathogenicity
Georg Jander
Technology Area:Enabling Technology
US Patent/Application(s): 7,166,270

Contact:

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