Postdoctoral position - A forward genetics analysis of Nicotiana attenuata’s interactions with arbuscular mycorrhizal fungi (AMF)


Prof. Ian Baldwin, Department of Molecular Ecology of the Max Planck Institute for Chemical Ecology

With our recently published high-through-put (HTP) screening method for AMF colonization (patent pending), by quantifying AMF-specific blumenol markers from minute amounts of leaf tissue (1; 2), we can readily quantify the strength of AMF associations in large forward-genetic N. attenuata populations (AI-RILs and MAGIC-RILs populations) growing in natural habitats. The first part of the project will be to use an established QTL pipeline to impute loci involved in AMF associations to identify target loci that will be subsequently manipulated by gene silencing or editing. Loci will be selected for their utility in answering questions about the ecological functions of AMF associations in nature (see below), silenced in the specific RILs which guided the imputations, and planted into hypothesis-structured populations at our field stations in Utah and Arizona to test functional inferences. All of these procedures are functional in our Department.

N. attenuata’s associations with Rhizophagus irregularis and F. mosseae AMF (3; 4) are clearly important
for P and N nutrition, when plants grow outside burned areas with fire-enhanced N and P supply rates,
however the AMF associations are detrimental, stunting growth at intermediate nutrient supply levels
(5). The frequency of plants harboring AMF associations is highly variable in natural populations, likely
reflecting other functional roles for this symbiosis. Recently we have shown in glasshouse experiments
that AMF networks transmit herbivore-elicited JA signaling among connected plants, and filter the direct
defense responses elicited by these signals (6). While we are currently able to completely abrogate AMF
associations by silencing components of the Symbiotic signaling pathway (e.g., CCaMK(3)), we are
confident that the MAGIC-RIL population, that captures the genetic variability of this native tobacco, will
harbor loci that allow for less ham-fisted means of manipulating this important ecological interaction.

Over the past three decades we have created a molecular-ecological toolbox for Nicotiana attenuata, a
native diploid tobacco that grows in the Great Basin Desert, to understand how this native plant survives
in the real world. The toolbox is composed of three support platforms (molecular, analytical and
ecological) which includes state-of-art molecular biological, genetic and analytical resources comparable
or better than what you can find dispersed across the entire Arabidopsis community, but also a field
station located in a nature preserve in the plant’s native habitat in SW Utah, at which communities of
transgenic plants, harboring silencing and over-expression constructs for plant and insect (through
plant-mediated RNAi) genes are regularly planted to test functional hypotheses about gene function (for
more information about these toolboxes see our webpages: http://www.ice.mpg.de/ext/molecular-
ecology.html
).

We are offering: A 3-year Post Doctoral position for creative biologists and independence to utilize the
tools of this remarkable molecular/ecological toolbox to explore hypotheses about the mechanisms and
functional consequences of AMF interactions. We offer competitive salaries according to MPG
guidelines, a stimulating work environment, and excellent mentoring for your transition to a
professorship or other positions in which your science can flourish.


We expect: A PhD in plant sciences; a track record of driving research projects to successful
publications; strong skills in plant molecular biology and genetics; an inquisitive mind; excellent verbal
and written communication skills; and a collaborative personality capable of taking full advantage of the
awesome genetic, analytical and ecological resources that the Department of Molecular Ecology has
developed for the Nicotiana attenuata model ecological expression system. Experience in QTL analysis,
reverse genetics and/or analytical chemistry would be a plus. Please read Baldwin’s Scientists' Creed for
an elaboration of the Department’s expectations.

How to apply: Send your CV, a summary of your previous research experience, a statement of research
interests and a short statement how you would take advantage of the N. attenuata toolbox to address
functional questions about N. attenuata’s interactions with AMF and contact information for at least
two references to Melanie Wilson who will be conducting the initial candidate screening. Suitable
candidates will be interviewed by phone by Ian Baldwin and asked to write a short proposal, followed by
an invitation for a seminar. The position is available immediately and will remain open until filled.

 

Contact:

Melanie Wilson
Department of Molecular Ecology
Max Planck Institute for Chemical Ecology
Hans-Knoell-Strasse 8
D-07745 Jena
application [at] ice.mpg.de

Further reading:

  1. Wang M, Schäfer M, Li D, Halitschke R, Dong C, McGale E, Paetz C, Song Y, Li S, Dong J, Heiling S, Groten K, Franken P, Bitterlich M, Harrison MJ, Paszkowski U,Baldwin IT (2018) Blumenols as shoot markers of root symbiosis with arbuscular mycorrhizal fungi. eLife 7: e37093

  2. Mindt E, Wang M, Schäfer M, Halitschke R,Baldwin IT (2019) Quantification of blumenol derivatives as leaf biomarkers for plant-AMF association. Bio-protocol 9: e3301

  3. Groten K, Nawaz A, Nguyen NHT, Santhanam R,Baldwin IT (2015) Silencing a key gene of the common symbiosis pathway in Nicotiana attenuata specifically impairs arbuscular mycorrhizal infection without influencing the root-associated microbiome or plant growth. Plant, Cell & Environment 38: 2398-2416

  4. Wang M, Wilde J, Baldwin IT,Groten K (2018) Nicotiana attenuata's capacity to interact with arbuscular mycorrhiza alters its competitive ability and elicits major changes in the leaf transcriptome. Journal of Integrative Plant Biology 60: 242-261

  5. Riedel T, Groten K,Baldwin IT (2008) Symbiosis between Nicotiana attenuata and Glomus intraradices: ethylene plays a role, jasmonic acid does not. Plant, Cell & Environment 31: 1203-1213

  6. Song Y, Wang M, Zeng R, Groten K,Baldwin IT (2019) Priming and filtering of anti-herbivore defenses among Nicotiana attenuata plants connected by mycorrhizal networks. Plant, Cell & Environment.