Karolina Mukhtar

 

Assistant Professor

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(205) 934-8340
205-975-2523 (Lab)

Plant Molecular Biology

PhD (Genetics), 2005, Max-Planck Institute for Plant Breeding Research, Cologne, Germany

Research Interests:

Plants, while lacking adaptive immunity observed in animals, have instead evolved complex innate immune systems that effectively defend them from versatile potential pathogens. Successful defense against pathogenic microbes requires host’s abilities to mount specific, fine-tuned, and temporally as well as spatially regulated responses to various biotic stresses. The research in my laboratory is focused on molecular mechanisms of cellular stress responses in model plant Arabidopsis thaliana.

Transcriptional regulatory network

Transcription regulatory networks are the central processing units of living cells. They allow cells to integrate different intracellular signals and extracellular stimuli and coordinate downstream signal transduction to provide hierarchical control of reactions. In Arabidopsis, induced defense responses involve perception of microbes, activation of signal transduction networks and rapid changes in expression affecting as many as 15% of all genes. This extensive transcriptional reprogramming re-directs cellular resources typically dedicated to steady-state growth-related regular activities towards de novo synthesis of a complex spectrum of defense-related anti-microbial compounds. The work in my laboratory focuses on the functional characterization of TBF1 (TL1-Binding Factor 1), a novel master transcriptional regulator mediating diverse types of disease resistance in Arabidopsis. Ongoing work concentrates on understanding how the master regulator controls the transcriptional regulatory network, how its translation is controlled and how it is linked to various defense mechanisms.

Unfolded Protein Response

Unfolded Protein Response (UPR), an evolutionarily conserved cellular stress response, activates upon accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) resulting from biotic/abiotic stresses. Initially UPR transduces signals to reinstate ER homeostasis. However, prolonged or acute ER stress may lead UPR signals to a transition that initiates programmed cell death. The action of UPR in plants is almost unknown. A long-term goal of my laboratory is to advance our understanding of the genetic and molecular basis of UPR in Arabidopsis as well as its role in defense against diverse pathogens. We are expecting to uncover the differences between the animal and plant UPR responses that make it a unique adaptive process in plant immunity. Our primary objective is to identify how various molecular chaperones are mechanistically involved during plant UPR. We are also working on identification of additional key regulatory transcription factors required for the activation of signal transduction pathways in ER-stress response.


Selected publications:
 

Moreno A*, Mukhtar MS*, Blanco F, Boatwright JL, Moreno I, Jordan MR, Chen Y, Brandizzi F, Dong X, Orellana A*, Pajerowska-Mukhtar KM* (2012) IRE1/bZIP60-Mediated Unfolded Protein Response Plays Distinct Roles in Plant Immunity and Abiotic Stress Responses. PLoS ONE 10.1371/journal.pone.0031944. *- authors contributed equally

 

Pajerowska-Mukhtar KM, Wang W, Tada Y, Oka N, Tucker CL, Fonseca JP, Dong X (2012) The HSF-like Transcription Factor TBF1 Is a Major Molecular Switch for Plant Growth-to-Defense Transition. Current Biology 22:1-10.

 

Pajerowska-Mukhtar KM, Dong X (2009) A Kiss of Death – Proteasome-Mediated Membrane Fusion and Programmed Cell Death in Plant Defense Against Bacterial Infection. Genes & Development 23:2449-2454.

 

Saijo Y, Lu X*, Tintor N* , Rauf P*, Pajerowska-Mukhtar KM*, Häweker H, Dong X, Robatzek S, Schulze-Lefert P (2009) Receptor quality control in the endoplasmic reticulum for plant innate immunity. EMBO J. 28:3439 – 3449. *- co-second author

 

Pajerowska-Mukhtar KM*, Stich B*, Achenbach U*, Ballvora A, Lübeck J, Strahwald J, Tacke E, Hofferbert H-R, Ilarionova E, Bellin D, Walkemeier B, Basekow R, Kersten B, Gebhardt C (2009) Single nucleotide polymorphisms in the allene oxide synthase 2 gene of potato (Solanum tuberosum) are associated with maturity-corrected resistance to late blight in tetraploid breeding populations. Genetics, 181:1115-1127. *- co-first author

 

Tada Y, Spoel SH, Pajerowska-Mukhtar KM, Mou Z, Song J, Dong X (2008) S-nitrosylation and thioredoxins regulate conformational changes of NPR1 in establishing plant immunity. Science 321:952-956.

 

Pajerowska-Mukhtar KM, Mukhtar MS, Guex N, Halim VA, Rosahl S, Somssich IE, Gebhardt C (2008) Natural variation of potato allene oxide synthase 2 causes differential levels of jasmonates and pathogen resistance in Arabidopsis. Planta 228:293–306.

 

Wang D*, Pajerowska-Mukhtar KM*, Culler AH, Dong X (2007) Salicylic acid inhibits pathogen growth in plants through repression of the auxin   signaling pathway. Current Biology, 17:1784-1790. *- co-first author

 

Gebhardt C, Li L, Pajerowska-Mukhtar KM, Achenbach U, Sattarzadeh A, Bormann C, Ilarionova E, Ballvora A (2007) Candidate Gene Approach to Identify Genes Underlying Quantitative Traits and Develop Diagnostic Markers in Potato. Crop Science 47:S-106-S-111.

 

Pajerowska KM, Parker JE, Gebhardt C (2005) Potato homologues of Arabidopsis thaliana genes functional in defence signalling – identification, genetic mapping and molecular cloning. Molecular Plant Microbe Interactions 18:1107-19.