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Halle (Saale), Germany

Torti S.,Max Planck Institute for Plant Breeding Research | Torti S.,Nomad Bioscience GmbH | Fornara F.,Max Planck Institute for Plant Breeding Research | Fornara F.,University of Milan
Plant Signaling and Behavior | Year: 2012

Arabidopsis plants flower in response to long days (LDs). Exposure of leaves to inductive day lengths activates expression of FLOWERING LOCUS T (FT) protein which moves to the shoot apical meristem (SAM) to induce developmental reprogramming. SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) and FRUITFULL (FUL) are induced by FT at the apex. We previously screened the SAM for mRNAs of genes required to promote the floral transition in response to photoperiod, and conducted detailed expression and functional analyses on several putative candidates. Here, we show that expression of AGAMOUS-LIKE 24 (AGL24) is detected at the SAM under SD conditions and increases upon exposure to LDs. Mutations in AGL24 further delay flowering of a soc1 ful double mutant, suggesting that flowering is controlled by AGL24 partly independently of SOC1 and FUL. © 2012 Landes Bioscience.

Geissler R.,Martin Luther University of Halle Wittenberg | Scholze H.,Martin Luther University of Halle Wittenberg | Hahn S.,Martin Luther University of Halle Wittenberg | Hahn S.,Nomad Bioscience GmbH | And 4 more authors.
PLoS ONE | Year: 2011

TAL (transcription activator-like) effectors are translocated by Xanthomonas bacteria into plant cells where they activate transcription of target genes. DNA target sequence recognition occurs in a unique mode involving a central domain of tandem repeats. Each repeat recognizes a single base pair in a contiguous DNA sequence and a pair of adjacent hypervariable amino acid residues per repeat specifies which base is bound. Rearranging the repeats allows the design of novel TAL proteins with predictable DNA-recognition specificities. TAL protein-based transcriptional activation in plant cells is mediated by a C-terminal activation domain (AD). Here, we created synthetic TAL proteins with designed repeat compositions using a novel modular cloning strategy termed "Golden TAL Technology". Newly programmed TAL proteins were not only functional in plant cells, but also in human cells and activated targeted expression of exogenous as well as endogenous genes. Transcriptional activation in different human cell lines was markedly improved by replacing the TAL-AD with the VP16-AD of herpes simplex virus. The creation of TAL proteins with potentially any desired DNA-recognition specificity allows their versatile use in biotechnology. © 2011 Geiβler et al.

Dorokhov Y.L.,Russian Academy of Sciences | Komarova T.V.,Moscow State University | Petrunia I.V.,Russian Academy of Sciences | Frolova O.Y.,Russian Academy of Sciences | And 2 more authors.
PLoS Pathogens | Year: 2012

Many plants release airborne volatile compounds in response to wounding due to pathogenic assault. These compounds serve as plant defenses and are involved in plant signaling. Here, we study the effects of pectin methylesterase (PME)-generated methanol release from wounded plants ("emitters") on the defensive reactions of neighboring "receiver" plants. Plant leaf wounding resulted in the synthesis of PME and a spike in methanol released into the air. Gaseous methanol or vapors from wounded PME-transgenic plants induced resistance to the bacterial pathogen Ralstonia solanacearum in the leaves of non-wounded neighboring "receiver" plants. In experiments with different volatile organic compounds, gaseous methanol was the only airborne factor that could induce antibacterial resistance in neighboring plants. In an effort to understand the mechanisms by which methanol stimulates the antibacterial resistance of "receiver" plants, we constructed forward and reverse suppression subtractive hybridization cDNA libraries from Nicotiana benthamiana plants exposed to methanol. We identified multiple methanol-inducible genes (MIGs), most of which are involved in defense or cell-to-cell trafficking. We then isolated the most affected genes for further analysis: β-1,3-glucanase (BG), a previously unidentified gene (MIG-21), and non-cell-autonomous pathway protein (NCAPP). Experiments with Tobacco mosaic virus (TMV) and a vector encoding two tandem copies of green fluorescent protein as a tracer of cell-to-cell movement showed the increased gating capacity of plasmodesmata in the presence of BG, MIG-21, and NCAPP. The increased gating capacity is accompanied by enhanced TMV reproduction in the "receivers". Overall, our data indicate that methanol emitted by a wounded plant acts as a signal that enhances antibacterial resistance and facilitates viral spread in neighboring plants. © 2012 Dorokhov et al.

Komarova T.V.,Moscow State University | Kosorukov V.S.,Russian Academy of Medical Sciences | Frolova O.Y.,Russian Academy of Sciences | Petrunia I.V.,Russian Academy of Sciences | And 3 more authors.
PLoS ONE | Year: 2011

Background: Plant biotechnology provides a valuable contribution to global health, in part because it can decrease the cost of pharmaceutical products. Breast cancer can now be successfully treated by a humanized monoclonal antibody (mAb), trastuzumab (Herceptin). A course of treatment, however, is expensive and requires repeated administrations of the mAb. Here we used an Agrobacterium-mediated transient expression system to produce trastuzumab in plant cells. Methodology/Principal Findings: We describe the cloning and expression of gene constructs in Nicotiana benthamiana plants using intron-optimized Tobacco mosaic virus- and Potato virus X-based vectors encoding, respectively, the heavy and light chains of trastuzumab. Full-size antibodies extracted and purified from plant tissues were tested for functionality and specificity by (i) binding to HER2/neu on the surface of a human mammary gland adenocarcinoma cell line, SK-BR-3, in fluorescence-activated cell sorting assay and (ii) testing the in vitro and in vivo inhibition of HER-2-expressing cancer cell proliferation. We show that plant-made trastuzumab (PMT) bound to the Her2/neu oncoprotein of SK-BR-3 cells and efficiently inhibited SK-BR-3 cell proliferation. Furthermore, mouse intraperitoneal PMT administration retarded the growth of xenografted tumors derived from human ovarian cancer SKOV3 Her2+ cells. Conclusions/Significance: We conclude that PMT is active in suppression of cell proliferation and tumor growth. © 2011 Komarova et al.

Engler C.,Nomad Bioscience GmbH | Marillonnet S.,Leibniz Institute of Plant Biochemistry
Methods in Molecular Biology | Year: 2013

A basic requirement for synthetic biology is the availability of efficient DNA assembly methods. We have previously reported the development of Golden Gate cloning, a method that allows parallel assembly of multiple DNA fragments in a one-tube reaction. Golden Gate cloning can be used for different levels of construct assembly: from gene fragments to complete gene coding sequences, from basic genetic elements to full transcription units, and finally from transcription units to multigene constructs. We provide here a protocol for DNA assembly using Golden Gate cloning, taking as an example the level of assembly of gene fragments to complete coding sequences, a level of cloning that can be used to perform DNA shuffling. Such protocol requires the following steps: (1) selecting fusion sites within parental sequences (sites at which parental sequences will be recombined), (2) amplifying all DNA fragments by PCR to add flanking restriction sites, (3) cloning the amplified fragments in intermediate constructs, and (4) assembling all or selected sets of intermediate constructs in a compatible recipient vector using a one-pot restriction-ligation. © 2013 Springer Science+Business Media, New York.

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