scholarly journals Tomato transgenic plants expressing hairpin construct of a nematode protease gene conferred enhanced resistance to root-knot nematodes

2015 ◽  
Vol 6 ◽  
Author(s):  
Tushar K. Dutta ◽  
Pradeep K. Papolu ◽  
Prakash Banakar ◽  
Divya Choudhary ◽  
Anil Sirohi ◽  
...  
2004 ◽  
Vol 84 (3) ◽  
pp. 785-790 ◽  
Author(s):  
Jianhong Yao, Xiuyun Zhao ◽  
Huaxiong Qi, Bingliang Wan ◽  
Fei Chen, Xiaofen Sun ◽  
Shanqian Yu ◽  
Kexuan Tang

Tobacco leaf discs were transformed with a plasmid, pBIAHA, containing the selectable marker neomycin phosphotransferase gene (nptII) and an Arisaema heterophyllum agglutinin gene (aha) via Agrobacterium tumefaciens-mediated transformation. Thirty-two independent transgenic tobacco plants were regenerated. PCR and Southern blot analyses confirmed that multiple copies of the aha gene had integrated into the plant genome. Northern blot analysis revealed that the aha gene was expressed at various levels in the transgenic plants. Insect bioassay test showed that transgenic plants expressing multiple copies of the aha gene reduced the rate of population increase of the peach potato aphid (Myzus persicae Sulzer). This is the first report that transgenic tobacco plants expressing the aha gene display enhanced resistance to aphids. Key words: Insect bioassay, Arisaema heterophyllum agglutinin, transformation, transgenic tobacco, peach potato aphid (Myzus persicae Sulzer)


2020 ◽  
Vol 110 (5) ◽  
pp. 1056-1066 ◽  
Author(s):  
Guixia Hao ◽  
Matthew G. Bakker ◽  
Hye-Seon Kim

The fungal pathogen Fusarium graminearum causes Fusarium head blight (FHB) on wheat, barley, and other grains. FHB results in yield reductions and contaminates grain with trichothecene mycotoxins, which threaten food safety and food security. Innovative mechanisms for controlling FHB are urgently needed. We have previously shown that transgenic tobacco and citrus plants expressing a modified thionin (Mthionin) exhibited enhanced resistance toward several bacterial pathogens. The aim of this study was to investigate whether overexpression of Mthionin could be similarly efficacious against F. graminearum, and whether transgenic expression of Mthionin impacts the plant microbiome. Transgenic Arabidopsis plants expressing Mthionin were generated and confirmed. When challenged with F. graminearum, Mthionin-expressing plants showed less disease and fungal biomass in both leaves and inflorescences compared with control plants. When infiltrated into leaves, macroconidia of F. graminearum germinated at lower rates and produced less hyphal growth in Arabidopsis leaves expressing Mthionin. Moreover, marker genes related to defense signaling pathways were expressed at significantly higher levels after F. graminearum infection in Mthionin transgenic Arabidopsis plants. However, Mthionin expression did not appreciably alter the overall microbiome associated with transgenic plants grown under controlled conditions; across leaves and roots of Mthionin-expressing and control transgenic plants, only a few bacterial and fungal taxa differed, and differences between Mthionin transformants were of similar magnitude compared with control plants. In sum, our data indicate that Mthionin is a promising candidate to produce transgenic crops for reducing FHB severity and ultimately mycotoxin contamination.


2011 ◽  
Vol 24 (7) ◽  
pp. 839-848 ◽  
Author(s):  
Leonardo F. da Silva ◽  
Cristiano V. Dias ◽  
Luciana C. Cidade ◽  
Juliano S. Mendes ◽  
Carlos P. Pirovani ◽  
...  

Oxalic acid (OA) and Nep1-like proteins (NLP) are recognized as elicitors of programmed cell death (PCD) in plants, which is crucial for the pathogenic success of necrotrophic plant pathogens and involves reactive oxygen species (ROS). To determine the importance of oxalate as a source of ROS for OA- and NLP-induced cell death, a full-length cDNA coding for an oxalate decarboxylase (FvOXDC) from the basidiomycete Flammulina velutipes, which converts OA into CO2 and formate, was overexpressed in tobacco plants. The transgenic plants contained less OA and more formic acid compared with the control plants and showed enhanced resistance to cell death induced by exogenous OA and MpNEP2, an NLP of the hemibiotrophic fungus Moniliophthora perniciosa. This resistance was correlated with the inhibition of ROS formation in the transgenic plants inoculated with OA, MpNEP2, or a combination of both PCD elicitors. Taken together, these results have established a pivotal function for oxalate as a source of ROS required for the PCD-inducing activity of OA and NLP. The results also indicate that FvOXDC represents a potentially novel source of resistance against OA- and NLP-producing pathogens such as M. perniciosa, the causal agent of witches' broom disease of cacao (Theobroma cacao L.).


2004 ◽  
Vol 2 (3) ◽  
pp. 25-31
Author(s):  
Elena A Andreeva ◽  
Ludmila A Lutova

Using agrobacterial transformation collection of /pr-transgenic plants based on cv. Adretta was obtained. Analysis of transgenic plants susceptibility to the exogenous phytohormones auxin (IAA) and cytokinin (kinetin) for 18 from 22 analyzed forms reveals altered reaction to hormones. Among 18 plants with altered reaction to phytohormones for 16 forms enhanced resistance to copper sulfate and/or nickel chloride was observed


2014 ◽  
Vol 5 ◽  
Author(s):  
Erich Y. T. Nakasu ◽  
Martin G. Edwards ◽  
Elaine Fitches ◽  
John A. Gatehouse ◽  
Angharad M. R. Gatehouse

2014 ◽  
Vol 27 (10) ◽  
pp. 1159-1169 ◽  
Author(s):  
Laura Campos ◽  
Purificación Lisón ◽  
María Pilar López-Gresa ◽  
Ismael Rodrigo ◽  
Laura Zacarés ◽  
...  

Hydroxycinnamic acid amides (HCAA) are secondary metabolites involved in plant development and defense that have been widely reported throughout the plant kingdom. These phenolics show antioxidant, antiviral, antibacterial, and antifungal activities. Hydroxycinnamoyl-CoA:tyramine N-hydroxycinnamoyl transferase (THT) is the key enzyme in HCAA synthesis and is induced in response to pathogen infection, wounding, or elicitor treatments, preceding HCAA accumulation. We have engineered transgenic tomato plants overexpressing tomato THT. These plants displayed an enhanced THT gene expression in leaves as compared with wild type (WT) plants. Consequently, leaves of THT-overexpressing plants showed a higher constitutive accumulation of the amide coumaroyltyramine (CT). Similar results were found in flowers and fruits. Moreover, feruloyltyramine (FT) also accumulated in these tissues, being present at higher levels in transgenic plants. Accumulation of CT, FT and octopamine, and noradrenaline HCAA in response to Pseudomonas syringae pv. tomato infection was higher in transgenic plants than in the WT plants. Transgenic plants showed an enhanced resistance to the bacterial infection. In addition, this HCAA accumulation was accompanied by an increase in salicylic acid levels and pathogenesis-related gene induction. Taken together, these results suggest that HCAA may play an important role in the defense of tomato plants against P. syringae infection.


2003 ◽  
Author(s):  
Radi Aly ◽  
James H. Westwood ◽  
Carole L. Cramer

Our overall goal was to engineer crop plants with enhanced resistance to Orobanche (broomrape) based on the inducible expression of sarcotoxin-like peptide (SLP). A secondary objective was to localize small proteins such as SLP in the host-parasite union in order to begin characterizing the mechanism of SLP toxicity to Orobanche. We have successfully accomplished both of these objectives and have demonstrated that transgenic tobacco plants expressing SLP under control of the HMG2 promoter show enhanced resistance to O. aegyptiaca and O. ramosa . Furthermore, we have shown that proteins much larger than the SLP move into Orobanche tubercles from the host root via either symplastic or apoplastic routes. This project was initiated with the finding that enhanced resistance to Orobanche could be conferred on tobacco, potato, and tomato by expression of SLP (Sarcotoxin IA is a 40-residue peptide produced as an antibiotic by the flesh fly, Sarcophaga peregrina ) under the control of a low-level, root-specific promoter. To improve the level of resistance, we linked the SLP gene to the promoter from HMG2, which is strongly inducible by Orobanche as it parasitizes the host. The resulting transgenic plants express SLP and show increased resistance to Orobanche. Resistance in this case is manifested by increased growth and yield of the host in the presence of the parasite as compared to non-transgenic plants, and decreased parasite growth. The mechanism of resistance appears to operate post-attachment as the parasite tubercles attached to the transgenic root plants turned necrotic and failed to develop normally. Studies examining the movement of GFP (approximately 6X the size of SLP) produced in tobacco roots showed accumulation of green fluorescence in tubercles growing on transformed plants but not in those growing on wild-type plants. This accumulation occurs regardless of whether the GFP is targeted to the cytoplasm (translocated symplastically) or the apoplastic space (translocated in xylem). Plants expressing SLP appear normal as compared to non-transgenic plants in the absence of Orobanche, so there is no obvious unintended impact on the host plant from SLP expression. This project required the creation of several gene constructs and generation of many transformed plant lines in order to address the research questions. The specific objectives of the project were to: 1. Make gene constructs fusing Orobanche-inducible promoter sequences to either the sarcotoxin-like peptide (SLP) gene or the GFP reporter gene. 2. Create transgenic plants containing gene constructs. 3. Characterize patterns of transgene expression and host-to-parasite movement of gene products in tobacco ( Nicotiana tabacum L.) and Arabidopsis thaliana (L.). 4. Characterize response of transgenic potato ( Solanum tuberosum L.) and tomato ( Lycopersicon esculentum Mill .) to Orobanche in lab, greenhouse, and field. Objectives 1 and 2 were largely accomplished during the first year during Dr. Aly's sabbatical visit to Virginia Tech. Transforming and analyzing plants with all the constructs has taken longer than expected, so efforts have concentrated on the most important constructs. Work on objective 4 has been delayed pending the final results of analysis on tobacco and Arabidopsis transgenic plants. The implications of this work are profound, because the Orobanche spp. is an extremely destructive weed that is not controlled effectively by traditional cultural or herbicidal weed control strategies. This is the first example of engineering resistance to parasitic weeds and represents a unique mode of action for selective control of these weeds. This research highlights the possibility of using this technique for resistance to other parasitic species and demonstrates the feasibility of developing other novel strategies for engineering resistance to parasitic weeds.


1993 ◽  
pp. 265-276 ◽  
Author(s):  
Richard Broglie ◽  
Karen Broglie ◽  
Dominique Roby ◽  
Ilan Chet

Science ◽  
1991 ◽  
Vol 254 (5035) ◽  
pp. 1194-1197 ◽  
Author(s):  
K. BROGUE ◽  
I. CHET ◽  
M. HOLLIDAY ◽  
R. CRESSMAN ◽  
P. BIDDLE ◽  
...  

2013 ◽  
Author(s):  
Eric L. Davis ◽  
Yuji Oka ◽  
Amit Gal-On ◽  
Todd Wehner ◽  
Aaron Zelcer

Root-knot nematodes (RKN), Meloidogyne spp., are extremely destructive pathogens of cucurbit crops grown in the United States and Israel. The safety and environmental concerns of toxic nematicides, and limited sources of natural cucurbit resistance to the four major species of Meloidogyne that threaten these crops in Israel and the U.S., have emphasized the use of biotechnology to develop cucurbits with novel RKN resistance. The U.S. scientists have identified over 40 unique RKN parasitism genes that encode nematode secretions involved in successful plant root infection by RKN, and they have demonstrated that expression of a double-stranded RNA (dsRNA) complementary to a RKN parasitism gene (called 16DIO) in Arabidopsis thaliana induced RNA interference (RNAi)-mediated silencing of the RKN16DlO gene and produced transgenic plants with strong resistance to all four major RKN species. The expression 8D05 parasitism gene was found to coincide with the timing of upregulation of NtCel7 promoter (identified to be upregulated in giantcells by US scientists). NtCel7 promoter was used to express the genes at the right time (early stages of infection) and in the right place (giant-cells) in transgenic plants. US partners produced NtCel7 (nematode-induced promoter)-driven 16DlO-RNAi and 8DOS-RNAi constructs, pHANNIBAL 4D03-RNAi construct and modified 16DlO-RNAi construct (for increased RNAi expression and efficacy) for cucurbit transformation in Israel. In Arabidopsis, some 16DlO-RNAi plant lines show greater levels of resistance to M. incognita than others, and within these lines resistance of greater than 90% reduction in infection is observed among almost all replicates in US. The level of observed nematode resistance is likely to be directly correlated with the level of RNAi expression in individual plants. In Israel, all the RKN parasitism genes-RNAi constructs were successfully transformed into cucumber and melon. The transgenic lines were evaluated for expression of the transgene siRNA in leaves and roots. Those displaying transgene siRNA accumulation were passed on for nematode resistance analysis. Rl seedlings from different lines were subjected to evaluation for resistance to M. javanica. None of the lines was resistant to the nematode in contrast with US partner's results in Arabidopsis. This could be for the following reasons: a) The level of transgene siRNA was insufficient in cucumber and tomato to cause resislance. b) 111e nemalode species on cucwnber IIlay be different ur act in a different manner. c) The assay was performed in soil with a high level of nematode inoculation, and not in petri dish, which may not permit the observation of a low level of resistance.


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