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- Abd El-Daim, Islam Ahmed Moustafa, et al.
(författare)
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Identifying potential molecular factors involved in Bacillus amyloliquefaciens 5113 mediated abiotic stress tolerance in wheat
- 2018
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Ingår i: Plant Biology. - : Wiley. - 1435-8603 .- 1438-8677. ; 20, s. 271-279
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Tidskriftsartikel (refereegranskat)abstract
- Abiotic stressors are main limiting factors for agricultural production around the world. Plant growth-promoting bacteria have been successfully used to improve abiotic stress tolerance in several crops including wheat. However, the molecular changes involved in the improvement of stress management are poorly understood. The present investigation addressed some molecular factors involved in bacterially induced plant abiotic stress responses by identifying differentially expressed genes in wheat (Triticum aestivum) seedlings treated with the beneficial bacterium Bacillus amyloliquefaciens subsp. plantarum UCMB5113 prior to challenge with abiotic stress conditions such as heat, cold or drought. cDNA-AFLP analysis revealed differential expression of more than 200 transcript-derived fragments (TDFs) in wheat leaves. Expression of selected TDFs was confirmed using RT-PCR. DNA sequencing of 31 differentially expressed TDFs revealed significant homology with both known and unknown genes in database searches. Virus-induced gene silencing of two abscisic acid-related TDFs showed different effects upon heat and drought stress. We conclude that treatment with B.amyloliquefaciens 5113 caused molecular modifications in wheat in order to induce tolerance against heat, cold and drought stress. Bacillus treatment provides systemic effects that involve metabolic and regulatory functions supporting both growth and stress management.
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| 2. |
- Bejai, Sarosh, et al.
(författare)
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ML3: a novel regulator of herbivory-induced responses in Arabidopsis thaliana
- 2013
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Ingår i: Journal of Experimental Botany. - : Oxford University Press (OUP). - 0022-0957 .- 1460-2431. ; 64, s. 935-948
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Tidskriftsartikel (refereegranskat)abstract
- ML (MD2-related lipid recognition) proteins are known to enhance innate immune responses in mammals. This study reports the analysis of the putative ML gene family in Arabidopsis thaliana and suggests a role for the ML3 gene in herbivory-associated responses in plants. Feeding by larvae of the Lepidopteran generalist herbivore Spodoptera littoralis and larvae of the specialist herbivore Plutella xylostella activated ML3 transcription in leaf tissues. ML3 loss-of-function Arabidopsis plants were compromised in the upregulation of herbivory-induced genes and displayed a semi-dwarf phenotype. Herbivory bioassays showed that larvae of S. littoralis fed on ml3 mutant plants gained more weight compared to larvae fed on wild-type plants while larvae of P. xylostella did not show any significant difference. Virus-induced gene silencing of ML3 expression in plants compromised in jasmonic acid (JA) and salicylic acid (SA) signalling revealed a complex role of ML3 in JA/defence signalling affecting both JA- and SA-dependent responses. The data suggest that ML3 is involved in herbivory-mediated responses in Arabidopsis and that it has a potential role in herbivory-associated molecular pattern recognition.
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| 3. |
- Fridborg, Ingela
(författare)
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A genetic approach to the identification of new components regulating development in Arabidopsis thaliana
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Two new genes involved in important processes of plant development were identified in the model plant Arabidopsis thaliana. The genes were isolated from mutants generated through insertional mutagenesis based on a transposon tagging approach.The first gene, ALB3, was isolated through the identification of the mutant albino3 (alb3), displaying severe defects in pigmentation and chloroplast biogenesis. The ALB3 protein shows sequence similarity to a yeast protein, OXA1, which is required in the mitochondria for proper assembly of the cytochrome oxidase complex. As ALB3 is localised in thylakoid membranes, we suggest that the ALB3 protein acts in the assembly of thylakoid membrane protein complexes and thereby is crucial for proper chloroplast development and function.The second gene, SHI, was identified through the short internodes (shi) mutation, a dwarfing mutation conferring a phenotype similar to mutants defective in the biosynthesis of the plant hormone gibberellin (GA). However, the shi mutant is unable to elongate following treatment with exogenous GA, which indicates that shi is defective in the response to GA. The level of active GA is elevated in the shi mutant, which is the expected result of reduced feedback control of GA biosynthesis. As the shi mutant phenotype is the result of overexpression of the SHI gene, we suggest that the SHI protein is a component of the GA signalling pathway, possibly acting as a repressor of GA-induced cell elongation.Sequence similarity database searches revealed that the SHI gene belongs to a new Arabidopsis gene family comprising at least eight members (SHI, LRP1, and SRS1 to SRS6). These genes encode regulatory proteins containing a putative zinc-binding RING finger-like domain. We have cloned SRS1 and SRS2, and have shown by overexpression of these genes in transgenic Arabidopsis that their gene products might function in similar processes as SHI.
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| 4. |
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| 5. |
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| 6. |
- Fridborg, Ingela, et al.
(författare)
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Varied response of Spodoptera littoralis against Arabidopsis thaliana with metabolically engineered glucosinolate profiles
- 2012
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Ingår i: Plant Physiology and Biochemistry. - : Elsevier BV. - 0981-9428 .- 1873-2690. ; 50, s. 72-78
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Tidskriftsartikel (refereegranskat)abstract
- Upon herbivory glucosinolates are known to be degraded into a cascade of secondary products that can be detrimental for certain herbivores. We performed herbivory bioassays using first and second instar generalist Lepidoptera larvae Spodoptera littoralis on Arabidopsis thaliana engineered to overexpress novel glucosinolates. A differential response in larval feeding patterns was observed on the plants engineered with novel glucosinolates. Larvae fed on plants overexpressing 4-hydroxybenzyl glucosinolate and isopropyl glucosinolate showed little response. Larvae fed on 35S:CYP79A2 plants engineered to overexpress benzyl glucosinolates, however, showed reduced larval and pupal weights. Upon herbivory a high expression of JA signalling gene LOX2 was observed on the 35S:CYP79A2 plants compared to the PR1a and VSP2 expression. To confirm the role of benzyl isothiocyanate (BITC), a degradation product of benzyl glucosinolate overexpressing plants, in the retarded larval growth we used Virus Induced Gene Silencing (VIGS) approach to silence LOX2 expression in the 35S:CYP79A2 plants. S. littoralis larvae fed on LOX2 silenced 35S:CYP79A2 plants exhibited a retarded larval growth thus indicating that BITC played a pivotal role in anti-herbivory and not only the JA signalling pathway. (C) 2011 Elsevier Masson SAS. All rights reserved.
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| 7. |
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| 8. |
- Martin, Thomas, et al.
(författare)
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A highly conserved NB-LRR encoding gene cluster effective against Setosphaeria turcica in sorghum
- 2011
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Ingår i: BMC Plant Biology. - : Springer Science and Business Media LLC. - 1471-2229. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Conclusions: Resistance genes to S. turcica, with a CC-NB-LRR protein domain architecture, have been found in maize and sorghum. VIGS analysis revealed their importance in the surveillance to S. turcica in sorghum. The St genes are highly conserved in sorghum, rice, foxtail millet, maize and Brachypodium, suggesting an essential evolutionary function.
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| 9. |
- Martin, Thomas, et al.
(författare)
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Two loci in sorghum with NB-LRR encoding genes confer resistance to Colletotrichum sublineolum
- 2012
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Ingår i: TAG Theoretical and Applied Genetics. - : Springer Science and Business Media LLC. - 0040-5752 .- 1432-2242. ; 124, s. 1005-1015
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this work was to identify plant resistance genes to the sorghum anthracnose fungus Colletotrichum sublineolum. cDNA-AFLP transcript profiling on two contrasting sorghum genotypes inoculated with C. sublineolum generated about 3,000 informative fragments. In a final set of 126 sequenced genes, 15 were identified as biotic stress related. Seven of the plant-derived genes were selected for functional analysis using a Brome mosaic virus-based virus-induced gene silencing (VIGS) system followed by fungal inoculation and quantitative real-time PCR analysis. The candidate set comprised genes encoding resistance proteins (Cs1A, Cs2A), a lipid transfer protein (SbLTP1), a zinc finger-like transcription factor (SbZnTF1), a rice defensin-like homolog (SbDEFL1), a cell death related protein (SbCDL1), and an unknown gene harboring a casein kinase 2-like domain (SbCK2). Our results demonstrate that down-regulation of Cs1A, Cs2A, SbLTP1, SbZnF1 and SbCD1 via VIGS, significantly compromised the resistance response while milder effects were observed with SbDEFL1 and SbCK2. Expanded genome analysis revealed that Cs1A and Cs2A genes are located in two different loci on chromosome 9 closely linked with duplicated genes Cs1B and Cs2B, respectively. The nucleotide binding-leucine rich repeat (NB-LRR) encoding Cs gene sequence information is presently employed in regional breeding programs.
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