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Delp, Gabriele
Publications (9 of 9) Show all publications
Larsson, K. A. E., Saheed, S. A., Gradin, T., Delp, G., Karpinska, B., Botha, C. E. J. & Jonsson, L. M. V. (2011). Differential regulation of 3-aminomethylindole/N-methyl-3-aminomethylindole N-methyltransferase and gramine in barley by both biotic and abiotic stress conditions. Plant physiology and biochemistry (Paris), 49(1), 96-102
Open this publication in new window or tab >>Differential regulation of 3-aminomethylindole/N-methyl-3-aminomethylindole N-methyltransferase and gramine in barley by both biotic and abiotic stress conditions
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2011 (English)In: Plant physiology and biochemistry (Paris), ISSN 0981-9428, E-ISSN 1873-2690, Vol. 49, no 1, p. 96-102Article in journal (Refereed) Published
Abstract [en]

The expression of NMT (3-aminomethylindole/N-methyl-3-aminomethylindole N-methyltransferase; EC 2.1.1.), involved in the biosynthesis of the indole alkaloid gramine, was investigated in aphid-infested barley (Hordeum vulgare L). NMT is induced by methyl jasmonate and it was hypothesized that the gene would be more strongly upregulated in aphid-resistant barley. We examined the effects of feeding by three aphid species; Russian wheat aphid (Diuraphis noxia Mordvilko), rose-grain aphid (Metopolophium dirhodum Walker) and bird cherry-oat aphid (Rhopalosiphum padi L.) on barley genotypes with varying resistance characteristics. The barley genotypes selected included the cultivar Libra, known to upregulate gramine after feeding by Schizaphis graminum. Infestation by R. padi and M. dirhodum resulted in higher NMT expression in the doubled haploid line 5172-28:4 (DH28:4), which has moderate resistance against R. padi, but not in other aphid barley combinations. None of the aphid plant combinations had however increased gramine, suggesting that aphid-induction of gramine is specific to S. graminum. The increased abundance of NMT transcript in aphid-infested DH28:4 did not lead to higher amounts of NMT protein or NMT enzyme activity, neither did 200 times upregulation of NMT transcript in cotyledons incubated with methyl jasmonate, illustrating that even large differences measured at transcript level may have no metabolic consequences. Drought stress or treatments with abscisic acid did lead to higher gramine concentrations in several barley cultivars, but without any concomitant increase of NMT transcripts. Thus, the regulation of the biosynthetic pathway to gramine at transcript and metabolite level diverges during two different stress conditions.

National Category
Botany
Identifiers
urn:nbn:se:sh:diva-14982 (URN)10.1016/j.plaphy.2010.10.005 (DOI)000286998800014 ()2-s2.0-78650257385 (Scopus ID)
Available from: 2012-01-24 Created: 2012-01-24 Last updated: 2017-12-08Bibliographically approved
Delp, G., Gradin, T., Ahman, I. & Jonsson, L. M. V. (2009). Microarray analysis of the interaction between the aphid Rhopalosiphum padi and host plants reveals both differences and similarities between susceptible and partially resistant barley lines. Molecular Genetics and Genomics, 281(3), 233-248
Open this publication in new window or tab >>Microarray analysis of the interaction between the aphid Rhopalosiphum padi and host plants reveals both differences and similarities between susceptible and partially resistant barley lines
2009 (English)In: Molecular Genetics and Genomics, ISSN 1617-4615, E-ISSN 1617-4623, Vol. 281, no 3, p. 233-248Article in journal (Refereed) Published
Abstract [en]

The bird cherry-oat aphid (Rhopalosiphum padi L.) is an important pest on cereals causing plant growth reduction without specific leaf symptoms. Breeding of barley (Hordeum vulgare L.) for R. padi resistance shows that there are several resistance genes, reducing aphid growth. To identify candidate sequences for resistance-related genes, we performed microarray analysis of gene expression after aphid infestation in two susceptible and two partially resistant barley genotypes. One of the four lines is a descendant of two of the other genotypes. There were large differences in gene induction between the four lines, indicating substantial variation in response even between closely related genotypes. Genes induced in aphid-infested tissue were mainly related to defence, primary metabolism and signalling. Only 24 genes were induced in all lines, none of them related to oxidative stress or secondary metabolism. Few genes were down-regulated, with none being common to all four lines. There were differences in aphid-induced gene regulation between resistant and susceptible lines. Results from control plants without aphids also revealed differences in constitutive gene expression between the two types of lines. Candidate sequences for induced and constitutive resistance factors have been identified, among them a proteinase inhibitor, a serine/threonine kinase and several thionins.

National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:sh:diva-13916 (URN)10.1007/s00438-008-0409-3 (DOI)000263684900001 ()19085010 (PubMedID)2-s2.0-61349106523 (Scopus ID)
Available from: 2011-12-14 Created: 2011-12-14 Last updated: 2017-12-08Bibliographically approved
Saheed, S., Cierlik, I., Larsson, K. A. E., Delp, G., Bradley, G., Jonsson, L. M. V. & Botha, C. E. J. (2009). Stronger induction of callose deposition in barley by Russian wheat aphid than bird cherry-oat aphid is not associated with differences in callose synthase or beta-1,3-glucanase transcript abundance. Physiologia Plantarum, 135(2), 150-161
Open this publication in new window or tab >>Stronger induction of callose deposition in barley by Russian wheat aphid than bird cherry-oat aphid is not associated with differences in callose synthase or beta-1,3-glucanase transcript abundance
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2009 (English)In: Physiologia Plantarum, ISSN 0031-9317, E-ISSN 1399-3054, Vol. 135, no 2, p. 150-161Article in journal (Refereed) Published
Abstract [en]

The effects of infestation by the bird cherry-oat aphid (BCA), (Rhopalosiphum padi L) and the Russian wheat aphid (RWA) (Diuraphis noxia Mordvilko) on callose deposition and transcription of genes related to callose accumulation were investigated in barley (Hordeum vulgare L. cv. Clipper). The BCA, which gives no visible symptoms, induced very limited callose deposition, even after 14 days of infestation. In contrast, RWA, which causes chlorosis, white and yellow streaking and leaf rolling, induced callose accumulation already after 24 h in longitudinal leaf veins. The deposition was pronounced after 72 h, progressing during 7 and 14 days of infestation. In RWA-infested source leaves, callose was also induced in longitudinal veins basipetal to the aphid-infested tissue, whereas in sink leaves, more callose deposition was found above the feeding sites. Eight putative callose synthase genes were identified in a database search, of which seven were expressed in the leaves, but with similar transcript accumulation in control and aphid-infested tissue. Five out of 12 examined beta-1,3-glucanases were expressed in the leaves. All five were upregulated in RWA-infested tissue, but only two in BCA-infested tissue, and to a lesser extent than by RWA. The results suggest that callose accumulation may be partly responsible for the symptoms resulting from RWA infestation and that a callose-inducing signal may be transported in the phloem. Furthermore, it is concluded that the absence of callose deposition in BCA-infested leaves is not because of a stronger upregulation of callose-degrading beta-1,3-glucanases in this tissue, as compared to RWA-infested leaves.

National Category
Botany
Identifiers
urn:nbn:se:sh:diva-13924 (URN)10.1111/j.1399-3054.2008.01180.x (DOI)000262487300005 ()19055542 (PubMedID)2-s2.0-58249120624 (Scopus ID)
Available from: 2011-12-14 Created: 2011-12-14 Last updated: 2022-05-10Bibliographically approved
Ban, L., Ahmed, E., Ninkovic, V., Delp, G. & Glinwood, R. (2008). Infection with an insect virus affects olfactory behaviour and interactions with host plant and natural enemies in an aphid. Entomologia Experimentalis et Applicata, 127(2), 108-117
Open this publication in new window or tab >>Infection with an insect virus affects olfactory behaviour and interactions with host plant and natural enemies in an aphid
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2008 (English)In: Entomologia Experimentalis et Applicata, ISSN 0013-8703, E-ISSN 1570-7458, Vol. 127, no 2, p. 108-117Article in journal (Refereed) Published
Abstract [en]

Aphid ecology and population dynamics are affected by a series of factors including behavioural responses to ecologically relevant chemical cues, capacity for population growth, and interactions with host plants and natural enemies. Using the aphid Rhopalosiphum padi (L.) (Homoptera: Aphididae), we showed that these factors were affected by infection with Rhopalosiphum padi virus (RhPV). Uninfected aphids were attracted to odour of uninfected aphids on the host plant, an aggregation mechanism. However, infected aphids were not attracted, and neither infected nor uninfected aphids were attracted to infected aphids on the plant. Infected aphids did not respond to methyl salicylate, a cue denoting host suitability. Infected aphids were more behaviourally sensitive to aphid alarm pheromone, and left the host plant more readily in response to it. RhPV reduced the lifespan and population growth rate of the aphid. The predacious ladybird, Coccinella septempunctata (L.) (Coleoptera: Coccinellidae), consumed more infected aphids than uninfected aphids in a 24-h period, and the aphid parasitoid Aphidius ervi Haliday (Hymenoptera: Aphidiidae) attacked more infected than uninfected aphids. However, the proportion of mummies formed was lower with infected aphids. The results represent further evidence that associated organisms can affect the behaviour and ecology of their aphid hosts.

National Category
Biological Sciences
Identifiers
urn:nbn:se:sh:diva-14158 (URN)10.1111/j.1570-7458.2008.00675.x (DOI)000255060200004 ()2-s2.0-42449153871 (Scopus ID)
Available from: 2011-12-18 Created: 2011-12-16 Last updated: 2017-12-08Bibliographically approved
Ban, L., Didon, A., Jonsson, L. M., Glinwood, R. & Delp, G. (2007). An improved detection method for the Rhopalosiphum padi virus (RhPV) allows monitoring of its presence in aphids and movement within plants. Journal of Virological Methods, 142(1-2), 136-142
Open this publication in new window or tab >>An improved detection method for the Rhopalosiphum padi virus (RhPV) allows monitoring of its presence in aphids and movement within plants
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2007 (English)In: Journal of Virological Methods, ISSN 0166-0934, E-ISSN 1879-0984, Vol. 142, no 1-2, p. 136-142Article in journal (Refereed) Published
Abstract [en]

Rhopalosiphumpadi virus (RhPV) is an insect RNA virus that infects aphids, reducing their lifespan and fecundity. It can be transmitted vertically between aphids and horizontally via the plant. An improved detection method for the virus in aphids and plants using RT-PCR was developed; this allowed individual aphids to be tested for RhPV. Testing of R. padi aphids collected from different sites in Sweden revealed the presence of RhPV in wild aphid populations for the first time in Europe. Virus could be detected in several life stages of R. padi, including sexual individuals and eggs, establishing an over-wintering route for the virus. Using RT-PCR, systemic transport of the virus in plants was tracked. Virus spread from the aphid feeding site to all parts of the plant, including roots, within 7 days, and could be acquired by virus-free aphids feeding on the same plant.

National Category
Biochemistry and Molecular Biology Microbiology
Identifiers
urn:nbn:se:sh:diva-14222 (URN)10.1016/j.jviromet.2007.01.014 (DOI)000246675900018 ()17328968 (PubMedID)2-s2.0-34247144526 (Scopus ID)
Available from: 2011-12-19 Created: 2011-12-19 Last updated: 2017-12-08Bibliographically approved
Saheed, S. A., Larsson, K. A. E., Delp, G., Botha, C. E., Jonsson, L. M. V. & Bradley, G. (2007). Wound callose synthesis in response to Russian wheat aphid and Bird cherry-oat aphid feeding on barley ev Clipper. South African Journal of Botany, 73(2), 310-310
Open this publication in new window or tab >>Wound callose synthesis in response to Russian wheat aphid and Bird cherry-oat aphid feeding on barley ev Clipper
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2007 (English)In: South African Journal of Botany, ISSN 0254-6299, E-ISSN 1727-9321, Vol. 73, no 2, p. 310-310Article in journal (Refereed) Published
National Category
Biological Sciences
Identifiers
urn:nbn:se:sh:diva-35662 (URN)10.1016/j.sajb.2007.02.110 (DOI)000246312700125 ()
Available from: 2018-06-25 Created: 2018-06-25 Last updated: 2018-06-25Bibliographically approved
Larsson, K. A. E., Zetterlund, I., Delp, G. & Jonsson, L. M. V. (2006). N-Methyltransferase involved in gramine biosynthesis in barley: Cloning and characterization. Phytochemistry, 67(18), 2002-2008
Open this publication in new window or tab >>N-Methyltransferase involved in gramine biosynthesis in barley: Cloning and characterization
2006 (English)In: Phytochemistry, ISSN 0031-9422, E-ISSN 1873-3700, Vol. 67, no 18, p. 2002-2008Article in journal (Refereed) Published
Abstract [en]

The indole alkaloid gramine occurs in leaves of certain barley (Hordeum vulgare L.) cultivars but not in others. A gene sequence in barley that earlier was characterized as a jasmonate-induced O-methyltransferase (MT) (EC 2.1.1.6, GenBank accession U54767) was here found to be absent in some barley cultivars and breeding lines that all lacked gramine. The cDNA was cloned and expressed in Escherichia coli and the recombinant protein purified. The purified recombinant protein methylated two substrates in the pathway to gramine: 3-aminomethylindole (AMI) and N-methyl-3-aminomethylindole (MAMI) at a high rate, with Km-values of 77 mu M and 184 mu M, respectively. In contrast, the protein did not exhibit any detectable methylation with the earlier suggested substrate for O-methylation, caffeic acid. A number of cultivars and breeding lines of barley were analyzed for presence of the U54767 gene sequence and NIT protein and the enzyme activity in vitro with MAMI or caffeic acid as substrates. The results showed a clear relationship between the presence of the MT gene, the NIT protein and N-methyltransferase activity, and confirmed the identification of the gene as coding for an N-methyltransferase (NMT, EC 2.1.1) and being involved in gramine biosynthesis.

National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:sh:diva-14281 (URN)10.1016/j.phytochem.2006.06.036 (DOI)000241205000004 ()16930646 (PubMedID)2-s2.0-33748189395 (Scopus ID)
Available from: 2011-12-21 Created: 2011-12-20 Last updated: 2017-12-08Bibliographically approved
Gao, L. L., Knogge, W., Delp, G., Smith, F. A. & Smith, S. E. (2004). Expression patterns of defense-related genes in different types of arbuscular mycorrhizal development in wild-type and mycorrhiza-defective mutant tomato. Molecular Plant-Microbe Interactions, 17(10), 1103-1113
Open this publication in new window or tab >>Expression patterns of defense-related genes in different types of arbuscular mycorrhizal development in wild-type and mycorrhiza-defective mutant tomato
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2004 (English)In: Molecular Plant-Microbe Interactions, ISSN 0894-0282, E-ISSN 1943-7706, Vol. 17, no 10, p. 1103-1113Article in journal (Refereed) Published
Abstract [en]

The expression of defense-related genes was analyzed in the interactions of six arbuscular mycorrhizal (AM) fungi with the roots of wild-type tomato (Lycopersicon esculentum Mill.) cv. 76R and of the near-isogenic mycorrhiza-defective mutant rmc. Depending on the fungal species, wild-type tomato forms both major morphological AM types, Arum and Paris. The mutant rmc blocks the penetration of the root surface or invasion of the root cortex by most species of AM fungi, but one fungus has been shown to develop normal mycorrhizas. In the wild-type tomato, accumulation of mRNA representing a number of defense-related genes was low in Arum-type interactions, consistent with findings for this AM morphotype in other plant species. In contrast, Paris-type colonization, particularly by members of the family Gigasporaceae, was accompanied by a substantial transient increase in expression of some defense-related genes. However, the extent of root colonization did not differ significantly in the two wild-type AM morphotypes, suggesting that accumulation of defense gene products per se does not limit mycorrhiza development. In the mutant, interactions in which the fungus failed to penetrate the root lacked significant accumulation of defense gene mRNAs. However, phenotypes in which the fungus penetrated epidermal or hypodermal cells were associated with an enhanced and more prolonged gene expression. These results are discussed in relation to the mechanisms that may underlie the specificity of the interactions between AM fungi and the rmc mutant.

National Category
Biochemistry and Molecular Biology Botany
Identifiers
urn:nbn:se:sh:diva-15464 (URN)10.1094/MPMI.2004.17.10.1103 (DOI)000223943400007 ()15497403 (PubMedID)2-s2.0-4544257650 (Scopus ID)
Available from: 2012-02-21 Created: 2012-02-20 Last updated: 2017-12-07Bibliographically approved
Larsson, K. A., Saheed, S. A., Gradin, T., Delp, G., Botha, C. E. & Jonsson, L. M. V.Tissue localization and aphid-induced regulation of N-methyltransferase involved in the synthesis of gramine in barly.
Open this publication in new window or tab >>Tissue localization and aphid-induced regulation of N-methyltransferase involved in the synthesis of gramine in barly
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(English)Manuscript (preprint) (Other academic)
National Category
Biological Sciences
Identifiers
urn:nbn:se:sh:diva-16729 (URN)
Note
Som manuskript i avhandling. As manuscript in dissertation.Available from: 2012-06-29 Created: 2012-06-29 Last updated: 2012-06-29Bibliographically approved
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