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An aphid-induced proteinase inhibitor from barley affects aphid performance in transgenic Arabidopsis
Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
(English)Manuscript (preprint) (Other academic)
National Category
Biological Sciences
Research subject
Plant Physiology
Identifiers
URN: urn:nbn:se:su:diva-126660OAI: oai:DiVA.org:su-126660DiVA: diva2:902147
Available from: 2016-02-10 Created: 2016-02-10 Last updated: 2016-02-12Bibliographically approved
In thesis
1. Candidate genes for resistance and susceptibility to the bird cherry-oat aphid (Rhopalosiphum padi L.) in barley (Hordeum vulgare L.)
Open this publication in new window or tab >>Candidate genes for resistance and susceptibility to the bird cherry-oat aphid (Rhopalosiphum padi L.) in barley (Hordeum vulgare L.)
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Bird cherry-oat aphid (Rhopalosiphum padi L.) is an important pest on spring-sown cereals. The aphid reduces yield and can act as a vector of barley yellow dwarf virus. R. padi does not give visible symptoms, but heavy infestation can reduce the yield substantially. R. padi is one of the most important pests of barley, which has the fourth rank among the cereals in global production. In order to overcome this problem, the plants are treated with pesticides. However, some of the pesticides are no longer permitted to use due to their negative environmental effects. Another problem is that the aphids develop resistance against them. Therefore, a new approach is to identify genetic factors that could be used in breeding host plants for resistance. There are many examples of successful plant breeding for resistance to aphids, but in the case of R. padi and barley, no resistant cultivar is commercially available. The aim of this thesis was to identify and characterise aphid resistance and susceptibility factors in barley. This was done using two major approaches. Firstly, constitutive and aphid-induced gene expression was studied in a large number of barley genotypes with known levels of resistance. Secondly, two cDNAs putatively adding to aphid resistance were transformed to Arabidopsis and barley and the effect of transformation on aphid performance and behaviour was evaluated.

     The study of constitutive transcript abundance in 23 barley genotypes gave suggestive evidence that two genes might be related to aphid resistance; a thionin and a proteinase inhibitor gene, and that a lipoxygenase gene might be related to aphid susceptibility.The study of both constitutive and aphid-induced transcript abundances of three glucanase genes, gave support to the idea that two of them might be susceptibility factors. The cDNA of the proteinase inhibitor mentioned above was expressed in Arabidopsis, under control of either a constitutive or a phloem-specific promoter and the effects were evaluated using the green peach aphid, Myzus persicae Sulzer. This aphid is a generalist, feeding on many different plant species, both monocot (such as barley) and dicot (such as Arabidopsis).  The results showed lower settling and fecundity on some of the transgenic lines as compared to on controls.  

     In conclusion, the thesis suggests a role in resistance against R. padi in barley for two genes encoding a thionin and a proteinase inhibitor. It has also given support for a role in susceptibility against R. padi of genes encoding a lipoxygenase and two glucanases. The work further shows that a cDNA from barley, selected based on the interaction between a monocot plant and an essentially monocot specialist aphid, affected the resistance of the dicot Arabidopsis against a generalist aphid.

 

 

Place, publisher, year, edition, pages
Stockholm: Department of Ecology, Environment and Plant Sciences, Stockholm University, 2016. 53 p.
Keyword
aphid resistance, aphid susceptibility, Rhopalosiphum padi, Myzus persicae, Hordeum vulgare
National Category
Genetics and Breeding
Research subject
Plant Physiology
Identifiers
urn:nbn:se:su:diva-126499 (URN)978-91-7649-339-7 (ISBN)
Public defence
2016-04-07, Vivi Täckholmsalen (Q-salen), NPQ-huset, Svante Arrhenius väg 20, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.

Available from: 2016-03-15 Created: 2016-02-04 Last updated: 2016-03-03Bibliographically approved

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Losvik, AleksandraMehrabi, SaraJonsson, Lisbeth
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