Project description:To investigate the impact of a plant´s response to abiotic stress on plant defense against subsequent biotic stress, we determined the transcriptional response of Arabidopsis thaliana to low temperature stress (4°C) and subsequent mechanical wounding or larval feeding damage by the herbivores Mamestra brassicae (generalist) and Pieris brassicae (specialist). In total, 21%, 4% and 14% of all genes responsive to M. brassicae, P. brassicae or mechanical wounding were differentially regulated in previously cold-treated compared to untreated plants.
Project description:Activation of plant defence in Brassica napus L. cv. Westar and transgenic MINELESS plants after attack by Mamestra brassicae (cabbage moth)
Project description:Plants within the Brassicaceae family have a unique defence mechanism known as the “glucosinolate-myrosinase” system. Upon tissue disruption by insect herbivores, glucosinolates are hydrolysed by the enzyme myrosinase (EC 3.2.1.147) into a variety of degradation products, which can deter insect herbivory. This process has been termed as “The Mustard Oil Bomb”. Seeds of Brassica napus have been genetically modified to remove myrosinase containing myrosin cells. The modified plants have been named MINELESS due to a lack of toxic mines in seeds. This study aimed to get insights into defence responses of B. napus wild-type and MINELESS seedlings, after being challenged by larvae of the generalist herbivore Mamestra brassicae. The microarray analysis showed 494 and 159 genes to be differentially regulated after M. brassicae feeding on wild-type and MINELESS seedlings, respectively. Many of the observed transcriptional responses i B. napus and the MINELESS mutant are related to those found in Arabidopsis thaliana plants when they are exposed to insects.
Project description:In Arabidopsis thaliana it is known that plants that harboured eggs of the White cabbage butterfly (Pieris brassicae) before larval feeding can defend better against the herbivore stress. As Arabidopsis thaliana is an annual plant we were interested in the plant defense and possible priming reaction of the closest biannual/perennial relative Arabidopsis lyrata. The main aim of the experiment was to compare the effect induced by insect egg deposition of Pieris brassicae between A. thaliana and A. lyrata plants grown in parallel on the transcriptional level. We used a full factorial setup consisting of a) untreated control plants , b) plants which experienced eggs for 6 days without larval feeding after that period, c) plants which experienced no eggs before larval feeding for 24 hours d) plants which experienced eggs for 6 days and larval herbivory for 24 hours. This setup was conducted with 7 week old vegetative plants For all treatments leaf tissue from the leaves that experienced egg oviposition and/or larval feeding were collected.
