Shraddha Neufeld, Michael Reichelt, Sandra S Scholz, Przemysław Wojtaszek, Axel Mithöfer
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引用次数: 0
Abstract
Plants are challenged regularly with multiple types of biotic stress factors, such as pathogens or insect herbivores, in their environment. To detect and defend against pathogens, plants have evolved an innate immune system in which intracellular receptors in the so-called effector-triggered immunity play a vital role. In Arabidopsis thaliana the Toll/interleukin-1 receptors (TIRs) domain is related to intracellular immunity receptors, for example in TIR-NBS-LRR (TNL) proteins. Among the TIR domain carrying proteins, very little is known about the function of the TIR-X proteins. Here, we focus on the recently described TIR-X (TIRP; At5g44900) to analyze its role in phytohormone-mediated plant defense through gene expression and phytohormone quantification. Therefore, we employed two fungal pathogens, the necrotrophic Alternaria brassicicola and the hemibiotrophic Verticillium dahliae, to infect A. thaliana WT (Col-0), TIRP knock-out, and TIRP overexpressing lines for comparative analyses. Furthermore, we included the insect herbivore Spodoptera littoralis and a treatment with S. littoralis egg extract on the plants to analyze any role of TIRP during these attacks. We found that both A. brassicicola and V. dahliae infections increased TIRP gene expression systemically. The salicylic acid content was higher in the TIRP overexpressing line, corresponding to a better S. littoralis larval growth performance in feeding assays. However, since we never observed clear infection-related differences in jasmonate or salicylic acid levels between the wild type and the two transgenic Arabidopsis lines, our results rule out the possibility that TIRP acts via the regulation of phytohormone synthesis and accumulation.
期刊介绍:
The International Journal of Molecular Sciences (ISSN 1422-0067) provides an advanced forum for chemistry, molecular physics (chemical physics and physical chemistry) and molecular biology. It publishes research articles, reviews, communications and short notes. Our aim is to encourage scientists to publish their theoretical and experimental results in as much detail as possible. Therefore, there is no restriction on the length of the papers or the number of electronics supplementary files. For articles with computational results, the full experimental details must be provided so that the results can be reproduced. Electronic files regarding the full details of the calculation and experimental procedure, if unable to be published in a normal way, can be deposited as supplementary material (including animated pictures, videos, interactive Excel sheets, software executables and others).