TALE-like proteins thus may play not only antagonistic roles in host-microbe interactions. TALE-like proteins are not restricted to the genus Xanthomonas, and have also been found in the plant pathogen Ralstonia solanacearum ( de Lange et al., 2014), and in the endosymbiont Burkholderia rhizoxinica ( de Lange et al., 2014 Juillerat et al., 2014). This property has been exploited for programmable DNA binding, and has allowed targeted genome editing by combining TALE DNA binding domains with nucleases (TALENs) ( Maggio and Gonçalves, 2015). The DNA binding domain consists of variable repeats that together account for a predictable DNA recognition code ( Boch et al., 2009 Moscou and Bogdanove, 2009). The bacteria inject TALEs via their Type III secretion system (T3SS) into host cells, where they translocate to the nucleus and bind host gene promoters in a sequence-specific manner. Transcription activator-like effectors (TALEs) are important effectors of plant pathogenic bacteria of the genus Xanthomonas ( Boch et al., 2009). Further work is now needed to see if the gene that encodes TFIIAγ in crop plants can be edited to achieve this goal, or whether genes encoding resistant variants of the protein already exist in other plant species. Uncovering how disease-causing Xanthomonas bacteria use TALEs to infect plants will hopefully help researchers to develop crop plants that are more resistant to these harmful bacteria. also identify the region of the TALE that binds to the transcription factor, and show that rice plants with lower levels of the transcription factor are protected against bacterial blight and bacterial streak. The transcription factor in question is rice’s version of a general transcription factor, called TFIIAγ, which is essential for gene activation in plants, animals and fungi. show that TALE-carrying bacteria do make use of at least one of rice’s own transcription factors to cause bacterial blight and bacterial streak. However, it was not clear if the TALEs hijack the plant’s transcriptional machinery to activate these “susceptibility genes” or if they activate the genes via some other means. Like other organisms, plants use proteins called transcription factors to switch genes on or off. The bacterial proteins are essentially injected into the plant’s cells where they activate specific plant genes that make the host more susceptible to infection. For example, at least five Xanthomonas species use proteins called transcription activator-like effectors (or TALEs for short) to infect their host plants. Plants do have an immune system that is able to detect invading microbes and trigger a defensive response against them however, many disease-causing bacteria have evolved ways to avoid or counteract this response. Xanthomonas is a particularly widespread genus of bacteria it consists of almost 30 species that cause diseases in more than 400 plant hosts, including bacterial blight and bacterial streak in rice plants. These results have important implications for formulating a widely applicable strategy with which to improve resistance of plants to TALE-carrying pathogens.Īround the world, bacterial infections reduce the yields of many important crops like rice, tomatoes, peppers and citrus fruits. Suppression or mutation of TFIIAγ5 can also reduce bacterial streak, another devastating disease of rice caused by TALE-carrying X. Conversely, reduced expression of the TFIIAγ5 host gene limits the induction of susceptibility genes and thus decreases bacterial blight symptoms. Direct interaction of several TALEs with TFIIAγ5 is required for activation of disease susceptibility genes. oryzae, the causal agent for bacterial blight. Here, we show that the basal transcription factor IIA gamma subunit TFIIAγ5 from rice is a key component for infection by the TALE-carrying bacterium Xanthomonas oryzae pv. However, it has been unclear how TALEs, after they have been injected into the host cells, activate transcription of host genes required for infection success. Transcription activator-like effectors (TALEs) are sequence-specific DNA binding proteins found in a range of plant pathogenic bacteria, where they play important roles in host-pathogen interactions.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |