- F. Govers (1)
- Christos Kissoudis (1)
- Pavel Křenek (1)
- C.G. Linden van der (1)
- P. Msimuko (1)
- Sri Sunarti (1)
- Anton Vels (1)
- Petra Vyplelová (1)
- R. Weide (1)
- Z. Zhao (1)
- Jozef Šamaj (1)
The role of tomato WRKY genes in plant responses to combined abiotic and biotic stresses
Bai, Yuling ; Sunarti, Sri ; Kissoudis, Christos ; Visser, Richard G.F. ; Linden, C.G. van der - \ 2018
Frontiers in Plant Science 9 (2018). - ISSN 1664-462X
Abiotic stress - Biotic stress - Combined stresses - Disease resistance - Effector-triggered immunity (ETI) - PAMP-triggered immunity (PTI)
In the field, plants constantly face a plethora of abiotic and biotic stresses that can impart detrimental effects on plants. In response to multiple stresses, plants can rapidly reprogram their transcriptome through a tightly regulated and highly dynamic regulatory network where WRKY transcription factors can act as activators or repressors. WRKY transcription factors have diverse biological functions in plants, but most notably are key players in plant responses to biotic and abiotic stresses. In tomato there are 83 WRKY genes identified. Here we review recent progress on functions of these tomato WRKY genes and their homologs in other plant species, such as Arabidopsis and rice, with a special focus on their involvement in responses to abiotic and biotic stresses. In particular, we highlight WRKY genes that play a role in plant responses to a combination of abiotic and biotic stresses.
RXLR effector diversity in Phytophthora infestans isolates determines recognition by potato resistance proteins; the case study AVR1 and R1
Du, Y. ; Weide, R. ; Zhao, Z. ; Msimuko, P. ; Govers, F. ; Bouwmeester, K. - \ 2018
Studies in Mycology 89 (2018). - ISSN 0166-0616 - p. 85 - 93.
Effector variation - Effector-triggered immunity (ETI) - Host defence - Late blight disease - Nucleotide-binding and leucine-rich repeat (NLR) protein - Potato resistance
Late blight disease caused by the plant pathogenic oomycete pathogen Phytophthora infestans is one of the most limiting factors in potato production. P. infestans is able to overcome introgressed late blight resistance by adaptation of effector genes. AVR1 is an RXLR effector that triggers immune responses when recognized by the potato resistance protein R1. P. infestans isolates avirulent on R1 plants were found to have AVR1 variants that are recognized by R1. Virulent isolates though, lack AVR1 but do contain a close homologue of AVR1, named A-L, of which all variants escape recognition by R1. Co-expression of AVR1 and R1 in Nicotiana benthamiana results in a hypersensitive response (HR). In contrast, HR is not activated when A-L is co-expressed with R1. AVR1 and A-L are highly similar in structure. They share two W motifs and one Y motif in the C-terminal part but differ in the T-region, a 38 amino acid extension at the carboxyl-terminal tail of AVR1 lacking in A-L. To pinpoint what determines R1-mediated recognition of AVR1 we tested elicitor activity of AVR1 and A-L chimeric and deletion constructs by co-expression with R1. The T-region is important as it enables R1-mediated recognition of A-L, not only when fused to A-L but also via trans-complementation. Yet, AVR1 lacking the T-region is still active as an elicitor of HR, but this activity is lost when certain motifs are swapped with A-L. These data show that A-L circumvents R1 recognition not only because it lacks the T-region, but also because of differences in the conserved C-terminal effector motifs.
Genome-wide analysis of the barley MAPK gene family and its expression patterns in relation to Puccinia hordei infection
Křenek, Pavel ; Niks, Rients E. ; Vels, Anton ; Vyplelová, Petra ; Šamaj, Jozef - \ 2015
Acta Physiologiae Plantarum 37 (2015)11. - ISSN 0137-5881 - p. 1 - 16.
Barley (Hordeumvulgare) - Barley leaf rust (Pucciniahordei) - Effector-triggered immunity (ETI) - Mitogen-activated protein kinase (MAPK) - qRT-PCR - Resistance
Mitogen-activated protein kinases (MAPKs) have been shown to act as key regulators of stress responses in model plant and crop species. So far, however, the MAPK family has not been systematically studied in barley. Herein, we identified 16 HvMAPKs (Hv—Hordeum vulgare) based on computational analysis of barley transcriptomics and genomics databases. HvMAPKs contain all canonical MAPK domains, except for HvMPK2, which lacks a MAPK domain signature. In addition, five HvMAPKs harbor TEY and ten HvMAPKs harbor TDY dual phosphorylation motif in the activation loop. Interestingly, HvMPK2 contains a MEY instead of TEY phosphorylation motif. We classified HvMAPKs into four major plant MAPK clades based on phylogeny reconstruction and anchored all HvMAPK genes to five out of seven barley chromosomes. Furthermore, we inoculated seedlings of susceptible barley line L94 and its isolines L94-Rph3 and L94-Rph7 with rust fungus Pucciniahordei and analyzed the expression of 16 HvMAPK genes using qRT-PCR at 1–4.5 days post inoculation. In total, six HvMAPK genes exhibited significantly altered expression by P. hordei infection. The expression of HvMPK5, HvMPK6, HvMPK7 and HvMPK12 (set one genes) was strongly induced especially during effector-triggered immunity (ETI), whereas the expression of HvMPK2 and HvMPK17 (set two genes) was specifically downregulated during ETI. Yet the expression of HvMPK8 was also specifically but weakly downregulated during ETI. Overall, the expression patterns suggest that set one genes positively regulate ETI in barley–P. hordei pathosystem, whereas set two genes negatively regulate ETI and/or programmed cell death in this pathosystem.