A Leucine-Rich Repeat Receptor-like Kinase TaBIR1 Contributes to Wheat Resistance against <i>Puccinia striiformis</i> f. sp. <i>tritici</i>
Plant cell surface-localized receptor-like kinases (RLKs) recognize invading pathogens and transduce the immune signals inside host cells, subsequently triggering immune responses to fight off pathogen invasion. Nonetheless, our understanding of the role of RLKs in wheat resistance to the biotrophic...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-03-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/24/7/6438 |
| Summary: | Plant cell surface-localized receptor-like kinases (RLKs) recognize invading pathogens and transduce the immune signals inside host cells, subsequently triggering immune responses to fight off pathogen invasion. Nonetheless, our understanding of the role of RLKs in wheat resistance to the biotrophic fungus <i>Puccinia striiformis</i> f. sp. <i>tritici</i> (<i>Pst</i>) remains limited. During the differentially expressed genes in <i>Pst</i> infected wheat leaves, a Leucine-repeat receptor-like kinase (LRR-RLK) gene <i>TaBIR1</i> was significantly upregulated in the incompatible wheat-<i>Pst</i> interaction. qRT-PCR verified that <i>TaBIR1</i> is induced at the early infection stage of <i>Pst</i>. The transient expression of TaBIR1-GFP protein in <i>N. bentamiana</i> cells and wheat mesophyll protoplasts revealed its plasma membrane location. The knockdown of <i>TaBIR1</i> expression by VIGS (virus induced gene silencing) declined wheat resistance to stripe rust, resulting in reduced reactive oxygen species (ROS) production, callose deposition, and transcripts of pathogenesis-related genes <i>TaPR1</i> and <i>TaPR2</i>, along with increased <i>Pst</i> infection area. Ectopic overexpression of <i>TaBIR1</i> in <i>N. benthamiana</i> triggered constitutive immune responses with significant cell death, callose accumulation, and ROS production. Moreover, <i>TaBIR1</i> triggered immunity is dependent on <i>NbBAK1</i>, the silencing of which significantly attenuated the defense response triggered by <i>TaBIR1</i>. TaBIR1 interacted with the NbBAK1 homologues in wheat, co-receptor TaSERK2 and TaSERK5, the transient expression of which could restore the impaired defense due to <i>NbBAK1</i> silencing. Taken together, <i>TaBIR1</i> is a cell surface RLK that contributes to wheat stripe rust resistance, probably as a positive regulator of plant immunity in a <i>BAK1</i>-dependent manner. |
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| ISSN: | 1661-6596 1422-0067 |