OsMKK6 Regulates Disease Resistance in Rice
Mitogen-activated protein kinase cascades play important roles in various biological programs in plants, including immune responses, but the underlying mechanisms remain elusive. Here, we identified the lesion mimic mutant <i>rsr25</i> (<i>rust spots rice 25</i>) and determin...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-08-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/24/16/12678 |
| Summary: | Mitogen-activated protein kinase cascades play important roles in various biological programs in plants, including immune responses, but the underlying mechanisms remain elusive. Here, we identified the lesion mimic mutant <i>rsr25</i> (<i>rust spots rice 25</i>) and determined that the mutant harbored a loss-of-function allele for <i>OsMKK6 (MITOGEN-ACTIVATED KINASE KINASE 6)</i>. <i>rsr25</i> developed reddish-brown spots on its leaves at the heading stage, as well as on husks. Compared to the wild type, the <i>rsr25</i> mutant exhibited enhanced resistance to the fungal pathogen <i>Magnaporthe oryzae</i> (<i>M. oryzae</i>) and to the bacterial pathogen <i>Xanthomonas oryzae</i> pv. <i>oryzae</i> (<i>Xoo</i>). OsMKK6 interacted with OsMPK4 (MITOGEN-ACTIVATED KINASE 4) in vivo, and OsMKK6 phosphorylated OsMPK4 in vitro. The <i>Osmpk4</i> mutant is also a lesion mimic mutant, with reddish-brown spots on its leaves and husks. Pathogen-related genes were significantly upregulated in <i>Osmpk4</i>, and this mutant exhibited enhanced resistance to <i>M. oryzae</i> compared to the wild type. Our results indicate that OsMKK6 and OsMPK4 form a cascade that regulates immune responses in rice. |
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| ISSN: | 1661-6596 1422-0067 |