An MAP kinase interacts with LHK1 and regulates nodule organogenesis in Lotus japonicus
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Symbiosis receptor-like kinase (SymRK) is a key protein mediating the legume-Rhizobium symbiosis. Our previous work has identified an MAP kinase kinase, SIP2, as a SymRK-interacting protein to positively regulate nodule organogenesis in Lotus japonicus, suggesting that an MAPK cascade might be involved in Rhizobium-legume symbiosis. In this study, LjMPK6 was identified as a phosphorylation target of SIP2. Stable transgenic L. japonicus with RNAi silencing of LjMPK6 decreased the numbers of nodule primordia (NP) and nodule, while plants overexpressing LjMPK6 increased the numbers of nodule, infection threads (ITs), and NP, indicating that LjMPK6 plays a positive role in nodulation. LjMPK6 could interact with a cytokinin receptor, LHK1 both in vivo and in vitro. LjMPK6 was shown to compete with LHP1 to bind to the receiver domain (RD) of LHK1and to downregulate the expression of two LjACS (1-aminocyclopropane-1-carboxylic acid synthase) genes and ethylene levels during nodulation. This study demonstrated an important role of LjMPK6 in regulation of nodule organogenesis and ethylene production in L. japonicus.
Keywordscytokinin ethylene biosynthesis LHK1 Lotus japonicus MAPK cascade root nodule symbiosis
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We thank Dr. K. Szczyglowski (Agriculture and Agri- Food Canada, University of Western Ontario, Canada) for kindly providing LHK1 mutants, Dr. A. Downie (John Innes Centre) for providing M. loti strain R7A carrying pMP2112, Dr. G. Wu (Shanghai Jiao Tong University, China) for providing M. loti MAFF303099, Dr. S. Wang (Huazhong Agricultural University, China) for providing pCAMBIA1301U, L. japonicus LORE1 mutant collection (Centre for Carbohydrate Recongnition and Signaling, Aarhus University, Denmark) for providing LjMPK6 mutants. This work was supported by the National Key R&D Program of China (2016YF0100700), the National Natural Science Foundation of China (31670240 and 31870219), the State Key Laboratory of Agricultural Microbiology (AMLKF201503 and AMLKF201608), the Graduate Education Innovation Fund of Huazhong Agricultural University (to Z.Z.), and Graduate Student Research Innovation Project of Huazhong Agricultural University (to J.Y.).
Compliance and ethics The author(s) declare that they have no conflict of interest.
- Berriri, S., Garcia, A.V., Frei dit Frey, N., Rozhon, W., Pateyron, S., Leonhardt, N., Montillet, J.L., Leung, J., Hirt, H., and Colcombet, J. (2012). Constitutively active mitogen-activated protein kinase versions reveal functions of Arabidopsis MPK4 in pathogen defense signaling. Plant Cell 24, 4281–4293.CrossRefGoogle Scholar
- Cardinale, F., Meskiene, I., Ouaked, F., and Hirt, H. (2002). Convergence and divergence of stress-induced mitogen-activated protein kinase signaling pathways at the level of two distinct mitogen-activated protein kinase kinases. Plant Cell 14, 703–711.Google Scholar
- Frankowski, K., Kesy, J., and Kopcewicz, J. (2007). Regulation of ethylene biosynthesis in plants. Postepy Biochem 53, 66–73.Google Scholar
- Han, L., Li, G.J., Yang, K.Y., Mao, G., Wang, R., Liu, Y., and Zhang, S. (2010). Mitogen-activated protein kinase 3 and 6 regulate Botrytis cinerea-induced ethylene production in Arabidopsis. Plant J 48, no.Google Scholar
- Jia, W., Li, B., Li, S., Liang, Y., Wu, X., Ma, M., Wang, J., Gao, J., Cai, Y., Zhang, Y., et al. (2016). Mitogen-activated protein kinase cascade MKK7-MPK6 plays important roles in plant development and regulates shoot branching by phosphorylating PIN1 in Arabidopsis. PLoS Biol 14, e1002550.CrossRefGoogle Scholar
- Kiegerl, S., Cardinale, F., Siligan, C., Gross, A., Baudouin, E., Liwosz, A., Eklöf, S., Till, S., Bögre, L., Hirt, H., et al. (2000). SIMKK, a mitogenactivated protein kinase (MAPK) kinase, is a specific activator of the salt stress-induced MAPK, SIMK. Plant Cell 12, 2247–2258.Google Scholar
- Miller, J.B., Pratap, A., Miyahara, A., Zhou, L., Bornemann, S., Morris, R. J., and Oldroyd, G.E.D. (2013). Calcium/Calmodulin-dependent protein kinase is negatively and positively regulated by calcium, providing a mechanism for decoding calcium responses during symbiosis signaling. Plant Cell 25, 5053–5066.CrossRefGoogle Scholar
- Morieri, G., Martinez, E.A., Jarynowski, A., Driguez, H., Morris, R., Oldroyd, G.E.D., and Downie, J.A. (2013). Host-specific Nod-factors associated with Medicago truncatula nodule infection differentially induce calcium influx and calcium spiking in root hairs. New Phytol 200, 656–662.CrossRefGoogle Scholar
- Stanko, V., Giuliani, C., Retzer, K., Djamei, A., Wahl, V., Wurzinger, B., Wilson, C., Heberle-Bors, E., Teige, M., and Kragler, F. (2015). Timing is everything: highly specific and transient expression of a MAP kinase determines auxin-induced leaf venation patterns in Arabidopsis. Mol Plant 8, 829.CrossRefGoogle Scholar
- Takahashi, F., Yoshida, R., Ichimura, K., Mizoguchi, T., Seo, S., Yonezawa, M., Maruyama, K., Yamaguchi-Shinozaki, K., and Shinozaki, K. (2007). The mitogen-activated protein kinase cascade MKK3-MPK6 is an important part of the jasmonate signal transduction pathway in Arabidopsis. Plant Cell 19, 805–818.CrossRefGoogle Scholar
- van Zeijl, A., Op den Camp, R.H.M., Deinum, E.E., Charnikhova, T., Franssen, H., Op den Camp, H.J.M., Bouwmeester, H., Kohlen, W., Bisseling, T., and Geurts, R. (2015). Rhizobium lipochitooligosaccharide signaling triggers accumulation of cytokinins in Medicago truncatula roots. Mol Plant 8, 1213–1226.CrossRefGoogle Scholar
- Zong, W., Tang, N., Yang, J., Peng, L., Ma, S., Xu, Y., Li, G., and Xiong, L. (2016). Feedback regulation of ABA signaling and biosynthesis by a bZIP transcription factor targets drought resistance related genes. Plant Physiol 171, 2810–2825.Google Scholar