MAPK20-mediated ATG6 phosphorylation is critical for pollen development in Solanum lycopersicum L.

Abstract

In flowering plants, male gametogenesis is tightly regulated by numerous genes. Mitogen-activated protein kinase (MAPK) plays a critical role in plant development and stress response, while its role in plant reproductive development is largely unclear. The present study demonstrated MAPK20 phosphorylation of ATG6 to mediate pollen development and germination in tomato (Solanum lycopersicum L.). MAPK20 was preferentially expressed in the stamen of tomato, and mutation of MAPK20 resulted in abnormal pollen grains and inhibited pollen viability and germination. MAPK20 interaction with ATG6 mediated the formation of autophagosomes. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis showed that ATG6 was phosphorylated by MAPK20 at Ser-265. Mutation of ATG6 in wild-type (WT) or in MAPK20 overexpression plants resulted in malformed and inviable pollens. Meanwhile, the number of autophagosomes in mapk20 and atg6 mutants was significantly lower than that of WT plants. Our results suggest that MAPK20-mediated ATG6 phosphorylation and autophagosome formation are critical for pollen development and germination.

Acknowledgements

We are grateful for Prof. Gang Lu of Zhejiang University for donating the CRISPR/Cas9 vector, and we thank Dr Ze Wu of Nanjing Agricultural University for donating the split-luciferase vector. This work was supported by the National Key R&D Program of China (2023YFD2300700), the National Natural Science Foundation of China (32272790), Zhejiang Province Science and Technology Plan (2023C02001), the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study (SN-ZJU-SIAS-0011), Collaborative Promotion Program of Zhejiang Provincial Agricultural Technology of China (2023ZDXT05), and the Jiangsu Provincial Association for Science and Technology Youth Science and Technology Talent Support Project (TJ-2023-003).

Author contributions

Y.W., J.Y., and J.Z conceived and designed the experiments. Y.W., D.X., X.Z., M.G., Z.Q., and P.Y. performed the experiments. Y.W., D.X., and J.Z. analysed the data. Y.W., D.X., and J.Z. wrote the article and all authors revised and approved the final manuscript.

Data availability

The data supporting the findings of this study are available within the paper and its supplementary information files.

Conflict of interest statement

The authors declare no potential conflicts of interest.

Supplementary data

Supplementary data is available at Horticulture Research online.

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