PROTEIN l-ISOASPARTYL O-METHYLTRANSFERASE (PIMT) affects seed vigor by repairing damaged proteins. While PIMT is capable of isoaspartyl (isoAsp) repair in all proteins, those proteins most susceptible to isoAsp formation have not been well characterized, and the mechanisms by which PIMT affects seed vigor remain largely unknown. Using co-immunoprecipitation and LC-MS/MS, we found that maize (Zea mays) PIMT2 (ZmPIMT2) interacted predominantly with both subunits of maize 3-METHYLCROTONYL COA CARBOXYLASE (ZmMCC). ZmPIMT2 is specifically expressed in the maize embryo. Both mRNA and protein levels of ZmPIMT2 increased during seed maturation and declined during imbibition. Maize seed vigor was decreased in the zmpimt2 mutant line, while overexpression of ZmPIMT2 in maize and Arabidopsis thaliana increased seed vigor upon artificial aging. ZmPIMT2 was localized in the mitochondria, as determined by subcellular localization assays using maize protoplasts. ZmPIMT2 binding to ZmMCCα was confirmed by luciferase complementation tests in both tobacco (Nicotiana benthamiana) leaves and maize protoplasts. Knockdown of ZmMCCα decreased maize seed aging tolerance. Furthermore, overexpression of ZmPIMT2 decreased the accumulation of isoAsp of ZmMCCα protein in seed embryos that underwent accelerated aging treatment. Taken together, our results demonstrate that ZmPIMT2 binds ZmMCCα in mitochondria, repairs isoAsp damage, and positively affects maize seed vigor.
|Number of pages||16|
|State||Published - Jul 2023|
Bibliographical noteFunding Information:
This work was supported by the National Natural Science Foundation of China (32101693) and the Key Research and Development Program of Shaanxi (2021ZDLNY01-06). LMAD and ABD were supported by a Hatch project (1019088). We thank the Teaching and Research Core Facility at the College of Life Science, NWAFU for technical support.
This work was supported by the National Natural Science Foundation of China (32101693) and the Key Research and Development Program of Shaanxi (2021ZDLNY01‐06). LMAD and ABD were supported by a Hatch project (1019088). We thank the Teaching and Research Core Facility at the College of Life Science, NWAFU for technical support.
© 2023 Society for Experimental Biology and John Wiley & Sons Ltd.
- 3-methylcrotonyl CoA carboxylase
- maize (Zea mays)
- seed vigor
ASJC Scopus subject areas
- Plant Science
- Cell Biology