A carlactonoic acid methyltransferase that contributes to the inhibition of shoot branching in Arabidopsis

Autor: Kiyoshi Mashiguchi, Yoshiya Seto, Yuta Onozuka, Sarina Suzuki, Kiyoko Takemoto, Yanting Wang, Lemeng Dong, Kei Asami, Ryota Noda, Takaya Kisugi, Naoki Kitaoka, Kohki Akiyama, Harro Bouwmeester, Shinjiro Yamaguchi
Přispěvatelé: SILS Other Research (FNWI), Plant Hormone Biology (SILS, FNWI)
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Proceedings of the National Academy of Sciences of the United States of America, 119(14):e2111565119. National Academy of Sciences
ISSN: 0027-8424
DOI: 10.1073/pnas.2111565119
Popis: Strigolactones (SLs) are plant hormones that regulate shoot branching and diverse developmental processes. They are biosynthesized from carotenoid molecules via a key biosynthetic precursor called carlactone (CL) and its carboxylated analog, carlactonoic acid (CLA). We have previously identified the methyl esterified derivative of CLA, methyl carlactonoate (MeCLA), as an endogenous SL-like molecule in Arabidopsis. Neither CL nor CLA could interact with the receptor protein, Arabidopsis DWARF14 (AtD14), in vitro, while MeCLA could, suggesting that the methylation step of CLA is critical to convert a biologically inactive precursor to a bioactive compound in the shoot branching inhibition pathway. Here, we show that a member of the SABATH protein family (At4g36470) efficiently catalyzes methyl esterification of CLA using S-adenosyl-L-methionine (SAM) as a methyl donor. We named this enzyme CLAMT for CLA methyltransferase. The Arabidopsis loss-of-function clamt mutant accumulated CLA and had substantially reduced MeCLA content compared with wild type (WT), showing that CLAMT is the main enzyme that catalyzes CLA methylation in Arabidopsis. The clamt mutant displayed an increased branching phenotype, yet the branch number was less than that of severe SL biosynthetic mutants. Exogenously applied MeCLA, but not CLA, restored the branching phenotype of the clamt mutant. In addition, grafting experiments using the clamt and other SL biosynthetic mutants suggest that CL and CLA are transmissible from root to shoot. Taken together, our results demonstrate a significant role of CLAMT in the shoot branching inhibition pathway in Arabidopsis.
植物の枝分かれ調節ホルモンの合成メカニズムを解明 --植物ホルモンを活性化する酵素タンパク質を発見--. 京都大学プレスリリース. 2022-03-30.
Databáze: OpenAIRE