ジャスモン酸シグナルがバミューダグラスの耐寒性を向上（Jasmonate Signaling Module Boosts Cold Tolerance in Bermudagrass）

2026-04-27

2026-04-21 中国科学院武漢植物園

中国科学院武漢植物園の研究チームは、暖地型芝草バミューダグラス（Cynodon dactylon）の耐寒性向上に関わるジャスモン酸（JA）シグナルの分子機構を解明した。メチルジャスモン酸（MeJA）処理により、JA-Ileなどの内因性ホルモンが増加し、低温耐性が強化されることを確認。新規タンパク質CdJACG1は低温やMeJAで誘導され、耐寒性の主要な正の制御因子として機能する。さらに転写因子CdMYC2がCdJACG1を活性化し、JA合成遺伝子（CdAOS2、CdOPR1）を促進するフィードバック機構を形成するほか、CdJACG1はCdDREB1.3を活性化し、CBF/DREB1経路と連結する。本研究は植物の低温適応機構を明確化し、耐寒性品種育種の有望な標的を示した。

＜関連情報＞

CdJACG1はジャスモン酸シグナル伝達経路とCBF経路を統合し、バミューダグラス（ Cynodon dactylon）に耐寒性を付与する CdJACG1 integrates jasmonic acid signaling and CBF pathways to confer cold tolerance in bermudagrass (Cynodon dactylon)

Xuebing Huang,Shurui Song,Miaomiao Zhou,Guangjing Ma,Zhengrong Hu,Liang Chen
Plant Physiology Published:09 March 2026
DOI:https://doi.org/10.1093/plphys/kiag129

Abstract

Cold stress limits the growth and distribution of warm-season grasses such as bermudagrass (Cynodon dactylon). While jasmonic acid (JA) accumulates under cold conditions, the regulatory mechanisms underlying cold adaptation in bermudagrass remain largely unknown. Here, we demonstrate that exogenous methyl jasmonate (MeJA) significantly enhances cold tolerance in bermudagrass. Proteomic analysis identified JA-Activated Cold-responsive Gene 1 (CdJACG1), which was found to accumulate under cold stress in bermudagrass. Overexpression of CdJACG1 enhanced cold tolerance, whereas knockdown of CdJACG1 expression increased cold susceptibility in bermudagrass. Protein–DNA interaction assays revealed that CdMYC2, a positive regulator of cold tolerance, directly binds to the promoter of CdJACG1, suggesting that it directly activates CdJACG1 expression. Both CdJACG1 and CdMYC2 bound to the promoters of allene oxide synthase 2 (CdAOS2) and 12-oxophytodienoate reductase 1 (CdOPR1), thereby amplifying JA accumulation. Heterologous expression of CdAOS2 or CdOPR1 in Arabidopsis thaliana enhanced cold tolerance. Beyond its role in JA signaling, CdJACG1 integrates with the C-repeat binding factor (CBF)-mediated cold signaling pathway by directly activating the expression of dehydration-responsive element-binding protein 1.3 (CdDREB1.3), a known positive regulator of plant cold tolerance. Collectively, our findings reveal a potential regulatory module involving CdJACG1 and CBF/DREB1. This module is likely directly regulated by CdMYC2 and synergistically integrates JA signaling with the CBF/DREB1-dependent pathway to enhance cold tolerance in bermudagrass. Our work thus provides crucial insights for molecular breeding of cold-tolerant warm-season grasses and crops.