Jasmonic Acid-Induced β-Cyclocitral Confers Resistance to Bacterial Blight and Negatively Affects Abscisic Acid Biosynthesis in Rice

• Published in: International journal of molecular sciences Vol. 24; no. 2; p. 1704
• Main Authors: Taniguchi, Shiduku, Takeda, Aya, Kiryu, Masaki, Gomi, Kenji
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 15.01.2023; MDPI
• Subjects: Abscisic acid; Abscisic Acid - metabolism; Acid resistance; Biosynthesis; Blight; Carotenoids; Chloroplasts; Cyclopentanes - metabolism; Cyclopentanes - pharmacology; Defense mechanisms; Dioxygenase; Disease resistance; Disease Resistance - genetics; Gene expression; Gene Expression Regulation, Plant; Genes; Infections; jasmonate; Jasmonic acid; Lignin; Oryza - metabolism; Oryza sativa; Pathogens; Plant Diseases - genetics; Plant Diseases - microbiology; Plant growth; Plant Proteins - genetics; Plant Proteins - metabolism; plant volatile; Proteins; rice; Virulence; Volatiles; Xanthomonas - physiology; Xanthomonas oryzae; Xanthomonas oryzae pv. oryzae; abscisic acid; Xanthomonas oryzae pv. oryzae; rice; jasmonate; plant volatile
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms24021704

Jasmonic acid (JA) regulates the production of several plant volatiles that are involved in plant defense mechanisms. In this study, we report that the JA-responsive volatile apocarotenoid, β-cyclocitral (β-cyc), negatively affects abscisic acid (ABA) biosynthesis and induces a defense response against pv. ( ), which causes bacterial blight in rice ( L.). JA-induced accumulation of β-cyc was regulated by OsJAZ8, a repressor of JA signaling in rice. Treatment with β-cyc induced resistance against and upregulated the expression of defense-related genes in rice. Conversely, the expression of ABA-responsive genes, including ABA-biosynthesis genes, was downregulated by JA and β-cyc treatment, resulting in a decrease in ABA levels in rice. β-cyc did not inhibit the ABA-dependent interactions between OsPYL/RCAR5 and OsPP2C49 in yeast cells. Furthermore, we revealed that JA-responsive rice carotenoid cleavage dioxygenase 4b (OsCCD4b) was localized in the chloroplast and produced β-cyc both in vitro and in planta. These results suggest that β-cyc plays an important role in the JA-mediated resistance against in rice.