Expression fo Antioxidant Isoenzyme Genes in Rice under Salt Stress and Effects of Jasmonic Acid and y-Radiation

• Published in: Journal of applied biological chemistry 2005, 48(1), , pp.1-6
• Main Authors: 김진홍, 정병엽, Myung-Hwa Baek(Korea Atomic Energy Research Institute, 위승곤, 양대화, 이명철, 김재성
• Format: Article
• Language: English
• Subjects: 농학
• ISSN: 1976-0442; 2234-7941

Analysis of chlorophyll (Chl) fluorescence implicated treatment of 40 mM NaCl decreased maximal photochemical efficiency of photosystem II (PSII) (Fv/Fm), actual quantum yield of PSII (ΦPSII), and photochemical quenching (qP) in rice, but increased non-photochemical quenching (NPQ). Decreases in Fv/Fm, ΦPSII, and qP were significantly alleviated by 30 µM jasmonic acid (JA), while NPQ increase was enhanced. Transcription levels of antioxidant isoenzyme genes were differentially modulated by NaCl treatment. Expression of cCuZn-SOD2 gene increased, while those of cAPXb, CATb, and CATc genes decreased. JA prevented salt-induced decrease of pCuZn-SOD gene expression, but caused greater decrease in mRNA levels of cAPXa and Chl_tAPX genes. Investigation of vacuolar Na+/H+ exchanger(NHX2) and 1-pyrroline-5-carboxylate synthetase (P5CS) gene expressions revealed transcription level of NHX2 gene was increased by JA, regardless of NaCl presence, while that of P5CS gene slightly increased only in co-presence of JA and NaCl. Unlike JA, γ-radiation rarely affected expressions of antioxidant isoenzyme, NHX2, and P5CS genes, except for increase in mRNA level of Chl_tAPX and decrease in that of pCuZn-SOD. These results demonstrate enhanced salt-tolerance in JA-treated rice seedlings may be partly due to high transcription levels of pCuZn-SOD, NHX2, and P5CS genes under salt stress. KCI Citation Count: 1