• 식물조직배양학회지
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• 제24권4호
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• pp.233-238
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• 1997

Salicylic acid (SA) is involved in the establishment of systemic acquired resistance (SAR) in many plant including tobacco. Considering the important role of SA in disease resistance, biosynthetic and metabolic pathways of SA in tobacco have been studied extensively: The initial step for biosynthetic pathway of SA is conversion of phenylalanine to trans-cinnamic acid, followed by decarboxylation of trans-cinnamic acid to benzoic acid and ie subsequent ring hydroxylation at the C-2 position to form SA. In TMV inoculated tobacco, most of the newly synthesized SA is glucosylated or methylated. Methyl salicylate has been identified as a biologically active, volatile signal. In contrast, the two glucosylated forms accumulate in the vicinity of lesions and consist of SA glucoside, a major metabolite, and SA glucose ester, a relatively minor from. Two enzymes involved in SA biosynthesis and metabolism have been purified and characterized : benzoic acid 2-hydroxylase which catalyzes conversion of benzoic acid to SA; UDP-Glucose: SA 1-O-D glucosyltransferase which converts SA to SA glucose ester. Further studies of the biosynthetic and metabolic pathways of SA will help to elucidate the SAR signal transduction pathway and provide potential tools for the manipulation of disease resistance.

• Journal of Crop Science and Biotechnology
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• 제10권1호
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• pp.39-44
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• 2007

The effect of inabenfide was investigated in rice seedlings subjected to salt stress in relation to changes in chlorophyll fluorescence(${\Delta}F/Fm'$), lipid peroxidation, salicylic acid(SA) content, and catalase(CAT) activity. A reduction in shoot growth of rice seedlings by 120 mM NaCl treatment was significantly alleviated by pretreatment with 30 ${\mu}M$ inabenfide. Sodium ion content was not affected by pretreatment with inabenfide, suggesting that alleviation was not due to a reduction in sodium ion uptake by the rice seedlings. At three days after NaCl treatment, the rice seedlings pretreated with inabenfide showed a higher ${\Delta}F/Fm'$(30%) and lower lipid peroxidation(28%) compared with the rice seedlings treated with NaCl alone. After NaCl treatment, CAT activity in the third leaf of rice seedlings decreased significantly but alleviated by pretreatment with inabenfide. Furthermore, pretreatment with inabenfide also reduced the level of SA which accumulated drastically in the third leaf of rice seedlings within a day after exposure to salt stress. These results suggest that inabenfide prevents SA accumulation in rice seedlings under salt stress which eventually induces the alleviation of salt stress damage.