Methodology Molecular cloning and characterization of gene coding for γ-tocopherol methyltransferase from lettuce (Lactuca sativa)

Abstract

ABSTRACT. γ-tocopherol methyltransferase is an important ratelimiting enzyme involved in tocopherol biosynthesis. The full-length cDNA encoding γ-tocopherol methyltransferase (designated as LsTMT) was cloned from Lactuca sativa for the first time by rapid amplification of cDNA ends and characterized by means of quantitative RT-PCR. The full-length cDNA of LsTMT was 1131 bp, with an open reading frame of 897 bp encoding a γ-tocopherol methyltransferase protein of 298 amino acids, with a calculated molecular mass of 33.06 kDa and an isoelectric point of 5.86. Comparative analysis revealed that LsTMT has a close similarity with γ-TMTs from other plant species. Bioinformatic analysis indicated that LsTMT shares a common evolutionary origin based on sequence similarity and has the closest relationship to γ-TMT from the sunflower, Helianthus annuus. Based on quantitative RT-PCR analysis, we found that expression of LsTMT is induced and strengthened by oxidative stresses such as strong light and drought. The cloning and characterization of LsTMT will be helpful to further understanding its role Cloning and characterization of LsTMT from Lactuca sativa in the tocopherol biosynthesis pathway. We consider it to be a candidate gene for metabolic engineering of vitamin E in vegetable crops.

Effect of arsenic stress on 5-methylcytosine, photosynthetic parameters and nutrient content in arsenic hyperaccumulator Pteris cretica (L.) var. Albo-lineata

“…Similar reports of WP reduction as a result of the lignification of conducting tissue in plants exposed to stress conditions were published by Hare and Cress [37] and Yamaguchi et al [38]. If the photosynthetic membrane system is protected by flavonoids, ascorbate and tocopherols [28,[39][40][41], then cell walls are protected by lignin [38]. Reduced DNA methylation in Pc-Al increases biosynthesis of sterols, tocopherols, flavonoids, isoflavonoids and lignins because these plant metabolites are epigenetically regulated by silencing genes [40,42,43].…”

Effect of arsenic stress on 5-methylcytosine, photosynthetic parameters and nutrient content in arsenic hyperaccumulator Pteris cretica (L.) var. Albo-lineata

“…Similar reports of WP reduction as a result of the lignification of conducting tissue in plants exposed to stress conditions were published by Hare and Cress [37] and Yamaguchi et al [38]. If the photosynthetic membrane system is protected by flavonoids, ascorbate and tocopherols [28,[39][40][41], then cell walls are protected by lignin [38]. Reduced DNA methylation in Pc-Al increases biosynthesis of sterols, tocopherols, flavonoids, isoflavonoids and lignins because these plant metabolites are epigenetically regulated by silencing genes [40,42,43].Cross-sections through adventitious roots of As 100 plants showed the deformation of root cell walls as a result of lignification (Figure 3).…”

Effect of arsenic stress on 5-methylcytosine, photosynthetic parameters and nutrient content in arsenic hyperaccumulator Pteris cretica (L.) var. Albo-lineata

“…Similar reports of WP reduction as a result of the lignification of conducting tissue in plants exposed to stress conditions were published by Hare and Cress [37] and Yamaguchi et al [38]. If the photosynthetic membrane system is protected by flavonoids, ascorbate and tocopherols [28,[39][40][41], then cell walls are protected by lignin [38]. Reduced DNA methylation in Pc-Al increases biosynthesis of sterols, tocopherols, flavonoids, isoflavonoids and lignins because these plant metabolites are epigenetically regulated by silencing genes [40,42,43].Cross-sections through adventitious roots of .…”