Increases in 1,5-Anhydroglucitol Levels in Germinating Amaranth Seeds and in Ripening Banana

• Published in: Bioscience, biotechnology, and biochemistry biotechnology, and biochemistry, 2000, Vol.64 (11), p.2462-2465
• Main Authors: KONISHI, Yotaro, HASHIMA, Keiko, KISHIDA, Kunihiro
• Format: Article
• Language: English
• Subjects: 1,5-Anhydroglucitol; Agronomy. Soil science and plant productions; amaranth; banana; Biological and medical sciences; Deoxyglucose - metabolism; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Germination - physiology; Magnoliopsida - chemistry; Magnoliopsida - metabolism; Metabolism; Net assimilation, photosynthesis, carbon metabolism. Photorespiration, respiration, fermentation (anoxia, hypoxia); Nutrition. Photosynthesis. Respiration. Metabolism; Photosynthesis, respiration. Anabolism, catabolism; Plant physiology and development; Seeds - chemistry; Seeds - physiology; Starch - metabolism; starch degradation; Zingiberales - chemistry; Zingiberales - metabolism
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.64.2462

To examine whether 1,5-anhydroglucitol (AG) is derived from starch degradation in plant tissues, we colorimetrically measured AG contents of germinating amaranth seeds and ripening banana pulp. In both cases, as starch degradation proceeded, AG levels were significantly increased, but were 1,700-5,000 times lower than those of total soluble carbohydrates. α-1,4-Glucan lyase activity, which is measured by the 1,5- anhydrofructose (AF) liberated from non-reducing glucose residues of starch or glycogen, was too low to be detected in amaranth or banana by the 3,5-dinitrosalicylic acid method. On the other hand, AF reductase, which reduces AF to AG, was detected in germinating amaranth seeds and banana pulp. Thus, the increases in AG levels are conceived to be derived from starch breakdown, although further investigation is needed to answer whether the starch degradation pathway via α-1,4-glucan lyase/AF reductase exists in plant tissues.