荔枝果实的氰不敏感呼吸

The Cyanlde-Insensitlve Respiration of Litchi Fruit

荔枝果实果皮和果肉的匀浆或组织的呼吸受KCN,SHAM和PG的抑制。KCN对呼吸的抑制达12％～58％。有KCN时,受SHAM抑制的呼吸为4％～29％。氰不敏感呼吸比率与果实成熟度有关,未熟绿果比半熟果和成熟果的高。乙烯利诱导成熟前果实呼吸增高但减少氰不敏感呼吸比率。DNP对绿果的总呼吸及氰不敏感呼吸均有轻微刺激作用,但对成熟果只明显刺激总呼吸率。

Litchi (Litchi chineasis) fruits were harvested with three degrees of maturation according to the color and contents of chlorophyll and anthocyanin. The respiration of homogenate and tissue in pericarp and aril was studied by using oxygen electrode. An increase of respiration was observed with the change of pericarp color from green to red. The total respiration is sensitive to cyanide or salicylhydroxamic acid and propyl gallate. In the presence of cyanide, 4 %～29% of total respiration rate was inhibited by salicylhydroxarnic acid, whereas 12%～58% of respiration was inhibited by cyanide alone. The ratio of cyanide-insensitive respiration to total respiration changed with fruit maturation. Green fruits showed higher cyanide-insensitive respiration than half-mature and mature fruits. Exogenous ethrel induced the rise of total respiration, but diminished the cyanide-insensitive respiration. The uncoupler dinitrophenol slightly stimulated total respiration and cyanide-insensitive respiration of green fruits, but markedly stimulated total respiration of mature fruits. These results indicate that alternate path may contribute to the respiration of litchi fruit, especially before ripening.