1986 Fiscal Year Final Research Report Summary

Cyanide metabolism in ethylene biosynthesis in horticultural crops

Research Project

Project/Area Number	60480041
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	園芸・造園学
Research Institution	Ehime University
Principal Investigator	MIZUTANI Fusao Ehime University, Associate Professor, 農学部, 助教授 (20026595)
Project Period (FY)	1985 – 1986
Keywords	Ethylene biosynthesis / Cyanide metabolism / ACC / Climacteric / Fruit ripening / β-シアノアラニン合成酵素
Research Abstract	Cyanide metabolism involved in ethylene biosynthesis was investigated with horticultural crops, especially with ripening fruits. Climacteric fruits, which show the typical climacteric increases in respiration and ethylene production, increased <beta> -cyanoalanine synthase activities during their ripening processes. On the other hand, non-climacteric fruits, which show neither increases in respiration nor in ethylene production, did not increase <beta> -cyanoalanine synthase activities during ripening processes. However, even the non-climacteric fruits showed a slight increase in ethylene production during their senescence processes; simultaneous increases in <beta> -cyanoalanine synthase activities were also observed although the levels were not comparable to those of climacteric fruits. Concomitant increases in the cyanide content and <beta> -cyanoalanine synthase activity were found in the ethylene biosynthesis induced by wounding apple flesh tissues. The development of cyanide-resistant respiration during the ripening processes of climacteric fruits may be associated with the increase in <beta> -cyanoalanine synthase activity. In conclusion, cyanide metabolism is closely linked with ethylene biosynthesis and thus ethylene biosynthesis is thought to be a part of amino acid metabolism in terms of nitrogen metabolism.