Mechanism and Regulation of Ethylene Biosynthesis

该奖项为杨世锋博士提供了进一步的资金，使他能够继续进行乙烯生物合成的研究。在国家科学基金会支持的其他年轻合作者的帮助下，杨证明了乙烯是由蛋氨酸通过S-腺苷蛋氨酸和1-氨基环丙烷-1-羧酸合成的。杨博士目前正在进行的项目的主要目标是(A)全面纯化和鉴定1-氨基环丙烷-1-羧酸合成酶，并确定从苹果和其他植物组织中分离的该酶活性部位周围的氨基酸序列，(B)从苹果中克隆该酶的基因，(C)表征S-腺苷甲硫氨酸对合成酶的失活与该酶在体内周转的关系，以及(D)表征参与所谓的蛋氨酸循环的酶。乙烯是一种植物激素，负责控制植物生长和发育的许多方面。这种激素在农业中具有重要的商业意义，与收获后的作物生理有关。这里要进行的工作旨在获得基本知识，这些知识以后可以用作控制植物中乙烯水平的基础，无论是向上还是向下。这是优化某些农业系统的一种很有前途的方法。杨博士的研究将为通过生物技术调控农作物产生乙烯提供有用的理论基础。

This award provides further funding for Dr. S. F. Yang, to enable him to continue his research on ethylene biosynthesis. Assisted by other NSF-supported younger collaborators, Yang has demonstrated that ethylene is synthesized from methionine via S- adenosylmethionine and 1-aminocyclopropane-1-carboxylic acid. The principal objectives of the project now to be carried out by Dr. Yang are (a) to purify fully and characterize 1- aminocyclopropane-1-carboxylic acid synthase and to determine the amino acid sequence around the active site of this enzyme isolated from apples and other plant tissues, (b) to clone the gene for this enzyme from apples, (c) to characterize the inactivation of the synthase by S-adenosylmethionine in relation to the enzyme's in vivo turnover, and (d) to characterize enzymes involved in the so-called methionine cycle. Ethylene is a plant hormone responsible for the control of numerous aspects of plant growth and development. This hormone is commercially important in agriculture and in relation to post- harvest crop physiology. The work to be pursued here is aimed at obtaining basic knowledge that can later be used as a basis for manipulating the levels of ethylene in plants, either upward or downward. This is a promising approach to optimizing certain agricultural systems. Dr. Yang's studies will provide a useful theoretical basis from which ethylene production by crop plants can be regulated via biotechnology.