外源生长调节物质对烟草茎髓愈伤组织形成和愈伤组织器官发生的作用

A Effect of Plant Growth Regulating Substance on Callus Formation of Tobacco Stem Pith and Organogenesis of Callus

烟草（红花大余元）茎髓细胞脱分化形成愈伤组织．生长素类物质是必需的．愈伤组织器官发生类型（形成芽或根）是受组织内激素ＩＡＡ和细胞分裂素的相对浓度调控的．分析表明，分化芽的愈伤组织和未分化的比较，前者的内源 ＩＡＡ含量仅为后者的 １／４，而细胞分裂素的含量则为后者的 １３倍．分化根的愈伤组织和未分化的相比较，前者的内源 ＩＡＡ约为后者的三倍多．分化芽的愈伤组织和分化根的相比较，愈者的内源细胞分裂素为后者的七倍，而ＩＡＡ的含量仅为后者的１／１２．外源生长调节物质（ＩＡＡ，ＫＴ）调控器官发生类型，可能是通过改变愈伤组织中内源激素含量而起作用的．改变内源激素含量（如ＩＡＡ）可能是通过影响有关激素“库”大小的酶活性（过氧化物酶和ＩＡＡ氧化酶）实现的．

Auxin is necessary during callus formation of Tobacco stem pith. the comparison type of callus (forming bud or forming root) is regulated by relative concentration of edogenous hormones (IAA and CK). The comparation between edogenous hormones content in callus of forming bud and that of callus shows, the content of edogeneous IAA in former was about 1/4 of that in latter, but the content of edogenous cytokinin in former was about 13 times larger than that of latter. The IAA content in callus of forming root was about 3 times larger than that of callus. The cytokinin contant in the callus of forming bud was about 7 times larger that of callus fomed root, but IAA content in the former was about 1/12 of that of latter. Regulative action of exogenous plant growth regulator (IAA, KT) on organogenesis of tobacco callus seems likely that growth regulator could change the content of edogenous hormones via influencing ezymatic activity (peroxidase, isoperoxidase, IAA-oxidase) in relation to 'hormone pool' size.