烟草组织培养中根的分化和过氧化物同工酶及内源激素的变化

本文研究了烟草茎表皮薄细胞层、茎皮层、髓和叶四种不同外植体根的分化及过氧化物同工酶和内源IAA、ABA的变化。结果表明:上述四种不同外植体形成能力和方式有明显差异,叶的分化能力最强并可直接分化出根;茎表皮薄细胞层对光等不同的环境条件的反应最为敏感,是研究影响根分化因素的较好材料。不同浓度NaCl对组织生长及根形成影响的结果表明,1％NaCl浓度下茎皮层使停止了分化而叶仍有30％分化出根,在2％NaCl浓度下叶外植体生长与分化受到严重抑制,但转移至无NaCl的培养基上能一定程度地恢复生长和分化。根形成过程中过氧化物同工酶表现出酶带迁移、酶带数增多及酶活的变化;在不同浓度NaCl培养基上,过氧化物同工酶的酶活表现了明显的减弱。在根形成中内源IAA出现了高峰期的变化而ABA的变化表现为由低到高逐渐增加。

In Vitro Root-forming of Nicotiana Tobaccum and some Changes in Isoproxidasc and Plant Hormone

When the explant of epidermal layers and other tissues from tobacco were cultured on MS medium, thin cell layers were highly sensitive to the culture conditions such as light, surose concentrations ect.. The results indicated that thin cell layers was very good experimental material for the study of root differentiation. Root-forming of leaf- cxplant was very different to other tissues. The paper also sudied the effect of various NaCl concentrations on the growth and dcdiffcrcntiation for different tissues. 30% root-forming of leaf-explant was very-well in the presence of 1 % NaCl, but there was no root-forming for dermis tissue in the same condition. The growth and dcdiffercntiation of lcaf-cxplant was transfered to the common MS medium the inhabitation could be raleased. During the period of root-forming, the pattern for isopcroxidase on the leaf-explant showed the Following changes: the removal ratio, number of bands and activity of isozymes. The level of endergenous IAA and ABA also showed some changes: IAA showed a peak period and ABA increased gradually during all period of cultures.