烟草叶块分化根和芽过程中内源激素水平的变化

THE CHANGES OF ENDOGENOUS LEVEL OF PLANT HORMONES DURING ROOT AND BUD FORMATION IN TOBACCO LEAF EXPLANTS

用ELISA测定了烟草叶块分化根或芽过程中4类内源激素含量的变化。结果表明:(1)与分化芽的叶块相比,分化根的叶块在其分化之前具有较高的IAA和较低的CTK含量,提示内源CTK/IAA较高时有利于芽原基的分化,较低时有利于根的分化;(2)在芽与根的原基大量形成前4d左右,ABA与GA_(1+3)含量均至少出现一个高峰值,与芽原基的分化相比,根原基的形成需要更高的ABA/GA_(1+3)。

During inducing the primordia of root or bud with exo-NAA and exo-6BA the inner levels of IAA, CTK, ABA and GA_(1+3) were measured with ELISA. The results were as follows: (1)Before differentiation, the leaf explants on the medium for root initiation had higher IAA and lower CTK levels than those on bud initiation medium. It suggested that higher ratio of endogenous CTK/IAA is beneficial to inducing bud primordia while the lower ratio leads up to root initiation. (2) At least one peak of endo-ABA or GA_(1+3) level appeared about 4 days before the formation of a spate of bud or root primordia. Compared with the formation of bud primodia, that of root primordia needed higher ratio of ABA to GA_(1+3).