长梗柳带叶插穗不定根形成中内源激素含量变化

Changes in endogenous hormone content in adventitious root formation of Salix dunnii leaf-bearing spikes

为了解长梗柳(Salix dunnii)带叶插穗在红光条件培养后的内源激素和不定根发育的响应,采用连续组织切片技术观察不定根发生过程,并利用酶联免疫法(ELISA)检测4种内源激素的含量。结果表明:长梗柳不定根起源于皮层,属于诱生根原基。在不定根形成过程中,随着皮层出现膨大圆点,皮部IAA含量显著上升;随着不定根的形成,插穗皮部IAA含量显著下降;插穗皮部ABA含量最高,BR含量较低,GA含量最低;而低浓度BR能诱导侧根的形成,少量GA有利于插穗基部的不定根诱导分化。通过对长梗柳bHLH基因表达量进行分析,进一步了解内源激素BR对长梗柳扦插生根的作用机理。因此,长梗柳带叶插穗的生根是由不同内源激素调控的复杂发育过程。

In order to understand the response of endogenous hormones and adventitious root development of Salix dunnii leaf-bearing cuttings after incubation under red light conditions,continuous tissue sectioning technique was used to observe the process of adventitious root development,and the contents of four endogenous hormones were measured by enzyme-linked immunoassay(ELISA).The results showed that Salix dunnii adventitious roots originated from the cortex were belonged to the induced root primordium.With the appearance of expansion dots in the cortex,the IAA content in the cortex increased significantly during the formation of adventitious root.With the construction of adventitious roots,the IAA content in the cortex of the spike decreased considerably.The ABA content of the cortex of the spike was the highest,the BR content was lower,and the GA content was the least.In contrast,the low concentration of BR induced the formation of lateral roots,and a small amount of GA was beneficial to the induction of adventitious root differentiation at the base of the spike.The expression of Salix dunnii bHLH gene was analyzed to further understand the mechanism of the endogenous hormone BR on the rooting of Salix dunnii cuttings.Accordingly,the rooting of Salix dunnii leaf-bearing cuttings was a complex developmental process regulated by different endogenous hormones.