白花泡桐不定根发生过程中内源激素和RNA的变化

CHANGES IN ENDOGENOUS PHYTOHORMONE AND RNA IN PAULOWNIA FORTUNEI (SEEM.) HEMSL. DURING THE DEVELOPMENT OF ADVENTITIOUS ROOT

摘要:

白花泡桐（Ｐａｕｌｏｗｎｉａｆｏｒｔｕｎｅｉ（Ｓｅｅｍ．）Ｈｅｍｓｌ．）成年型和幼年型茎切段体外培养时不定根发生过程中内源ＩＡＡ、ＣＴＫ和ＡＢＡ含量测定表明：幼年型材料中内源ＩＡＡ和ＣＴＫ的含量在诱导的第２天同时达到高峰，而成年型材料中ＩＡＡ和ＣＴＫ含量的高峰则在第４天出现．两种类型切段根原基出现的时间都与其内源ＩＡＡ和ＣＴＫ的高峰一致．幼年型材料的内源ＡＢＡ含量在第４天达到高峰，随后迅速下降．成年型材料中内源ＡＢＡ则逐步下降．成年型和幼年型材料中ＲＮＡ的变化相同，在诱导的第２天稍有下降，随后显著增加．结果显示，不定根的发生与其内源激素和ＲＮＡ的变化密切相关．

Abstract:

The changes in contents of endogenous IAA,CTK, ABA and RNA in the in vitro cultural cutting stem excised from mature and juvenile plant of tube plantlet of Paulownia fortunei(Seem.)Hemsl. were analysed during the development of adventitious root.The endogenous hormones were measured by HPLC. The results showed that the contents of endogenous IAA and CTK in the stem cutting from plantlet(juvenile state)reached their peaks on the second day of culture, whereas the peaks of endogenous IAA and CTK in stem cutting from mature plant (mature state) appeared on the fourth day. From the stem paraffin sections, it was observed that the emergence time of root primordia was the same as that of endogenous IAA and CTK peaks in two states of cultural materials. However, the variation in endogenous ABA content was different between juvenile and mature states. During the rooting period,the level of RNA in both juvenile and mature states of stem cutting slightly decreased on the second day of culture, and then increased markedly.The origin of root primordia come from some peripheral cells of vascular cylinder,and some cells between vascular bundles as well as some pith cells recovering cell division. But the emergence of root primordia in mature stem cutting was 2 days later than that in juvenile cutting of plantlets,and the number of adventitious root in the former was less than that in the latter.