Participation of gibberellins in the formation of root primordia and their development in the propagules of Kandelia candel

本研究以秋茄（Kandelia candel）为材料，研究了秋茄根原基形成和根伸长过程中的内源激素。2.根的形成见于30 mm或更长的繁殖体。结果表明：1.长60 mm的繁殖体上有芽，短41 mm的繁殖体上无芽。3.赤霉素处理促进了根的形成，表明赤霉素在秋茄根的形成中起作用。4.赤霉素（GA_4）作为一种内源激素，在成熟的繁殖体中检测到了GA_4活性。5.GA_4活性是参与秋茄繁殖体根形成的内源性GAs。6.用赤霉素生物合成抑制剂处理繁殖体，根的形成和根的伸长受到抑制，表明内源GAs的参与。7.用抑制剂处理后再用GA_3处理，可逆转抑制作用，促进根的形成和伸长。这些结果表明，赤霉素参与根的形成在秋茄的繁殖体。

The purpose of this study was to identify the endogenous plant hormones involved in the formation of root primordia in the propagules and in the elongation of the roots in Kandelia candel, a mangrove.1.Root primordia were formed on the propagules of K.candel, 33 mm or longer. 2.The formation of roots was seen in the propagules 30 mm or longer. The shoots developed on the propagules that were 60 mm or longer, but not on those shorter than 41 mm. 3.Gibberellin treatment of the propagules promoted the formation of their roots suggesting that gibberellins play a role in the formation of roots in K.candel. 4.As an endogenous gibberellin (GAs), GA_4 activity was detected in mature propagules. 5.GA_4 activity was detected as an endogenous GAs participating in the formation of roots in the propagules of K.candel. 6.The formation of roots and root elongation were inhibited by the treatment of propagules with an inhibitor of gibberellin biosynthesis, suggesting the participating of endogenous GAs. 7.The treatment of propagules with GA_3 after the treatment with the inhibitor reversed the inhibition and promoted the formation of roots and their elongation. These results showed that gibberellins participate in the root formation in the propagules of K.candel.