外源JA的移动对巴西橡胶树萌条次生乳管分化的诱导效应

Effect on the Induction of the Secondary Laticifer Differentiation by the Transportation of Exogenous JA in Hevea brasiliensis

利用碘-溴染色法结合石蜡切片技术,研究移动的JA(Jasmonic Acid,茉莉酸)对橡胶树萌条次生乳管分化的诱导效应。结果表明:在自然条件下,第一和第二叶蓬均无次生乳管分化,但第一叶蓬经0.07%JA处理,40 d后在施用部位、施用部位上下5 cm、10 cm处及远离施用部位的下一叶蓬均有次生乳管分化,该乳管细胞大小相近,离形成层区的远近相似,可见这些乳管是同期被诱导出来的,外源JA的移动是施用部位之外的茎皮分化次生乳管的原因。同一萌条的不同叶蓬同时施加JA比单叶蓬施加JA更易诱导次生乳管,表明移动的JA诱导乳管分化具有叠加效应和剂量效应。本研究为茉莉酸的信号传导及诱导橡胶树乳管分化机制的深入研究奠定基础。

By using iodine-bromine dyeing and paraffin section techniques, the effect of the transportation of exogenous JA （jasmonic acid）on inducing the secondary latcicifer differentiation in epicormic shoot of Hevea brasiliensis was revealed. The results showed that no secondary laticifer differentiated in the first and second foliage clusters under natural conditions while a row of secondary laticifers appeared in the bark of the first foliage cluster 40 d after being treated with 0.07% JA. Meanwhile, the secondary laticifers were present in the bark of the sites 10 cm and 5 cm up and down from the treated site as well as in the bark of the next foliage cluster respectively. The secondary laticifers in different sites were of similar size and uniform distance far from the cambia region, suggesting that these laticifers differentiated at the same period and induced by the transportation of JA. The effect of JA application on several foliage clusters of a single shoot at the same time was much stronger than those treated separately, implying the effect of mobile JA on the induction of the secondary laticifer had the dose-effect and the superimpose dose. This study had provided the basis for lucubrating the signal transduction of JA and the mechanism of laticifer differentiation in rubber tree.