HbNIN2基因在巴西橡胶树嫩皮和中脉中的RNA原位杂交分析

在橡胶树（Hevea brasiliensis）中，转化酶基因HbNIN2被证明是决定产胶细胞乳管中蔗糖代谢的关键基因，同时在叶片、树皮等多种组织中均有表达。为进一步研究HbNIN2基因的功能，利用原位杂交（in situ hybridization）技术对HbNIN2基因在橡胶树嫩皮和中脉两种组织中的表达区域与表达特点进行研究。结果显示，在橡胶树嫩皮中，HbNIN2基因主要在韧皮部中表达，而在中脉中，HbNIN2基因在除木质部外的其它部位均有表达，同时在两种组织的乳管细胞中HbNIN2基因均有明显的表达信号。比较而言，HbNIN2基因在中脉中的表达量远高于嫩皮。结合其它研究结果，推测HbNIN2基因可能参与橡胶树乳管蔗糖代谢、叶片生长发育调控等。

In situ Hybridization Analysis of HbNIN2 Gene in Young Barks and Midribs of Hevea brasiliensis

In para rubber tree(Hevea brasiliensis), an invertase gene, HbNIN2 has been identified as the key gene responsible for sucrose catabolism in rubber-producing laticifers. To further investigate the function of HbNIN2 gene, digoxigenin-labeled cRNA probes were used in situ hybridization to detect the distribution pattern of HbNIN2 mRNA in tissues of rubber young barks and midribs. The results showed that in young barks, HbNIN2 gene was mainly expressed in phloem, whereas it was expressed in all tissues of midribs except for xylem. In both tissues, the expression of HbNIN2 was apparently detected in the laticifer-like cells. In addition, the expression of HbNIN2 in midribs was much higher than that in young barks. Combined with the results in other studies, HbNIN2 gene was likely to play a critical role in the regulation of sucrose metabolism in the laticifers, and leaf development in rubber tree.