Abstract:

A new full-length MADS-box gene named FDRMADS8 was isolated from rice (Oryza sativa L.) by 3′RACE and 5′RACE using degenerate primer designed according to the MADS-box conserved region. The analyses of cDNA sequence showed that FDRMADS8 has 1 406 bp and encoded 233 amino acids which displayed the structure of typical plant MADS-box protein. The deduced amino acid sequence showed that it shared 50% identity with AGL14 of Arabidopsis. The RT-PCR expression analysis results from rice root, shoot and flower showed that the FDRMADS8 transcript was detectable in all three tissues, but the expression was lower in root and shoot. In situ hybridization experiments were performed on inflorescences and roots to analyze their temporal and spatial expression pattern. At the early stage of rice flower development, FDRMADS8 was mainly detectable in the bracts, bract hairs and inflorescence stems, while lower expression was detected in the apical meristem. Later in development, the expression of FDRMADS8 was detected in glumes and inflorescence stems. In root, the expression of FDRMADS8 was mainly localized in the elongation and mature region. No apparent expression signal was detected in the root cap, root meristem and pericycle cells. The results suggest that the MADS-box genes play a key role in the rice flower development though not restrict to it.

一个新的水稻MADS-box基因的克隆及表达分析
贾红武¹  罗达^2* 丛斌¹ 高之桢¹  邵坚寅¹ 曹凯鸣¹ 孙崇荣^1**

（1. 复旦大学生命科学学院生化系，上海200433；2.  中国科学院上海植物生理研究所，上海200032）

摘要：根据ＭＡＤＳ－ｂｏｘ基因保守区结构，设计简并性引物，利用３＇ＲＡＣＥ从水稻（Ｏｒｙｚａ ｓａｔｉｖａ Ｌ．）中克隆了１个新的水稻ＭＡＤＳ－ｂｏｘ基因的ｃＤＮＡ片段，同时利用５＆ＲＡＣＥ获得了全长ｃＤｎＡ命名为ＦＤＲＭＡＤＳＳ。序列分析表明，该ｃＤＮＡ全长１４０６ｂｐ，开放阅读框共编码２３３个到，具有典型的植物ＭＡＤＳ－ｂｏｘ基因的结构。推测的氨基酸序列与拟南芥的ＭＡＤＳ－ｂｏｘ基因，ＡＧＬ１４同源性为50%。应用RT-PCR表达分析表明，FDRMADS8在根、叶和花中均有表达，但在根和叶中表达较低。利用RNA原位杂交对其时空表达模式研究表明：在花发育早期,在苞片、苞毛和花序茎中有大量表达，但在顶端分生组织中表达量较少；在花发育后期，FDRMADS8在颖片以及花序茎中有明显表达，而在外稃、内稃、浆片、雄蕊和心皮原基中表达均不明显。在根中，FDRMADS8 在伸长区和根毛区的皮层中有大量表达，在根冠、根尖分生区和根毛区的中柱鞘细胞中却无明显表达。结果表明水稻MADS-box 基因的功能并不限于控制花发育。

关键词： 水稻MADS-box. 基因；3＇RACE;5＇RACE;RNA原位杂交

Key words: rice MADS-box gene, 3′RACE, 5′RACE, in situ hybridization