【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 (OryzasativaL .)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FDRMADS8。序列分析表明 ,该cDNA全长 140 6bp ,开放阅读框共编码 2 33个氨基酸 ,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 5 0 %。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 ,FDRMADS8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。更多还原

【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.更多还原