论文部分内容阅读
利用减法杂交和RACEs从水稻颖花中克隆了一个编码富含脯氨酸残基多肽的cDNA,并将其相应的基因命名为OsPRP1.OsPRP1由2个外显子和1内含子组成,编码的蛋白由224个氨基酸残基组成,其中脯氨酸含量最高,占14.29％.该蛋白由一个21个氨基酸残基组成的信号肽,一个N-端结构域和一个C-端结构域组成.C-端含有2个18个氨基酸长的、嵌合PEPK基元(motif)的富含脯氨酸的重复序列.Southern blot及序列分析结果表明,水稻基因组中存在4个拷贝的OsPRP1,它们定位在第10染色体的20 kb的DNA片段上.RT-PCR表明,OsPRP1在幼芽和颖花中表达量较高,在根和叶中有少量表达.用花和幼芽进行原位杂交分析证明在花中,OsPRP1在花粉母细胞、绒毡层细胞和花器官的维管束细胞中表达;该基因的表达有明显的时间特异性,在花粉母细胞中表达量最高,在单核期的小孢子中几乎不表达;在芽中,该基因在胚芽鞘和叶原基的表皮细胞中表达.从该基因编码蛋白的特点可以看出它极可能是一种细胞壁蛋白.
A cDNA encoding a polypeptide rich in proline residues was cloned from rice spike using subtractive hybridization and RACEs and the corresponding gene was named OsPRP1.OsPRP1 consisted of two exons and one intron and encoded Of the protein consists of 224 amino acid residues, of which the proline content is the highest, accounting for 14.29% .The protein consists of a signal peptide consisting of 21 amino acid residues, an N-terminal domain and a C-terminal domain. The proline-rich repeats containing two 18-amino-acid long, chimeric PEPK motifs at the C-terminus were analyzed by Southern blot and sequence analysis.The results showed that there are 4 copies of OsPRP1 in rice genome On the 20 kb DNA fragment on chromosome 10, RT-PCR indicated that OsPRP1 was highly expressed in young shoots and spikelets with a small amount of expression in roots and leaves. In situ hybridization with flowers and shoots demonstrated that In flowers, OsPRP1 was expressed in vascular bundles of pollen mother cells, tapetal cells and floral organs. The expression of OsPRP1 was obviously time-specific and highest in pollen mother cells. Spores hardly express; in bud, the gene is in coleoptile and leaf primordia Expression of epidermal cells from the characteristics of the gene encoding the protein can be seen that it is very likely to be a cell wall proteins.