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体细胞胚胎发生不仅是植物微繁、种质保存的有效手段,同时也是研究高等植物胚胎发育和遗传转化的模式系统之一.本研究从马尾松未成熟合子胚诱导的胚性细胞团中成功克隆了体胚发生受体激酶基因PmSERKl.该基因全长2 303bp,包含完整的开放阅读框,编码626个氨基酸,其蛋白分子量约为69kD.序列分析发现PmSERKl与其它植物的SERK基因高度同源.系统进化树重建表明,PmSERKl与已知参与体胚发生的关键SERK基因聚为一类,如MtSERKl、CuSERKl、AtSERKl和DcSERK.表达分析显示:PmSERKl在主要的组织器官(根、茎、针叶等)略有表达;但在诱导培养的非胚性愈伤中没有检测到表达,而在经继代培养的胚性愈伤中表达很高且逐渐增加,且在培养20 d时达到最高.另外,在再生的子叶胚中,PmSERKl的表达量也很高.综上所述表明,PmSERKl是与体胚发生相关的关键SERK基因的直系同源基因,可以作为愈伤组织胚性的标记基因.“,”Somatic embryogenesis is not only the most effective way to micro-propagation and germplasm conservation of plant,and also as a suitable model system for embryogenesis and genetic transformation of higher plants.We have cloned and characterized a somatic embryogenesis receptor kinase (SERK) gene nemed PmSERKl from the embryogenic cell aggregates induced by immature zygotic embryos of Masson pine (Pinus massoniana Lamb.).The full-length cDNA of PmSERKl is 2 303 bp,contain an open reading frame,encoded a 626 amino acids peptide with protein of 69 kD.Sequence analysis of PmSERKl revealed high levels of homology to other plant SERK gene.Phylogenetic tree reconstruction showed PmSERKl and other key SERK genes involved in evoking somatic embryogenesis such as MtSERKl,CuSERKl,AtSERKl,and DcSERK,were classified to one cluster.The expression analysis indicate that PmSERKl expression were seen a little in the major plant tissues,such as root,stem,leave etc.;the PmSERKl expression were barely detected in proliferating non-embryogenic calli,However,they could be detected in the secondary culture embryogenic calli,and the expression level was increased gradually,with a peak at the 20 days after subculture.Otherwise,the high expression level of PmSERKl was detected in the regenerated cotyledonary embryos.The results suggest that the isolated PmSERKl could have homologous sequences of the key genes involved in somatic embryogenesis and might be as a marker gene of embryonic capability of calli.