美洲黑杨材性相关候选基因PdCYTOB的功能鉴定

摘要

We used quantitative real-time RT-PCR to investigate the tissue expression patterns of cytokinin binding-protein PdCYTOB, which is related to the wood properties of Populus deltoides. PdCYTOB was expressed predominantly in immature xylem, immature phloem and the phloem zone of the stem of P. Deltoides. Southern blot and RT-PCR were used to detect antisense PdCYTOS-transgenic Populus davidiana x P. Bolleana plants. The antisense PdCYTOB gene was integrated into the genome of the poplar and expressed. Phenotype, anatomical studies and microfibrillar angle analysis revealed the plant height of transgenic poplar higher than that of untransformed lines, as well as xylem and the phloem zone of plants with antisense PdCYTOB wider than those of untransformed lines. In addition, the microfibrillar angle of transgenic plants was decreased in the test field. Thus, pulping and papermaking properties might be improved in antisense-PdCYTOB transformed lines. Our study sheds light on the molecular mechanism of PdCYTOB in wood formation in P. Deltoides.%利用RT-PCR技术研究了美洲黑杨(Populus deltoides)材性相关候选基因细胞分裂素结合蛋白(cytokinin binding protein)基因PdCYTOB的表达谱,结果显示,在未成熟木质部、未成熟韧皮部和韧皮部中PdCTOB基因具有较高水平的表达量.对导入反义PdCYTOB的山新杨(Populus davidiana x P.bolleana)植株进行Southern杂交和RT-PCR检测,证实反义PdCYTOB基因已整合到杨树基因组中并表达.对大田转基因株系及对照植株进行表型观察、组织切片和微纤丝角的测定,结果表明,转反义PdCYTOB基因植株的高度明显增加,木质部、韧皮部变宽,微纤丝角明显变小,初步表明转基因杨树在造纸性能上有所改良.这些研究结果对于阐明PdCYTOB在美洲黑杨木材形成中的分子作用机制具有重要的理论意义.