超量表达FBL1对84K杨根系和生长量影响研究

生长素及其信号转导系统对植物的生长发育具有重要的影响。本研究从银腺杨'84K'(Populus alba × P. glandulosa cl. '84K')中分离了生长素受体基因PtrFBL1,利用PMDC32构建了PMDC32-PtrFBL1超量表达载体,并通过遗传转化获得了超量表达植株17个。对温室定植的3个转基因株系和对照植株的根系、生长量和光合指标等性状分析结果显示:转基因株系总根长和总根面积达到显著或极显著差异,而根系干质量、平均不定根系长度、平均不定根直径差异不显著;株高、平均节间长、地径和高径比皆高于对照,且大多数转基因株系达到显著差异;除气孔限制值(Ls)低于对照外,气孔导度(Cd)、水分利用效率(WUE)、光能利用效率(LUE)和叶绿素相对含量皆高于对照,且大多数转基因株系达到显著或极显著差异。以上结果表明,可能是FBL1超表达增加了转基因株系根系面积,提高了水分和养分的吸收利用,进而导致转基因株系光能吸收和转化效率提高,引起转基因株系生长加快。

Over-expressing FBL1 Receptor Led to Root Formation and Growth of Populus alba×P. glandulosa cl.'84K'

Poplar is one of the major fast-growing tree species in China, but little was known about the effect of auxin on fast growth and secondary growth of poplar plants. In this study, PtrFBL1 for auxin receptor gene was cloned in poplar, the over-expression vector of PMDC32-PtrFBL1 based on PMDC32 was constructed and 17PtrFBL1 over-expressed plants of P. alba × P. glandulosa cl. '84K' were obtained. The root, growth and photosynthetic indexes of 3 transgenic lines and the control were analyzed. The results showed that the total root length and total root area of transgenic lines were higher than those of the non-transgenic control lines, and the differences were all significant or extremely significant. On the other hand, the mean adventitious root length, mean adventitious root diameter and root biomass were not significant. The plant height, average internode length, average internode diameter and ratio of height and diameter were higher than these of the control lines. In addition to lower limitation of stoma(Ls), all the other indexes, i.e. the stomatal conductance(Cd), water use efficiency(WUE), light use efficiency(LUE) and relative contents of chlorophyll were higher than those of the controls, and the differences from most transgenic lines reached significant or extremely significant levels. The transgenic lines increased the root areas, and had stronger photosynthetic efficiency and rate of water consumption, and promoted biomass accumulation on ground, thus had the accelerated speed of growth. Therefore, the PtrFBL1 gene has the potential to be manipulated to improve the growth.