Vertical Distribution and Seasonal Dynamics of Effects of Shading on Leaf Shape and Photosynthetic Characteristics of the Transgenic Lespedeza formosa with Expressing BADH Gene | 遮荫对转BADH基因的美丽胡枝子叶片形态和光合特性的影响

Chinese. 为探索外源甜菜碱醛脱氢酶（BADH）基因的导入对美丽胡枝子耐荫性的影响，选用2个转入BADH基因的美丽胡枝子株系和对照用非转基因植株进行遮荫处理，测定不同遮荫处理下（透光率分别为100％，75％，34％，11％）的转基因株系与非转基因植株的甜菜碱含量、甜菜碱醛脱氢酶活性、叶绿素含量、叶形态指标、净光合速率、蒸腾速率、光补偿点和光饱和点等。结果表明：1）在弱光环境下，转BADH基因的美丽胡枝子T1代植株呈现绿色与黄色性状分化，表现出3：1的分离规律；2）弱光能诱导BADH基因的表达，增加BADH活性和积累更多甜菜碱；3）在透光率34％，11％的弱光条件下，转BADH基因美丽胡枝子的叶绿素a、b含量、叶长、叶宽、比叶干质量、单位叶面积鲜质量、日净光合速率、日蒸腾速率、表观量子效率显著高于非转基因植株，而叶绿素a／b值、比叶面积、光饱和点、光补偿点显著低于非转基因植株；4）在自然光照和透光率75％环境下，转基因株系的多项指标与非转基因植株间差异不显著；5）转基因美丽胡枝子比非转基因植株更能适应弱光环境。

English. The aim of this study was to investigate the effects of shading on the transgenic Lespedeza formosa with expressing BADH. Two transgenic L. formosa lines and wild-type plants were selected as materials and were shaded. The betaine aldehyde dehydrogenase activity, glycinbetaine, chlorophyll, leaf shape, net photosynthetic rate, transpiration rate, light compensation point, light saturation point et al. were assayed in transgenic and wild-type plants under different irradiation regimes （light transmittance 100% , 75% , 34% and 11% ）. The result was as follows： 1 ） The T1 generation of transgenic L. formosa plants showed trait differentiation in leaf color. The proportion of green leaves and yellow leaves was 3：1 and accorded with Mendelian Law separation. 2） Low light induced the expression of BADH gene and increased betaine aldehyde dehydrogenase activity. Higher glycinbetaine content was accumulated under low light. 3 ） The chlorophyll a and b concentrations, leaf length, leaf width, specific leaf dry mass, fresh mass per unit area of leaf, daily net photosynthetic rate, daily transpiration rate and apparent quantum yield in transgenic plants were significantly higher than those in wild-type plants under low light of light transmittance 34% or 11%. But chlorophyll a/b ratio, specific leaf area, light compensation point and light saturation point in transgenic plants were significantly lower than those in wild- type plants. 4）There was no significant difference between transgenic and wild-type plants in most of assayed indexes when plants grew in full nature light or light transmittance 75%. 5）The transgenic L. formosa with expressing BADH could more adapt to weak light than wild-type plants.