【摘要】 为明确大豆节间木质素积累规律，深入理解木质素积累与大豆植株抗倒伏间的关系，进而为调控大豆植株表型和抗倒伏大豆新品种选育提供参考依据，选取具有代表性的有限生长习性品种Charleston,按照20,35株/m² 的2种密度种植桶栽大豆，在2种不同密度下测定主茎的木质素含量，分析Charleston主茎第3节间的细胞伸长区（EZ）和次生细胞壁成熟区（MZ）木质素含量、在木质素合成过程中的4-香豆酸：辅酶A连接酶（4CL）、苯丙氨酸转氨酶（PAL）、肉桂酸脱氢酶（CAD）等关键酶活性以及对应基因的表达量。手工切片及分光光度计测定的结果表明，大豆主茎木质素含量由形态学上端向下端逐渐增加。低密度处理主茎中的木质素含量高于高密度。无论是高密度还是低密度处理，单一节间（茎3）木质素含量均为MZ>EZ;低密度处理茎中4CL、PAL、CAD的活性高于高密度处理。2个密度处理下茎中4CL、PAL、CAD活性变化规律较为一致，与基因表达结果相符合。大豆植株主茎中木质素含量受到木质素合成途径中的多种酶调控。木质素合成的关键酶基因多以基因家族形式存在，同一基因家族中的酶基因在同一物种植株的相同部位表达存在差异，同一基因在同一物种的不同组织和器官中的表达情况也不尽相同。更多还原

【Abstract】 To clarify the lignin accumulation ways in the stem of soybean variety, and further understand the relation between the lignin accumulation and lodging resistance of soybean plant, which could give the theory evidence for plant phenotype regulation and new soybean variety breeding under different planting densities, Charleston, a representative variety with determinate growth habit, was selected in current study and were planted with two densities of 20,35 plants/m~2.The lignin content in the elongation zone(EZ)and the secondary cell wall maturation zone(MZ)at the third internode of Charleston′s stem were measured and the activities of key enzymes such as 4-Coumarate: coenzyme A ligase(4 CL)and phenylalanine aminotransferase(PAL)and cinnamate dehydrogenase(CAD)involved in the lignin synthesis were determined at two different densities.The results showed that lignin content in the stem of Charleston under low density was higher than that under high density.The content of lignin in single internode(stem 3)of Charleston under both high and low density treatments was MZ>EZ.4 CL,PAL and CAD activities in low density Charleston stem were higher than those in high density of Charleston and in accordance with gene expression levels.The key genes for lignin synthesized were distributed in soybean genome in different gene families.Moreover, different enzyme gene in one gene family showed different expression style in the same section.Same results could be observed in different organ for one gene.更多还原