Estabrook E M, Sengupta-Gopalan C
Department of Agronomy, New Mexico State University, Las Cruces 88003.
Plant Cell. 1991 Mar;3(3):299-308. doi: 10.1105/tpc.3.3.299.
We have used conserved and nonconserved regions of cDNA clones for phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS) isolated from a soybean-nodule cDNA library to monitor the expression of members of the two gene families during the early stages of the soybean-Bradyrhizobium japonicum symbiosis. Our results demonstrate that subsets of the PAL and CHS gene families are specifically induced in soybean roots after infection with B. japonicum. Furthermore, by analyzing a supernodulating mutant line of soybean that differs from the wild-type parent in the number of successful infections, we show that the induction of PAL and CHS is related to postinfection events. Nodulated roots formed by a Nod+ Fix- strain of B. japonicum, resembling a pathogenic association, display induction of another distinct set of PAL and CHS genes. Our results suggest that the symbiosis-specific PAL and CHS genes in soybean are not induced by stress or pathogen interaction.
我们利用从大豆根瘤cDNA文库中分离出的苯丙氨酸解氨酶（PAL）和查尔酮合酶（CHS）的cDNA克隆的保守区和非保守区，来监测大豆 - 慢生根瘤菌共生早期阶段这两个基因家族成员的表达情况。我们的结果表明，在大豆被日本慢生根瘤菌感染后，PAL和CHS基因家族的一些亚群在大豆根中被特异性诱导。此外，通过分析一个在成功感染数量上与野生型亲本不同的大豆超级结瘤突变系，我们发现PAL和CHS的诱导与感染后事件有关。由日本慢生根瘤菌的一个Nod + Fix - 菌株形成的根瘤，类似于致病关联，显示出另一组不同的PAL和CHS基因的诱导。我们的结果表明，大豆中与共生特异性相关的PAL和CHS基因不是由胁迫或病原体相互作用诱导的。
