Goormachtig S, Valerio-Lepiniec M, Szczyglowski K, Van Montagu M, Holsters M, de Bruijn F J
Laboratorium voor Genetica, Universiteit Gent, Belgium.
Mol Plant Microbe Interact. 1995 Nov-Dec;8(6):816-24. doi: 10.1094/mpmi-8-0816.
Upon infection of the tropical legume Sesbania rostrata with Azorhizobium caulinodans ORS571, nodules are formed on the roots as well as on the stems. Stem nodules appear at multiple predetermined sites consisting of dormant root primordia, which are positioned in vertical rows along the stem of the plant. We used the differential display method to isolate and characterize three cDNA clones (differential display; didi-2, didi-13, and didi-20), corresponding to genes whose expression is enhanced in the dormant root primordia after inoculation. Database searches revealed that the deduced (partial) didi-2 gene product shares significant similarity with hydroxyproline-rich cell wall proteins. The (partial) didi-13 and didi-20 products are similar to chitinases and chalcone reductases, respectively. Transcripts corresponding to the cDNA clones didi-2 and didi-13 were first detectable 1 day after inoculation. In contrast, didi-20 transcripts were found at low levels in uninfected root primordia and were enhanced significantly around 3 days after inoculation. In addition, a cDNA was isolated (didi-42) that corresponds to the previously identified leghemoglobin gene Srlb6. These studies show that differential display is a useful method for the isolation of infection-related genes.
热带豆科植物喙荚田菁被茎瘤固氮根瘤菌ORS571侵染后，根和茎上都会形成根瘤。茎瘤出现在多个由休眠根原基组成的预定部位，这些根原基沿植物茎干垂直排列。我们利用差异显示法分离并鉴定了三个cDNA克隆（差异显示；didi - 2、didi - 13和didi - 20），它们对应接种后在休眠根原基中表达增强的基因。数据库搜索显示，推导的（部分）didi - 2基因产物与富含羟脯氨酸的细胞壁蛋白有显著相似性。（部分）didi - 13和didi - 20产物分别与几丁质酶和查尔酮还原酶相似。对应cDNA克隆didi - 2和didi - 13的转录本在接种后1天首次可检测到。相比之下，didi - 20转录本在未感染的根原基中含量较低，在接种后约3天显著增加。此外，还分离出一个与先前鉴定的豆血红蛋白基因Srlb6对应的cDNA（didi - 42）。这些研究表明，差异显示是分离感染相关基因的一种有用方法。
