ABSTRACT

Gummosis (Phytophthora root and crown rot) is an important and destructive disease that affects fruit trees like pistachio (Pistacia vera L.). Although many studies have been performed on the possibility of biological control of gummosis, up to now few studies have been done on transcriptionally induced resistance genes in pistachio against Phytophthora disease. In the present research, the cDNA-AFLP method was used to analyze the transcriptionally regulated genes during the interaction between susceptible (Sarakhs) and resistant (Badami-Rize Zarandi) pistachio cultivars with Pseudomonas fluorescens and/or Phytophthora parsiana. Using 12 AFLP primer combinations, approximately 740 different cDNA-AFLP fragments with sizes ranged from 50 to 700 bp were generated for susceptible and resistant pistachio cultivars. Forty six TDFs (transcript derived fragments) were then selected for susceptible cultivar and 24 TDFs for resistant cultivar. Accordingly, each one of these TDFs was recognized by similarity search using the BlastX program against the NCBI GenBank nucleotide database. Notably, 18.5% of TDFs were hypothetical or uncharacterized proteins and 1.4% of them indicated no significant similarity to the known genes. Among the TDFs with known function, disease resistance proteins were identified, which were newly regulated in response to pathogen or rhizobacterium. Furthermore, we found that the expression level of different growth-regulatory or defense-related genes was higher after the exposure to Pseudomonas fluorescens and/or Phytophthora parsiana. To better understand the defense mechanism of pistachio plants and recognition of P. fluorescens-activated genes, which induce resistance against P. parsiana, would significantly assist in the development of new resistant pistachio cultivars.

摘要

牙龈病（疫霉根和冠腐病）是一种重要的破坏性疾病，会影响开心果（Pistacia vera L.）等果树。尽管已经进行了许多关于牙龈病的生物控制的可能性的研究，但是到目前为止，关于开心果抗疫霉病的转录诱导的抗性基因的研究还很少。在本研究中，cDNA-AFLP方法用于分析易感性（Sarakhs）和抗性（Badami-Rize Zarandi）开心果品种与荧光假单胞菌和/或疫霉菌之间的转录调控基因。。使用12种AFLP引物组合，为易感和抗性开心果栽培品种产生了大约740个不同的cDNA-AFLP片段，大小在50到700 bp之间。然后选择46种TDF（转录本衍生片段）用于易感品种，选择24种TDF用于抗性品种。因此，通过使用针对NCBI GenBank核苷酸数据库的BlastX程序进行相似性搜索来识别这些TDF中的每一个。值得注意的是，有18.5％的TDF是假定的或未表征的蛋白质，其中1.4％的TDF与已知基因没有显着相似性。在功能已知的TDF中，鉴定出了抗病蛋白，这些蛋白可响应病原体或根瘤菌而受到新的调节。此外，荧光假单胞菌和/或疫霉。为了更好地了解开心果植物的防御机制，并认识到荧光假单胞菌激活的基因（诱导对欧芹假单胞菌具有抗性），将大大有助于开发新型的开心果抗性品种。