Drought stress is one of the major abiotic stresses that adversely affect rice production. Four rice genotypes, Giza177, IR64 (as sensitive genotypes) and Vandana, Orabi3 (as tolerant genotypes) were used to screen and characterize the soil microbes associated with each genotype under drought stress. The soil microbes associated with the tolerant genotypes showed high drought tolerance and high levels of enzyme activity. The most drought-tolerant isolates were inoculated with the sensitive genotype Giza177 under drought conditions. Some morphological, biochemical and molecular responses of inoculated plants were estimated. Inoculated plants showed regulation of some growth and stress-related genes (COX1, AP2-EREBP, GRAM, NRAMP6, NAM, GST, DHN and three genes of expansin (EXP1, EXP2 and EXP3) under drought conditions. Expression profiling of these genes were highly induced in plants inoculated with 4E11 and were correlated with improved growth status under drought stress. Based on this, drought-tolerant plant growth-promoting rhizobacteria (PGPRs) were associated with the drought-tolerant genotype (Orabi 3). They were related to the significant increase in soil enzymes activities (dehydrogenase, nitrogenase, urease and alkaline phosphatase) in the rhizosphere of tolerant genotype. Inoculation the drought-sensitive genotype (Giza 177) with the most drought-tolerant isolates improved the tolerance status of the sensitive rice genotype and induced the expression of some growth and stress-responsive genes. AP2-EREBP, NRAMP6, DHN and all expansin genes (EXP1, EXP2 and EXP3) were the highly induced genes in inoculated plants with 4E11 strain and the consortium of three selected strains under drought condition.

中文翻译：

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敏感水稻基因型接种根际细菌后某些生长和胁迫相关基因表达水平的改变以减轻其耐旱性

干旱胁迫是对水稻生产产生不利影响的主要非生物胁迫之一。四种水稻基因型 Giza177、IR64（作为敏感基因型）和 Vandana、Orabi3（作为耐受基因型）用于筛选和表征干旱胁迫下与每种基因型相关的土壤微生物。与耐受基因型相关的土壤微生物表现出高耐旱性和高水平的酶活性。最耐旱的分离株在干旱条件下接种敏感基因型 Giza177。估计了接种植物的一些形态、生化和分子反应。在干旱条件下，接种的植物显示出一些生长和胁迫相关基因（COX1、AP2-EREBP、GRAM、NRAMP6、NAM、GST、DHN 和三个扩展蛋白基因（EXP1、EXP2 和 EXP3）的调节）。这些基因的表达谱在接种 4E11 的植物中被高度诱导，并且与干旱胁迫下生长状况的改善相关。基于此，耐旱植物促生长根际细菌 (PGPRs) 与耐旱基因型 (Orabi 3) 相关。它们与耐受基因型根际土壤酶活性（脱氢酶、固氮酶、脲酶和碱性磷酸酶）显着增加有关。用最耐旱的菌株接种干旱敏感基因型（Giza 177）改善了敏感水稻基因型的耐受状态，并诱导了一些生长和胁迫响应基因的表达。AP2-EREBP、NRAMP6、DHN 和所有扩展蛋白基因（EXP1、