Barely Hordeum vulgare L. is considered one of the most important cereal crops with economic and industrial importance in the world, but its productivity is affected by climate change and abiotic stresses. One of the most recent and important microbiological promising aspects is the use of associated microorganisms, especially the endophytic bacteria producers for non-ribosomal peptides which play an important role in promoting plant growth, productivity, and tolerance to biotic and abiotic stresses. This work aims to identify vertically transferred or inherited endophytic bacterial communities in barely seeds, detect the presence of non-ribosomal peptides from these isolated endophytic strains and study their effect on protein patterns as a response to salinity stress. From two different tolerant (Giza 126) and sensitive (Giza 123) barely seeds cultivars, six different endophytic bacterial strains were isolated and identified using 16S rRNA. Bacterial strains belonged to Bacillus, Paenibacillus, Staphylococcus and Acinetobacter genera. Three of them have been isolated from both sensitive and tolerant barely cultivar (Uncultured Staphylococcus, Acinetobacter and Priestia endophytica or Bacillus endophyticus), while the other three endophytes have been isolated uniquely from the tolerant barely cultivar (Paenibacillus glucanolyticus, Bacillus cereus and Bacillus sp.). Non-ribosomal peptide synthetases genes NRPs of two lipopeptide families; surfactins and kurstakins have been detected using both bioinformatic analysis and degenerate primers. On the other hand, fragments similar to NRPs genes might be considered new NRPS molecules in Paenibacillus glucanolyticus, Acinetobacter and Priestia endophytica which have been detected using degenerate primers and required whole genome sequencing. The effect of soaking barely seeds exposed to 2.5% NaCl using SDS-PAGE electrophoresis revealed the presence of 24 bands, 10 of them were monomorphic with 41.5%, and 14 were polymorphic with 58.5% polymorphism. The overnight soaking and co-cultivation of isolated endophytic strains with barely seeds before planting proved their capability in conferring salt stress tolerance to barely seedlings which appeared in protein patterns. We could consider these barely seeds endophytic among the PGPR strains promising to improve plant growth during abiotic stresses.

中文翻译：

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种子中相关内生细菌的分离和鉴定含有非核糖体肽并增强对盐度胁迫的耐受性

大麦被认为是世界上具有经济和工业重要性的最重要的谷类作物之一，但其生产力受到气候变化和非生物胁迫的影响。最近最重要的微生物学前景之一是使用相关微生物，特别是非核糖体肽的内生细菌生产者，其在促进植物生长、生产力以及对生物和非生物胁迫的耐受性方面发挥重要作用。这项工作的目的是鉴定种子中垂直转移或遗传的内生细菌群落，检测这些分离的内生菌株中非核糖体肽的存在，并研究它们对蛋白质模式的影响作为对盐度胁迫的反应。从两个不同的耐受性 (Giza 126) 和敏感性 (Giza 123) 几乎没有种子的品种中，使用 16S rRNA 分离并鉴定了六种不同的内生细菌菌株。细菌菌株属于芽孢杆菌属、类芽孢杆菌属、葡萄球菌属和不动杆菌属。其中三种内生菌是从敏感和耐受的硬质品种（未培养的葡萄球菌、不动杆菌和内生芽孢杆菌）中分离出来的，而另外三种内生菌是从耐性的硬质品种（解葡糖类芽孢杆菌、蜡状芽孢杆菌和芽孢杆菌）中分离出来的。 ）。两个脂肽家族的非核糖体肽合成酶基因NRP；使用生物信息学分析和简并引物已检测到表面活性素和库斯塔金。另一方面，与NRPs基因相似的片段可能被认为是解葡糖类芽孢杆菌、不动杆菌和内生Priestia中新的NRPS分子，这些分子已使用简并引物检测到并需要全基因组测序。 SDS-PAGE电泳检测2.5% NaCl浸种效果，发现24条带，其中单态性条带10条，多态性占41.5%；多态性条带14条，多态性占58.5%。种植前分离的内生菌株与裸苗的过夜浸泡和共培养证明了它们能够赋予裸苗以蛋白质模式出现的盐胁迫耐受性。我们可以认为这些几乎没有种子的 PGPR 菌株是内生的，有望在非生物胁迫期间改善植物生长。