Low-quality water and soil salinization are increasingly becoming limiting factors for food production, including olive – a major fruit crop in several parts of the world. Identifying putative salinity-stress tolerance in olive would be helpful in the future development of new tolerant varieties. In this study, novel salinity-responsive biomarkers (SRBs) were characterized in the species, namely, monooxygenase 1 (OeMO1), cation calcium exchanger 1 (OeCCX1), salt tolerance protein (OeSTO), proteolipid membrane potential modulator (OePMP3), universal stress protein (OeUSP2), adaptor protein complex 4 medium mu4 subunit (OeAP-4), WRKY1 transcription factor (OeWRKY1) and potassium transporter 2 (OeKT2). Unique structural features were highlighted for encoded proteins as compared with other plant homologues. The expression of olive SRBs was investigated in leaves of young plantlets of two cultivars, ‘Nabali’ (moderately tolerant) and ‘Picual’ (tolerant). At 60 mM NaCl stress level, OeMO1, OeSTO, OePMP3, OeUSP2, OeAP-4 and OeWRKY1 were up-regulated in ‘Nabali’ as compared with ‘Picual’. On the other hand, OeCCX1 and OeKT2 were up-regulated at three stress levels (30, 60 and 90 mM NaCl) in ‘Picual’ as compared to ‘Nabali’. Salinity tolerance in olive presumably engages multiple sets of responsive genes triggered by different stress levels.

中文翻译：

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橄榄（Olea europaea L.）中推定的盐度反应生物标志物的表征

低质量的水和土壤盐渍化正日益成为粮食生产的限制因素，其中包括橄榄——世界若干地区的主要水果作物。确定橄榄中假定的盐胁迫耐受性将有助于未来开发新的耐受性品种。在这项研究中，新的盐度响应生物标志物 (SRB) 在该物种中进行了表征，即单加氧酶 1 (OeMO1), 阳离子钙交换剂 1 (OECCX1), 耐盐蛋白 (奥斯托), 蛋白脂质膜电位调节剂 (OePMP3), 通用应激蛋白 (OEUSP2), 衔接蛋白复合物 4 培养基 mu4 亚基 (OeAP-4), WRKY1 转录因子 (OeWRKY1) 和钾转运蛋白 2 (OEKT2）。与其他植物同源物相比，编码的蛋白质突出了独特的结构特征。研究了橄榄 SRBs 在两个品种“Nabali”（中度耐受）和“Picual”（耐受）的幼苗叶片中的表达。在 60 mM NaCl 压力水平下，OeMO1,奥斯托,OePMP3,OEUSP2,OeAP-4和OeWRKY1与 'Picual' 相比，'Nabali' 上调。另一方面，OECCX1和OEKT2与“Nabali”相比，“Picual”中的三个应激水平（30、60 和 90 mM NaCl）上调。橄榄的耐盐性可能涉及由不同压力水平触发的多组响应基因。