Abstract Abiotic stresses pose adverse impact on plant growth and development and exploring the stress tolerance genes from dominant species is still urgent. The desert shrub, Haloxylon ammodendron, a C4 and succulent xero-halophyte species, has great drought and salt tolerance. Here, we reported the isolation and functions analysis of HaASR1 (abscisic acid, stress, and ripening) from H. ammodendron. HaASR1 interacts with HaPrxQ and HaBADH and may function in preventing PrxQ and BADH from denaturation in plants under drought stress. Overexpression of HaASR1 reduces the sensitivity of Arabidopsis plants to exogenous ABA and decreases the endogenous ABA level through down-regulating ABA biosynthesis genes under drought stress, which making the plants display less inhibition of shoot growth and enhanced drought tolerance. Overexpression of HaASR1 significantly enhances photosynthetic capacity of Arabidopsis plants under drought stress by reducing H2O2 accumulation through up-regulating AtCAT2, AtAPX1 and AtPrxQ and maintaining relatively integrity of chloroplasts. Overexpression of HaASR1 also significantly improves water-retaining ability. Taken together, we propose that HaASR1 plays critical roles in plant drought stress adaptation by making the plants partially defective in ABA signaling and participating in drought tolerance regulation through nonstomatal pathways, enhancing ROS-scavenging ability and water-retaining ability, which is different from the functions of previously reported ASR genes from other plant species. This research also reveals that HaASR1 gene from the desert shrub, Haloxylon ammodendron, has potential application values in improving abiotic stresses of other plant species by genetic engineering.

中文翻译：

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从沙漠灌木梭梭中克隆的 HaASR1 基因赋予转基因拟南芥耐旱性

摘要 非生物胁迫对植物生长发育产生不利影响，探索优势种的胁迫耐受基因仍是当务之急。沙漠灌木梭梭是一种 C4 多汁的旱盐植物，具有很强的耐旱性和耐盐性。在这里，我们报告了从 H. ammodendron 分离 HaASR1（脱落酸、胁迫和成熟）的分离和功能分析。HaASR1 与 HaPrxQ 和 HaBADH 相互作用，可能在干旱胁迫下防止植物中的 PrxQ 和 BADH 变性。HaASR1的过表达通过在干旱胁迫下下调ABA生物合成基因，降低拟南芥植物对外源ABA的敏感性，降低内源ABA水平，使植物对地上部生长的抑制作用减弱，耐旱性增强。HaASR1 的过表达通过上调 AtCAT2、AtAPX1 和 AtPrxQ 并保持叶绿体的相对完整性来减少 H2O2 的积累，从而显着增强了干旱胁迫下拟南芥植物的光合能力。HaASR1的过表达也显着提高了保水能力。综上所述，我们认为 HaASR1 通过使植物部分缺乏 ABA 信号并通过非气孔途径参与抗旱调节，增强 ROS 清除能力和保水能力，在植物干旱胁迫适应中发挥关键作用，这不同于先前报道的来自其他植物物种的 ASR 基因的功能。该研究还揭示了来自沙漠灌木梭梭、梭梭、