Abstract：
Haloxylon ammodendron, an important shrub utilized for afforestation in desert areas, can withstand harsh ecological conditions such as drought, high salt and extreme heat. A better understanding of the stress adaptation mechanisms of H. ammodendron is vital for ecological improvement in desert areas. In this study, the role of the H. ammodendron 14-3-3 protein HaFT-1 in thermotolerance was investigated. qRT-PCR analysis showed that heat stress (HS) priming (the first HS) enhanced the expression of HaFT-1 during the second HS and subsequent recovery phase. The subcellular localization of YFP-HaFT-1 fusion protein was mainly detected in cytoplasm. HaFT-1 overexpression increased the germination rate of transgenic Arabidopsis seeds, and the survival rate of HaFT-1 overexpression seedlings was higher than that of wild-type (WT) Arabidopsis after priming-and-triggering and non-primed control treatments. Cell death staining showed that HaFT-1 overexpression lines exhibited significantly reduced cell death during HS compared to WT. Transcriptome analysis showed that genes associated with energy generation, protein metabolism, proline metabolism, autophagy, chlorophyll metabolism and reactive oxygen species (ROS) scavenging were important to the thermotolerance of HS-primed HaFT-1 transgenic plants. Growth physiology analysis indicated that priming-and-triggering treatment of Arabidopsis seedlings overexpressing HaFT-1 increased proline content and strengthened ROS scavenging activity. These results demonstrated that overexpression of HaFT-1 increased not only HS priming but also tolerance to the second HS of transgenic Arabidopsis, suggesting that HaFT-1 is a positive regulator in acquired thermotolerance.
摘要：
梭梭,一种用于沙漠地区植树造林的重要灌木，可以承受干旱等恶劣的生态条件，高盐和极端高温。更好地了解水华的胁迫适应机制对于沙漠地区的生态改善至关重要。在这项研究中,研究了H.ammodendron14-3-3蛋白HaFT-1在耐热性中的作用。qRT-PCR分析显示热应激(HS)引发(第一HS)在第二HS和随后的恢复期期间增强HaFT-1的表达。YFP-HaFT-1融合蛋白的亚细胞定位主要在细胞质中。HaFT-1过表达提高了转基因拟南芥种子的发芽率,在引发和触发和非引发对照处理后，HaFT-1过表达幼苗的存活率高于野生型（WT）拟南芥。细胞死亡染色显示,与WT相比,HaFT-1过表达系在HS期间表现出显著减少的细胞死亡。转录组分析表明，与能量产生相关的基因，蛋白质代谢，脯氨酸代谢，自噬,叶绿素代谢和活性氧（ROS）清除对HS引发的HaFT-1转基因植物的耐热性很重要。生长生理分析表明，过表达HaFT-1的拟南芥幼苗的引发和触发处理增加了脯氨酸含量并增强了ROS清除活性。这些结果表明，HaFT-1的过表达不仅增加了HS引发，而且增加了转基因拟南芥对第二个HS的耐受性，这表明HaFT-1是获得耐热性的正调节因子。
