Central Laboratories, King Faisal University, PO Box 31982, Al-Ahsa, Saudi Arabia.
Date Palm Research Center of Excellence, King Faisal University, PO Box 31982, Al-Ahsa, Saudi Arabia.
Sci Rep. 2024 Oct 5;14(1):23186. doi: 10.1038/s41598-024-74422-4.
This study extends our prior research on drought responses in three date palm cultivars (Khalas, Reziz, and Sheshi) under controlled conditions. Here, we investigated their drought stress adaptive strategies under ambient environment. Under natural field drought conditions, three date palm cultivars experienced significantly (p ≤ 0.05) varying regulations in their physiological attributes. Specifically, chlorophyll content, leaf RWC, photosynthesis, stomatal conductance, and transpiration reduced significantly, while intercellular CO concentration and water use efficiency increased. Through suppression subtraction hybridization (SSH), a rich repertoire (1026) of drought-responsive expressed sequence tags (ESTs) were identified: 300 in Khalas, 343 in Reziz, and 383 in Sheshi. Functional analysis of ESTs, including gene annotation and KEGG pathways elucidation, unveiled that these cultivars withstand drought by leveraging indigenous and multifaceted pathways. While some pathways aligned with previously reported drought resilience mechanism observed under controlled conditions, several new indigenous pathways were noted, pinpointing cultivar-specific adaptations. ESTs identified in three date palm cultivars were enriched through GSEA analysis. Khalas exhibited enrichment in cellular and metabolic processes, catalytic activity, and metal ion binding. Reziz showed enrichment in biological regulation, metabolic processes, signaling, and nuclear functions. Conversely, Sheshi displayed enrichment in organelle, photosynthetic, and ribosomal components. Notably, ca. 50% of the ESTs were unique and novel, underlining the complexity of their adaptive genetic toolkit. Overall, Khalas displayed superior drought tolerance, followed by Reziz and Sheshi, highlighting cultivar-specific variability in adaptation. Conclusively, date palm cultivars exhibited diverse genetic and physiological strategies to cope with drought, demonstrating greater complexity in their resilience compared to controlled settings.
本研究扩展了我们先前在控制条件下对三种枣椰品种（Khalas、Reziz 和 Sheshi）干旱响应的研究。在这里，我们研究了它们在自然环境下的干旱胁迫适应策略。在自然田间干旱条件下，三种枣椰品种的生理特性发生了显著变化（p≤0.05）。具体来说，叶绿素含量、叶片相对含水量、光合作用、气孔导度和蒸腾作用显著降低，而胞间 CO 浓度和水分利用效率增加。通过抑制差减杂交（SSH），鉴定出丰富的 1026 个干旱响应表达序列标签（EST）：Khalas 中有 300 个，Reziz 中有 343 个，Sheshi 中有 383 个。ESTs 的功能分析，包括基因注释和 KEGG 途径阐明，揭示了这些品种通过利用本土和多方面的途径来抵御干旱。虽然一些途径与之前在控制条件下观察到的耐旱性恢复机制一致，但也发现了一些新的本土途径，指出了品种特异性的适应。通过 GSEA 分析对三种枣椰品种的 ESTs 进行了富集。Khalas 在细胞和代谢过程、催化活性和金属离子结合方面表现出富集。Reziz 在生物调节、代谢过程、信号转导和核功能方面表现出富集。相反，Sheshi 在细胞器、光合作用和核糖体成分方面表现出富集。值得注意的是，大约 50%的 ESTs 是独特和新颖的，强调了它们适应性遗传工具包的复杂性。总体而言，Khalas 表现出较高的耐旱性，其次是 Reziz 和 Sheshi，突出了适应的品种特异性变异性。总之，枣椰品种表现出多样化的遗传和生理策略来应对干旱，表明它们在应对干旱方面的恢复能力比在控制环境下更为复杂。
