Chen Haiyan, Shen Yongbao
College of Forestry, Nanjing Forestry University, 159 Longpan Road, Xuanwu District, Nanjing, 210037, China.
Co-Innovation Center for Sustainable Forestry in Southern China, Southern Tree Inspection Center National Forestry Administration, 159 Longpan Road, Xuanwu District, Nanjing, 210037, China.
Plant Mol Biol. 2025 May 26;115(3):68. doi: 10.1007/s11103-025-01596-4.
The preservation of recalcitrant seeds is crucial for sustainable forest management and biodiversity conservation, particularly for economically important species like Quercus acutissima. However, these seeds pose serious challenges for ex situ conservation due to their high sensitivity to desiccation. This study employed integrated physiological, cytological, and proteomic approaches to systematically reveal the characteristics of viability loss during desiccation of Q. acutissima seeds. The results showed that fresh seeds had an initial moisture content of 38.8% (IM) with a germination percentage of 99%, while the semi-lethal (SLM) and lethal moisture (LM) contents were 26.8% and 14.8%, respectively. Desiccation caused cell wall collapse, membrane system rupture, and cytoplasmic degradation, while physiological and proteomic results revealed distinct responses during different desiccation stages. In the early stages, downregulation of iron superoxide dismutase indicated antioxidant system impairment, while lipoxygenase-mediated membrane lipid peroxidation triggered reactive oxygen species and malondialdehyde accumulation. During the deep desiccation stages (LM), we observed active energy metabolism with isocitrate dehydrogenase [NADP] upregulation. Additionally, the downregulation of phospholipase D and acyl-CoA synthetase may promote abnormal accumulation of free fatty acids; these factors collectively exacerbated membrane system disintegration. Furthermore, the glutathione-ascorbic acid cycle failed at later stages, translation mechanisms were imbalanced (ribosomal protein upregulation and tRNA synthetase downregulation), programmed cell death -related proteins were upregulated, while protective protein systems (insufficient late embryogenesis abundant expression and delayed small heat shock protein response) failed to effectively mitigate damage. The results suggest that the desiccation sensitivity of Q. acutissima seeds stems from a multi-cascade reaction involving oxidative damage, membrane system collapse, translation dysregulation, and programmed cell death. This study provides a theoretical basis for optimizing recalcitrant seed preservation strategies: comprehensive approaches should include antioxidant protection, membrane stabilization techniques, and metabolic regulation to holistically address multi-system damage during desiccation.
顽拗性种子的保存对于可持续森林管理和生物多样性保护至关重要，特别是对于像麻栎这样具有重要经济价值的物种。然而，由于这些种子对干燥高度敏感，给迁地保护带来了严峻挑战。本研究采用综合生理学、细胞学和蛋白质组学方法，系统揭示麻栎种子干燥过程中活力丧失的特征。结果表明，新鲜种子初始含水量为38.8%（IM），发芽率为99%，而半致死含水量（SLM）和致死含水量（LM）分别为26.8%和14.8%。干燥导致细胞壁塌陷、膜系统破裂和细胞质降解，而生理学和蛋白质组学结果揭示了不同干燥阶段的不同反应。在早期阶段，铁超氧化物歧化酶的下调表明抗氧化系统受损，而脂氧合酶介导的膜脂过氧化引发活性氧和丙二醛积累。在深度干燥阶段（LM），我们观察到异柠檬酸脱氢酶[NADP]上调导致的活跃能量代谢。此外，磷脂酶D和酰基辅酶A合成酶的下调可能促进游离脂肪酸的异常积累；这些因素共同加剧了膜系统的解体。此外，谷胱甘肽-抗坏血酸循环在后期失效，翻译机制失衡（核糖体蛋白上调和tRNA合成酶下调），程序性细胞死亡相关蛋白上调，而保护蛋白系统（晚期胚胎丰富蛋白表达不足和小热激蛋白反应延迟）未能有效减轻损伤。结果表明，麻栎种子的干燥敏感性源于涉及氧化损伤、膜系统崩溃、翻译失调和程序性细胞死亡的多步骤反应。本研究为优化顽拗性种子保存策略提供了理论依据：综合方法应包括抗氧化保护、膜稳定技术和代谢调节，以全面应对干燥过程中的多系统损伤。
