Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, PR China.
Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, PR China.
Plant Physiol Biochem. 2021 Jan;158:475-485. doi: 10.1016/j.plaphy.2020.11.031. Epub 2020 Nov 23.
Seed viability is an important trait in agriculture which directly influences seedling emergence and crop yield. However, even when stored under optimal conditions, all seeds will eventually lose their viability. Our primary aims were to describe factors influencing seed deterioration, determine the morphological, physiological, and biochemical changes that occur during the process of seed ageing, and explore the mechanisms involved in seed deterioration. High relative humidity and high temperature are two factors that accelerate seed deterioration. As seeds age, frequently observed changes include membrane damage and the destruction of organelle structure, an increase in the loss of seed leachate, decreases of respiratory rates and ATP production, and a loss of enzymatic activity. These phenomena could be inter-related and reflect the general breakdown in cellular organization. Many processes can result in seed ageing; it is likely that oxidative damage caused by free radicals and reactive oxygen species (ROS) is primarily responsible. ROS can have vital interactions with any macromolecule of biological interest that result in damage to various cellular components caused by protein damage, lipid peroxidation, chromosomal abnormalities, and DNA lesions. Further, ROS may also cause programmed cell death by inducing the opening of mitochondrial permeability transition pores and the release of cytochrome C. Some repairs can occur in the early stages of imbibition, but repair processes fail if sufficient damage has been caused to critical functional components. As a result, a given seed will lose its viability and eventually fail to germinate in a relatively short time period.
种子活力是农业中的一个重要特性，它直接影响幼苗的出现和作物的产量。然而，即使在最佳条件下储存，所有种子最终都会失去活力。我们的主要目的是描述影响种子劣化的因素，确定在种子老化过程中发生的形态、生理和生化变化，并探讨种子劣化涉及的机制。高相对湿度和高温是加速种子劣化的两个因素。随着种子的老化，经常观察到的变化包括膜损伤和细胞器结构的破坏、种子浸出物损失的增加、呼吸速率和 ATP 产生的减少以及酶活性的丧失。这些现象可能相互关联，反映了细胞组织的普遍崩溃。许多过程都可能导致种子老化；自由基和活性氧（ROS）引起的氧化损伤可能是主要原因。ROS 可以与任何生物感兴趣的大分子发生重要相互作用，导致蛋白质损伤、脂质过氧化、染色体异常和 DNA 损伤等各种细胞成分的损伤。此外，ROS 还可以通过诱导线粒体通透性转换孔的开放和细胞色素 C 的释放来引起程序性细胞死亡。在吸胀的早期阶段可能会发生一些修复，但如果对关键功能成分造成足够的损伤，修复过程就会失败。因此，给定的种子将失去活力，并在相对较短的时间内最终无法发芽。
