Forage Seed Laboratory, College of Grassland Science and Technology, China Agricultural University, Beijing 100193, PR China.
Forage Seed Laboratory, College of Grassland Science and Technology, China Agricultural University, Beijing 100193, PR China.
Int J Biol Macromol. 2024 Oct;277(Pt 3):134300. doi: 10.1016/j.ijbiomac.2024.134300. Epub 2024 Aug 3.
Extensive bodies of research are dedicated to the study of seed aging with a particular focus on the roles of reactive oxygen species (ROS), and the ensuing oxidative damage during storage, as a primary cause of seed vigor decreasing. ROS diffuse to the nucleus and damage the telomeres, resulting in a loss of genetic integrity. Protection of telomeres 1 (POT1) is a telomeric protein that binds to the telomere region, and plays an essential role in maintaining genomic stability in plants. In this study, there were totally four MsPOT1 genes obtained from alfalfa genome. Expression analysis of four MsPOT1 genes in germinated seed presented the different expressions. Four MsPOT1 genes displayed high expression levels at the early stage of seed germination, Among the four POT1 genes, it was found that MS. gene040108 was significantly up-regulated in the early germination stage of CK seeds, but down-regulated in aged seeds. RT-qPCR assays and RNA-seq data revealed that MsPOT1-X gene was significantly induced by seed aging treatment. Transgenic seeds overexpressing MsPOT1-X gene in Arabidopsis thaliana and Medicago trunctula exhibited enhanced seed vigor, telomere length, telomerase activity associated with reduced HO content. These results would provide a new way to understand aging stress-responsive MsPOT1 genes for genetic improvement of seed vigor. Although a key gene regulating seed vigor was identified in this study, the specific mechanism of MsPOT1-X gene regulating seed vigor needs to be further explored.
大量研究致力于研究种子衰老，特别关注活性氧（ROS）的作用，以及在储存过程中随之发生的氧化损伤，这是种子活力下降的主要原因。ROS 扩散到细胞核并损伤端粒，导致遗传完整性丧失。端粒保护蛋白 1（POT1）是一种与端粒区域结合的端粒蛋白，在维持植物基因组稳定性方面发挥着重要作用。在这项研究中，总共从紫花苜蓿基因组中获得了 4 个 MsPOT1 基因。萌发种子中 4 个 MsPOT1 基因的表达分析显示出不同的表达模式。4 个 MsPOT1 基因在种子萌发的早期表现出高表达水平，在这 4 个 POT1 基因中，发现 MS.基因 040108 在 CK 种子的早期萌发阶段显著上调，但在老化种子中下调。RT-qPCR 分析和 RNA-seq 数据显示 MsPOT1-X 基因在种子老化处理后显著诱导。在拟南芥和紫花苜蓿中过表达 MsPOT1-X 基因的转基因种子表现出增强的种子活力、端粒长度、与 HO 含量降低相关的端粒酶活性。这些结果为理解衰老应激响应的 MsPOT1 基因提供了一种新方法，可用于遗传改良种子活力。尽管本研究鉴定了一个调控种子活力的关键基因，但 MsPOT1-X 基因调控种子活力的具体机制仍需要进一步探索。
