National Centre for Plant Genetic Resources, Plant Breeding and Acclimatization Institute (IHAR)-National Research Institute, 05-870 Radzików, Poland.
Department of Plant Genetics, Breeding, and Biotechnology, Warsaw University of Life Sciences, 02-787 Warsaw, Poland.
Int J Mol Sci. 2021 Apr 21;22(9):4315. doi: 10.3390/ijms22094315.
Seed aging is a complex biological process that has been attracting scientists' attention for many years. High-throughput small RNA sequencing was applied to examine microRNAs contribution in barley seeds senescence. Unique samples of seeds that, despite having the same genetic makeup, differed in viability after over 45 years of storage in a dry state were investigated. In total, 61 known and 81 novel miRNA were identified in dry seeds. The highest level of expression was found in four conserved miRNA families, i.e., miR159, miR156, miR166, and miR168. However, the most astonishing result was the lack of significant differences in the level of almost all miRNAs in seed samples with significantly different viability. This result reveals that miRNAs in dry seeds are extremely stable. This is also the first identified RNA fraction that is not deteriorating along with the loss of seed viability. Moreover, the novel miRNA hvu-new41, with higher expression in seeds with the lowest viability as detected by RT-qPCR, has the potential to become an indicator of the decreasing viability of seeds during storage in a dry state.
种子老化是一个复杂的生物学过程，多年来一直吸引着科学家的注意。高通量小 RNA 测序被应用于研究 microRNAs 在大麦种子衰老过程中的作用。对经过 45 多年干燥储存后具有相同遗传背景但活力不同的独特种子样本进行了研究。在干燥种子中共鉴定出 61 个已知和 81 个新的 miRNA。在四个保守的 miRNA 家族（miR159、miR156、miR166 和 miR168）中发现了最高水平的表达。然而，最令人惊讶的结果是，在活力差异显著的种子样本中，几乎所有 miRNA 的水平都没有显著差异。这一结果表明，干燥种子中的 miRNA 极其稳定。这也是第一个被鉴定的 RNA 片段，它不会随着种子活力的丧失而恶化。此外，通过 RT-qPCR 检测到，表达水平较高的新型 miRNA hvu-new41，可能成为干燥状态下种子活力下降的一个指标。
