PDF(Pubmed)
Abstract：
The global expansion of rapeseed seed quality has been focused on maintaining glucosinolate (GSL) and erucic acid (EA) contents. However, the influence of seed GSL and EA contents on the germination process under drought stress remains poorly understood. Herein, 114 rapeseed accessions were divided into four groups based on GSL and EA contents to investigate their performance during seed imbibition under drought stress. Our results revealed significant variations in seed germination-related traits, particularly with higher GSL and EA, which exhibited higher germination % (G%) and lower mean germination time (MGT) under drought stress conditions. Moreover, osmoregulation, enzymatic system and hormonal regulation were improved in high GSL and high EA (HGHE) versus low GSL and low EA (LGLE) seeds, indicating the essential protective role of GSL and EA during the germination process in response to drought stress. The transcriptional regulation mechanism for coordinating GSL-EA-related pathways in response to drought stress during seed imbibition was found to involve the differential expression of sugar metabolism-, antioxidant-, and hormone-related genes with higher enrichment in HGHE compared to LGLE seeds. GO enrichment analysis showed higher variations in transcription regulator activity and DNA-binding transcription factors, as well as ATP and microtubule motor activity in GSL-EA-related pathways. Furthermore, KEGG analysis identified cellular processes, environmental information processing, and metabolism categories, with varied gene participation between GSL, EA and GSL-EA-related pathways. For further clarification, QY7 (LGLE) seeds were primed with different concentrations of GSL and EA under drought stress conditions. The results showed that 200 μmol/L of GSL and 400 μmol/L of EA significantly improved G%, MGT, and seedling fresh weight, besides regulating stress and fatty acid responsive genes during the seed germination process under drought stress conditions. Conclusively, exogenous application of GSL and EA is considered a promising method for enhancing the drought tolerance of LGLE seeds. Furthermore, the current investigation could provide a theoretical basis of GSL and EA roles and their underlying mechanisms in stress tolerance during the germination process.
摘要：
油菜种子质量的全球扩展一直集中在保持芥子油苷（GSL）和芥酸（EA）含量上。然而,干旱胁迫下种子GSL和EA含量对发芽过程的影响尚不清楚。在这里，根据GSL和EA含量将114个油菜品种分为四组，以研究其在干旱胁迫下种子吸胀过程中的表现。我们的结果揭示了种子萌发相关性状的显着差异，特别是对于更高的GSL和EA，在干旱胁迫条件下表现出较高的发芽率（G％）和较低的平均发芽时间（MGT）。此外，渗透调节，与低GSL和低EA（LGLE）种子相比，高GSL和高EA（HGHE）种子的酶系统和激素调节得到了改善，表明GSL和EA在发芽过程中对干旱胁迫具有重要的保护作用。发现在种子吸胀过程中协调GSL-EA相关途径以响应干旱胁迫的转录调控机制涉及糖代谢的差异表达-，抗氧化剂-，和激素相关基因在HGHE中的富集度高于LGLE种子。GO富集分析显示转录调节因子活性和DNA结合转录因子的变化较高，以及GSL-EA相关途径中的ATP和微管运动活动。此外，KEGG分析确定了细胞过程，环境信息处理,和新陈代谢类别，GSL之间有不同的基因参与，EA和GSL-EA相关通路。为了进一步澄清，在干旱胁迫条件下，用不同浓度的GSL和EA引发QY7（LGLE）种子。结果表明,200μmol/L的GSL和400μmol/L的EA显著提高了G%,MGT,和幼苗的鲜重，除了在干旱胁迫条件下调节种子萌发过程中的胁迫和脂肪酸响应基因。最后，外源施用GSL和EA被认为是增强LGLE种子耐旱性的有希望的方法。此外，目前的研究可以为GSL和EA在发芽过程中的作用及其在胁迫耐受性中的潜在机制提供理论基础。
