PDF(Pubmed)
Abstract：
Asparagus is a nutritionally dense stem vegetable whose growth and development are correlated with its quality and yield. To investigate the dynamic changes and underlying mechanisms during the elongation and growth process of asparagus stems, we documented the growth pattern of asparagus and selected stem segments from four consecutive elongation stages using physiological and transcriptome analyses. Notably, the growth rate of asparagus accelerated at a length of 25 cm. A significant decrease in the concentration of sucrose, fructose, glucose, and additional sugars was observed in the elongation region of tender stems. Conversely, the levels of auxin and gibberellins(GAs) were elevated along with increased activity of enzymes involved in sucrose degradation. A significant positive correlation existed between auxin, GAs, and enzymes involved in sucrose degradation. The ABA content gradually increased with stem elongation. The tissue section showed that cell elongation is an inherent manifestation of stem elongation. The differential genes screened by transcriptome analysis were enriched in pathways such as starch and sucrose metabolism, phytohormone synthesis metabolism, and signal transduction. The expression levels of genes such as ARF, GA20ox, NCED, PIF4, and otherswere upregulated during stem elongation, while DAO, GA2ox, and other genes were downregulated. The gene expression level was consistent with changes in hormone content and influenced the cell length elongation. Additionally, the expression results of RT-qPCR were consistent with RNA-seq. The observed variations in gene expression levels, endogenous hormones and sugar changes during the elongation and growth of asparagus tender stems offer valuable insights for future investigations into the molecular mechanisms of asparagus stem growth and development and provide a theoretical foundation for cultivation and production practices.
摘要：
芦笋是一种营养丰富的茎类蔬菜，其生长发育与其品质和产量相关。研究芦笋茎伸长和生长过程中的动态变化及其潜在机制。我们使用生理和转录组分析记录了芦笋的生长模式，并从四个连续的伸长阶段选择了茎段。值得注意的是,25厘米长的芦笋生长速度加快。蔗糖浓度显著降低，果糖,葡萄糖，在嫩茎的伸长区域观察到额外的糖。相反，生长素和赤霉素（GA）的水平随着参与蔗糖降解的酶活性的增加而升高。生长素之间存在显著的正相关,GAs,和参与蔗糖降解的酶。ABA含量随茎伸长而逐步增长。组织切片显示细胞伸长是茎伸长的固有表现。通过转录组分析筛选的差异基因在淀粉和蔗糖代谢等途径进行富集,植物激素合成代谢，和信号转导。ARF等基因的表达水平，GA20ox,NCED,在茎伸长过程中，PIF4和其他蛋白上调，而DAO,GA2ox,和其他基因下调。基因表达水平与激素含量的变化一致，并影响细胞长度伸长。此外,RT-qPCR表达结果与RNA-seq一致。观察到的基因表达水平的变化，芦笋嫩茎伸长和生长过程中内源激素和糖的变化为今后研究芦笋茎生长发育的分子机制提供了有价值的见解，为栽培和生产实践提供了理论基础。
