Background

Nitrogen-based nutrients are the main factors affecting rice growth and development. Root systems play an important role in helping plants to obtain nutrients from the soil. Root morphology and physiology are often closely related to above-ground plant organs performance. Therefore, it is important to understand the regulatory effects of nitrogen (N) on rice root growth to improve nitrogen use efficiency.

Results

In this study, changes in the rice root traits under low N (13.33 ppm), normal N (40 ppm) and high N (120 ppm) conditions were performed through root morphology analysis. These results show that, compared with normal N conditions, root growth is promoted under low N conditions, and inhibited under high N conditions. To understand the molecular mechanism underlying the rice root response to low and high N conditions, comparative proteomics analysis was performed using a tandem mass tag (TMT)-based approach, and differentially abundant proteins (DAPs) were further characterized. Compared with normal N conditions, a total of 291 and 211 DAPs were identified under low and high N conditions, respectively. The abundance of proteins involved in cell differentiation, cell wall modification, phenylpropanoid biosynthesis, and protein synthesis was differentially altered, which was an important reason for changes in root morphology. Furthermore, although both low and high N can cause nitrogen stress, rice roots revealed obvious differences in adaptation to low and high N.

Conclusions

These results provide insights into global changes in the response of rice roots to nitrogen availability and may facilitate the development of rice cultivars with high nitrogen use efficiency through root-based genetic improvements.

中文翻译：

---

蛋白质组学分析揭示了根对低氮和高氮的适应机制

背景

氮基养分是影响水稻生长发育的主要因素。根系在帮助植物从土壤中获取营养方面发挥着重要作用。根的形态和生理通常与地上植物器官的表现密切相关。因此，重要的是要了解氮对水稻根系生长的调节作用，以提高氮的利用效率。

结果

在这项研究中，通过根系形态分析对低氮（13.33 ppm），正常氮（40 ppm）和高氮（120 ppm）条件下水稻根系性状的变化进行了研究。这些结果表明，与正常的N条件相比，在低N条件下促进根生长，而在高N条件下抑制根生长。为了了解水稻根系对低氮和高氮条件响应的分子机制，使用基于串联质量标签（TMT）的方法进行了比较蛋白质组学分析，并进一步鉴定了差异丰富的蛋白质（DAP）。与正常N条件相比，在低N和高N条件下分别鉴定出总共291和211 DAP。参与细胞分化，细胞壁修饰，苯丙烷类生物合成的大量蛋白质 蛋白质合成也发生差异性变化，这是改变根系形态的重要原因。此外，尽管低氮和高氮都会引起氮胁迫，但水稻根系显示出对低氮和高氮的适应性明显差异。

结论

这些结果为深入了解水稻根系对氮素有效性的响应提供了见识，并可能通过基于根的遗传改良而促进具有高氮素利用效率的水稻品种的发展。