Responses of Cell Wall Components to Low Nitrogen in Rapeseed Roots

作者：Hui Qiao Tian, Haixing Song, Xiuwen Wu, Zhenhua Zhang · 发表于：Agronomy · 年份：2022 · DOI：10.3390/agronomy12051044 · 被引用次数：13 · 研究领域：Plant nutrient uptake and metabolism、Plant Micronutrient Interactions and Effects、Plant Molecular Biology Research

Rapeseed (Brassica napus L.) is a major oil crop in China, with the world’s largest planted area and total yield. Rapeseed has a high demand for nitrogen (N), and nitrogen deficiency in soil is an important limiting factor for rapeseed production. However, rapeseed responds to N deprivation by regulating its own morphology, structure, and physiology. We carried out the current experiment by utilizing low N (LN: 0.3 mM NO3−) and normal N (CK: 6.0 mM NO3−) treatments using Brassica napus as the experimental material. The study results showed that low N induced root elongation in rapeseed, and the root length of LN treatment was 2.37 times that of HN treatment. The dry matter of roots also significantly increased due to low N treatment. Meanwhile, low N treatment decreased photosynthetic pigment (including chlorophyll a, chlorophyll b, and carotenoids) contents and dry mass accumulation of leaves. A higher root/shoot ratio and N physiological efficiency were observed under low N treatment. The changes in cell wall components (pectin, cellulose, hemicellulose, and lignin), related enzymes, and genes’ transcription levels in roots were determined and the results suggested that low N promoted the demethylation of ion-bound pectin (ISP) and covalently bound pectin (CSP), the content of CSP and cellulose. The promoted pectin methylesterase (PME) activity, inhibited pectin and cellulose degradation enzymes, and up/downregulation of related genes also confirming the results of cell wal...