Root endodermal suberization induced by nitrate stress regulate apoplastic pathway rather than nitrate uptake in tobacco (Nicotiana tabacum L.)

• Published in: Plant physiology and biochemistry 2024-11, Vol.216, p.109166, Article 109166
• Main Authors: Zhang, Biao, Xu, Yunxiang, Zhang, Liwen, Yu, Shunyang, Zhu, Yingying, Liu, Chunju, Wang, Peng, Shi, Yi, Li, Lianzhen, Liu, Haiwei
• Format: Article
• Language: English
• Subjects: Abscisic acid; Abscisic Acid - metabolism; Biological Transport; Endodermis; Gene Expression Regulation, Plant - drug effects; Nicotiana - drug effects; Nicotiana - genetics; Nicotiana - growth & development; Nicotiana - metabolism; Nitrates - metabolism; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Roots - drug effects; Plant Roots - genetics; Plant Roots - growth & development; Plant Roots - metabolism; Radial transport; Stress, Physiological; Suberin
• ISSN: 0981-9428; 1873-2690; 1873-2690
• DOI: 10.1016/j.plaphy.2024.109166

Nitrogen levels and distribution in the rhizosphere strongly regulate the root architecture. Nitrate is an essential nutrient and an important signaling molecule for plant growth and development. Hydroponic experiments were conducted to investigate the differences in endodermal suberization in tobacco (Nicotiana tabacum L.) roots at three nitrate levels. Nitrogen accumulation was detected in the roots, shoots, and xylem sap. Nitrate influx on the root surface was also measured using the non-invasive self-referencing microsensor technique (SRMT). RNA-Seq analysis was performed to identify the genes related to endodermal suberization, nitrate transport, and endogenous abscisic acid (ABA) biosynthesis. The results showed that root length, root-shoot ratio, nitrate influx on the root surface, and NiA and NRT2.4 genes were regulated to maintain the nitrogen nutrient supply in tobacco under low nitrate conditions. Low nitrate levels enhanced root endodermal suberization and hence reduced the apoplastic transport pathway, and genes from the KCS, FAR, PAS2, and CYP86 families were upregulated. The results of exogenous fluridone, an ABA biosynthesis inhibitor, indicated that suberization of the tobacco root endodermis had no relevance to radial nitrate transport and accumulation. However, ABA enhances suberization, relating to ABA biosynthesis genes in the CCD family and degradation gene ABA8ox1. [Display omitted] •Low nitrate enhanced root endodermal suberization and reduced apoplastic transport.•Suberin biosynthesis and fatty acids elongation genes were promoted by low nitrate.•ABA involves in the root endodermal suberization induced by low nitrate.•ABA biosynthesis genes and degradation genes were regulated by low nitrate.•Root endodermal suberization has weak link with nitrate transport and accumulation.