Enhancement patterns of potassium on nitrogen transport and functional genes in cotton vary with nitrogen levels

Peng Chen; Linyang Li; Shujie Xia; Runhua Zhang; Runqin Zhang; Xiao-Min Zeng; Du Shuai; Yi Liu; Zhi-Guo Li

doi:10.1016/j.plantsci.2023.111824

Enhancement patterns of potassium on nitrogen transport and functional genes in cotton vary with nitrogen levels

Plant Sci. 2023 Oct:335:111824. doi: 10.1016/j.plantsci.2023.111824. Epub 2023 Aug 10.

Authors

Peng Chen¹, Linyang Li¹, Shujie Xia¹, Runhua Zhang², Runqin Zhang¹, Xiao-Min Zeng³, Du Shuai³, Yi Liu⁴, Zhi-Guo Li⁵

Affiliations

¹ Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China.
² Wuhan Academy of Agriculture Science and Technology, Vegetable Research Institute, Wuhan 430345, China.
³ College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
⁴ Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China; Center of Conservation Biology / Economic Botany / Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China. Electronic address: liuyi@wbgcas.cn.
⁵ Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China. Electronic address: lzg360@wbgcas.cn.

PMID: 37572966
DOI: 10.1016/j.plantsci.2023.111824

Abstract

The application of potassium (K) in conjunction with nitrogen (N) has been shown to enhance N use efficiency. However, there is still a need for further understanding of the optimal ratios and molecular regulatory mechanisms, particularly in soil-cotton systems. Here, a field trial was conducted, involving varying rates of N and K, alongside pot and hydroponic experiments. The objective was to assess the impact of N-K interaction on the absorption, transport and distribution of N in cotton. The results showed that K supply at 90 and 240 kg ha^-1 had a beneficial impact on N uptake and distribution to both seed and lint, resulting in the highest N use efficiency ranging from 22% to 62% and yield improvements from 20% to 123%. The increase in stem and root diameters, rather than the quantify of xylem vessels and phloem sieve tubes, facilitated the uptake and transport of N due to the provision of K. At the molecular level, K supply upregulated the expression levels of genes encoding GhNRT2.1 transporter and GhSLAH3 channel in cotton roots to promote N uptake and GhNRT1.5/NPF7.3 genes to transport N to shoot under low-N conditions. However, under high-N conditions, K supply induced anion channel genes (GhSLAH4) of roots to promote N uptake and genes encoding GhNRT1.5/NPF7.3 and GhNRT1.8/NPF7.2 transporters to facilitate NO₃^- unloading from xylem to mesophyll cell in high-N plants. Furthermore, K supply resulted in the upregulation of gene expression for GhGS2 in leaves, while simultaneously downregulating the expression of GhNADH-GOGAT, GhGDH1 and GhGDH3 genes in high-N roots. The enzyme activities of nitrite reductase and glutamine synthetase increased and glutamate dehydrogenase decreased, but the concentration of NO₃^- and soluble protein exhibited a significant increase and free amino acid decreased in the shoots subsequent to K supply.

Keywords: N transporter; N-K interaction; Nitrogen use efficiency (NUE); Nutrient cycling and recycling; Phloem and xylem transport.

MeSH terms

Biological Transport
Membrane Transport Proteins / metabolism
Nitrates / metabolism
Nitrogen / metabolism
Plant Roots* / metabolism
Potassium* / metabolism

Substances

Potassium
Nitrogen
Nitrates
Membrane Transport Proteins