Morphological and Transcriptome Analysis of Wheat Seedlings Response to Low Nitrogen Stress.

Wang Wang,Sun Sun,Song Song,Xue Xue,Pan Pan,Qin Qin

doi:10.3390/plants8040098

Abstract

Nitrogen (N) is one of the essential macronutrients that plays an important role in plant growth and development. Unfortunately, low utilization rate of nitrogen has become one of the main abiotic factors affecting crop growth. Nevertheless, little research has been done on the molecular mechanism of wheat seedlings resisting or adapting to low nitrogen environment. In this paper, the response of wheat seedlings against low nitrogen stress at phenotypic changes and gene expression level were studied. The results showed that plant height, leaf area, shoot and root dry weight, total root length, and number under low nitrogen stress decreased by 26.0, 28.1, 24.3, 38.0, 41.4, and 21.2 percent, respectively compared with plants under normal conditions. 2265 differentially expressed genes (DEGs) were detected in roots and 2083 DEGs were detected in leaves under low nitrogen stress (N-) compared with the control (CK). 1688 genes were up-regulated and 577 genes were down-regulated in roots, whilst 505 genes were up-regulated and 1578 were down-regulated in leaves. Among the most addressed Gene Ontology (GO) categories, oxidation reduction process, oxidoreductase activity, and cell component were mostly represented. In addition, genes involved in the signal transduction, carbon and nitrogen metabolism, antioxidant activity, and environmental adaptation were highlighted. Our study provides new information for further understanding the response of wheat to low nitrogen stress.

Highlights

Wheat is one of the most widely grown cereal crops all over the world [1]
N- led to a significant (p < 0.05) decrease in plant height, leaf area, shoot dry weight, root dry weight, total root length, and total root number by 26.0, 28.1, 24.3, 38.0, 41.4 and 21.2 percent, respectively, compared to CK (Table 1)
These results suggest that wheat seedlings are highly sensitive to low nitrogen environments, and low nitrogen stress seriously affected the growth of wheat

Summary

Introduction

Low utilization rate of nitrogen (N) fertilizer severely limits the yield and quality of wheat [2]. Excessive application of nitrogen fertilizer is one of the main ways to ensure crop yield and quality, yet plants can only use Plants 2019, 8, 98; doi:10.3390/plants8040098 www.mdpi.com/journal/plants. Plants 2019, 8, 98 about 30% to 40% of the applied nitrogen fertilizer. No less than 40% of the nitrogen fertilizer applied is lost by leaching into the groundwater, lakes, rivers and atmosphere, giving rise to severe pollution [3]. Evidence from Jeuffroy et al indicated that nitrogen deficiency of winter wheat generally can result in slow growth, fewer tillers, and yellowish leaves [7].

Methods

Results

Discussion

Conclusion