Comprehensive evaluation of physiological traits under nitrogen stress and participation of linolenic acid in nitrogen-deficiency response in wheat seedlings

Xiaoxiao Liu,Shiwen Wang,Zhiyong Zhang,Lina Yin,Xiping Deng

doi:10.1186/s12870-020-02717-5

Abstract

BackgroundNitrogen (N) deficiency is a major constraint for plant production in many areas. Developing the new crop genotypes with high productivity under N deficiency is an important approach to maintain agricultural production. Therefore, understanding how plant response to N deficiency and the mechanism of N-deficiency tolerance are very important for sustainable development of modern crop production.ResultsIn this study, the physiological responses and fatty acid composition were investigated in 24 wheat cultivars under N-deficient stress. Through Pearson’s correlation analysis and principal component analysis, the responses of 24 wheat cultivars were evaluated. The results showed that the plant growth and carbohydrate metabolism were all differently affected by N deficiency in all tested wheat cultivars. The seedlings that had high shoot biomass also maintained high level of chlorophyll content under N deficiency. Moreover, the changes in fatty acid composition, especially the linolenic acid (18:3) and the double bond index (DBI), showed close positive correlations with the shoot dry weight and chlorophyll content alterations in response to N-deficient condition. These results indicated that beside the chlorophyll content, the linolenic acid content and DBI may also contribute to N-deficiency adaptation, thus could be considered as efficient indicators for evaluation of different response in wheat seedlings under N-deficient condition.ConclusionsThe alteration in fatty acid composition can potentially contribute to N-deficiency tolerance in plants, and the regulation of fatty acid compositions maybe an effective strategy for plants to adapt to N-deficient stress.

Highlights

Nitrogen (N) deficiency is a major constraint for plant production in many areas
The coefficient of variation (CV) of root dry weight and root length were higher than shoot dry weight, total dry weight and root/shoot ratio, indicating that N deficient stress had significant effects on the root growth in those 24 wheat cultivars
The root length, carbohydrates contents, damage in plasma membrane integrity, Hydrogen peroxide (H2O2) accumulation and lipid peroxidation were all increased after exposed to N deficient stress, suggesting that the N-deficiency induced damages were occurred in those wheat seedlings, which were similar with previous studies [2, 7, 41,42,43]

Summary

Introduction

Nitrogen (N) deficiency is a major constraint for plant production in many areas. Developing the new crop genotypes with high productivity under N deficiency is an important approach to maintain agricultural production. Plants quickly perceive and respond to the stress of N deficiency via a large number of physiological and metabolic events Such as the degradation of proteins, decrease of the related enzyme activities, accumulation in carbohydrates, especially the starch, inducing oxidative stresses by generation of H2O2 and causing lipid peroxidation [5,6,7]. Among those events, the reduction of photosynthetic capacity is one of the most major Ndeficiency-induced damages that inhibits plant growth and development [8]. Since photosynthesis is one of the key detrimental factors for plant biomass accumulation [13], and more than half of the total leaf N is allocated to the photosynthetic apparatus [14], it is important to understand how photosynthetic unit responses to N deficiency, especially in crops

Methods

Results

Discussion

Conclusion