Affiliation:
1. College of Landscape Architecture, Northeast Forestry University, Harbin 150040, China
2. National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Zhejiang Provincial Key Laboratory for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China
Abstract
The early seedling stage is considered the most vulnerable period for plants, especially under salinity conditions. The castor plant (Ricinus communis) is a well-known oil and energy crop worldwide that can survive under stressful conditions. However, the specific mechanisms of this species during its early seedling stage under salt stress are still not clearly understood. Here, the physiological and transcriptome changes in the cotyledons and roots of the castor plant were evaluated. The results indicated that salt stress (150 mM NaCl, 6 d) increased malondialdehyde (MDA) and proline content, whereas it decreased dry weight (DW) and soluble sugar content. The Illumina Hiseq 2500 platform was used to analyze transcriptome profiles in the cotyledons and roots under salt stress conditions. The results showed that 1580 differentially expressed genes (DEGs) were found in the cotyledons (880 upregulated and 700 downregulated) and 1502 DEGs in the roots (732 upregulated and 770 downregulated). Furthermore, we found that salt stress significantly regulated 22 genes (e.g., 29520.t000005, 29633.t000030, and 29739.t000024) involved in protein processing in the endoplasmic reticulum of the cotyledons. However, salt stress induced the expression of 25 genes (e.g., 30068.t000101, 30076.t000022, 29970.t000022, and 29957.t000027) involved in phenylpropanoid biosynthesis in the roots. In addition, a large number of genes participating in plant hormone signal transduction, starch and sucrose metabolisms, and arginine and proline metabolisms were induced in both cotyledons and roots. In conclusion, this study demonstrated that the different expression patterns in cotyledons and roots as well as their synergic relationship contributed to enhancing the salt tolerance of castor plants.
Funder
Natural Science Foundation of Heilongjiang Province
Postdoctoral Foundation of Heilongjiang Province
Subject
Agronomy and Crop Science
Reference55 articles.
1. Plant responses to drought, salinity and extreme temperatures: Towards genetic engineering for stress tolerance;Wang;Planta,2003
2. Salinity tolerance of crops–what is the cost?;Munns;New Phytol.,2015
3. Saline alkali water desalination project in Southern Xinjiang of China: A review of desalination planning, desalination schemes and economic analysis;Fang;Renew. Sustain. Energy Rev.,2019
4. Zhao, S., Zhang, Q., Liu, M., Zhou, H., Ma, C., and Wang, P. (2021). Regulation of plant responses to salt stress. Int. J. Mol. Sci., 22.
5. Plant salt-tolerance mechanism: A review;Liang;Biochem. Biophys. Res. Commun.,2018