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Drought stress, an important abiotic stress, has affected global agricultural production by limiting the yield and the quality of crops. Tiger nuts (Cyperus esculentus L.) are C4 crops in the Cyperaceae family, which have high-quality wholesome ingredients. However, data on mechanisms underlying the response of tiger nuts to drought stress are few. Here, the variety of Jisha 1 and 15% polyethylene glycol (PEG; a drought stress simulator) were used to study the mechanisms of stress response in tiger nuts. Our evaluation of the changes in physiological indicators such as electrolyte leakage (El), malondialdehyde (MDA), hydrogen peroxide (H2O2), superoxide anion (O2−) and activities of reactive oxygen species (ROS) showed that 12 h was the most suitable time point to harvest and analyze the response to drought stress. Thereafter, we performed transcriptome (RNA-Seq) analysis in the control (CK) and stress treatment groups and showed that there was a total of 1760 differentially expressed genes (DEGs). Gene Ontology (GO) analysis showed that the DEGs were enriched in abscisic acid (ABA) terms, and pathways such as starch and sucrose metabolism (ko00500), phenylpropanoid biosynthesis (ko00940) and plant hormone signal transduction (ko04075) were significantly enriched in the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. In addition, quantitative real-time PCR (qRT-PCR) analysis of the DEGs demonstrated an upregulation of ABA and lignin content, as well as enzyme activities in enriched pathways, which validated the RNA-Seq data. These results revealed the pathways and mechanisms adopted by the tiger nuts in response to drought stress. [ABSTRACT FROM AUTHOR]

Cyperus (Cyperus esculentus L.) is an edible perennial grass-like plant, which propagates exclusively with underground tubers. Its tubers are rich in starch (20–30%), fat (25–35%), sugar (10–20%), protein (10–15%) and dietary fiber (8–9%). In addition, the tubers also contain alkaloids, organic acids, vitamins (C and E), steroids, terpenoids and other active components. The contents of oleic acid and linoleic acid in Cyperus oil are very high, which have important medicinal value and health-promoting properties. Most of the extracts from the tubers, stems and leaves of Cyperus have allelopathic potential and antibacterial, antioxidant and insecticidal activities. In recent years, the planting area of Cyperus has increased significantly all over the world, especially in China and some other countries. This paper presents the current status of Cyperus and the recent trend in research in this area. Published reports on its nutritional contents, active ingredients, medicinal efficacy, antibacterial activity and allelopathic potential were also reviewed. [ABSTRACT FROM AUTHOR]

Salt stress is a major abiotic stress with detrimental effects on plants. Sucrose, the main product of photosynthesis in plants, is used as a source of energy for the development of Chinese rose (Rosa chinensis). Hua Xianzi, a variety of Chinese rose, was investigated in this study. Phenotypic traits such as digital biomass, greenness average, leaf angle and leaf area, as well as physiological characters such as proline (Pro), malondialdehyde (MDA), H2O2, O2- and antioxidant enzymes such as SOD (Superoxide Dismutase), POD (Peroxidase), CAT (Catalase) and APX (Ascorbate Peroxidase), changed significantly in response to salt stress (150 mmol/L NaCl for 72 h). The physiological changes were examined based on photosynthetic and fluorescence indicators. Salt stress increased the concentration of glucose, fructose and sucrose, upregulated the expression of Rc-SS1, Rc-SS2, Rc-SPS1, Rc-SPS2, Rc-αA1, Rc-αA2, Rc-αA3, Rc-βA1 and Rc-βA3 genes. Finally, it decreased the starch content in leaves. This study revealed that salt stress disrupted the equilibrium of sucrose metabolism in leaves. This finding provides the basis for further research into the mechanism of salt tolerance adaption. [ABSTRACT FROM AUTHOR]