ABSTRACT
Proton nuclear magnetic resonance (1H NMR) based metabolomics was applied to characterize the fecal metabolic profiles of chronic unpredictable mild stress (CUMS)-depression (CUMS-D) and CUMS-resilience (CUMS-R) rats. The fecal biomarkers and metabolic pathways involved in CUMS-D and CUMS-R were screened and identified, revealing the underlying mechanisms of two different responses of the body to the same stresses. Firstly, the classic depression model, i.e. CUMS, was constructed. According to the fecal metabolomics profiles, the model rats were divided into two groups, i.e. the CUMS-D group and the CUMS-R group. And then, the depression statuses of CUMS-D rats and CUMS-R rats were verified by their sucrose preference rates. Lastly, multivariate data analysis was applied to clarify the fecal biomarkers and corresponding metabolic pathways involving in CUMS-D and CUMS-R. The results show that compared with the control rats, the sucrose preference rates of CUMS-D rats were significantly reduced. By contrast, the sucrose preference rates of CUMS-R rats had no significant difference. At the same time, CUMS-D and CUMS-R showed both unique and shared biomarkers and pathways. Three pathways are significantly related to CUMS-D, including taurine and hypotaurine metabolism, alanine, aspartate and glutamate metabolism, and arginine and proline metabolism. Glycerolipid metabolism and tryptophan metabolism are specific pathways related to CUMS-R. This study explores the mechanisms of the emergence of susceptible and resilience of rats under the same stimulus from a metabolomics perspective. The current findings provide not only a new perspective for studying depression, and personalized and precision treatments in clinic, but also the research and development of antidepressants.
ABSTRACT
Rice (Oryza sativa L.) is the most important cereal crop and a major staple food for majority of the human populations worldwide. Rice crop is sensitive to salinity. In spite of large number of studies on salinity tolerance of rice, our knowledge on the overall effect of salinity on rice seedling growth is limited. Improvement in salt tolerance of crop plants remains indescribable, largely due to the fact that salinity is a complex trait which affects almost every aspect of the physiology, biochemistry and genomics of plants. The present investigation was conducted to establish the relationship between various morphological, physiological traits and stress indices. A set of 131 rice accessions was evaluated in two levels namely, non-stress (EC ~ 1.2 dS/m) and saline stress (EC ~ 10 dS/m) in hydroponics at seedling stage. Root length and shoot lengths were reduced by 52 and 50%, respectively in saline stress compared to non-stress conditions. There was a significant correlation between various morphological and physiological parameters in non-saline in addition to saline stress as well as non-stress. The effect of the increased Na+ concentration in the medium is detrimental to root length and shoot length as observed by reduction in root length and a concomitant reduction in shoot length. Increased concentration of Na+ led to augmented Na+/K+ ratio with increased stress in the medium and decreased expression of traits. A significant positive correlation (r=0.60) was noticed between stress tolerance index (STI) of root and shoot length. The stress susceptibility index (SSI) for root length was expressed significant positive correlation with SSI for shoot length (r=0.43). SSI for K+ content was registered significant negative correlation with STI for Na+ content (r=-0.43). The three accessions namely, IC 545004, IC 545486 and IC 545215 were found to be the best performers adjudged on the morphological and physiological criteria in saline stress situation. These three rice accessions could be used as a donor parent or for genotypic studies in future breeding programs.