This study evaluated the metabolism of proline in rice based on the expression pattern of genes involved in biosynthesis and catabolism of amino acid and determined the correlation with the proline content produced under stress. In stage V4, genotypes with a differentiated response to salinity and low-temperature stresses were exposed separately to two test conditions: 150 mM NaCl and 13°C. Proline increased in both genotypes and stresses. The expression of P5CS1 was increased in both genotypes and conditions, while P5CS2 was responsive in the sensitive genotype under salinity. High correlations between proline content/P5CS1, proline content/P5CS2, P5CS1/P5CR, and P5CS2/P5CR were observed for the tolerant genotype under salt stress. The correlation between proline content/PDH was 0.42 and-0.13 (tolerant genotype) and-0.54 and 0.15 (sensitive genotype) under salinity and cold, respectively. P5CDH was positively correlated with proline content under salinity for both genotypes. Under salt stress, there was a positive correlation between proline content/OAT in the tolerant genotype. It was concluded that the increase in proline content is greater for the tolerant genotype. Under salt stress, the levels of transcript genes are more correlated with the proline content in the tolerant genotype, while at 13°C, the correlation of the sensitive genotype was higher.
Different rice (Oryza sativa L.) genotypes were subjected to high salinity and low temperature (150 mM NaCl and 13°C, respectively) for 0, 6, 24, 48, or 72 h. We evaluated the simultaneous expression of the genes OsCATA, OsCATB, and OsCATC, correlated gene expression with enzyme activity, and verified the regulation of these genes through identification of cis-elements in the promoter region. The hydrogen peroxide content increased in a tolerant genotype and decreased in a sensitive genotype under both stress conditions. Lipid peroxidation increased in the tolerant genotype when exposed to cold, and in the sensitive genotype when exposed to high salinity. Catalase activity significantly increased in both genotypes when subjected to 13°C. In the tolerant genotype, OsCATA and OsCATB were the most responsive to high salinity and cold, while in the sensitive genotype, OsCATA and OsCATC responded positively to saline stress, as did OsCATA and OsCATB to low temperature. Cis-element analysis identified different regulatory sequences in the catalase promoter region of each genotype. The sensitive genotype maintained a better balance between hydrogen oxyacid levels, catalase activity, and lipid peroxidation under low temperature than the resistant genotype. OsCATA and OsCATB were the most responsive in the salt-tolerant genotype to cold, OsCATA and OsCATC were the most responsive to saline stress, and OsCATA and OsCATB were the most responsive to chilling stress in the sensitive genotype. There were positive correlations between catalase activity and OsCATB expression in the tolerant genotype under saline stress and in the sensitive genotype under cold stress.
ABSTRACT. Saline stress is one of the primary factors limiting increased rice productivity in the southern region of Brazil. Farming can be affected by salinity that is due to both the origin of the soils as well as the irrigation water. Lipid transfer proteins (LTPs) have many physiological functions, including in the response to saline stress. Therefore, the objective of this study was to quantify the relative expression of 11 genetic isoforms that encode LTP1-type proteins in rice genotypes tolerant and sensitive to saline stress in the vegetative period. When the plants reached development stage V4, alternating irrigation was started with nutritive solution and water containing 150 mM NaCl. The LTP7 gene showed an increase in expression by 13.81-fold after 96 h of stress exposure in the saline-tolerant group, whereas the LTP10 gene expression level was increased by 71.10-fold after 96 h in the saline-sensitive group. The LTP26, LTP23, and LTP18 genes showed increased expression in both genotypes; however, the expression levels and response times were different. Thus, LTP7 and LTP10 showed the highest response to salinity. The LTP18, LTP23, and LTP26 genes were negatively correlated with the response to salinity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.