Combined transcriptomic and metabolomic analysis of alginate oligosaccharides alleviating salt stress in rice seedlings

Abstract

Background Salt stress is one of the key factors limiting rice production. Alginate oligosaccharides (AOS) enhance plant stress resistance. However, the molecular mechanism underlying salt tolerance in rice induced by AOS remains unclear. FL478, which is a salt-tolerant indica recombinant inbred line and IR29, a salt-sensitive rice cultivar, were used to comprehensively analyze the effects of AOS sprayed on leaves in terms of transcriptomic and metabolite profiles of rice seedlings under salt stress. Results In this experiment, exogenous application of AOS increased SOD, CAT and APX activities, as well as GSH and ASA levels to reduce the damage to leaf membrane, increased rice stem diameter, the number of root tips, aboveground and subterranean biomass, and improved rice salt tolerance. Comparative transcriptomic analyses showed that the regulation of AOS combined with salt treatment induced the differential expression of 305 and 1030 genes in FL478 and IR29. The expressed genes enriched in KEGG pathway analysis were associated with antioxidant levels, photosynthesis, cell wall synthesis, and signal transduction. The genes associated with light-trapping proteins and RLCK receptor cytoplasmic kinases, including CBA, LHCB, and Lhcp genes, were fregulated in response to salt stress. Treatment with AOS combined with salt induced the differential expression of 22 and 50 metabolites in FL478 and IR29. These metabolites were mainly related to the metabolism of amino and nucleotide sugars, tryptophan, histidine, and β -alanine. The abundance of metabolites associated with antioxidant activity, such as 6-hydroxymelatonin, wedelolactone and L-histidine increased significantly. Combined transcriptomic and metabolomic analyses revealed that dehydroascorbic acid in the glutathione and ascorbic acid cycles plays a vital role in salt tolerance mediated by AOS. Conclusion AOS activate signal transduction, regulate photosynthesis, cell wall formation, and multiple antioxidant pathways in response to salt stress. This study provides a molecular basis for the alleviation of salt stress-induced damage by AOS in rice.

Effects of Exogenous Isosteviol on the Physiological Characteristics of Brassica napus Seedlings under Salt Stress

“…Salt stress is a common abiotic stress to crops and has become a serious environmental problem that affects plant growth and development. Recently, many studies have shown that plant seed germination is not significantly affected by low concentrations of salt stress, while higher concentrations of salt stress inhibit plant seed germination and the growth and development of seedlings [ 19 , 20 ]. Ren et al (2020) found that 100 mM NaCl stress significantly inhibited the development of pak choi ( Brassica chinensis L.) seed germination vigor, germination index, vigor index, and growth of the radicle and embryo [ 21 ].…”

Sorghum's Survival Strategy Against Drought During Early Growth Under PEG- Simulated Conditions Based on Transcriptome Analysis

“…7-a), suggesting a potential association between sucrose synthase and drought tolerance in sorghum. Alginate, a non-reducing disaccharide, plays a crucial role in mitigating drought [35] and salt stresses [36].…”

Alginate Oligosaccharides Alleviate Salt Stress in Rice Seedlings by Regulating Cell Wall Metabolism to Maintain Cell Wall Structure and Improve Lodging Resistance

“…Plants 2024, 13, x FOR PEER REVIEW 7 of 17 18.20%, respectively, in the leaves of both cultivars, while it significantly decreased stems' laccase activity by 10.68% of IR29.…”

“…AOS regulated the pectin, cellulose, and hemicellulose content of strawberry cell walls [17]. Our previous study demonstrated that alginate oligosaccharides specifically activated genes related to cell walls in rice under salt stress [18]. The regulatory mechanism of alginate oligosaccharides on rice cell wall metabolism under salt stress remains unclear.…”