Physiological and transcriptomic analyses of yellow horn (Xanthoceras sorbifolia) provide important insights into salt and saline-alkali stress tolerance

Abstract

Yellow horn (Xanthoceras sorbifolia) is an oil-rich woody plant cultivated for bio-energy production in China. Soil saline-alkalization is a prominent agricultural-related environmental problem limiting plant growth and productivity. In this study, we performed comparative physiological and transcriptomic analyses to examine the mechanisms of X. sorbifolia seedling responding to salt and alkaline-salt stress. With the exception of chlorophyll content, physiological experiments revealed significant increases in all assessed indices in response to salt and saline-alkali treatments. Notably, compared with salt stress, we observed more pronounced changes in electrolyte leakage (EL) and malondialdehyde (MDA) levels in response to saline-alkali stress, which may contribute to the greater toxicity of saline-alkali soils. In total, 3,087 and 2,715 genes were differentially expressed in response to salt and saline-alkali treatments, respectively, among which carbon metabolism, biosynthesis of amino acids, starch and sucrose metabolism, and reactive oxygen species signaling networks were extensively enriched, and transcription factor families of bHLH, C2H2, bZIP, NAC, and ERF were transcriptionally activated. Moreover, relative to salt stress, saline-alkali stress activated more significant upregulation of genes related to H+ transport, indicating that regulation of intracellular pH may play an important role in coping with saline-alkali stress. These findings provide new insights for investigating the physiological changes and molecular mechanisms underlying the responses of X. sorbifolia to salt and saline-alkali stress.

Salinity Tolerance, Ion Accumulation Potential and Osmotic Adjustment In Vitro and In Planta of Different Armeria maritima Accessions from a Dry Coastal Meadow

“…There is a reason to suggest that for typical high salt-adapted species native to saline habitats (halophytes) high level of K + in substrate will have the same negative effects than Na + [ 9 ]. It was also shown that for halophytes, NaCl toxicity is related mainly to the effect of Cl – [ 10 ].…”

Growth, Physiological, and Photosynthetic Responses of Xanthoceras sorbifolium Bunge Seedlings Under Various Degrees of Salinity

“…Numerous studies have reported on the effect of salt stress on leaves and roots, and their results revealed that salt stress exerted distinct effects on growth, photosynthesis, membrane permeability, osmotic adjustment substance, enzyme activity, and so on (Sorkheh et al, 2012 ; Kargbo et al, 2019 ; Yang et al, 2020 ). In addition, researchers have provided important insights into salt and saline-alkali stress tolerance of yellow horn ( X. sorbifolium ) on physiological and transcriptomic levels (Wang et al, 2020 ). In the study, Zhang X. Y. et al ( 2013 ) compared the effects of five concentrations of sodium chloride (NaCl) on X. sorbifolium , and it was found that the plant could alleviate the osmotic stress induced by NaCl solution, proving the salt tolerance of the species.…”

Comprehensive Analysis of Differentially Expressed Genes and Epigenetic Modification-Related Expression Variation Induced by Saline Stress at Seedling Stage in Fiber and Oil Flax, Linum usitatissimum L.

“…TFs receive stress signals and bind to cis-regulatory sequences to regulate downstream gene expression [ 49 , 50 , 51 , 52 ]. In soybean, GmMYB68 overexpression enhanced salt–alkali resistance in transgenic plants [ 18 ].…”