De Novo Transcriptome Characterization, Gene Expression Profiling and Ionic Responses of Nitraria sibirica Pall. under Salt Stress

Abstract

Nitraria sibirica Pall., a typical halophyte of great ecological value, is widely distributed in desert, saline, and coastal saline-alkali environments. Consequently, researching the salt tolerance mechanism of N. sibirica Pall. has great significance to the cultivation and utilization of salt-tolerant plants. In this research, RNA-seq, digital gene expression (DGE), and high flux element analysis technologies were used to investigate the molecular and physiological mechanisms related to salt tolerance of N. sibirica Pall. Integrative analysis and de novo transcriptome assembly generated 137,421 unigenes. In total, 58,340 and 34,033 unigenes were annotated with gene ontology (GO) terms and mapped in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. Three differentially expressed genes (DEGs) libraries were subsequently constructed from the leaves of N. sibirica Pall. seedlings under different treatments: control (CK), light short-term salt stress (CL2), and heavy long-term salt stress (CL6). Eight hundred and twenty-six, and 224 differentially expressed genes were identified in CL2 and CL6 compared to CK, respectively. Finally, ionomic analysis of N. sibirica Pall. seedlings treated with 0, 100, 200 or 300 mM concentrations of NaCl for one day showed that the uptake and distribution of Ca, Cu, Fe, Mg and K in different organs of N. sibirica Pall. were significantly affected by salt stress. Our findings have identified potential genes involved in salt tolerance and in the reference transcriptome and have revealed the salt tolerance mechanism in N. sibirica Pall. These findings will provide further insight into the molecular and physiological mechanisms related to salt stress in N. sibirica Pall. and in other halophytes.

Transcriptome Sequence Analysis Elaborates a Complex Defensive Mechanism of Grapevine (Vitis vinifera L.) in Response to Salt Stress

“…The high-affinity K + transporters (HKTs) can mediate Na + transport and Na + –K + symport, while the over-expressed Arabidopsis AtHKT1 showed high Na + in leaves and reduced accumulation in roots [52], favor our findings of higher Na + accumulation in grapevine leaf tissues as compared to root. The inhibition of Na + influx is the correlative index of cyclic nucleotide-gated ion channels CNGCs that were up-regulated in this study, which is in good agreement with the findings reported in halophyte shrub ( Nitraria sibirica ) [53]. The genetic factors that control the accumulation and transport of Cl − from root to leaf tissues or enable plants to maintain low leaf Cl − level are the critical determinant of salt stress tolerance in plants [54], while higher accumulation of Cl − was observed in roots as compared to leaves in our findings, intimating that grapevine possesses the salt tolerance mechanism.…”

De novo transcriptome sequencing and analysis of genes related to salt stress response in Glehnia littoralis

“…chinensis ( Gu et al, 2018 ), Kochia sieversiana ( Zhao et al, 2017 ), Nitraria sibirica Pall. ( Li et al, 2017a ), Suaeda maritima ( Gharat et al, 2016 ), Sporobolus virginicus ( Yamamoto et al, 2015 ), and Mesembryanthemum crystallinum ( Oh et al, 2015 ). In one such study, Wang et al (2015) compared the transcriptomes of H. glomeratus exposed to NaCl for 6, 12, 24, and 72 h and discovered 2,223, 5,643, 7,510 and 10,908 DEGs, respectively.…”

Comprehensive transcriptome and metabolome profiling reveal metabolic mechanisms of Nitraria sibirica Pall. to salt stress

“…The hydroponic solution was renewed every 4 days, and the pH was maintained at 6.0. The seedlings were grown in the greenhouse at 25 ± 3 °C under 14-h days/20 ± 2 °C under 10-h nights 60 .…”

“…The analysis methods of transcriptome and qPCR were referred to the author's previous published articles 60 .…”

“…Many salt tolerance genes of Nitraria L., including NsNHX1 , NtNHX1 , NtP5CS and NtCIPK2 , have been cloned and functionally analyzed 54 – 59 . In our previous study, we characterized the transcriptome, gene expression profile and ionic responses of N. sibirica under salt stress 60 .…”