scholarly journals PHYSIOLOGICAL AND MOLECULAR MECHANISMS UNDERLYING SALT STRESS TOLERANCE IN JOJOBA (SIMMONDSIA CHINENSIS)

2021 ◽  
Vol 19 (3) ◽  
pp. 1953-1982
Author(s):  
B.A. ALGHAMDI ◽  
S.O. BAFEEL ◽  
S. EDRIS ◽  
A. ATEF ◽  
M. AL-MATARY ◽  
...  
2021 ◽  
Vol 18 (1) ◽  
pp. 37-57
Author(s):  
Budour A. Alghamdi ◽  
Sameera O. Bafeel ◽  
Sherif Edris ◽  
Ahmed Atef ◽  
Mohammed Al-Matary ◽  
...  

The aim of this study was todetect the expression profiles of salt-related genes in the leaf transcriptome of Jojoba (Simmondsia chinensis) to decipher the molecular mechanisms underlying salt stress tolerance in this plant species. The analyzed RNA-Seq data identified numerous differentially expressed genesthat were mostly upregulated under salt (NaCl) stress conditions. The genes varied in their ability to limit cellular damage under stress conditions by regulatingthe production of reactive oxygen species (ROS). Some genes demonstrated the use of methylation/demethylation followed by intergenerational transmission of a “stress memory”. Other genes are known for their potential to produce proteins with superoxide dismutase (SOD) activity, the ability to detoxify metal ions and to produce molecular chaperones. Additional activities include regulating signal transductionandthe ion transport processes, the reprogramming of selective gene expression andthe maintenance of balanced sucrose content, ethylene signaling and homeostasis, the regulating of plasmodesmal permeability, ubiquitination,and selective protein degradation. Moreover, genes were also identified to be associated with cell wall remodeling, alleviating chlorophyll content, and accumulatinglower levels of sodium (Na+) and chloride (Cl-), as well as increased levels of lignin that function to support a plant’s integrity under salt stress. Overall, these data provide new insights into the molecular mechanisms at play during conditions of salt stress. These mechanisms ensure a plant’s survival and help to maintain its natural chemical compounds. These findings may be beneficial in furthering the use of this economically important plant.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 782
Author(s):  
Joon-Yung Cha ◽  
Sang-Ho Kang ◽  
Myung Geun Ji ◽  
Gyeong-Im Shin ◽  
Song Yi Jeong ◽  
...  

Humic acid (HA) is a principal component of humic substances, which make up the complex organic matter that broadly exists in soil environments. HA promotes plant development as well as stress tolerance, however the precise molecular mechanism for these is little known. Here we conducted transcriptome analysis to elucidate the molecular mechanisms by which HA enhances salt stress tolerance. Gene Ontology Enrichment Analysis pointed to the involvement of diverse abiotic stress-related genes encoding HEAT-SHOCK PROTEINs and redox proteins, which were up-regulated by HA regardless of salt stress. Genes related to biotic stress and secondary metabolic process were mainly down-regulated by HA. In addition, HA up-regulated genes encoding transcription factors (TFs) involved in plant development as well as abiotic stress tolerance, and down-regulated TF genes involved in secondary metabolic processes. Our transcriptome information provided here provides molecular evidences and improves our understanding of how HA confers tolerance to salinity stress in plants.


2018 ◽  
Vol 12 (1) ◽  
pp. 204-218
Author(s):  
Wei Tang

Background:WRKY transcription factors play important roles in the responses to abiotic stresses, seed dormancy, seed germination, developmental processes, secondary metabolism, and senescence in plants. However, molecular mechanisms of WRKY transcription factors-related abiotic stress tolerance have not been fully understood.Methods:In this investigation, transcription factor AtWRKY57 was introduced into cell lines of rice (Oryza sativaL.), tobacco (Nicotiana tabacum), and white pine (Pinus strobesL.) for characterization of its function in salt stress tolerance. The purpose of this investigation is to examine the function of AtWRKY in a broad sample of plant species including monocotyledons, dicotyledons, and gymnosperms.Results:The experimental results demonstrated that heterologous expression of transcription factor AtWRKY57 improves salt stress tolerance by decreasing Thiobarbituric Acid Reactive Substance (TBARS), increasing Ascorbate Peroxidase (APOX) and Catalase (CAT) activity under salt stress. In rice, overexpression of transcription factor AtWRKY57 enhances expression of Ca2+-dependent protein kinase genesOsCPk6andOsCPk19to counteract salt stress.Conclusion:These results indicated that transcription factor AtWRKY57 might have practical application in genetic engineering of plant salt tolerance throughout the plant kingdom.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Diana Duarte-Delgado ◽  
Said Dadshani ◽  
Heiko Schoof ◽  
Benedict C. Oyiga ◽  
Michael Schneider ◽  
...  

Abstract Background Bread wheat is one of the most important crops for the human diet, but the increasing soil salinization is causing yield reductions worldwide. Improving salt stress tolerance in wheat requires the elucidation of the mechanistic basis of plant response to this abiotic stress factor. Although several studies have been performed to analyze wheat adaptation to salt stress, there are still some gaps to fully understand the molecular mechanisms from initial signal perception to the onset of responsive tolerance pathways. The main objective of this study is to exploit the dynamic salt stress transcriptome in underlying QTL regions to uncover candidate genes controlling salt stress tolerance in bread wheat. The massive analysis of 3′-ends sequencing protocol was used to analyze leave samples at osmotic and ionic phases. Afterward, stress-responsive genes overlapping QTL for salt stress-related traits in two mapping populations were identified. Results Among the over-represented salt-responsive gene categories, the early up-regulation of calcium-binding and cell wall synthesis genes found in the tolerant genotype are presumably strategies to cope with the salt-related osmotic stress. On the other hand, the down-regulation of photosynthesis-related and calcium-binding genes, and the increased oxidative stress response in the susceptible genotype are linked with the greater photosynthesis inhibition at the osmotic phase. The specific up-regulation of some ABC transporters and Na+/Ca2+ exchangers in the tolerant genotype at the ionic stage indicates their involvement in mechanisms of sodium exclusion and homeostasis. Moreover, genes related to protein synthesis and breakdown were identified at both stress phases. Based on the linkage disequilibrium blocks, salt-responsive genes within QTL intervals were identified as potential components operating in pathways leading to salt stress tolerance. Furthermore, this study conferred evidence of novel regions with transcription in bread wheat. Conclusion The dynamic transcriptome analysis allowed the comparison of osmotic and ionic phases of the salt stress response and gave insights into key molecular mechanisms involved in the salt stress adaptation of contrasting bread wheat genotypes. The leveraging of the highly contiguous chromosome-level reference genome sequence assembly facilitated the QTL dissection by targeting novel candidate genes for salt tolerance.


2020 ◽  
Vol 21 (6) ◽  
pp. 2177 ◽  
Author(s):  
Bo Li ◽  
Jia-Cheng Zheng ◽  
Ting-Ting Wang ◽  
Dong-Hong Min ◽  
Wen-Liang Wei ◽  
...  

Vascular plant one-zinc-finger (VOZ) transcription factor, a plant specific one-zinc-finger-type transcriptional activator, is involved in regulating numerous biological processes such as floral induction and development, defense against pathogens, and response to multiple types of abiotic stress. Six VOZ transcription factor-encoding genes (GmVOZs) have been reported to exist in the soybean (Glycine max) genome. In spite of this, little information is currently available regarding GmVOZs. In this study, GmVOZs were cloned and characterized. GmVOZ genes encode proteins possessing transcriptional activation activity in yeast cells. GmVOZ1E, GmVOZ2B, and GmVOZ2D gene products were widely dispersed in the cytosol, while GmVOZ1G was primarily located in the nucleus. GmVOZs displayed a differential expression profile under dehydration, salt, and salicylic acid (SA) stress conditions. Among them, GmVOZ1G showed a significantly induced expression in response to all stress treatments. Overexpression of GmVOZ1G in soybean hairy roots resulted in a greater tolerance to drought and salt stress. In contrast, RNA interference (RNAi) soybean hairy roots suppressing GmVOZ1G were more sensitive to both of these stresses. Under drought treatment, soybean composite plants with an overexpression of hairy roots had higher relative water content (RWC). In response to drought and salt stress, lower malondialdehyde (MDA) accumulation and higher peroxidase (POD) and superoxide dismutase (SOD) activities were observed in soybean composite seedlings with an overexpression of hairy roots. The opposite results for each physiological parameter were obtained in RNAi lines. In conclusion, GmVOZ1G positively regulates drought and salt stress tolerance in soybean hairy roots. Our results will be valuable for the functional characterization of soybean VOZ transcription factors under abiotic stress.


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