scholarly journals Evaluation of salt tolerance in Eruca sativa accessions based on morpho-physiological traits

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9749
Author(s):  
Sadia Afsar ◽  
Gulnaz Bibi ◽  
Raza Ahmad ◽  
Muhammad Bilal ◽  
Tatheer Alam Naqvi ◽  
...  

Background Salinity is one of the most lethal abiotic stresses which affect multiple aspects of plant physiology. Natural variations in plant germplasm are a great resource that could be exploited for improvement in salt tolerance. Eruca sativa (E. sativa) exhibits tolerance to abiotic stresses. However, thorough evaluation of its salt stress tolerance and screening for traits that could be reliably applied for salt tolerance needs to be studied. The current study was designed to characterize 25 E. sativa accessions, originating from diverse geographical regions of Pakistan, for the salt stress tolerance. Methods Salt stress (150 mM NaCl) was applied for 2 weeks to the plants at four leaf stage in hydroponics. Data of the following morpho-physiological traits were collected from control and treated plants of all the accessions: root length (RL), shoot length (SL), plant height (PH), leaf number (LN), leaf area (LA), fresh weight (FW), dry weight (DW), chlorophyl content (SPAD), electrolyte leakage (EL), relative water content (RWC), gas exchange parameters and mineral ion content. Salt tolerance was determined based on membership function value (MFV) of the tested traits. Results Compared with control, the salt-stressed group had significantly reduced mean SL, RL, PH, LN, LA, FW, DW and SPAD. NaCl treatment triggered a slight increase in EL in few accessions. Mean RWC of control and treated groups were not significantly different although few accessions exhibited variation in this trait. Salt stress caused a significant reduction in photosynthesis rate (PR), transpiration rate (TR) and stomatal conductance (SC) but intercellular CO2 (Ci) was not significantly different between control and treated groups. Compared with control, the salt-stressed plants accumulated significantly higher Na+, K+ and Ca2+ while significantly lower Mg2+. K+/Na+ ratio was significantly decreased in salt-stressed plants compared with control. Importantly, significant inter-accession variations were found for all the tested traits. The principal component analysis identified SL, RL, PH, LN, LA, FW, DW and PR as the most significant traits for resolving inter-accession variability. Based on MFV of the tested traits, accessions were categorized into five standard groups. Among 25 accessions, one accession was ranked as highly tolerant, four as tolerant while 15 accessions were ranked as moderately tolerant. Of the remaining five accessions, four were ranked as sensitive while one accession as highly sensitive. Conclusion E. sativa accessions were found to exhibit significant genetic diversity in all the tested traits. A few most significant traits for dissecting the genetic variability were identified that could be used for future large-scale germplasm screening in E. sativa. Salt tolerant accessions could be a good resource for future breeding programs aiming to improve salt stress tolerance.

HortScience ◽  
2015 ◽  
Vol 50 (10) ◽  
pp. 1518-1523 ◽  
Author(s):  
Shanshan Sun ◽  
Mengying An ◽  
Liebao Han ◽  
Shuxia Yin

Perennial ryegrass (Lolium perenne L.) is a widely used turfgrass. In this study, the effect of exogenously applied 24-epibrassinolide (EBR) on salt stress tolerance of perennial ryegrass was investigated. The results indicated that pretreatment with four concentrations of EBR (0, 0.1, 10, 1000 nM) improved salt tolerance of perennial ryegrass. Exogenous EBR treatment decreased electrolyte leakage (EL), malondialdehyde (MDA), and H2O2 contents and enhanced the leaf relative water content (RWC), proline, soluble sugar, and soluble protein content under salt stress condition. Meanwhile, EBR reduced the accumulation of Na+ and increased K+, Ca2+, and Mg2+ contents in leaves after salt treatment. Moreover, EBR pretreatment also increased superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) activity, as well as ascorbic acid (AsA) and glutathione contents. These results suggested that EBR improved salt tolerance by enhancing osmotic adjustment and antioxidant defense systems in perennial ryegrass.


BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Delong Wang ◽  
Xuke Lu ◽  
Xiugui Chen ◽  
Shuai Wang ◽  
Junjuan Wang ◽  
...  

Abstract Background Cotton (Gossypium hirsutum) is considered a fairly salt tolerant crop however, salinity can still cause significant economic losses by affecting the yield and deteriorating the fiber quality. We studied a salt-tolerant upland cotton cultivar under temporal salt stress to unfold the salt tolerance molecular mechanisms. Biochemical response to salt stress (400 mM) was measured at 0 h, 3 h, 12 h, 24 h and 48 h post stress intervals and single-molecule long-read sequencing technology from Pacific Biosciences (PacBio) combined with the unique molecular identifiers approach was used to identify differentially expressed genes (DEG). Results Antioxidant enzymes including, catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) were found significantly induced under temporal salt stress, suggesting that reactive oxygen species scavenging antioxidant machinery is an essential component of salt tolerance mechanism in cotton. We identified a wealth of novel transcripts based on the PacBio long reads sequencing approach. Prolonged salt stress duration induces high number of DEGs. Significant numbers of DEGs were found under key terms related to stress pathways such as “response to oxidative stress”, “response to salt stress”, “response to water deprivation”, “cation transport”, “metal ion transport”, “superoxide dismutase”, and “reductase”. Key DEGs related to hormone (abscisic acid, ethylene and jasmonic acid) biosynthesis, ion homeostasis (CBL-interacting serine/threonine-protein kinase genes, calcium-binding proteins, potassium transporter genes, potassium channel genes, sodium/hydrogen exchanger or antiporter genes), antioxidant activity (POD, SOD, CAT, glutathione reductase), transcription factors (myeloblastosis, WRKY, Apetala 2) and cell wall modification were found highly active in response to salt stress in cotton. Expression fold change of these DEGs showed both positive and negative responses, highlighting the complex nature of salt stress tolerance mechanisms in cotton. Conclusion Collectively, this study provides a good insight into the regulatory mechanism under salt stress in cotton and lays the foundation for further improvement of salt stress tolerance.


2020 ◽  
Vol 61 (5) ◽  
pp. 942-956 ◽  
Author(s):  
Takumi Tomoi ◽  
Kensuke Kawade ◽  
Munenori Kitagawa ◽  
Yoichi Sakata ◽  
Hirokazu Tsukaya ◽  
...  

Abstract Cell-to-cell communication is tightly regulated in response to environmental stimuli in plants. We previously used a photoconvertible fluorescent protein Dendra2 as a model reporter to study this process. This experiment revealed that macromolecular trafficking between protonemal cells in Physcomitrella patens is suppressed in response to abscisic acid (ABA). However, it remains unknown which ABA signaling components contribute to this suppression and how. Here, we show that ABA signaling components SUCROSE NON-FERMENTING 1-RELATED PROTEIN KINASE 2 (PpSnRK2) and ABA INSENSITIVE 3 (PpABI3) play roles as an essential and promotive factor, respectively, in regulating ABA-induced suppression of Dendra2 diffusion between cells (ASD). Our quantitative imaging analysis revealed that disruption of PpSnRK2 resulted in defective ASD onset itself, whereas disruption of PpABI3 caused an 81-min delay in the initiation of ASD. Live-cell imaging of callose deposition using aniline blue staining showed that, despite this onset delay, callose deposition on cross walls remained constant in the PpABI3 disruptant, suggesting that PpABI3 facilitates ASD in a callose-independent manner. Given that ABA is an important phytohormone to cope with abiotic stresses, we further explored cellular physiological responses. We found that the acquisition of salt stress tolerance is promoted by PpABI3 in a quantitative manner similar to ASD. Our results suggest that PpABI3-mediated ABA signaling may effectively coordinate cell-to-cell communication during the acquisition of salt stress tolerance. This study will accelerate the quantitative study for ABA signaling mechanism and function in response to various abiotic stresses.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 602
Author(s):  
Julia Medrano Macías ◽  
María Guadalupe López Caltzontzit ◽  
Erika Nohemi Rivas Martínez ◽  
Willian Alfredo Narváez Ortiz ◽  
Adalberto Benavides Mendoza ◽  
...  

Iodine is a non-essential element for land plants, but is considered as a beneficial element, related to antioxidant capacity, environmental adaptations and improvement of plant growth. Salinity is one of the more recurrent abiotic stresses worldwide, seriously affecting vegetal production. The aim of this work was to evaluate iodine application (Q products® and KIO3, Quimcasa de México, Naucalpan, Mexico) in strawberry plants under normal and salt stress conditions. Growth, antioxidant content, essential minerals, iodine accumulation and fruit quality were evaluated. The results showed that, under stress conditions, the application of Q products increased ascorbate peroxidase (APX) and catalase (CAT) activity as well as glutathione (GSH) content and yield in fruit, without avoiding biomass loss; with the application of KIO3 an increase in GSH and APX activity as well as P and K concentrations were obtained. In leaves an increase in P, Ca, Mn and iodine accumulation was evidenced with the application of Q products, and an increased concentration of ascorbic acid and iodine with KIO3 treatments. Under normal conditions in fruits, the application of Q products increased phenolic compounds synthesis; additionally, an increase in Ca and Mn concentrations was shown. KIO3 application increased the firmness and Mn. In leaves, the application of Q products increased chlorophyll a, b and calcium. In conclusion, the application of iodine improves the quality value of strawberries under normal conditions and provides an enhancement of salt stress tolerance.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 764
Author(s):  
Minh Thi Thanh Hoang ◽  
Mai Thi Anh Doan ◽  
Thuong Nguyen ◽  
Dong-Phuong Tra ◽  
Thanh Nguyen Chu ◽  
...  

Ascorbic acid (AsA) and glutathione (GSH) are considered important factors to protect plants against abiotic stress. To investigate whether altered endogenous GSH and AsA affect seed germination, plant performance and the abiotic stress tolerance, GSH deficient mutant cad2-1 and AsA-deficient mutants (vtc2-4 and vtc5-2) were phenotypically characterized for their seed germination, shoot growth, photosynthetic activity and root architecture under abiotic stresses. The cad2-1, vtc2-4 and vtc5-2 mutants showed a decrease in osmotic and salt stress tolerance, in sensitivity to ABA during seed germination, and in plant performance under severe abiotic stresses. GSH deficiency in the cad2-1 plants affected plant growth and root development in plants exposed to strong drought, oxidative and heavy metal stress conditions. Plants with lower GSH did not show an increased sensitivity to strong salt stress (100 mM NaCl). In contrast, the mutants with lower AsA enhanced salt stress tolerance in the long-term exposures to strong salt stress since they showed larger leaf areas, longer primary roots and more lateral root numbers. Limitations on AsA or GSH synthesis had no effect on photosynthesis in plants exposed to long-term strong salt or drought stresses, whereas they effected on photosynthesis of mutants exposed to CdCl2. Taken together, the current study suggests that AsA and GSH are important for seed germination, root architecture, shoot growth and plant performance in response to different abiotic stresses, and their functions are dependent on the stress-inducing agents and the stress levels.


2021 ◽  
Vol 13 (6) ◽  
pp. 3369
Author(s):  
Annie Irshad ◽  
Rana Naveed Ur Rehman ◽  
Muhammad Mohsin Abrar ◽  
Qudsia Saeed ◽  
Rahat Sharif ◽  
...  

The effects of salt stress on the growth, nodulation, and nitrogen (N) fixation of legumes are well known, but the relationship between symbiotic nitrogen fixation (SNF) driven by rhizobium–legume symbiosis and salt tolerance in Medicago truncatula is not well studied. The effects of the active nodulation process on salt stress tolerance of Medicago truncatula were evaluated by quantifying the compatible solutes, soluble sugars, and antioxidants enzymes, as well as growth and survival rate of plants. Eight weeks old plants, divided in three groups: (i) no nodules (NN), (ii) inactive nodules (IN), and (iii) active nodules (AN), were exposed to 150 mM of NaCl salt stress for 0, 8, 16, 24, 32, 40, and 48 h in hydroponic system. AN plants showed a higher survival rate (30.83% and 38.35%), chlorophyll contents (37.18% and 44.51%), and photosynthesis compared to IN and NN plants, respectively. Improved salt tolerance in AN plants was linked with higher activities of enzymatic and nonenzymatic antioxidants and higher K+ (20.45% and 39.21%) and lower Na+ accumulations (17.54% and 24.51%) when compared with IN and NN plants, respectively. Additionally, higher generation of reactive oxygen species (ROS) was indicative of salt stress, causing membrane damage as revealed by higher electrolyte leakage and lipid peroxidation. All such effects were significantly ameliorated in AN plants, showing higher compatible solutes (proline, free amino acids, glycine betaine, soluble sugars, and proteins) and maintaining higher relative water contents (61.34%). This study advocates positive role of Rhizobium meliloti inoculation against salt stress through upregulation of antioxidant system and a higher concentration of compatible solutes.


2021 ◽  
Vol 12 ◽  
Author(s):  
Binghui Shan ◽  
Wei Wang ◽  
Jinfeng Cao ◽  
Siqi Xia ◽  
Ruihua Li ◽  
...  

REVEILLE (RVE) genes generally act as core circadian oscillators to regulate multiple developmental events and stress responses in plants. It is of importance to document their roles in crops for utilizing them to improve agronomic traits. Soybean is one of the most important crops worldwide. However, the knowledge regarding the functional roles of RVEs is extremely limited in soybean. In this study, the soybean gene GmMYB133 was shown to be homologous to the RVE8 clade genes of Arabidopsis. GmMYB133 displayed a non-rhythmical but salt-inducible expression pattern. Like AtRVE8, overexpression of GmMYB133 in Arabidopsis led to developmental defects such as short hypocotyl and late flowering. Seven light-responsive or auxin-associated genes including AtPIF4 were transcriptionally depressed by GmMYB133, suggesting that GmMYB133 might negatively regulate plant growth. Noticeably, the overexpression of GmMYB133 in Arabidopsis promoted seed germination and plant growth under salt stress, and the contents of chlorophylls and malondialdehyde (MDA) were also enhanced and decreased, respectively. Consistently, the expressions of four positive regulators responsive to salt tolerance were remarkably elevated by GmMYB133 overexpression, indicating that GmMYB133 might confer salt stress tolerance. Further observation showed that GmMYB133 overexpression perturbed the clock rhythm of AtPRR5, and yeast one-hybrid assay indicated that GmMYB133 could bind to the AtPRR5 promoter. Moreover, the retrieved ChIP-Seq data showed that AtPRR5 could directly target five clients including AtPIF4. Thus, a regulatory module GmMYB133-PRR5-PIF4 was proposed to regulate plant growth and salt stress tolerance. These findings laid a foundation to further address the functional roles of GmMYB133 and its regulatory mechanisms in soybean.


HortScience ◽  
2011 ◽  
Vol 46 (1) ◽  
pp. 80-85 ◽  
Author(s):  
Pilar Andreu ◽  
Arancha Arbeloa ◽  
Pilar Lorente ◽  
Juan A. Marín

Salt tolerance varies between species and genotypes of plants, but evaluation of these differences is cumbersome, because whole plants that are highly complex systems show a variety of responses depending on the applied methodology. However, focusing on plant roots, which are in direct contact with the soil, could offer a simpler and more efficient model for analyzing salt stress tolerance in different species. This study explores whether root growth under salt stress is associated with genotypic differences in Prunus species with different degrees of salt tolerance. Excised root cultures were grown in vitro under increasing salt concentrations (0, 20, 60, and 180 mm NaCl). Root tips taken from in vitro-rooted shoots of Prunus species with different salt tolerance were measured after 3 weeks of culture in a shaker, and changes in their anatomy were examined. Both growth and starch content of in vitro root cultures were affected by salt concentration. Root length increments were related to salt stress tolerance at 60 mm NaCl, in which significant differences were also found between species. A significant inverse correlation was found between salt tolerance and starch accumulation in the maturation zone of root tips. Genotypic differences were observed in agreement with species' salt stress tolerance in vivo. These results suggest the use of excised root cultures for rapid, early detection of salt stress tolerance in plants. Chemical names: sodium chloride (NaCl).


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