Large-scale integrated evaluation of salt tolerance in japonica rice at the germination stage

Abstract Background: Salt stress, one of the most important abiotic stresses, severely reduces crop yields. Identifying salt-tolerant rice germplasm resources at the germination stage, developing salt tolerance indicators, and cultivating salt-tolerant rice cultivars are crucial for improving rice production in saline soil.Results: We measured the germination parameters of 140 japonica rice cultivars on the 7 day after sowing (DAS) in 0 and 150 mmol L−1 NaCl. To accurately assess salt tolerance and identify reliable indicators of salt tolerance, we measured the shoot length (SL), root length (RL), root fresh weight (RFW), shoot fresh weight (SFW), total fresh weight (TFW) and salt tolerance (STI) index after 7 days of salt-stress treatment. The 140 rice cultivars were divided into four categories based on the mean MFVs: highly salt tolerant (HST: 19 cultivars), salt tolerant (ST: 74 cultivars), weakly salt tolerant (WST: 43 cultivars), and salt sensitive (SS: 4 cultivars). Based on the physiological indicators, we established a mathematical model to accurately evaluate salt tolerance in japonica rice cultivars. STI of TFW under 150 mmol L−1 NaCl treatment showed the highest correlation with salt tolerance during the germination stage.Conclusions: We determined the optimum NaCl concentration (150 mmol L−1) for evaluating salt tolerance in japonica rice at the germination stage. We identified 19 HST, 74 ST, 43 WST, and 4 SS japonica rice cultivars during the germination stage and proposed a mathematical model to evaluate salt tolerance. STI of TFW is a reliable, accurate indicator for evaluating salt tolerance in japonica rice. These findings should greatly facilitate the evaluation of japonica rice cultivars during seed germination and the breeding of salt-tolerant rice cultivars.

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Salinity Effects on Gene Expression, Morphological, and Physio-Biochemical Responses of Stevia rebaudiana Bertoni In Vitro

Plants ◽

10.3390/plants10040820 ◽

2021 ◽

Vol 10 (4) ◽

pp. 820

Author(s):

Clara Azzam ◽

Sudad Al-Taweel ◽

Ranya Abdel-Aziz ◽

Karim Rabea ◽

Alaa Abou-Sreea ◽

...

Keyword(s):

Salt Tolerance ◽

Biochemical Parameters ◽

Large Scale ◽

Stevia Rebaudiana ◽

Multiple Shoots ◽

High Salt ◽

Stress Factors ◽

Stevia Rebaudiana Bertoni ◽

Nacl Concentration

Stevia rebaudiana Bertoni is a little bush, which is cultivated on a large scale in many countries for medicinal purposes and used as a natural sweetener in food products. The present work aims to conduct a protocol for stevia propagation in vitro to produce and introduce Stevia rebaudiana plants as a new sweetener crop to Egyptian agriculture. To efficiently maximize its propagation, it is important to study the influence of stress factors on the growth and development of Stevia rebaudiana grown in vitro. Two stevia varieties were investigated (Sugar High A3 and Spanti) against salt stress. Leaves were used as the source of explants for callus initiation, regeneration, multiplication and rooting. Some stress-related traits, i.e., photosynthetic pigments, proline contents, and enzyme activity for peroxidase (POD), polyphenol oxidase (PPO), and malate dehydrogenase (MDH) were studied. Murashig and Skoog (MS) medium was supplemented with four NaCl concentrations: 500, 1000, 2000, and 3000 mgL−1, while a salt-free medium was used as the control. The data revealed that salinity negatively affected all studied characters: the number of surviving calli, regeneration%, shoot length, the number of multiple shoots, number of leaf plantlets−1, number of root plantlets−1, and root length. The data also revealed that Sugar High A3 is more tolerant than Spanti. The total chlorophyll content decreased gradually with increasing NaCl concentration. However, the opposite was true for proline content. Isozyme’s fractionation exhibited high levels of variability among the two varieties. Various biochemical parameters associated with salt tolerance were detected in POD. Namely, POD4, POD6, POD 9 at an Rf of 0.34, 0.57, and 0.91 in the Sugar High A3 variety under high salt concentration conditions, as well as POD 10 at an Rf of 0.98 in both varieties under high salt concentrations. In addition, the overexpression of POD 5 and POD 10 at Rf 0.52 and 0.83 was found in both varieties at high NaCl concentrations. Biochemical parameters associated with salt tolerance were detected in PPO (PPO1, PPO2 and PPO4 at an Rf of 0.38, 0.42 and 0.62 in the Sugar High A3 variety under high salt concentrations) and MDH (MDH 3 at an Rf of 0.40 in both varieties at high salt concentrations). Therefore, these could be considered as important biochemical markers associated with salt tolerance and could be applied in stevia breeding programs (marker-assisted selection). This investigation recommends stevia variety Sugar High A3 to be cultivated under salt conditions.

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Salt-tolerance screening in Limonium sinuatum varieties with different flower colors

Scientific Reports ◽

10.1038/s41598-021-93974-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Xiaojing Xu ◽

Yingli Zhou ◽

Ping Mi ◽

Baoshan Wang ◽

Fang Yuan

Keyword(s):

Salt Tolerance ◽

Photosynthetic Rate ◽

Large Scale ◽

Soluble Sugars ◽

Dry Weight ◽

Salt Gland ◽

Salt Glands ◽

Chlorophyll Contents ◽

Relative Water ◽

Whole Plants

AbstractLimonium sinuatum, a member of Plumbaginaceae commonly known as sea lavender, is widely used as dried flower. Five L. sinuatum varieties with different flower colors (White, Blue, Pink, Yellow, and Purple) are found in saline regions and are widely cultivated in gardens. In the current study, we evaluated the salt tolerance of these varieties under 250 mmol/L NaCl (salt-tolerance threshold) treatment to identify the optimal variety suitable for planting in saline lands. After the measurement of the fresh weight (FW), dry weight (DW), contents of Na+, K+, Ca2+, Cl−, malondialdehyde (MDA), proline, soluble sugars, hydrogen peroxide (H2O2), relative water content, chlorophyll contents, net photosynthetic rate, and osmotic potential of whole plants, the salt-tolerance ability from strongest to weakest is identified as Pink, Yellow, Purple, White, and Blue. Photosynthetic rate was the most reliable and positive indicator of salt tolerance. The density of salt glands showed the greatest increase in Pink under NaCl treatment, indicating that Pink adapts to high-salt levels by enhancing salt gland formation. These results provide a theoretical basis for the large-scale planting of L. sinuatum in saline soils in the future.

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A Genome-Wide Association Study Reveals Candidate Genes Related to Salt Tolerance in Rice (Oryza sativa) at the Germination Stage

International Journal of Molecular Sciences ◽

10.3390/ijms19103145 ◽

2018 ◽

Vol 19 (10) ◽

pp. 3145 ◽

Cited By ~ 8

Author(s):

Jie Yu ◽

Weiguo Zhao ◽

Wei Tong ◽

Qiang He ◽

Min-Young Yoon ◽

...

Keyword(s):

Salt Tolerance ◽

Association Study ◽

Candidate Genes ◽

Genome Wide Association Study ◽

Rice Genome ◽

Genome Wide Association ◽

Phenotypic Correlation ◽

Genome Wide ◽

A Genome ◽

Germination Stage

Salt toxicity is the major factor limiting crop productivity in saline soils. In this paper, 295 accessions including a heuristic core set (137 accessions) and 158 bred varieties were re-sequenced and ~1.65 million SNPs/indels were used to perform a genome-wide association study (GWAS) of salt-tolerance-related phenotypes in rice during the germination stage. A total of 12 associated peaks distributed on seven chromosomes using a compressed mixed linear model were detected. Determined by linkage disequilibrium (LD) blocks analysis, we finally obtained a total of 79 candidate genes. By detecting the highly associated variations located inside the genic region that overlapped with the results of LD block analysis, we characterized 17 genes that may contribute to salt tolerance during the seed germination stage. At the same time, we conducted a haplotype analysis of the genes with functional variations together with phenotypic correlation and orthologous sequence analyses. Among these genes, OsMADS31, which is a MADS-box family transcription factor, had a down-regulated expression under the salt condition and it was predicted to be involved in the salt tolerance at the rice germination stage. Our study revealed some novel candidate genes and their substantial natural variations in the rice genome at the germination stage. The GWAS in rice at the germination stage would provide important resources for molecular breeding and functional analysis of the salt tolerance during rice germination.

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A Salt Tolerance Evaluation Method for Sunflower (Helianthus annuus L.) at the Seed Germination Stage

Scientific Reports ◽

10.1038/s41598-020-67210-3 ◽

2020 ◽

Vol 10 (1) ◽

Cited By ~ 1

Author(s):

Wenhui Li ◽

Huizhen Zhang ◽

Youling Zeng ◽

Lijun Xiang ◽

Zhonghua Lei ◽

...

Keyword(s):

Salt Tolerance ◽

Seed Germination ◽

Helianthus Annuus ◽

Evaluation Method ◽

Helianthus Annuus L ◽

Germination Stage

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Screening, Inheritance and Linkage Marker Analyses of Salt Tolerance in Mutated Scented Japonica Rice (Oryza sativaL.)

Plant Production Science ◽

10.1626/pps.14.260 ◽

2011 ◽

Vol 14 (3) ◽

pp. 260-269 ◽

Cited By ~ 2

Author(s):

Ching-Chu Yen ◽

Jenq-Horng Lin

Keyword(s):

Salt Tolerance ◽

Japonica Rice ◽

Linkage Marker

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Comprehensive Evaluation of Salt Tolerance in Asparagus Germplasm Accessions (Asparagus officinalis L.) at Different Growth Stages

Journal of Food Quality ◽

10.1155/2021/6626112 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Huimin Gao ◽

Xuhong Zhang ◽

Yuqin Liang ◽

Lingdi Dong ◽

Changzhi Han ◽

...

Keyword(s):

Salt Tolerance ◽

Adult Stage ◽

Seedling Stage ◽

Asparagus Officinalis ◽

Growth Stages ◽

Salt Tolerant ◽

Aboveground Part ◽

The Mean ◽

Germplasm Accessions ◽

Germination Stage

The screening and cultivation of salt-tolerant crops are becoming more and more important owing to the constant increase in the saline soil area worldwide. Asparagus (A. officinalis L.) is a highly nutritious vegetable crop and widely consumed globally for a long time; however, little research has been done on asparagus. In this study, the salt tolerance of 95 asparagus germplasm accessions was evaluated at three growth stages (germination, seedling, and adult stages) under both salt-stressed and control conditions. Results showed that the growth parameters of most germplasm accessions were obviously inhibited by salt stress. The mean value of the seed germination rate at the germination stage decreased by half under salt-stressed conditions, the mean salt-injury index at the seedling stage reached 57.68%, and the fresh weight of the aboveground part (FWA) and the dry weight of the aboveground part (DWA) decreased the most among the traits determined at the adult stage by more than 60%. Our study screened out 30, 19, and 18 tolerant germplasm accessions (including highly salt-tolerant and salt-tolerant germplasm accessions) at the germination stage, seedling stage, and adult stage, respectively. Among them, two germplasm accessions (Ji08-2 and Jx1502) were simultaneously identified to be tolerant in all three growth stages, while other germplasm accessions were tolerant only at one or two stages. Thus, the salt tolerance of asparagus has periodic characteristics and changes throughout the lifecycle, and the identification of salt tolerance at all the main growth stages facilitates adequate assessment and application of tolerant germplasm accessions.

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Omeprazole Promotes Chloride Exclusion and Induces Salt Tolerance in Greenhouse Basil

Agronomy ◽

10.3390/agronomy9070355 ◽

2019 ◽

Vol 9 (7) ◽

pp. 355 ◽

Cited By ~ 7

Author(s):

Petronia Carillo ◽

Pasqualina Woodrow ◽

Giampaolo Raimondi ◽

Christophe El-Nakhel ◽

Antonio Pannico ◽

...

Keyword(s):

Salt Tolerance ◽

Large Scale ◽

Molecular Mechanisms ◽

Benzimidazole Derivative ◽

Ion Homeostasis ◽

Chloride Concentration ◽

Co2 Assimilation ◽

Stomatal Resistance ◽

Bioactive Molecules ◽

Proton Pumps

The role of small bioactive molecules (<500 Da) in mechanisms improving resource use efficiency in plants under stress conditions draws increasing interest. One such molecule is omeprazole (OMP), a benzimidazole derivative and inhibitor of animal proton pumps shown to improve nitrate uptake and exclusion of toxic ions, especially of chloride from the cytosol of salt-stressed leaves. Currently, OMP was applied as substrate drench at two rates (0 or 10 μM) on hydroponic basil (Ocimum basilicum L. cv. Genovese) grown under decreasing NO3−:Cl− ratio (80:20, 60:40, 40:60, or 20:80). Chloride concentration and stomatal resistance increased while transpiration, net CO2 assimilation rate and beneficial ions (NO3−, PO43−, and SO42−) decreased with reduced NO3−:Cl− ratio under the 0 μM OMP treatment. The negative effects of chloride were not only mitigated by the 10 μM OMP application in all treatments, with the exception of 20:80 NO3−:Cl−, but plant growth at 80:20, 60:40, and 40:60 NO3−:Cl− ratios receiving OMP application showed maximum fresh yield (+13%, 24%, and 22%, respectively), shoot (+10%, 25%, and 21%, respectively) and root (+32%, 76%, and 75%, respectively) biomass compared to the corresponding untreated treatments. OMP was not directly involved in ion homeostasis and compartmentalization of vacuolar or apoplastic chloride. However, it was active in limiting chloride loading into the shoot, as manifested by the lower chloride concentration in the 80:20, 60:40, and 40:60 NO3−:Cl− treatments compared to the respective controls (−41%, −37%, and −24%), favoring instead that of nitrate and potassium while also boosting photosynthetic activity. Despite its unequivocally beneficial effect on plants, the large-scale application of OMP is currently limited by the molecule’s high cost. However, further studies are warranted to unravel the molecular mechanisms of OMP-induced reduction of chloride loading to shoot and improved salt tolerance.

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Evaluation of salt-tolerant germplasm and screening of the salt-tolerance traits of sweet sorghum in the germination stage

Functional Plant Biology ◽

10.1071/fp18009 ◽

2018 ◽

Vol 45 (10) ◽

pp. 1073 ◽

Cited By ~ 15

Author(s):

Tonglou Ding ◽

Zhen Yang ◽

Xiaocen Wei ◽

Fang Yuan ◽

Shanshan Yin ◽

...

Keyword(s):

Salt Tolerance ◽

Sweet Sorghum ◽

Development Process ◽

Salt Tolerant ◽

Comprehensive Index ◽

Starting Point ◽

High Salt Tolerance ◽

Sorghum Bicolor L ◽

Germination Stage ◽

Selection Of

Soil salinity is one of the major abiotic stresses that reduces agricultural productivity and affects large terrestrial areas around the world. Germination is the starting point of the growth and development process of all crops, and it is severely affected by salt stress. Sweet sorghum (Sorghum bicolor (L.) Moench.) is one of the most promising crops that has a relatively high salt tolerance and biomass. However, few studies have evaluated the salt tolerance or screened the reliable evaluation traits of sweet sorghum. In this study, the membership function value of five traits was used as a comprehensive index for the evaluation and selection of salt tolerance in 300 sweet sorghum germplasms. After salt tolerance evaluation, 23 highly salt-tolerant, 38 salt-tolerant, 195 moderately salt-tolerant, 38 salt-sensitive and 6 highly salt-sensitive germplasms during the germination stage were screened. Moreover, the germination index under the 200 mM NaCl treatment showed the highest correlation with salt tolerance during the germination stage. This information can be used for effectively evaluating sweet sorghum during the germination stage. These results are important for the evaluation of the salt tolerance of sweet sorghum germplasms during the germination stage.

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