Salt tolerance mechanisms in Salt Tolerant Grasses (STGs) and their prospects in cereal crop improvement

Canola (Brassica napus L.) is widely cultivated around the world for the production of edible oils and biodiesel fuel. Despite many canola varieties being described as ‘salt-tolerant’, plant yield and growth decline drastically with increasing salinity. Although many studies have resulted in better understanding of the many important salt-response mechanisms that control salt signaling in plants, detoxification of ions, and synthesis of protective metabolites, the engineering of salt-tolerant crops has only progressed slowly. Genetic engineering has been considered as an efficient method for improving the salt tolerance of canola but there are many unknown or little-known aspects regarding canola response to salinity stress at the cellular and molecular level. In order to develop highly salt-tolerant canola, it is essential to improve knowledge of the salt-tolerance mechanisms, especially the key components of the plant salt-response network. In this review, we focus on studies of the molecular response of canola to salinity to unravel the different pieces of the salt response puzzle. The paper includes a comprehensive review of the latest studies, particularly of proteomic and transcriptomic analysis, including the most recently identified canola tolerance components under salt stress, and suggests where researchers should focus future studies.

Download Full-text

Whole genome sequence analysis of rice genotypes with contrasting response to salinity stress

Scientific Reports ◽

10.1038/s41598-020-78256-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Prasanta K. Subudhi ◽

Rama Shankar ◽

Mukesh Jain

Keyword(s):

Salt Tolerance ◽

Dna Polymorphisms ◽

Whole Genome Sequence ◽

Whole Genome ◽

Salt Tolerant ◽

Tolerance Mechanisms ◽

Rice Varieties ◽

Genome Wide ◽

Rice Genotypes ◽

Genome Level

AbstractSalinity is a major abiotic constraint for rice farming. Abundant natural variability exists in rice germplasm for salt tolerance traits. Since few studies focused on the genome level variation in rice genotypes with contrasting response to salt stress, genomic resequencing in diverse genetic materials is needed to elucidate the molecular basis of salt tolerance mechanisms. The whole genome sequences of two salt tolerant (Pokkali and Nona Bokra) and three salt sensitive (Bengal, Cocodrie, and IR64) rice genotypes were analyzed. A total of 413 million reads were generated with a mean genome coverage of 93% and mean sequencing depth of 18X. Analysis of the DNA polymorphisms revealed that 2347 nonsynonymous SNPs and 51 frameshift mutations could differentiate the salt tolerant from the salt sensitive genotypes. The integration of genome-wide polymorphism information with the QTL mapping and expression profiling data led to identification of 396 differentially expressed genes with large effect variants in the coding regions. These genes were involved in multiple salt tolerance mechanisms, such as ion transport, oxidative stress tolerance, signal transduction, and transcriptional regulation. The genome-wide DNA polymorphisms and the promising candidate genes identified in this study represent a valuable resource for molecular breeding of salt tolerant rice varieties.

Download Full-text

Molecular response of canola to salt stress: insights on tolerance mechanisms

10.7287/peerj.preprints.26716v1 ◽

2018 ◽

Author(s):

Reza Shokri-Gharelo ◽

Pouya Motie-Noparvar

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Edible Oils ◽

Biodiesel Fuel ◽

Molecular Response ◽

Salt Tolerant ◽

Tolerance Mechanisms ◽

Brassica Napus L ◽

Salt Response ◽

The Many

Canola (Brassica napus L.) is widely cultivated around the world for the production of edible oils and biodiesel fuel. Despite many canola varieties being described as ‘salt-tolerant’, plant yield and growth decline drastically with increasing salinity. Although many studies have resulted in better understanding of the many important salt-response mechanisms that control salt signaling in plants, detoxification of ions, and synthesis of protective metabolites, the engineering of salt-tolerant crops has only progressed slowly. Genetic engineering has been considered as an efficient method for improving the salt tolerance of canola but there are many unknown or little-known aspects regarding canola response to salinity stress at the cellular and molecular level. In order to develop highly salt-tolerant canola, it is essential to improve knowledge of the salt-tolerance mechanisms, especially the key components of the plant salt-response network. In this review, we focus on studies of the molecular response of canola to salinity to unravel the different pieces of the salt response puzzle. The paper includes a comprehensive review of the latest studies, particularly of proteomic and transcriptomic analysis, including the most recently identified canola tolerance components under salt stress, and suggests where researchers should focus future studies.

Download Full-text

Molecular response of canola to salt stress: insights on tolerance mechanisms

PeerJ ◽

10.7717/peerj.4822 ◽

2018 ◽

Vol 6 ◽

pp. e4822 ◽

Cited By ~ 15

Author(s):

Reza Shokri-Gharelo ◽

Pouya Motie Noparvar

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Edible Oils ◽

Biodiesel Fuel ◽

Molecular Response ◽

Salt Tolerant ◽

Tolerance Mechanisms ◽

Brassica Napus L ◽

Salt Response ◽

The Many

Canola (Brassica napus L.) is widely cultivated around the world for the production of edible oils and biodiesel fuel. Despite many canola varieties being described as ‘salt-tolerant’, plant yield and growth decline drastically with increasing salinity. Although many studies have resulted in better understanding of the many important salt-response mechanisms that control salt signaling in plants, detoxification of ions, and synthesis of protective metabolites, the engineering of salt-tolerant crops has only progressed slowly. Genetic engineering has been considered as an efficient method for improving the salt tolerance of canola but there are many unknown or little-known aspects regarding canola response to salinity stress at the cellular and molecular level. In order to develop highly salt-tolerant canola, it is essential to improve knowledge of the salt-tolerance mechanisms, especially the key components of the plant salt-response network. In this review, we focus on studies of the molecular response of canola to salinity to unravel the different pieces of the salt response puzzle. The paper includes a comprehensive review of the latest studies, particularly of proteomic and transcriptomic analysis, including the most recently identified canola tolerance components under salt stress, and suggests what researchers should focus on in future studies.

Download Full-text

Transcriptomic Analysis Reveals Salt Tolerance Mechanisms Present in Date-Plum Persimmon Rootstock (Diospyros lotus L.)

Agronomy ◽

10.3390/agronomy10111703 ◽

2020 ◽

Vol 10 (11) ◽

pp. 1703

Author(s):

Francisco Gil-Muñoz ◽

Nicolas Delhomme ◽

Ana Quiñones ◽

Maria del Mar Naval ◽

Maria Luisa Badenes ◽

...

Keyword(s):

Salt Tolerance ◽

Transcriptome Profiling ◽

Rna Seq ◽

Salt Tolerant ◽

Tolerance Mechanisms ◽

Diospyros Lotus ◽

And Control ◽

Different Levels ◽

Tolerance To Salinity

Agriculture needs solutions for adapting crops to increasing salinity globally. Research on physiological and molecular responses activated by salinity is needed to elucidate mechanisms of salinity tolerance. Transcriptome profiling (RNA-Seq) is a powerful tool to study the transcriptomic profile of genotypes under stress conditions. Persimmon species have different levels of tolerance to salinity, this variability may provide knowledge on persimmon species and development of salt--tolerant rootstocks. In this study, we conducted a physiological and transcriptomic profiling of roots and leaves in tolerant and sensitive plants of persimmon rootstock grown under saline and control conditions. Characterization of physiological responses along with gene expression changes in roots and leaves allowed the identification of several salt tolerance mechanisms related to ion transport and thermospermine synthesis. Differences were observed in putative H+/ATPases that allow transmembrane ionic transport and chloride channel protein-like genes. Furthermore, an overexpression of thermospermine synthase found in the roots of tolerant plants may indicate that alterations in root architecture could act as an additional mechanism of response to salt stress. These results indicate that Diospyros lotus L. exhibits genetically-controlled variability for salt tolerance traits which opens potential opportunities for breeding salt-tolerant persimmon rootstocks in a Mediterranean environment challenged by drought and salinity.

Download Full-text

Application of SSR Technique for the Identification of Markers Linked to Salinity Tolerance in Rice

Progressive Agriculture ◽

10.3329/pa.v19i2.16929 ◽

2013 ◽

Vol 19 (2) ◽

pp. 57-65

Author(s):

MH Kabir ◽

MM Islam ◽

SN Begum ◽

AC Manidas

Keyword(s):

Salt Tolerance ◽

Ssr Markers ◽

Salinity Tolerance ◽

Seedling Stage ◽

Phenotypic Screening ◽

Salt Tolerant ◽

Marker Assisted Breeding ◽

Hydroponic System ◽

Rice Landrace ◽

Salt Susceptible

A cross was made between high yielding salt susceptible BINA variety (Binadhan-5) with salt tolerant rice landrace (Harkuch) to identify salt tolerant rice lines. Thirty six F3 rice lines of Binadhan-5 x Harkuch were tested for salinity tolerance at the seedling stage in hydroponic system using nutrient solution. In F3 population, six lines were found as salt tolerant and 10 lines were moderately tolerant based on phenotypic screening at the seedling stage. Twelve SSR markers were used for parental survey and among them three polymorphic SSR markers viz., OSR34, RM443 and RM169 were selected to evaluate 26 F3 rice lines for salt tolerance. With respect to marker OSR34, 15 lines were identified as salt tolerant, 9 lines were susceptible and 2 lines were heterozygous. While RM443 identified 3 tolerant, 14 susceptible and 9 heterozygous rice lines. Eight tolerant, 11 susceptible and 7 heterozygous lines were identified with the marker RM169. Thus the tested markers could be efficiently used for tagging salt tolerant genes in marker-assisted breeding programme.DOI: http://dx.doi.org/10.3329/pa.v19i2.16929 Progress. Agric. 19(2): 57 - 65, 2008

Download Full-text

Genetic Potential for Salt Tolerance During Germination in Lycopersicon Species

HortScience ◽

10.21273/hortsci.32.2.296 ◽

1997 ◽

Vol 32 (2) ◽

pp. 296-300 ◽

Cited By ~ 46

Author(s):

M.R. Foolad ◽

G.Y. Lin

Keyword(s):

Salt Stress ◽

Salt Tolerance ◽

Genotypic Variation ◽

Control Treatment ◽

Molar Ratio ◽

Wild Accession ◽

Salt Tolerant ◽

Plant Introductions ◽

Genetic Potential ◽

Stress Levels

Seed of 42 wild accessions (Plant Introductions) of Lycopersicon pimpinellifolium Jusl., 11 cultigens (cultivated accessions) of L. esculentum Mill., and three control genotypes [LA716 (a salt-tolerant wild accession of L. pennellii Corr.), PI 174263 (a salt-tolerant cultigen), and UCT5 (a salt-sensitive breeding line)] were evaluated for germination in either 0 mm (control) or 100 mm synthetic sea salt (SSS, Na+/Ca2+ molar ratio equal to 5). Germination time increased in response to salt-stress in all genotypes, however, genotypic variation was observed. One accession of L. pimpinellifolium, LA1578, germinated as rapidly as LA716, and both germinated more rapidly than any other genotype under salt-stress. Ten accessions of L. pimpinellifolium germinated more rapidly than PI 174263 and 35 accessions germinated more rapidly than UCT5 under salt-stress. The results indicate a strong genetic potential for salt tolerance during germination within L. pimpinellifolium. Across genotypes, germination under salt-stress was positively correlated (r = 0.62, P < 0.01) with germination in the control treatment. The stability of germination response at diverse salt-stress levels was determined by evaluating germination of a subset of wild, cultivated accessions and the three control genotypes at 75, 150, and 200 mm SSS. Seeds that germinated rapidly at 75 mm also germinated rapidly at 150 mm salt. A strong correlation (r = 0.90, P < 0.01) existed between the speed of germination at these two salt-stress levels. At 200 mm salt, most accessions (76%) did not reach 50% germination by 38 days, demonstrating limited genetic potential within Lycopersicon for salt tolerance during germination at this high salinity.

Download Full-text

Evaluation of salinity tolerance indices in North African barley accessions at reproductive stage

Czech Journal of Genetics and Plant Breeding ◽

10.17221/50/2017-cjgpb ◽

2019 ◽

Vol 55 (No. 2) ◽

pp. 61-69 ◽

Cited By ~ 3

Author(s):

Dorsaf Allel ◽

Anis BenAmar ◽

Mounawer Badri ◽

Chedly Abdelly

Keyword(s):

Salt Tolerance ◽

Grain Yield ◽

Salinity Tolerance ◽

Selection Criteria ◽

Reproductive Stage ◽

Shoot Biomass ◽

Salt Tolerant ◽

North African ◽

Grain Number ◽

Selection Indices

Soil salinity is one of the main factors limiting cereal productivity in worldwide agriculture. Exploitation of natural variation in local barley germplasm is an effective approach to overcome yield losses. Three gene pools of North African Hordeum vulgare L. grown in Tunisia, Algeria and Egypt were evaluated at the reproductive stage under control and saline conditions. Assessment of stress tolerance was monitored using morphological, yield-related traits and phenological parameters of reproductive organs showing significant genetic variation. High heritability and positive relationships were found suggesting that some traits associated with salt tolerance could be used as selection criteria. The phenotypic correlations revealed that vegetative traits including shoot biomass, tiller number and leaf number along with yield-related traits such as spike number, one spike dry weight, grain number/plant and grain number/spike were highly positively correlated with grain yield under saline conditions. Hence, these traits can be used as reliable selection criteria to improve barley grain yield. Keeping a higher shoot biomass and longer heading and maturity periods as well as privileged filling ability might contribute to higher grain production in barley and thus could be potential target traits in barley crop breeding toward improvement of salinity tolerance. Multiple selection indices revealed that salt tolerance trait index provided a better discrimination of barley landraces allowing selection of highly salt-tolerant and highly productive genotypes under severe salinity level. Effective evaluation of salt tolerance requires an integration of selection indices to successfully identify and characterize salt tolerant lines required for valuable exploitation in the management of salt-affected areas.

Download Full-text

Early Growth Stage Characterization and the Biochemical Responses for Salinity Stress in Tomato

Plants ◽

10.3390/plants10040712 ◽

2021 ◽

Vol 10 (4) ◽

pp. 712

Author(s):

Md Sarowar Alam ◽

Mark Tester ◽

Gabriele Fiene ◽

Magdi Ali Ahmed Mousa

Keyword(s):

Salt Tolerance ◽

Salinity Tolerance ◽

Salinity Treatment ◽

Salt Tolerant ◽

Improvement Program ◽

Biochemical Basis ◽

Elevated Salinity ◽

Tolerance Indices ◽

Promising Source ◽

Tomato Genotypes

Salinity is one of the most significant environmental stresses for sustainable crop production in major arable lands of the globe. Thus, we conducted experiments with 27 tomato genotypes to screen for salinity tolerance at seedling stage, which were treated with non-salinized (S1) control (18.2 mM NaCl) and salinized (S2) (200 mM NaCl) irrigation water. In all genotypes, the elevated salinity treatment contributed to a major depression in morphological and physiological characteristics; however, a smaller decrease was found in certain tolerant genotypes. Principal component analyses (PCA) and clustering with percentage reduction in growth parameters and different salt tolerance indices classified the tomato accessions into five key clusters. In particular, the tolerant genotypes were assembled into one cluster. The growth and tolerance indices PCA also showed the order of salt-tolerance of the studied genotypes, where Saniora was the most tolerant genotype and P.Guyu was the most susceptible genotype. To investigate the possible biochemical basis for salt stress tolerance, we further characterized six tomato genotypes with varying levels of salinity tolerance. A higher increase in proline content, and antioxidants activities were observed for the salt-tolerant genotypes in comparison to the susceptible genotypes. Salt-tolerant genotypes identified in this work herald a promising source in the tomato improvement program or for grafting as scions with improved salinity tolerance in tomato.

Download Full-text