scholarly journals Transcriptional profiling of two contrasting genotypes uncovers molecular mechanisms underlying salt tolerance in alfalfa

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rakesh Kaundal ◽  
Naveen Duhan ◽  
Biswa R. Acharya ◽  
Manju V. Pudussery ◽  
Jorge F. S. Ferreira ◽  
...  

AbstractAlfalfa is an important forage crop that is moderately tolerant to salinity; however, little is known about its salt-tolerance mechanisms. We studied root and leaf transcriptomes of a salt-tolerant (G03) and a salt-sensitive (G09) genotype, irrigated with waters of low and high salinities. RNA sequencing led to 1.73 billion high-quality reads that were assembled into 418,480 unigenes; 35% of which were assigned to 57 Gene Ontology annotations. The unigenes were assigned to pathway databases for understanding high-level functions. The comparison of two genotypes suggested that the low salt tolerance index for transpiration rate and stomatal conductance of G03 compared to G09 may be due to its reduced salt uptake under salinity. The differences in shoot biomass between the salt-tolerant and salt-sensitive lines were explained by their differential expressions of genes regulating shoot number. Differentially expressed genes involved in hormone-, calcium-, and redox-signaling, showed treatment- and genotype-specific differences and led to the identification of various candidate genes involved in salinity stress, which can be investigated further to improve salinity tolerance in alfalfa. Validation of RNA-seq results using qRT-PCR displayed a high level of consistency between the two experiments. This study provides valuable insight into the molecular mechanisms regulating salt tolerance in alfalfa.

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Md. Mia Mukul ◽  
Sheikh Shorif Uddin Ahmed ◽  
Nargis Akter ◽  
Md. Golam Mostofa ◽  
Md. Sohanur Rahman ◽  
...  

Salinity is a serious abiotic stress to Jute and other crop cultivation at saline regions in the world. No salt tolerant Tossa Jute (Corchorus olitorius L.) variety was developed in Bangladesh. Hence, six Tossa Jute accessions were investigated at germination stage against six concentration levels (0.00 or d.H2O, 8.0, 10.0, 12.0, 14.0 and 16.0 dS m-1) of salt (NaCl) using RCB design at Bangladesh Jute Research Institute (BJRI) during March-July, 2020. Jute seeds collected from Gene Bank of BJRI were allowed to germinate under laboratory condition. Seed germination rate was adversely affected as well as delay in germination was prolonged with increasing the salt concentration. In control, seeds were germinated up to 14.0 dS m-1 salt solution. Among six genotypes, Acc. 1141 and Acc. 3801 showed the highest germination rate (86.67 %); Acc. 3801 gave maximum root length (17.0 mm), dry biomass (6.37 mg); and Acc. 1089 showed higher shoot length (10.0 mm), fresh weight (43.93 mg) and salt tolerance index (60.69 %) under 14.0 dS m-1 level. Higher relative salt harm rate (7.14 %) was observed in both Acc. 1141 and Acc. 3801 under 14.0 dS m-1 salinity indicating highly tolerance to salinity. Acc. 3801 and Acc. 1141 were found good for germination under salt stresses; Acc. 3801, Acc. 1089 for fiber yield and salt tolerance; Acc. 3801 and Acc. 1407 for higher fiber yield. Acc. 3801 was found good for salt tolerance and fiber yield content. The genotypes with good desirable characters would be used as breeding materials to develop high yielding salt tolerant Tossa Jute variety.


2021 ◽  
Author(s):  
Zeliang Zhang ◽  
Juyun Zheng ◽  
Zhaolong Gong ◽  
Yajun Liang ◽  
Zhiwei Sang ◽  
...  

Soil salinization is the main abiotic stress factor affecting agricultural production worldwide, and salt stress has a significant impact on plant growth and development. Cotton is one of the most salt-tolerant crops. Its salt tolerance varies greatly depending on the variety, growth stage, organs, and soil salt types. Therefore, the selection and utilization of excellent salt-tolerant germplasm resources and the excavation of excellent salt-tolerant salt and salt resistance genes play important roles in improving cotton production in saline-alkali soils. In this study, we analysed the population structure and genetic diversity of 144 elite Gossypium hirsutum cultivar accessions collected from around the world, and especially from China. Illumina Cotton SNP 70K was used to obtain genome-wide single-nucleotide polymorphism (SNP) data for 149 experimental materials, and 18,432 highly consistent SNP loci were obtained by filtering. PCA (principal component analysis)indicated that 149 upland cotton materials could be divided into 2 subgroups, including subgroup 1 with 78 materials and subgroup 2 with 71 materials. Using the obtained SNP and other marker genotype test results, under salt stress, the salt tolerance traits 3d_Germination_potential, 3d_Bud_length_drop_rate, 7d_Germination_rate, 7d_Bud_length_drop_rate, 7d_Germination_weight, 3d_Bud_length, 7d_Bud_length, relative_germination_potential, Relative_germination_rate, 7d_Bud_weight_drop_rate, Salt tolerance index 3d_Germination_potential_index, 3d_Bud_length_index, 7d_Bud_length_index, 7d_Bud_weight_index, and 7d_Germination_rate_index were evaluated by genome association analysis. A total of 27 SNP markers closely related to salt tolerance traits and 15 SNP markers closely related to salt tolerance index were detected. At the SNP locus associated with the traits of the bud length decline rate at 7 days, alleles Gh_A01G0034 and Gh_D01G0028 related to plant salt tolerance were detected, and they are related to intracellular transport, membrane microtubule formation and actin network. This study provides a theoretical basis for the selection and breeding of salt-tolerant upland cotton varieties.


HortScience ◽  
2017 ◽  
Vol 52 (9) ◽  
pp. 1168-1176 ◽  
Author(s):  
Waltram Second Ravelombola ◽  
Ainong Shi ◽  
Yuejin Weng ◽  
John Clark ◽  
Dennis Motes ◽  
...  

Cowpea is a leguminous and versatile crop which provides nutritional food for human consumption. However, salinity unfavorably reduces cowpea seed germination, thus significantly decreasing cowpea production. Little has been done for evaluating and developing salt-tolerant cowpea genotypes at germination stage. The objectives of this research were to evaluate the response of cowpea genotypes to salinity stress through seed germination rate and to select salt-tolerant cowpea genotypes. The seed germination rates under nonsalt condition and salinity stress (150 mm NaCl) were evaluated in 151 cowpea genotypes. Four parameters, absolute decrease (AD), the inhibition index (II), the relative salt tolerance (RST), and the salt tolerance index (STI) were used to measure salt tolerance in cowpea. The results showed that there were significant differences among the 151 cowpea genotypes for all parameters (P values <0.0001). The AD in germination rate was 5.8% to 94.2%; the II varied from 7.7% to 100%; the RST ranged from 0 to 0.92; and STI varied from 0 to 0.92. A high broad sense heritability (H2) was observed for all four parameters. High correlation coefficients (r) were estimated among the four parameters. PI582422, 09–529, PI293584, and PI582570 were highly salt tolerant at germination stage. In addition, genotypes from the Caribbean and Southern Asia exhibited better tolerance to salinity, whereas those from Europe and North America were the most salt-susceptible.


2019 ◽  
Vol 55 (No. 2) ◽  
pp. 61-69 ◽  
Author(s):  
Dorsaf Allel ◽  
Anis BenAmar ◽  
Mounawer Badri ◽  
Chedly Abdelly

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.  


2020 ◽  
Author(s):  
Jingjing Wang ◽  
Cong An ◽  
Hailin Guo ◽  
Xiangyang Yang ◽  
Jingbo Chen ◽  
...  

Abstract Background: Areas with saline soils are sparsely populated and have fragile ecosystems, which severely restricts the sustainable development of local economies. Zoysia grasses are recognized as excellent warm-season turfgrasses worldwide, with high salt tolerance and superior growth in saline-alkali soils. However, the mechanism underlying the salt tolerance of Zoysia species remains unknown. Results: The phenotypic and physiological responses of two contrasting materials, Zoysia japonica Steud. Z004 (salt sensitive) and Z011 (salt tolerant) in response to salt stress were studied. The results show that Z011 was more salt tolerant than was Z004, with the former presenting greater K+/Na+ ratios in both its leaves and roots. To study the molecular mechanisms underlying salt tolerance further, we compared the transcriptomes of the two materials at different time points (0 h, 1 h, 24 h, and 72 h) and from different tissues (leaves and roots) under salt treatment. The 24-h time point and the roots might make significant contributions to the salt tolerance. Moreover, GO and KEGG analyses of different comparisons revealed that the key DEGs participating in the salt-stress response belonged to the hormone pathway, various TF families and the DUF family. Conclusions: Z011 may have improved salt tolerance by reducing Na+ transport from the roots to the leaves, increasing K+ absorption in the roots and reducing K+ secretion from the leaves to maintain a significantly greater K+/Na+ ratio. Twenty-four hours might be a relatively important time point for the salt-stress response of zoysiagrass. The auxin signal transduction family, ABA signal transduction family, WRKY TF family and bHLH TF family may be the most important families in Zoysia salt-stress regulation. This study provides fundamental information concerning the salt-stress response of Zoysia and improves the understanding of molecular mechanisms in salt-tolerant plants.


2020 ◽  
Vol 21 (21) ◽  
pp. 8385
Author(s):  
Hua Qin ◽  
Yuxiang Li ◽  
Rongfeng Huang

Soil salinization and a degraded ecological environment are challenging agricultural productivity and food security. Rice (Oryza sativa), the staple food of much of the world’s population, is categorized as a salt-susceptible crop. Improving the salt tolerance of rice would increase the potential of saline-alkali land and ensure food security. Salt tolerance is a complex quantitative trait. Biotechnological efforts to improve the salt tolerance of rice hinge on a detailed understanding of the molecular mechanisms underlying salt stress tolerance. In this review, we summarize progress in the breeding of salt-tolerant rice and in the mapping and cloning of genes and quantitative trait loci (QTLs) associated with salt tolerance in rice. Furthermore, we describe biotechnological tools that can be used to cultivate salt-tolerant rice, providing a reference for efforts aimed at rapidly and precisely cultivating salt-tolerance rice varieties.


2015 ◽  
Vol 42 (11) ◽  
pp. 1026 ◽  
Author(s):  
Ping Deng ◽  
Dan Jiang ◽  
Yanmin Dong ◽  
Xingyu Shi ◽  
Wen Jing ◽  
...  

Salt-tolerant mutants are valuable resources for basic and applied research on plant salt tolerance. Here, we report the isolation and characterisation of a salt-tolerant rice (Oryza sativa L.) mutant. This mutant was identified from an ethyl methanesulfonate-induced Nipponbare mutant library, designated as rice salt tolerant 1 (rst1). The rst1 mutant was tolerant to salt stress and showed significantly higher shoot biomass and chlorophyll content, but lower lipid peroxidation and electrolyte leakage under NaCl stress. The improved salt tolerance of this mutant may be due mainly to its enhanced ability to restrict Na+ accumulation in shoots under salt stress conditions. Genetic analysis indicated that the salt tolerance of the rst1 mutant was controlled by a single recessive gene. Quantitative trait locus (QTL) mapping for salt tolerance was performed using an F2 population of rst1 × Peiai 64. Two QTLs were detected, in which the locus on chromosome 6 was determined to be the candidate locus of the rst1 gene. The rst1 locus was subsequently shown to reside within a 270.4-kb region defined by the markers IM29432 and IM29702. This result will be useful for map-based cloning of the rst1 gene and for marker-assisted breeding for salt tolerance in rice.


Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2549
Author(s):  
Md Al Samsul Huqe ◽  
Md Sabibul Haque ◽  
Ashaduzzaman Sagar ◽  
Md Nesar Uddin ◽  
Md Alamgir Hossain ◽  
...  

Increasing soil salinity due to global warming severely restricts crop growth and yield. To select and recommend salt-tolerant cultivars, extensive genotypic screening and examination of plants’ morpho-physiological responses to salt stress are required. In this study, 18 prescreened maize hybrid cultivars were examined at the early growth stage under a hydroponic system using multivariate analysis to demonstrate the genotypic and phenotypic variations of the selected cultivars under salt stress. The seedlings of all maize cultivars were evaluated with two salt levels: control (without NaCl) and salt stress (12 dS m−1 simulated with NaCl) for 28 d. A total of 18 morpho-physiological and ion accumulation traits were dissected using multivariate analysis, and salt tolerance index (STI) values of the examined traits were evaluated for grouping of cultivars into salt-tolerant and -sensitive groups. Salt stress significantly declined all measured traits except root–shoot ratio (RSR), while the cultivars responded differently. The cultivars were grouped into three clusters and the cultivars in Cluster-1 such as Prabhat, UniGreen NK41, Bisco 51, UniGreen UB100, Bharati 981 and Star Beej 7Star exhibited salt tolerance to a greater extent, accounting for higher STI in comparison to other cultivars grouped in Cluster-2 and Cluster-3. The high heritability (h2bs, >60%) and genetic advance (GAM, >20%) were recorded in 13 measured traits, indicating considerable genetic variations present in these traits. Therefore, using multivariate analysis based on the measured traits, six hybrid maize cultivars were selected as salt-tolerant and some traits such as Total Fresh Weight (TFW), Total Dry Weight (TDW), Total Na+, Total K+ contents and K+–Na+ Ratio could be effectively used for the selection criteria evaluating salt-tolerant maize genotypes at the early seedling stage.


2018 ◽  
Vol 20 (2) ◽  
pp. 53-66
Author(s):  
E Sultana ◽  
MA Hasan ◽  
S Sikder ◽  
MS Rana ◽  
F Alam

An experiment was conducted to evaluate seedling growth of wheat under saline condition. Thirty wheat genotypes were grown in trays containing different levels of salinity (Control, 6 and 12 dSm-1) during October to December, 2013. Seedling emergence index, shoot and root length, shoot and root dry weight were found to be reduced with the increases of soil salinity level but the degree of reduction were not similar for all wheat genotypes. Salt tolerance index (STI) also indicated a wide difference in salt tolerance among the wheat genotypes. Sourav, Gourav, Shatabdi, BAW 1185, BAW 1186, BAW 1187, BAW 1189 and BAW 1193 were more salt tolerance while BAW 1177, BAW 1190 and BAW 1198 showed greater salt sensitivity than the other wheat genotypes at 6 dS m-1. However, at 12 dS m-1, Sourav, Gourav, Shatabdi, Sufi and BAW 1184 showed more salt tolerance and BAW 1183, BAW 1190, BAW 1192, BAW 1194 and BAW 97 provided greater stress sensitivity among the testing wheat genotypes. Considering both saline stress Sourav, Gourav and Shatabdi were found to be salt tolerant and BAW 1190 was saline sensitive wheat genotypes.Bangladesh Agron. J. 2017, 20(2): 53-66


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