Recent advancement of molecular understanding for combating salinity stress in maize.

Author(s):  
Yi-bo Cao ◽  
Yi-qiao Wang ◽  
Cai-fu Jiang

Abstract This chapter reviews recent progress in the fundamental understanding of maize salt tolerance and the advancement of molecular breeding for salt-tolerant maize. Great progress has been made towards the molecular understanding of maize salt tolerance in recent years. Nevertheless, the breeding of commercial salt-tolerant maize hybrids remains challenging. Some issues that may facilitate maize molecular breeding for combating salinity stress are enumerated.

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254189
Author(s):  
Nazanin Amirbakhtiar ◽  
Ahmad Ismaili ◽  
Mohammad-Reza Ghaffari ◽  
Raheleh Mirdar Mansuri ◽  
Sepideh Sanjari ◽  
...  

Salinity is one of the main abiotic stresses limiting crop productivity. In the current study, the transcriptome of wheat leaves in an Iranian salt-tolerant cultivar (Arg) was investigated in response to salinity stress to identify salinity stress-responsive genes and mechanisms. More than 114 million reads were generated from leaf tissues by the Illumina HiSeq 2500 platform. An amount of 81.9% to 85.7% of reads could be mapped to the wheat reference genome for different samples. The data analysis led to the identification of 98819 genes, including 26700 novel transcripts. A total of 4290 differentially expressed genes (DEGs) were recognized, comprising 2346 up-regulated genes and 1944 down-regulated genes. Clustering of the DEGs utilizing Kyoto Encyclopedia of Genes and Genomes (KEGG) indicated that transcripts associated with phenylpropanoid biosynthesis, transporters, transcription factors, hormone signal transduction, glycosyltransferases, exosome, and MAPK signaling might be involved in salt tolerance. The expression patterns of nine DEGs were investigated by quantitative real-time PCR in Arg and Moghan3 as the salt-tolerant and susceptible cultivars, respectively. The obtained results were consistent with changes in transcript abundance found by RNA-sequencing in the tolerant cultivar. The results presented here could be utilized for salt tolerance enhancement in wheat through genetic engineering or molecular breeding.


Author(s):  
Nidhi Chakma ◽  
Moutoshi Chakraborty ◽  
Salma Bhyan ◽  
Mobashwer Alam

Abstract This chapter discusses current progress and prospects of molecular breeding and strategies for developing better saline-tolerant sorghum (Sorghum bicolor) varieties. Most molecular breeding techniques for salt tolerance have been carried out in controlled environments where the plants were not exposed to any variation of the surrounding environment, producing reliable results. Due to the polygenic nature of salt tolerance, the identified quantitative trait loci (QTLs) could be false QTLs. Therefore, QTL validation is important in different plant populations and field conditions. Subsequently, marker validation is important before utilizing marker-assisted selection for screening salt-tolerant plants. Combining molecular breeding with conventional breeding can hasten the development of salt-tolerant sorghum varieties.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1149d-1149
Author(s):  
Mahdi S. Abdal ◽  
Jagan N. Sharma

Eggplant is an important vegetable crop in Kuwait. Eggplant is considered to have moderately sensitive salt-tolerance, though no quantitative information is available on its salt sensitivity. Selecting salt-tolerant genotypes in eggplant is an ongoing project at Kuwait Institute for Scientific Research. Towards the goal of selecting salt-tolerant genotypes in eggplant a completely randomized experiment using 10 cultivars, replicated 3 times were tested against 2 levels of high salinity stress (EC MS.cm-1 at 25°C, 15.0 and 18.0) along with the control (EC MS.cm-1 at 25°C, 3.0). The experiment was conducted on 15 days old seedlings inside a greenhouse. Data on shoot length and visual observations on leaf necrosis, leaf collapse and root color was also recorded. There was a clear degree of variability as well as significant differences in growth and final survival, between cultivars at 2 levels of salinity stress. Those genotypes that showed significant higher growth rates and survival without any signs on leaf necrosis and root collapse formed the basis salt-tolerant genotypes.


HortScience ◽  
2019 ◽  
Vol 54 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Adam Bolton ◽  
Philipp Simon

Global carrot production is limited by the crop’s high susceptibility to salinity stress. Not much public research has been conducted to screen for genetic salinity stress tolerance in carrot, and few resources exist to aid plant breeders in improving salinity tolerance in carrot. The objectives of this study were to evaluate the response of diverse carrot germplasm to salinity stress, identify salt-tolerant carrot germplasm that may be used by breeders, and define appropriate screening criteria for assessing salt tolerance in germinating carrot seed. Carrot plant introductions (PIs) (n = 273) from the U.S. Department of Agriculture (USDA) National Plant Germplasm System representing 41 different countries, inbred lines from the USDA Agricultural Research Service (n = 16), and widely grown commercial hybrids (n = 5) were screened for salinity tolerance under salinity stress and nonstress conditions (150 and 0 mm NaCl, respectively) by measuring the absolute decrease (AD) in the percent of germination, inhibition index (II), relative salt tolerance (RST), and salt tolerance index (STI) of germinating seeds. All salt tolerance measurements differed significantly between accessions; AD ranged from −4.2% to 93.0%; II ranged from −8.0% to 100.0%; RST ranged from 0.0 to 1.08; and STI ranged from 0.0 to 1.38. Broad sense heritability calculations for these measurements were 0.87 or more, indicating a strong genetic contribution to the variation observed. Six accessions identified as salt-tolerant or salt-susceptible were evaluated in a subsequent experiment conducted at salt concentrations of 0, 50, 100, 150, 200, and 250 mm NaCl. Variations between mean AD, II, RST, and STI of tolerant and susceptible lines were greatest at 150 mm NaCl, validating the use of 150 mm NaCl concentrations during salt tolerance screening of carrot seed. Wild carrot accessions displayed little tolerance, and PI 256066, PI 652253, PI 652402, and PI 652405 from Turkey were most salt-tolerant.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Md. Amirul Alam ◽  
Abdul Shukor Juraimi ◽  
M. Y. Rafii ◽  
Azizah Abdul Hamid ◽  
Farzad Aslani

Purslane (Portulaca oleraceaL.) is an herbaceous leafy vegetable crop, comparatively more salt-tolerant than any other vegetables with high antioxidants, minerals, and vitamins. Salt-tolerant crop variety development is of importance due to inadequate cultivable land and escalating salinity together with population pressure. In this view a total of 25 purslane accessions were initially selected from 45 collected purslane accessions based on better growth performance and subjected to 5 different salinity levels, that is, 0.0, 10.0, 20.0, 30.0, and 40.0 dS m−1NaCl. Plant height, number of leaves, number of flowers, and dry matter contents in salt treated purslane accessions were significantly reduced (P≤0.05) and the enormity of reduction increased with increasing salinity stress. Based on dry matter yield reduction, among all 25 purslane accessions 2 accessions were graded as tolerant (Ac7 and Ac9), 6 accessions were moderately tolerant (Ac3, Ac5, Ac6, Ac10, Ac11, and Ac12), 5 accessions were moderately susceptible (Ac1, Ac2, Ac4, Ac8, and Ac13), and the remaining 12 accessions were susceptible to salinity stress and discarded from further study. The selected 13 purslane accessions could assist in the identification of superior genes for salt tolerance in purslane for improving its productivity and sustainable agricultural production.


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.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Dezong Sui ◽  
Baosong Wang

Salinity stress is one of the most devastating abiotic stresses limiting plant growth and productivity. As a moderately salt-tolerant crop, shrub willow (Salix spp.) is widely distributed over the world and can provide multiple bioenergy product and environmental benefits. To delve into the salt tolerance mechanism and screen out salt-tolerant genes, two shrub willow cultivars (a salt-sensitive genotype JW9-6 and a salt-tolerant genotype JW2372) at three time points (0, 2, and 12 h) after NaCl treatments were used for RNA sequencing. A comparative analysis between genotypes and time points showed 1,706 differentially expressed genes (DEGs), of which 1,029 and 431 DEGs were only found in the JW9-6 and JW2372, respectively. Gene Ontology (GO) and MapMan annotations suggested that many DEGs were involved in various defense-related biological pathways, including cell wall integrity, hormone signaling, antioxidant system, heat shock proteins, and transcription factors. Compared to JW9-6, JW2372 contained more DEGs involved in the maintenance of the cell wall integrity, ABA, and ethylene signal transduction pathways. In addition, more DEGs encoding heat shock proteins were found in JW2372. Instead, transcription factors including ERF, MYB, NAC, and WRKY were found to be more differentially expressed in JW9-6 under salinity stress. Furthermore, expressions of nine randomly selected DEGs were verified by qRT-PCR analysis. This study contributes in new perspicacity into underlying the salt tolerance mechanism of a shrub willow at the transcriptome level and also provides numerous salt-tolerant genes for further genetic engineering and breeding purposes in the future.


Author(s):  
Rinny Swain ◽  
Surabhika Panda ◽  
Gyana Ranjan Rout

Silicon (Si) is known to improve salt tolerance in rice. However, the correlation of silicon with different physiological and biochemical indices of salt tolerance is not properly understood. Two rice genotypes with different silicon accumulation ability were evaluated along with two standard checks in response to 10 dS/m salinity stress (NaCl) and external Si source (1mM) during their seedling stage. All evaluated genotypes showed an evident decrease in biomass and chlorophyll content under salinity stress, while reporting an enhances in Si accumulation, Na+/K+ ratio, proline, electrolyte leakage, lipid peroxidation, hydrogen peroxide, and antioxidant activities. The external Si supplementation significantly improved rice tolerance to salinity through increased Si content, low Na+/K+ ratio, better osmolyte production, reduced membrane permeability, and improved antioxidant enzyme activities. Multivariate factor analysis with principal component factor statistically correlates and visualizes silicon accumulation with salt tolerance indices. The Hierarchical clustering in rice obtained based on the study of salt tolerance indices, distinguishes genotypes with different treatments into three clusters. In conclusion, the clustering grouped salt-tolerant Var.Lunishree and salt stress high silicon accumulating Var.Swarna together validates silicon mitigating effect on salinity in rice.


2013 ◽  
Vol 19 (2) ◽  
pp. 57-65
Author(s):  
MH Kabir ◽  
MM Islam ◽  
SN Begum ◽  
AC Manidas

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


HortScience ◽  
1997 ◽  
Vol 32 (2) ◽  
pp. 296-300 ◽  
Author(s):  
M.R. Foolad ◽  
G.Y. Lin

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.


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