scholarly journals Improvement in Salinity Tolerance in Rice Using Biotechnology

2021 ◽  
Vol 9 (11) ◽  
pp. 551-560
Author(s):  
Ankita Roy
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Rice Crop ◽  
Cereal Crop ◽  
Rice Varieties ◽  
The Past ◽  
The Future ◽  
Staple Diet ◽  
Held Back

Abstract: Rice has been amongst the most important cereal crop on earth, or more correctly the second most staple diet of people after wheat. The statement is self-explanatory to the demand of rice worldwide and the supply. But with increasing population, the demand of rice is also undoubtedly increasing. The increase in supply is though held back by many factors that adversely affect the growth of a healthy rice crop. One of these factors is salinity. Rice being a glycophyte has very low tolerance to salt, and salt stress results in a damaged yield. However, rice has its own mechanisms for salt tolerance to a certain level, the knowledge of which scientists have put in use to develop the few improvements in rice varieties providing them with better tolerance. Though these improvements have faced many challenges themselves, science still strives to make further achievements. This study aims to highlight the mechanisms rice use to tolerate salt up to a certain level and how they are affected by salinity at levels above that. It also aims to enumerate the methods biotechnology has developed in the past years to improve the varieties, the advantages they have had, the increase in yield they have shown and the challenges they have had to face. Also, it includes if there are any further developments undergoing and the future scope of salinity tolerance increase in rice, with the help of biotechnology.

Matching physiological traits and ion concentrations associated with salt stress in cowpea genotypes

2002 ◽  
Vol 53 (11) ◽  
pp. 1243 ◽  
Author(s):  
Bernardo Murillo-Amadot ◽  
Enrique Troyo-Diéguez ◽  
Raúl López-Aguilar ◽  
Alejandro López-Cortés ◽  
Clara L. Tinoco-Ojanguri ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Growth Stage ◽  
Seedling Survival ◽  
Nutrient Deficiency ◽  
Chloride Concentration ◽  
Sodium Concentration ◽  
Ion Concentrations ◽  
Survival Percentage

The salt tolerance of 25 cowpea genotypes (Vigna unguiculata L. Walp.) was studied during early vegetative growth. Salinity treatments were applied by irrigating with a nutrient solution containing 0, 85, and 170 mmol NaCl/L. Seedling survival decreased linearly as salinity increased, but this enabled cowpea genotypes to be ranked for salinity tolerance according to the magnitudes of slopes of regression of survival percentage on salinity. Sodium concentration was higher in roots than in shoots in all genotypes, and increased significantly in both roots and shoots as salinity increased. Chloride concentration in both roots and shoots increased with increasing salinity in all genotypes, and was higher in shoots than in roots at 85 and 170 mmol NaCl/L. In some cases, Ca, Mg, K, and P concentrations were reduced by an increase in salinity, but none of the genotypes appeared to suffer any nutrient deficiency. We observed wide differences in responses to salinity, and our results suggest that during the growth stage studied, 7 of the 25 genotppes tested could be classified as tolerant or relatively tolerant to salinity (Sonorense, CB3, CB27, Cuarenteño, CB46, Paceño, and IT82D-889).

scholarly journals Physiological and Biochemical Responses to Salt Stress of Alfalfa Populations Selected for Salinity Tolerance and Grown in Symbiosis with Salt-Tolerant Rhizobium

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 569
Author(s):  
Annick Bertrand ◽  
Craig Gatzke ◽  
Marie Bipfubusa ◽  
Vicky Lévesque ◽  
Francois P. Chalifour ◽  
...  
Keyword(s):  
Amino Acids ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Water Content ◽  
Salinity Tolerance ◽  
Osmotic Adjustment ◽  
Recurrent Selection ◽  
Aromatic Amino Acids ◽  
Nacl Stress ◽  
Salt Tolerant

Alfalfa and its rhizobial symbiont are sensitive to salinity. We compared the physiological responses of alfalfa populations inoculated with a salt-tolerant rhizobium strain, exposed to five NaCl concentrations (0, 20, 40, 80, or 160 mM NaCl). Two initial cultivars, Halo (H-TS0) and Bridgeview (B-TS0), and two populations obtained after three cycles of recurrent selection for salt tolerance (H-TS3 and B-TS3) were compared. Biomass, relative water content, carbohydrates, and amino acids concentrations in leaves and nodules were measured. The higher yield of TS3-populations than initial cultivars under salt stress showed the effectiveness of our selection method to improve salinity tolerance. Higher relative root water content in TS3 populations suggests that root osmotic adjustment is one of the mechanisms of salt tolerance. Higher concentrations of sucrose, pinitol, and amino acid in leaves and nodules under salt stress contributed to the osmotic adjustment in alfalfa. Cultivars differed in their response to recurrent selection: under a 160 mM NaCl-stress, aromatic amino acids and branched-chain amino acids (BCAAs) increased in nodules of B-ST3 as compared with B-TS0, while these accumulations were not observed in H-TS3. BCAAs are known to control bacteroid development and their accumulation under severe stress could have contributed to the high nodulation of B-TS3.

scholarly journals QTLs for seedling traits under salinity stress in hexaploid wheat

2018 ◽  
Vol 48 (3) ◽  
Author(s):  
Yongzhe Ren ◽  
Yanhua Xu ◽  
Wan Teng ◽  
Bin Li ◽  
Tongbao Lin
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Hexaploid Wheat ◽  
Dry Weight ◽  
Interval Mapping ◽  
Mapping Method ◽  
Stress Conditions ◽  
Wheat Varieties ◽  
Seedling Traits

ABSTRACT: Soil salinity limits agricultural production and is a major obstacle for increasing crop yield. Common wheat is one of the most important crops with allohexaploid characteristic and a highly complex genome. QTL mapping is a useful way to identify genes for quantitative traits such as salinity tolerance in hexaploid wheat. In the present study, a hydroponic trial was carried out to identify quantitative trait loci (QTLs) associated with salinity tolerance of wheat under 150mM NaCl concentration using a recombinant inbred line population (Xiaoyan 54×Jing 411). Values of wheat seedling traits including maximum root length (MRL), root dry weight (RDW), shoot dry weight (SDW), total dry weight (TDW) and the ratio of TDW of wheat plants between salt stress and control (TDWR) were evaluated or calculated. A total of 19QTLs for five traits were detected through composite interval mapping method by using QTL Cartographer version 2.5 under normal and salt stress conditions. These QTLs distributed on 12 chromosomes explained the percentage of phenotypic variation by individual QTL varying from 7.9% to 19.0%. Among them, 11 and six QTLs were detected under normal and salt stress conditions, respectively and two QTLs were detected for TDWR. Some salt tolerance related loci may be pleiotropic. Chromosome 1A, 3A and 7A may harbor crucial candidate genes associated with wheat salt tolerance. Our results would be helpful for the marker assisted selection to breed wheat varieties with improved salt tolerance.

scholarly journals QTL mapping and candidate gene identification in rice using a Kalarata-Azucena population under salt stress

2020 ◽  
Author(s):  
Marjorie P. de Ocampo ◽  
Ho Viet The ◽  
Michael J. Thomson ◽  
Shiro Mitsuya ◽  
Akira Yamauchi ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Candidate Gene ◽  
Candidate Genes ◽  
Evaluation System ◽  
Average Distance ◽  
Chlorophyll Concentration ◽  
Interval Mapping ◽  
Chromosome 1 ◽  
Rice Varieties

Abstract Background Salt stress is a major constraint across large rice production areas in Asia, because of the high sensitivity of modern rice varieties. To identify quantitative trait loci (QTL) associated with salt tolerance in rice, we developed an F2 population from a cross between the salt-tolerant landrace, Kalarata, and the salt-sensitive parent, Azucena. An F2 population was used for DNA extraction, and F2:3 families from this population were screened in a phytotron in a saline nutrient solution at the seedling stage. Results After 2 weeks at an EC of 12 dS m− 1, the F2:3 families were scored for salt tolerance using IRRI’s Standard evaluation system (SES). Growth, biomass, Na+ and K+ concentrations in leaf tissues, and chlorophyll concentration were determined. A genetic linkage map was constructed with 151 SSRs and InDel markers, which cover 1463 cM with an average distance of 9.69 cM between loci. A total of 13 QTL were identified using Composite Interval Mapping for 16 traits. The short arm of chromosome 1 had the highest density of QTL associated with salt tolerance, which coincides with the Saltol locus; emphasizing the importance of this locus for candidate gene discovery and for use in rice breeding. Several novel QTL were identified on other chromosomes. Conclusions The novel QTL identified in this study constitute future targets for molecular breeding, to combine them with other QTLs identified before, for higher and stable performance of rice varieties in salt affected soils. Candidate genes for the large effect QTL on chromosome 3 were found to be involved in diverse biological processes, cellular components, and molecular functions. Several candidate genes in this locus were functionally associated with salt stress tolerance and should further be considered for genetic improvement of rice varieties.

scholarly journals Effect of salt stress on physiological response and leaf polyamine content in NERICA rice seedlings

2011 ◽  
Vol 57 (No. 12) ◽  
pp. 571-576 ◽  
Author(s):  
A. Yamamoto ◽  
H. Sawada ◽  
I.S. Shim ◽  
K. Usui ◽  
S. Fujihara
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Rice Variety ◽  
West African ◽  
Rice Seedlings ◽  
Rice Varieties ◽  
Stress Injury ◽  
African Rice ◽  
Polyamine Content ◽  
Vigorous Growth

NERICA is a new African rice variety, developed by the West African Rice Development Association (WARDA) in 1990s. NERICA rice shows both vigorous growth and tolerance of stressors such as drought and disease. The purpose of this study was to clarify the physiological and biochemical responses to salt stress of NERICA rice seedlings. The degree of growth inhibition caused by salt stress was small in NERICA rice varieties as compared with japonica Nipponbare. Na accumulation in leaf blades was high in salt-sensitive varieties. Accumulation of proline, a known compatible solute, was also induced by salt stress, especially in salt-sensitive varieties; it was thought that this accumulation was brought on salt-stress injury. The contents of polyamines, especially spermidine, were high in the pre-stressed leaf blades of NERICA rice seedlings. After the salt-stress treatment, the polyamine content of leaf blades differed with the degree of salt tolerance of the NERICA rice seedlings. These results suggested that the salt tolerance of NERICA rice seedlings might be associated not only with the regulation of Na absorption and translocation but also with their ability to maintain leaf polyamine levels under salt-stress conditions.  

scholarly journals Genomic and transcriptomic analysis reveal molecular basis of salinity tolerance in a novel strong salt-tolerant rice landrace Changmaogu

Rice ◽  
2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Bing-Rui Sun ◽  
Chong-Yun Fu ◽  
Zhi-Lan Fan ◽  
Yu Chen ◽  
Wen-Feng Chen ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Molecular Basis ◽  
Carotenoid Biosynthesis ◽  
Seedling Stage ◽  
Differentially Expressed ◽  
Salt Tolerant ◽  
Transcriptomic Sequencing ◽  
Rice Landrace

Abstract Background Salt stress is an important factor that limits rice yield. We identified a novel, strongly salt tolerant rice landrace called Changmaogu (CMG) collected from a coastal beach of Zhanjiang, Guangdong Province, China. The salt tolerance of CMG was much better than that of the international recognized salt tolerant rice cultivar Pokkali in the germination and seedling stages. Results To understand the molecular basis of salt tolerance in CMG, we performed BSA-seq for two extreme bulks derived from the cross between CMG and a cultivar sensitive to salt, Zhefu802. Transcriptomic sequencing was conducted for CMG at the germination and young seedling stages. Six candidate regions for salt tolerance were mapped on Chromosome 1 by BSA-seq using the extreme populations. Based on the polymorphisms identified between both parents, we detected 32 genes containing nonsynonymous coding single nucleotide polymorphisms (SNPs) and frameshift mutations in the open reading frame (ORF) regions. With transcriptomic sequencing, we detected a large number of differentially expressed genes (DEGs) at the germination and seedling stages under salt stress. KEGG analysis indicated two of 69 DEGs shared at the germination and seedling stages were significantly enriched in the pathway of carotenoid biosynthesis. Of the 169 overlapping DEGs among three sample points at the seedling stage, 13 and six DEGs were clustered into the pathways of ABA signal transduction and carotenoid biosynthesis, respectively. Of the 32 genes carrying sequence variation, only OsPP2C8 (Os01g0656200) was differentially expressed in the young seedling stage under salt stress and also showed sequence polymorphism in the ORFs between CMG and Zhefu802. Conclusion OsPP2C8 was identified as the target candidate gene for salinity tolerance in the seedling stage. This provides an important genetic resource for the breeding of novel salt tolerant rice cultivars.

scholarly journals AtCIPK16 Mediates Salt Stress Through Phytohormones and Transcription Factors

2020 ◽  
Author(s):  
Shanika L. Amarasinghe ◽  
Wenmian Huang ◽  
Nathan S. Watson-Haigh ◽  
Matthew Gilliham ◽  
Stuart J. Roy ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Food Production ◽  
Rna Seq ◽  
Productivity Losses ◽  
Global Food

AbstractSoil salinity causes large productivity losses for agriculture worldwide. “Next-generation crops” that can tolerate salt stress are required for the sustainability of global food production. Previous research in Arabidopsis thaliana aimed at uncovering novel factors underpinning improved plant salinity tolerance identified the protein kinase AtCIPK16. Overexpression of AtCIPK16 enhanced shoot Na+ exclusion and increased biomass in both Arabidopsis and barley. Here, a comparative transcriptomic study on Arabidopsis lines expressing AtCIPK16 was conducted in the presence and absence of salt stress, using an RNA-Seq approach, complemented by AtCIPK16 interaction and localisation studies. We are now able to provide evidence for AtCIPK16 activity in the nucleus. Moreover, the results manifest the involvement of a transcription factor, AtTZF1, phytohormones and the ability to quickly reach homeostasis as components important for improving salinity tolerance in transgenics overexpressing AtCIPK16. Furthermore, we suggest the possibility of both biotic and abiotic tolerance through AtCIPK16, and propose a model for the salt tolerance pathway elicited through AtCIPK16.

scholarly journals Insights into the Physiological and Biochemical Impacts of Salt Stress on Plant Growth and Development

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 938 ◽  
Author(s):  
Muhammad Adnan Shahid ◽  
Ali Sarkhosh ◽  
Naeem Khan ◽  
Rashad Mukhtar Balal ◽  
Shahid Ali ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Salinity Tolerance ◽  
Antioxidant Activities ◽  
Soil Salinization ◽  
Crop Plants ◽  
Cellular Damage ◽  
Relative Water ◽  
Ionic Imbalance ◽  
Highly Correlated

Climate change is causing soil salinization, resulting in crop losses throughout the world. The ability of plants to tolerate salt stress is determined by multiple biochemical and molecular pathways. Here we discuss physiological, biochemical, and cellular modulations in plants in response to salt stress. Knowledge of these modulations can assist in assessing salt tolerance potential and the mechanisms underlying salinity tolerance in plants. Salinity-induced cellular damage is highly correlated with generation of reactive oxygen species, ionic imbalance, osmotic damage, and reduced relative water content. Accelerated antioxidant activities and osmotic adjustment by the formation of organic and inorganic osmolytes are significant and effective salinity tolerance mechanisms for crop plants. In addition, polyamines improve salt tolerance by regulating various physiological mechanisms, including rhizogenesis, somatic embryogenesis, maintenance of cell pH, and ionic homeostasis. This research project focuses on three strategies to augment salinity tolerance capacity in agricultural crops: salinity-induced alterations in signaling pathways; signaling of phytohormones, ion channels, and biosensors; and expression of ion transporter genes in crop plants (especially in comparison to halophytes).

scholarly journals Regulation of enzymatic and non-enzymatic antioxidants contributes to salt tolerance in hitherto unknown upland farmer rice varieties.

2020 ◽  
pp. 18-27
Author(s):  
Lins Simon ◽  
Yusuf Akkara
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Stability Index ◽  
Monodehydroascorbate Reductase ◽  
Enzymatic Antioxidants ◽  
Salt Tolerant ◽  
Sod Activity ◽  
Rice Varieties ◽  
Pronounced Increase ◽  
Nacl Concentration

Salt tolerance potential of the three upland farmer varieties, koduvelliyan, mullankayama and marathondi was evaluated by comparing with the released salt-tolerant pokkali variety, vytilla-2. The salt tolerance exhibited by the upland varieties was identical with the salt tolerant variety. The superoxide (O2-) content in the upland varieties was lower; however, the hydrogen peroxide (H2O2) content increased with the salt concentration. The lesser malondialdehyde (MDA) content in the koduvelliyan variety was equivalent to the vytilla-2 and slight increase was observed in mullankayama and marathondi. The ascorbate (AsA) content in the upland varieties was comparable to vytilla-2 and upon exposure to increased concentration of NaCl, the AsA level reduced in all the treatments. Reduced glutathione (GSH) content was uniform in all the varieties up to a concentration of 100mM NaCl, however, in 125-150mM NaCl, mullankayama showed a pronounced increase in GSH content. Under salt stress, due to the formation of O2-, the oxidation of GSH was higher, maintaining a stable GSH/GSSG ratio. Superoxide dismutase (SOD) and catalase (CAT) activity of the upland varieties was higher than vytilla-2 up to 100mM NaCl, however, in 125-150mM NaCl the SOD activity increased slightly and the CAT activity decreased. Ascorbate peroxidase (APX) activity increased in upland varieties up to 125mM NaCl, and in 150mM NaCl, maintained a steady level in all the varieties. Glutathione reductase (GR) activity increased proportionate with NaCl concentration; with highest activity in all the upland varieties. Monodehydroascorbate reductase (MDHAR) activity was uniform in all the varieties up to 100mM NaCl, however, in 125 and 150mM NaCl, vytilla-2 showed higher MDHAR activity. Dehydroascorbate reductase (DHAR) activity was lesser in upland varieties under salt stress compared to vytilla-2. The GSH/GSSG ratio decreased in marathondi and koduvelliyan varieties with the increase in NaCl concentration, however, in mullankayama and vytilla-2, the GSH/GSSG ratio was higher. The membrane stability index of all the varieties was uniform in all the concentrations of NaCl used, except marathondi. The Na+ content in all the varieties increased in relation to NaCl concentration and the K+ efflux was higher suggesting a higher Na+/K+ ratio, with increased NaCl concentration.

scholarly journals Improvement of a RD6 Rice Variety for Blast Resistance and Salt Tolerance through Marker-Assisted Backcrossing

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1118 ◽  
Author(s):  
Korachan Thanasilungura ◽  
Sukanya Kranto ◽  
Tidarat Monkham ◽  
Sompong Chankaew ◽  
Jirawat Sanitchon
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Agronomic Traits ◽  
Blast Resistance ◽  
Rice Variety ◽  
Gene Pyramiding ◽  
Blast Disease ◽  
Resistance Qtls ◽  
Rice Varieties ◽  
Marker Assisted Backcrossing

RD6 is one of the most favorable glutinous rice varieties consumed throughout the north and northeast of Thailand because of its aroma and softness. However, blast disease and salt stress cause decreases in both yield quantity and quality during cultivation. Here, gene pyramiding via marker-assisted backcrossing (MAB) using combined blast resistance QTLs (qBl 1, 2, 11, and 12) and Saltol QTL was employed in solving the problem. To pursue our goal, the RD6 introgression line (RGD07005-12-165-1), containing four blast-resistant QTLs, were crossed with the Pokkali salt tolerant variety. Blast resistance evaluation was thoroughly carried out in the fields, from BC2F2:3 to BC4F4, using the upland short-row and natural field infection methods. Additionally, salt tolerance was validated in both greenhouse and field conditions. We found that the RD6 “BC4F4 132-12-61” resulting from our breeding programme successfully resisted blast disease and tolerated salt stress, while it maintained the desirable agronomic traits of the original RD6 variety. This finding may provide a new improved rice variety to overcome blast disease and salt stress in Northeast Thailand.

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