Ecotoxicology of salinity tolerance in Daphnia pulex: interactive effects of clonal variation, salinity stress and predation

Abstract Background: Environmental stress is a crucial factor restricting plant growth as well as crop productivity, thus influencing the agricultural sustainability. Biochar addition is proposed as an effective management to improve crop performance. However, there were few studies focused on the effect of biochar addition on crop growth and productivity under interactive effect of abiotic stress (e.g., drought and salinity). This study was conducted with a pot experiment to investigate the interaction effects of drought and salinity stress on soybean yield, leaf gaseous exchange and water use efficiency (WUE) under biochar addition. Results: Drought and salinity stress significantly depressed soybean phenology (e.g. flowering time) and all the leaf gas exchange parameters, but had inconsistent effects on soybean root growth and WUE at leaf and yield levels. Salinity stress significantly decreased photosynthetic rate, stomatal conductance, intercellular CO2 concentration and transpiration rate by 20.7%, 26.3%, 10.5% and 27.2%, respectively. Lower biomass production and grain yield were probably due to the restrained photosynthesis under drought and salinity stress. Biochar addition significantly enhanced soybean grain yield by 3.1-14.8%. Drought stress and biochar addition significantly increased WUE-yield by 27.5% and 15.6%, respectively, while salinity stress significantly decreased WUE-yield by 24.2%. Drought and salinity stress showed some negative interactions on soybean productivity and leaf gaseous exchange. But biochar addition alleviate the negative effects on soybean productivity and water use efficiency under drought and salinity stress. Conclusions: The results of the present study indicated that drought and salinity stress could significantly depress soybean growth and productivity. There exist interactive effects of drought and salinity stress on soybean productivity and water use efficiency, while we could employ biochar to alleviate the negative effects. We should consider the interactive effects of different abiotic restriction factors on crop growth thus for sustainable agriculture in the future.

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The Tolerance of Salinity in Rice Requires the Presence of a Functional Copy of FLN2

Biomolecules ◽

10.3390/biom10010017 ◽

2019 ◽

Vol 10 (1) ◽

pp. 17 ◽

Cited By ~ 1

Author(s):

Guang Chen ◽

Jiang Hu ◽

Liuliu Dong ◽

Dali Zeng ◽

Longbiao Guo ◽

...

Keyword(s):

Salinity Stress ◽

Salinity Tolerance ◽

Sugar Metabolism ◽

Invertase Activity ◽

Leaf Sheath ◽

Japonica Rice ◽

Wild Type ◽

Bisphosphate Carboxylase ◽

Genes Encoding ◽

Knockout Line

A panel of ethane-methyl-sulfonate-mutagenized japonica rice lines was grown in the presence of salinity in order to identify genes required for the expression of salinity tolerance. A highly nontolerant selection proved to harbor a mutation in FLN2, a gene which encodes fructokinase-like protein2. Exposure of wild-type rice to salinity up-regulated FLN2, while a CRISPR/Cas9-generated FLN2 knockout line was hypersensitive to the stress. Both ribulose 1,5-bisphosphate carboxylase/oxygenase activity and the abundance of the transcript generated by a number of genes encoding components of sucrose synthesis were lower in the knockout line than in wild-type plants’ leaves, while the sucrose contents of the leaf and root were, respectively, markedly increased and decreased. That sugar partitioning to the roots was impaired in FLN2 knockout plants was confirmed by the observation that several genes involved in carbon transport were down-regulated in both the leaf and in the leaf sheath. The levels of sucrose synthase, acid invertase, and neutral invertase activity were distinctly lower in the knockout plants’ roots than in those of wild-type plants, particularly when the plants were exposed to salinity stress. The compromised salinity tolerance exhibited by the FLN2 knockout plants was likely a consequence of an inadequate supply of the assimilate required to support growth, a problem which was rectifiable by providing an exogenous supply of sucrose. The conclusion was that FLN2, on account of its influence over sugar metabolism, is important in the context of seedling growth and the rice plant’s response to salinity stress.

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The evolution of Daphnia pulex in a temporally varying environment

Genetics Research ◽

10.1017/s0016672398003322 ◽

1998 ◽

Vol 72 (1) ◽

pp. 25-37 ◽

Cited By ~ 43

Author(s):

SAMUEL M. SCHEINER ◽

LEV Yu YAMPOLSKY

Keyword(s):

Genetic Variation ◽

Temperature Change ◽

Local Population ◽

Daphnia Pulex ◽

Selection Response ◽

Clonal Variation ◽

Offspring Size ◽

Malthusian Parameter ◽

Offspring Number ◽

Variable Environments

We investigated three aspects of adaptation to variable environments in Daphnia pulex (Cladocera: Crustacea): (1) effects of temporal variation on the evolution of phenotypic plasticity ; (2) plasticity in sexual versus asexual lineages; (3) maintenance of genetic variation in variable environments. We performed a 72-day quasi-natural selection experiment comparing three patterns of variation: constant temperatures, varying but predictable temperature change, and unpredictable temperature change. All populations were begun with an identical array of 34 clones. During selection clonal variation declined in all populations and different patterns of environmental variation had little effect on amounts of genetic variation. Sexual and asexual lineages differed in size and growth rate, but did not differ in amounts of plasticity or in adaptation to variable environments. The primary target of selection was the Malthusian parameter (r) and life history traits of development time, offspring size and offspring number. The heritability of plasticity was generally lower than trait heritability. Because of this difference, the selection response on the mean of the traits overwhelmed the selection response on plasticity. Lower heritabilities of plasticity are very typical, suggesting that our results will be typical of responses to selection in nature. Our results suggest that selection will act mostly on trait means within environments and that plasticity will evolve often as a correlated trait. Because selection on plasticity is based on its across-deme, global fitness, this process will usually be slow. Comparative studies need to shift from closely related, local population differences to those of more distantly related populations or even different species.

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Screening of jute and kenaf varieties for salinity tolerance

International Journal of Advanced Geosciences ◽

10.14419/ijag.v6i2.13773 ◽

2018 ◽

Vol 6 (2) ◽

pp. 214

Author(s):

Md. Isfatuzzaman Bhuyan ◽

K M. Mehadi Hassan ◽

Nowrose Jahan Lipi ◽

Md Rafiq Uddin ◽

Md Monirul Islam ◽

...

Keyword(s):

Plant Height ◽

Salinity Stress ◽

Salinity Tolerance ◽

Dry Weight ◽

Germination Inhibition ◽

Germination Test ◽

Salinity Levels ◽

Total Plant ◽

Number Of Leaves ◽

Total Dry Weight

A study was conducted in the Department of Agronomy, Bangladesh Agricultural University (BAU), Mymensingh from April to August 2012 to examine the salinity tolerance of eight jute varieties (CVE-3, C-83, CVL-1, BJC-7370, O-795, O-9897, OM-1, O-72) and two kenaf varieties (HC-95 and HC-2). Initially germination of these varieties were evaluated under six salinity levels viz. 0mM, 20mM, 40mM, 60mM, 80mM, and 100mM NaCl in the seed laboratory of the Department of Agronomy. Afterwards, all the varieties was grown in pots in the net house under four salinity levels viz. 0mM, 25mM, 50mM, and 75mM. The results from the germination study revealed that under control condition (0mM NaCl) all the jute varieties showed germination more than 80% both at 7 and at 14 days after seed sowing, whereas kenaf varieties had germination a little less than 80%. Among the jute varieties, O-72 showed the highest germination (92%), which was statistically similar with those of OM-1(91%), O-795 (90%), and C-83(87%). Salinity stress decreased germination drastically in all of the jute and kenaf varieties. A salinity level of 100mM caused the highest germination inhibition (74.70%) in jute variety CVL-1, which was very close to those of BJC-7370 and O-72. On the other hand, the lowest germination inhibition (51.11%) was recorded in jute variety O-795. The results of the pot trail showed that the plant characters of jute and kenaf varieties were affected significantly by salinity stress. All the varieties produced their respective plant height, number of leaves per plant, and plant dry weight under control condition (no salinity). Among these varieties, CVE-3 produced the highest plant height (145.2cm), and total dry weight (22.55g), whereas O-72 produced the highest number of leaves per plant (24.67). All these plant characters decreased sharply due to salinity stress irrespective of variety. However, the rate of decrease of plant characters occurred differentially in the jute and kenaf varieties. The highest rate of decrease in number of leaves (74.22%) was found from the variety CVE-3, whereas the lowest one was recorded from the variety HC-2 (51.68%). Salinity stress caused the highest decrease in total plant dry weight (73.68%) in the variety CVL-1 and plant height (73.64%) also in the variety CVL-1. On the contrary, the lowest decrease in plant dry weight (50.99%) was found in the variety O-9897 and plant height also in variety O-9897 (50.88%). Based on the results from germination test and pot trail, it can be inferred that jute variety O-9897 appeared to be the most salt tolerant followed by O-795, HC-2, HC-95, CVE-3, O-72, C-83, BJC-7370, OM-1, and CVL-1.

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Determining the main and interactive effect of age and clone on wood density, microfibril angle, and modulus of elasticity for Pinus radiata

Canadian Journal of Forest Research ◽

10.1139/x10-095 ◽

2010 ◽

Vol 40 (8) ◽

pp. 1550-1557 ◽

Cited By ~ 12

Author(s):

Michael S. Watt ◽

Charles Sorensson ◽

Dave J. Cown ◽

Heidi S. Dungey ◽

Robert Evans

Keyword(s):

Pinus Radiata ◽

Modulus Of Elasticity ◽

Interactive Effect ◽

Microfibril Angle ◽

Wood Properties ◽

Radiata Pine ◽

Linear Increase ◽

Interactive Effects ◽

Tree Age ◽

Clonal Variation

Detailed radial measurements of wood properties, taken at breast height, were obtained from control pollinated seedlings and a selection of 13 year old radiata pine ( Pinus radiata D. Don) clones. Using these data the key objectives of this study were to determine (i) the magnitude of mean clonal variation in modulus of elasticity (MOE) and properties affecting MOE (density and microfibril angle (MFA)) and (ii) whether there is a significant age × clone interaction for these traits. All wood properties were significantly affected by the main and interactive effects of age and clone. There was a relatively linear increase in both MOE and density with tree age, while MFA declined linearly with tree age. Values of density and MOE diverged between the clonal extremes from age 3 to age 12. After diverging markedly up to age 6, differences in MFA between clonal extremes remained relatively constant to age 12. At age 12, values for density, MFA, and MOE varied between clonal extremes by, respectively, 194 kg·m–3 (465–659 kg·m–3), 11.3° (9.6–20.9°), and 11.2 GPa (10.4–21.6 GPa). The seedling material had a relatively intermediate ranking, across the age range, for all traits considered.

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Identification and Characterization of Chromosome Regions Associated With Salinity Tolerance in Rice

Journal of Agricultural Science ◽

10.5539/jas.v10n11p57 ◽

2018 ◽

Vol 10 (11) ◽

pp. 57

Author(s):

Nguyen Thi Thu Thuy ◽

Misato Tokuyasu ◽

Nguyen Sao Mai ◽

Yoshihiko Hirai

Keyword(s):

Plant Growth ◽

Salinity Stress ◽

Salinity Tolerance ◽

World Population ◽

Chromosome 2 ◽

Substitution Lines ◽

Chromosome Segment Substitution Lines ◽

Panicle Number ◽

Segment Substitution

Rice, the major crop sustaining approximately half the world population, has been extensively reported to be sensitive to saline conditions. However, the genetic and physiological understanding related to long-term salinity stress remains unclear so far. The aim of this study was to evaluate the mechanisms of salinity tolerance in a salinity-tolerant variety of rice, Nona Bokra, and to detect the chromosomal regions responsible for it. We utilized chromosome segment substitution lines (CSSLs) carrying segments from Nona Bokra in the genetic background of a salt-sensitive variety Koshihikari by investigating the plant growth, grain productivity, and ion contents in plants subjected to long-term salinity stress. Comparison of plant growth and grain yield of CSSLs grown under long-term saline conditions suggests that the salinity tolerance of Nona Bokra involves the improvement of plant dry matter, panicle number, and percentage of ripened grains. Nona Bokra has the chromosomal regions for the improvement of the panicle number on chromosome 2 and the percentage of ripened grains on chromosome 6 or 10 under salinity conditions. It was suggested that these chromosomal regions were related to Na+ and Cl- exclusion. Low Na+ and Cl- contents in whole plant at full heading stage would be vital for improving the yield under long-term saline conditions.

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Comparative Phenotypic and Transcriptomic Analysis Reveals Key Responses of Upland Cotton to Salinity Stress During Postgermination

Frontiers in Plant Science ◽

10.3389/fpls.2021.639104 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jingxia Zhang ◽

Pei Zhang ◽

Xuehan Huo ◽

Yang Gao ◽

Yu Chen ◽

...

Keyword(s):

Salinity Stress ◽

Salinity Tolerance ◽

Molecular Mechanisms ◽

Germination Rate ◽

Primary Root ◽

Carotenoid Biosynthesis ◽

Mapk Signaling ◽

Ethylene Response Factor ◽

Sod Activity ◽

As Stress

To understand the molecular mechanisms of salinity tolerance during seed germination and post-germination stages, this study characterized phenotypic and transcriptome responses of two cotton cultivars during salinity stress. The two cultivars were salt-tolerant (ST) LMY37 and salt-sensitive (SS) ZM12, with the former exhibiting higher germination rate, growth, and primary-root fresh weight under salinity stress. Transcriptomic comparison revealed that up-regulation of differentially expressed genes (DEGs) was the main characteristic of transcriptional regulation in ST, while SS DEGs were mainly down-regulated. GO and KEGG analyses uncovered both common and specific responses in ST and SS. Common processes, such as reactive oxygen species (ROS) metabolism and cell wall biosynthesis, may be general responses to salinity in cotton. In contrast, DEGs involved in MAPK-signaling pathway activated by ROS, carotenoid biosynthesis pathway and cysteine and methionine metabolism pathway [producing the precursors of stress hormone abscisic acid (ABA) and ethylene (ET), respectively] as well as stress tolerance related transcription factor genes, showed significant expression differences between ST and SS. These differences might be the molecular basis leading to contrasting salinity tolerance. Silencing of GhERF12, an ethylene response factor gene, caused higher salinity sensitivity and increased ROS accumulation after salinity stress. In addition, peroxidase (POD) and superoxide dismutase (SOD) activity obviously declined after silencing GhERF12. These results suggest that GhERF12 is involved in salinity tolerance during early development. This study provides a novel and comprehensive perspective to understand key mechanisms of salinity tolerance and explores candidate genes that may be useful in developing stress-tolerant crops through biotechnology.

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Advanced Breeding Strategies and Future Perspectives of Salinity Tolerance in Rice

Agronomy ◽

10.3390/agronomy11081631 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1631

Author(s):

Md Azadul Haque ◽

Mohd Y. Rafii ◽

Martini Mohammad Yusoff ◽

Nusaibah Syd Ali ◽

Oladosu Yusuff ◽

...

Keyword(s):

Genome Editing ◽

Salinity Stress ◽

Salinity Tolerance ◽

High Salinity ◽

Abiotic Factors ◽

Rice Production ◽

Salt Tolerant ◽

Rice Varieties ◽

Rice Plants ◽

Breeding Techniques

Rice, generally classified as a typical glycophyte, often faces abiotic stresses such as excessive drought, high salinity, prolonged submergence, cold, and temperature, which significantly affects growth, development, and ultimately, grain yield. Among these negative impacts of abiotic factors in rice production, salinity stress is a major constraint, followed by drought. There is considerable research on the use of marker-assisted selection (MAS), genome editing techniques, and transgenic studies that have profoundly improved the present-day rice breeders’ toolboxes for developing salt-tolerant varieties. Salinity stresses significantly affect rice plants during seedling and reproductive stages. Hence, greater understanding and manipulation of genetic architecture in developing salt-tolerant rice varieties will significantly impact sustainable rice production. Rice plants’ susceptibility or tolerance to high salinity has been reported to be the result of coordinated actions of multiple stress-responsive quantitative trait loci (QTLs)/genes. This paper reviews recent literature, updating the effects of salinity stress on rice plants and germplasm collections and screening for salinity tolerance by different breeding techniques. Mapping and identification of QTLs salt tolerance genes are illuminated. The present review updates recent breeding for improvement in rice tolerance to salinity stress and how state-of-the-art tools such as MAS or genetic engineering and genome editing techniques, including mutagenesis and conventional breeding techniques, can assist in transferring salt-tolerant QTLs genes into elite rice genotypes, accelerating breeding of salt-resistant rice cultivars.

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Salinity Tolerance of Ryegrass Turf Cultivars

HortScience ◽

10.21273/hortsci.45.12.1882 ◽

2010 ◽

Vol 45 (12) ◽

pp. 1882-1884 ◽

Cited By ~ 11

Author(s):

Kenneth B. Marcum ◽

Mohammad Pessarakli

Keyword(s):

Salinity Stress ◽

Salinity Tolerance ◽

Dry Weight ◽

Green Leaf ◽

Rooting Depth ◽

Root Weight ◽

Salt Tolerant ◽

Leaf Clipping ◽

Canopy Area ◽

Leaf Canopy

Relative salinity tolerance of 32 perennial (Lolium perenne L.) and three intermediate (Lolium ×hybridum Hausskn.) ryegrass turf cultivars was determined by measuring turf leaf clipping dry weight, root weight, rooting depth, and percent green leaf canopy area relative to control (non-salinized) plants. After gradual acclimation, grasses were exposed to moderate salinity stress (6 dS·m−1) for 6 weeks through solution culture in a controlled environment greenhouse. Shoot parameters were highly correlated, being mutually effective predictors of salinity tolerance. After 6 weeks of salinity stress, percent green leaf canopy area (GL) was correlated with relative (to control) final week leaf clipping weight (LWREL) (r = 0.90) and with linear slope of decline of weekly leaf clipping weight over the 6-week exposure to salinity (LWSLOPE) (r = 0.66). Rooting parameters root dry weight (RW) and rooting depth (RD), although significantly correlated with all shoot parameters, were only moderately effective in predicting relative salinity tolerance. ‘Paragon’ was the most salt-tolerant as indicated by all parameters. Other salt-tolerant cultivars included Divine and Williamsburg. Intermediate ryegrass cultivars (Froghair, Midway, and Transist) were invariably found within the most salt-sensitive category for all parameters.

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