scholarly journals Evaluation of Drought Tolerance of Five Maize Genotypes by Virtue of Physiological and Molecular Responses

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 59
Author(s):  
Khalil M. Saad-Allah ◽  
Afaf A. Nessem ◽  
Mohsen K. H. Ebrahim ◽  
Dina Gad
Keyword(s):  
Water Stress ◽  
Drought Tolerance ◽  
Expression Patterns ◽  
Soluble Sugars ◽  
Transcriptional Level ◽  
Maize Production ◽  
Maize Genotypes ◽  
Severe Water Stress ◽  
Metabolic Activities ◽  
Primary Focus

Drought has been recognized as a potential challenge to maize production around the world, particularly in arid and semi-arid regions. The primary focus of the present study was to investigate the metabolic and physiological adjustment mechanisms as well as drought-responsive gene expression patterns in five maize (Zea mays L.) genotypes (G314, G2, G10, G123, and G326) with varying drought-tolerance capacities at the vegetative stage. Twenty-one days-old maize plants from five maize genotypes were submitted to a well-watered (10 days) watering interval as a control, mild water stress (15 day interval), and severe water stress (20 day interval) treatments in a field experiment for two successive seasons (2019 and 2020). For all maize genotypes, the results showed that water stress significantly reduced plant height, leaf area, biomass, and yield characteristics. However, water stress, which was associated with the length of the watering interval, increased the concentrations of glycine betaine, amino acids, proline, phenols, flavonoids, soluble proteins, and soluble sugars, as well as catalase and peroxidase activities. On the transcriptional level, prolonged water stress increased the expression of drought-responsive genes (LOS5, Rad17, NCED1, CAT1, and ZmP5CS1), with G10 and G123 genotypes being the most drought-resistant. Herein, genotypes G10 and G123 were shown in this study to be relatively water stress tolerant due to improved osmoregulatory, antioxidant, and metabolic activities under water stress conditions, as well as the fact that they were endowed with stress-responsive genes.

Stomatal conductance and growth of five Alnusglutinosa clones in response to controlled water stress

1988 ◽  
Vol 18 (4) ◽  
pp. 421-426 ◽  
Author(s):  
T. C. Hennessey ◽  
E. M. Lorenzi ◽  
R. W. McNew
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Drought Tolerance ◽  
Leaf Area ◽  
Water Status ◽  
Height Growth ◽  
Plant Water ◽  
Black Alder ◽  
Severe Water Stress ◽  
Progressive Water Stress

An experiment to quantify the response of unnodulated, fertilized European black alder (Alnusglutinosa (L.) Gaertn.) seedlings to progressive water stress showed contrasting drought tolerance among five clones, using stomatal conductance, leaf area, and height as indices of drought sensitivity. In particular, one rapidly growing clone (AG 8022-14) showed the ability to moderate changes in water stress more efficiently than the more slowly growing clones. After 30 days of moderate levels of water stress, clones that had higher stomatal conductance also had greater leaf area and height growth. Leaf area and height were both sensitive to plant water status, although no threshold of stress associated with a cessation of leaf area or height expansion was found even though stomatal conductance decreased to 0.05 cm s−1 under severe water stress.

scholarly journals Genome-Wide Identification and Transcriptional Regulation of Aquaporin Genes in Bread Wheat (Triticum aestivum L.) under Water Stress

Genes ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 497 ◽  
Author(s):  
José Madrid-Espinoza ◽  
Nidia Brunel-Saldias ◽  
Fernando Guerra ◽  
Adelina Gutiérrez ◽  
Alejandro del Pozo
Keyword(s):  
Triticum Aestivum ◽  
Water Stress ◽  
Functional Divergence ◽  
Expression Patterns ◽  
Structure And Function ◽  
Transcriptional Level ◽  
Severe Drought ◽  
Crop Species ◽  
Intrinsic Protein ◽  
And Function

Aquaporins (AQPs) are transmembrane proteins essential for controlling the flow of water and other molecules required for development and stress tolerance in plants, including important crop species such as wheat (Triticum aestivum). In this study, we utilized a genomic approach for analyzing the information about AQPs available in public databases to characterize their structure and function. Furthermore, we validated the expression of a suite of AQP genes, at the transcriptional level, including accessions with contrasting responses to drought, different organs and water stress levels. We found 65 new AQP genes, from which 60% are copies expanded by polyploidization. Sequence analysis of the AQP genes showed that the purifying selection pressure acted on duplicate genes, which was related to a high conservation of the functions. This situation contrasted with the expression patterns observed for different organs, developmental stages or genotypes under water deficit conditions, which indicated functional divergence at transcription. Expression analyses on contrasting genotypes showed high gene transcription from Tonoplast Intrinsic Protein 1 (TIP1) and 2 (TIP2), and Plasma Membrane Intrinsic Protein 1 (PIP1) and 2 (PIP2) subfamilies in roots and from TIP1 and PIP1 subfamilies in leaves. Interestingly, during severe drought stress, 4 TIP genes analyzed in leaves of the tolerant accession reached up to 15-fold the level observed at the susceptible genotype, suggesting a positive relationship with drought tolerance. The obtained results extend our understanding of the structure and function of AQPs, particularly under water stress conditions.

scholarly journals Nutrient Concentration of African Horned Cucumber (Cucumis metuliferus L) Fruit under Different Soil Types, Environments, and Varying Irrigation Water Levels

Horticulturae ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 76
Author(s):  
Mdungazi K Maluleke ◽  
Shadung J Moja ◽  
Melvin Nyathi ◽  
David M Modise
Keyword(s):  
Water Stress ◽  
Nutrient Concentration ◽  
Soluble Sugars ◽  
Soil Types ◽  
Loamy Soil ◽  
Total Soluble Sugars ◽  
Stress Treatment ◽  
Cucumber Fruit ◽  
Severe Water Stress ◽  
Β Carotene

The nutrient concentration of most crops depends on factors such as amount of water, growing environment, sunlight, and soil types. However, the factors influencing nutrient concentration of African horned cucumber fruit are not yet known. The objective of the study was to determine the effect of different water stress levels, soil types, and growing environments on the nutrient concentration of African horned cucumber fruit. Freeze-dried fruit samples were used in the quantification of β-carotene and total soluble sugars. The results demonstrated that plants grown under the shade net, combined with severe water stress level and loamy soil, had increased total soluble sugars (from 8 to 16 °Brix). Under the shade-net environment, the combination of moderate water stress level and loamy soil resulted in increased crude protein content (from 6.22 to 6.34% °Brix). In addition, the severe water stress treatment combined with loamy soil, under greenhouse conditions, resulted in increased β-carotene content (from 1.5 to 1.7 mg 100 g−1 DW). The results showed that African horned cucumber fruits are nutrient-dense when grown under moderate water stress treatment on the loamy or sandy loam substrate in the shade-net and open-field environments.

scholarly journals Thermal imaging to phenotype traditional maize landraces for drought tolerance

2015 ◽  
Vol 6 (3) ◽  
pp. 334 ◽  
Author(s):  
Joaquim Miguel Costa ◽  
Ivan Francisco Garcia Tejero ◽  
Victor Hugo Duran Zuazo ◽  
Roberta Samara Nunes da Lima ◽  
Maria Manuela Chaves ◽  
...  
Keyword(s):  
Water Stress ◽  
Thermal Imaging ◽  
Leaf Temperature ◽  
New Crops ◽  
Maize Genotypes ◽  
Severe Water Stress ◽  
Screening Protocol ◽  
Maize Landraces ◽  
Low Altitude ◽  
Stable Leaf

Searching and identification of new crops or varieties with higher adaptation or resistance to water stress is one of the strategies to make agriculture profitable and more sustainable. Especially en arid and semi areas with limiting water resources. This study establishes a practical, fast and replicable protocol to select maize genotypes for its capability to respond to water stress. Eight Portuguese maize landraces (LD), traditionally grown in areas with different altitude and subjected to potentially different degrees of water stress (low altitude = potentially lower stress; high altitude = potentially higher stress) was used. Seedlings were subjected to continuous watering (FI) or forced to water withholding (non-irrigated) for a period of 7-8 days followed by re-watering (NI). Leaf temperature was determined every 48 h by thermal imaging and the temperature difference between NI and FI plants (ΔTNI-FI) was calculated. We found that those genotypes that traditionally had been grown at higher altitudes kept more stable leaf temperature values under dry or wet conditions (small ΔTNI-FI) even under severe water stress. These results will help to optimize a screening protocol for maize seedlings and select novel genotypes or LDs better adapted to water stress, especially in regions where irrigation water is scarce.

ROOT CHARACTERISTICS IN COWPEA RELATED TO DROUGHT TOLERANCE AT THE SEEDLING STAGE

2003 ◽  
Vol 39 (1) ◽  
pp. 29-38 ◽  
Author(s):  
T. MATSUI ◽  
B. B. SINGH
Keyword(s):  
Water Stress ◽  
Drought Tolerance ◽  
Leaf Area ◽  
Dry Matter ◽  
Stress Conditions ◽  
Root Characteristics ◽  
Severe Water Stress ◽  
Cowpea Varieties ◽  
Root Box ◽  
Mild Water Stress

Cowpea (Vigna unguiculata) has relatively higher drought tolerance than other legume crops. It is widely grown in semi-arid regions, particularly in West Africa. One objective of the present study was to determine the effects of soil moisture stress on the length, dry matter and distribution of the roots of two cowpea varieties with different drought tolerances. Another objective was to evaluate the pin-board root-box as a method for identifying the role of root characteristics in drought tolerance. Two cowpea varieties, IT96D-604 (drought tolerant) and TVu7778 (drought susceptible), were used in this study. There were three watering treatments, T1 (well-watered), T2 (mild water stress) and T3 (severe water stress). Between varieties, there were no significant differences in shoot and root characteristics except for leaf area in T1. Under T2, the shoot:root ratio (S:R ratio) of IT96D-604 was significantly decreased compared with that under T1 as a result of the increase in root dry matter and decrease in leaf area without significant differences in total dry matter. In addition, the root dry matter per leaf area, which indicates the capacity to absorb water, of IT96D-604 was significantly higher than that of TVu7778. Under T3, the total dry matter of TVu7778 was about one third of those of the other treatments for the same variety, whereas that of IT96D-604 was more than half. Regarding root distribution, the centres of root dry matter and root length density of both varieties moved downwards significantly under water-stress conditions compared with those of the well-watered condition. This tendency was more pronounced in IT96D-604 than in TVu7778. Drought tolerance in IT96D-604 was associated with the increase in root dry matter per leaf area under mild water-stress conditions, and downward movement of roots (increasing access and use of soil moisture in deep soil layers) under mild and severe water stress conditions. In addition, the root-box method was versatile and can be used for studying root responses to edaphic factors relevant to root growth.

The response of different almond genotypes to moderate and severe water stress in order to screen for drought tolerance

2011 ◽  
Vol 129 (3) ◽  
pp. 403-413 ◽  
Author(s):  
A. Yadollahi ◽  
K. Arzani ◽  
A. Ebadi ◽  
M. Wirthensohn ◽  
S. Karimi
Keyword(s):  
Water Stress ◽  
Drought Tolerance ◽  
Severe Water Stress

scholarly journals Drought Stress-Mediated Transcriptome Profile Reveals NCED as a Key Player Modulating Drought Tolerance in Populus davidiana

2021 ◽  
Vol 12 ◽  
Author(s):  
Sang-Uk Lee ◽  
Bong-Gyu Mun ◽  
Eun-Kyung Bae ◽  
Jae-Young Kim ◽  
Hyun-Ho Kim ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Stress Responses ◽  
Expression Patterns ◽  
Pcr Analysis ◽  
Transcriptional Level ◽  
Rna Seq ◽  
Drought Tolerant ◽  
Populus Davidiana ◽  
Strict Regulation

Populus trichocarpa has been studied as a model poplar species through biomolecular approaches and was the first tree species to be genome sequenced. In this study, we employed a high throughput RNA-sequencing (RNA-seq) mediated leaf transcriptome analysis to investigate the response of four different Populus davidiana cultivars to drought stress. Following the RNA-seq, we compared the transcriptome profiles and identified two differentially expressed genes (DEGs) with contrasting expression patterns in the drought-sensitive and tolerant groups, i.e., upregulated in the drought-tolerant P. davidiana groups but downregulated in the sensitive group. Both these genes encode a 9-cis-epoxycarotenoid dioxygenase (NCED), a key enzyme required for abscisic acid (ABA) biosynthesis. The high-performance liquid chromatography (HPLC) measurements showed a significantly higher ABA accumulation in the cultivars of the drought-tolerant group following dehydration. The Arabidopsis nced3 loss-of-function mutants showed a significantly higher sensitivity to drought stress, ~90% of these plants died after 9 days of drought stress treatment. The real-time PCR analysis of several key genes indicated a strict regulation of drought stress at the transcriptional level in the P. davidiana drought-tolerant cultivars. The transgenic P. davidiana NCED3 overexpressing (OE) plants were significantly more tolerant to drought stress as compared with the NCED knock-down RNA interference (RNAi) lines. Further, the NCED OE plants accumulated a significantly higher quantity of ABA and exhibited strict regulation of drought stress at the transcriptional level. Furthermore, we identified several key differences in the amino acid sequence, predicted structure, and co-factor/ligand binding activity of NCED3 between drought-tolerant and susceptible P. davidiana cultivars. Here, we presented the first evidence of the significant role of NCED genes in regulating ABA-dependent drought stress responses in the forest tree P. davidiana and uncovered the molecular basis of NCED3 evolution associated with increased drought tolerance.

scholarly journals The Physiological Impact of GFLV Virus Infection on Grapevine Water Status: First Observations

Plants ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 161
Author(s):  
Anastazija Jež-Krebelj ◽  
Maja Rupnik-Cigoj ◽  
Marija Stele ◽  
Marko Chersicola ◽  
Maruša Pompe-Novak ◽  
...  
Keyword(s):  
Water Stress ◽  
Virulent Strain ◽  
Water Status ◽  
Expression Patterns ◽  
Vessel Occlusion ◽  
Biotic Stresses ◽  
Severe Water Stress ◽  
Different Types ◽  
Physiological Impact ◽  
The Impact

In a vineyard, grapevines are simultaneously exposed to combinations of several abiotic (drought, extreme temperatures, salinity) and biotic stresses (phytoplasmas, viruses, bacteria). With climate change, the incidences of drought in vine growing regions are increased and the host range of pathogens with increased chances of virulent strain development has expanded. Therefore, we studied the impact of the combination of abiotic (drought) and biotic (Grapevine fanleaf virus (GFLV) infection) stress on physiological and molecular responses on the grapevine of cv. Schioppettino by studying the influence of drought and GFLV infection on plant water status of grapevines, on grapevine xylem vessel occlusion, and on expression patterns of 9-cis-epoxycarotenoid dioxygenase 1 (NCED1), 9-cis-epoxycarotenoid dioxygenase 2 (NCED2), WRKY encoding transcription factor (WRKY54) and RD22-like protein (RD22) genes in grapevines. A complex response of grapevine to the combination of drought and GFLV infection was shown, including priming in the case of grapevine water status, net effect in the case of area of occluded vessels in xylem, and different types of interaction of both stresses in the case of expression of four abscisic acid-related genes. Our results showed that mild (but not severe) water stress can be better sustained by GFLV infection rather than by healthy vines. GFLV proved to improve the resilience of the plants to water stress, which is an important outcome to cope with the challenges of global warming.

scholarly journals Ameliorative Effects of Calcium Sprays on Yield and Grain Nutritional Composition of Maize (Zea mays L.) Cultivars under Drought Stress

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 285
Author(s):  
Mohamed Abbas ◽  
Hashim Abdel-Lattif ◽  
Mohamed Shahba
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Grain Yield ◽  
Water Regime ◽  
Foliar Application ◽  
Maize Yield ◽  
Maize Production ◽  
Total Sugars ◽  
Maize Cultivars

Drought stress is seriously affecting maize production. To investigate the influence of calcium (Ca) foliar application on maize production and chemical composition of grains under drought stress, two experiments were carried out at Cairo University Research Station, Giza, Egypt, during the summer seasons of 2018 and 2019. The experimental design was split-split plot design with a completely randomized blocks arrangement with three replications. Water regimes were assigned to the main plots [100 (control), 75, and 50% of estimated evapotranspiration]. Calcium levels (zero and 50 mg/L) were assigned to the sub plots. Maize cultivars (SC-P3444, Sammaz-35 and EVDT) were assigned to the sub-sub plots. Three maize cultivars were sprayed with Ca solution concentration (50 mg/L) under normal and drought conditions. The control treatment (0 mg/L) was sprayed with an equal amount of distilled water for comparison. Results indicated a significant decrease in total yield and grain characteristics [protein, ash, total sugars, nitrogen (N), phosphorus (P), potassium (K), and iron (Fe) contents] as a response of drought. Calcium foliar application significantly increased maize yield, protein, ash, carbohydrates, starch, total sugars, and ionic contents of grains, except for manganese (Mn), under all irrigation levels. Based on the drought tolerance index (DTI), only cultivar SC-P3444 showed drought tolerance while cultivars Sammaz-35 and EVDT were sensitive to drought stress. Foliar application of Ca on SC-P3444 cultivar achieved the highest grain yield per hectare (8061 kg) under the water regime of 100% of the total evapotranspiration, followed by Sammaz-35 (7570 kg), and EVDT (7191 kg) cultivars. At the water regime of 75% of estimated evapotranspiration (75% irrigation), Ca foliar application increased grain yield by 16, 13 and 14% in SC-P3444, Sammaz-35, and EVDT, respectively. At the water regime of 50% of the estimated evapotranspiration (50% irrigation), Ca foliar application increased grain yield by 17, 16, and 13% in SC-P3444, Sammaz-35, and EVDT, respectively. In brief, Ca had a clear impact on productivity and grain quality with important implications for maize yield under normal and water stress conditions. Our findings demonstrate that foliar application of Ca enabled drought stressed maize plants to survive better under stress. The most water stress tolerant cultivar was SC-P3444 followed by Sammaz-35 and EVDT under drought stress.

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