scholarly journals Physiological and Gene-Expression Variations in Watermelon (Citrullus lanatus L.) Cultivars Exposed to Drought Stress

2020 ◽  
Vol 89 (2) ◽  
Author(s):  
Mehmet Emre Erez ◽  
Behçet İnal ◽  
Muhemet Zeki Karipçin ◽  
Serdar Altıntaş
Keyword(s):  
Drought Stress ◽  
Citrullus Lanatus ◽  
Gene Location ◽  
Carotenoid Content ◽  
Molecular Characteristics ◽  
Antioxidant Enzyme Activities ◽  
Qrt Pcr ◽  
Drought Conditions ◽  
Drought Resistant ◽  
Effects Of Drought

Drought conditions may have direct or indirect effects on plant physiology, biochemistry, and molecular characteristics. The purpose of this study was to investigate the effects of drought stress on the physiological, biochemical, and molecular responses of three different watermelon cultivars with varying levels of drought tolerance (24: drought resistant, CS: moderately tolerant, and 98: drought sensitive). The cultivars exhibited different responses to cope with water stress according to their tolerance level. Drought induced significant reductions in chlorophyll <em>a</em>, total chlorophyll and carotenoid content and glutation reductase and ascorbate peroxidase activity in the sensitive cultivar unlike in the moderately tolerant and drought resistant cultivars. Additionally, the expression levels of <em>NAC1</em>, <em>NAC2</em>, <em>ORE1</em>, <em>WRKY24</em>, <em>SAG12</em>, <em>SAG13</em>, <em>KCS2</em>, <em>CER1</em>, <em>DREB2A</em>, <em>LTP3</em>, <em>SWEET15</em>, and <em>PYL9</em> genes were measured using qRT-PCR. The expression ratios of the genes significantly varied depending on the gene location and on the tolerance of the cultivars. Results showed that the physiology and biochemical and molecular pathways of tolerant cultivars change to adapt to drought conditions. Therefore, the drought-resistant cultivar copes with drought stress by increasing proline content and antioxidant enzyme activities, as well as by increasing the expression of specific genes.

scholarly journals Enhancement of drought tolerance in diverse Vicia faba cultivars by inoculation with plant growth-promoting rhizobacteria under newly reclaimed soil conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elsayed Mansour ◽  
Hany A. M. Mahgoub ◽  
Samir A. Mahgoub ◽  
El-Sayed E. A. El-Sobky ◽  
Mohamed I. Abdul-Hamid ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Plant Growth ◽  
Plant Growth Promoting Rhizobacteria ◽  
Severe Drought ◽  
Drought Conditions ◽  
Moderate Drought ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Effects Of Drought

AbstractWater deficit has devastating impacts on legume production, particularly with the current abrupt climate changes in arid environments. The application of plant growth-promoting rhizobacteria (PGPR) is an effective approach for producing natural nitrogen and attenuating the detrimental effects of drought stress. This study investigated the influence of inoculation with the PGPR Rhizobium leguminosarum biovar viciae (USDA 2435) and Pseudomonas putida (RA MTCC5279) solely or in combination on the physio-biochemical and agronomic traits of five diverse Vicia faba cultivars under well-watered (100% crop evapotranspiration [ETc]), moderate drought (75% ETc), and severe drought (50% ETc) conditions in newly reclaimed poor-fertility sandy soil. Drought stress substantially reduced the expression of photosynthetic pigments and water relation parameters. In contrast, antioxidant enzyme activities and osmoprotectants were considerably increased in plants under drought stress compared with those in well-watered plants. These adverse effects of drought stress reduced crop water productivity (CWP) and seed yield‐related traits. However, the application of PGPR, particularly a consortium of both strains, improved these parameters and increased seed yield and CWP. The evaluated cultivars displayed varied tolerance to drought stress: Giza-843 and Giza-716 had the highest tolerance under well-watered and moderate drought conditions, whereas Giza-843 and Sakha-4 were more tolerant under severe drought conditions. Thus, co-inoculation of drought-tolerant cultivars with R. leguminosarum and P. putida enhanced their tolerance and increased their yield and CWP under water-deficit stress conditions. This study showed for the first time that the combined use of R. leguminosarum and P. putida is a promising and ecofriendly strategy for increasing drought tolerance in legume crops.

scholarly journals Effects of drought stress on shoot development of tomato (Solanum lycopersicum L.)

2021 ◽  
Vol 5 (2) ◽  
pp. 1208-1215
Author(s):  
Tuan Minh Nguy ◽  
Thang Thanh Tran ◽  
Huong Thanh Tran
Keyword(s):  
Drought Stress ◽  
Stress Tolerance ◽  
Leaf Area ◽  
Stress Condition ◽  
Carotenoid Content ◽  
Shoot Height ◽  
Drought Stress Tolerance ◽  
Drought Stress Condition ◽  
Number Of Leaves ◽  
Effects Of Drought

In recent years, drought stress was strongly affected on the development and yield of tomatoes. There are increasing interests in the study of physiological transformations in adaption to stress in plants In this study, effects of drought stress (mannitol at different concentration) on the development of tomato shoot were studied. Morphological and physiological changes during the development of shoot under drought stress conditions were analyzed. Based on the analysis results, the combination of cytokinin and gibberellin was treated to increase the drought stress tolerance of plants. Results showed that mannitol at 20 g/L induced tomato drought stress. Shoot height, number of leaves, leaf area, and the number of roots significantly decreased in the drought stress condition compared to the control. The formation superoxide (O2-) and hydrogen peroxide (H2O2) occurred in the meristem, elongation region and cap of the roots in the drought stress condition instead of only cap root in the control. In the drought stress condition, there was an increase in respiration intensity, proline and carotenoid content, and abscisic acid activity. In contrast, the content of chlorophyll, photosynthesis intensity, cytokinin and gibberellin activity decreased in comparison with the control. The combination treatment of zeatin 0.5 mg/L and GA3 0.5 mg/L improved the drought stress tolerance of plants. The shoot height, number of leaves, leaf area and number of roots of the treated plants were higher than those of the control plants.

Effects of exogenous abscisic acid on foliar anthocyanin accumulation and drought tolerance in purple rice

Biologia ◽  
2015 ◽  
Vol 70 (7) ◽  
Author(s):  
Parinyaphorn Ploenlap ◽  
Wattana Pattanagul
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Reproductive Organs ◽  
Antioxidant Enzyme Activities ◽  
Rice Cultivars ◽  
Anthocyanin Accumulation ◽  
Exogenous Aba ◽  
Antioxidant Mechanism ◽  
Effects Of Drought ◽  
Dpph Scavenging

AbstractThe effects of drought and exogenous ABA on foliar anthocyanin accumulation and its role in drought tolerance were studied in two purple rice cultivars GS. No. 00621 and GS. No. 21427. The seedlings were grown for 14 days and separated into four groups including control (well-watered), drought (withholding water), ABA (foliar sprayed with 20 mg L−1 ABA and well-watered), ABA and drought (foliar sprayed with 20 mg L−1 ABA and withholding water). Drought was imposed by withholding water for 7 days. The results showed that drought significantly reduced root and shoot growth in GS. No. 00621, while had little effect on GS. No. 21427. Drought stress also induced anthocyanin overaccumulation in GS. No. 21427, whereas its content was reduced in GS. No. 00621. Exogenous ABA had no effect on anthocyanin in both wellwatered and drought conditions in both cultivars. Higher anthocyanin in GS. No. 21427 was coincided with higher DPPH scavenging ability, antioxidant enzyme activities as well as higher relative water content. It is, therefore, concluded that drought-induced anthocyanin overaccumulation may be different between purple rice cultivars and anthocyanin is beneficial for the response to drought stress by protecting plant antioxidant mechanism. Unlike anthocyanin in plant reproductive organs, exogenous ABA has no effect on foliar anthocyanin accumulation in purple rice. It is possible that anthocyanin accumulation in leaf and reproductive organs may be regulated differently or triggered by different mechanisms.

scholarly journals Plant virus evolution under strong drought conditions results in a transition from parasitism to mutualism

2020 ◽  
Author(s):  
Rubén González ◽  
Anamarija Butkovic ◽  
Francisco Escaray ◽  
Javier Martínez-Latorre ◽  
Ízan Melero ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Abiotic Stress ◽  
Drought Stress ◽  
Plant Virus ◽  
Virus Evolution ◽  
Drought Conditions ◽  
Effects Of Drought ◽  
Plant Virus Evolution ◽  
Virus Adaptation ◽  
Host Genes

Abstract Environmental conditions are an important factor driving pathogens evolution. Here we explore the effects of drought stress in plant virus evolution. We evolved a potyvirus in well-watered and drought conditions in Arabidopsis thaliana accessions that differ in their response to virus infection. Virus adaptation occurred in all accessions independently of watering status. Drought-evolved viruses conferred a significantly higher tolerance to drought to infected plants. By contrast, non-significant increases in tolerance were observed in plants infected with viruses evolved under standard watering. The magnitude of this effect was dependent on the plant accessions. Differences in tolerance were correlated to alterations in the expression of host genes, some involved in regulation of the circadian clock, as well as in deep changes in the balance of phytohormones regulating defense and growth signaling pathways. Our results show that viruses can promote host survival in situations of abiotic stress, being the magnitude of such benefit a selectable trait.

scholarly journals Effect of SiO2 nanoparticles on drought resistance in hawthorn seedlings

2015 ◽  
Vol 76 (4) ◽  
pp. 350-359 ◽  
Author(s):  
Peyman Ashkavand ◽  
Masoud Tabari ◽  
Mehrdad Zarafshar ◽  
Ivana Tomášková ◽  
Daniel Struve
Keyword(s):  
Drought Stress ◽  
Drought Resistance ◽  
Crop Production ◽  
Plant Biomass ◽  
Proline Content ◽  
Carotenoid Content ◽  
Biochemical Basis ◽  
Positive Effects ◽  
Drought Conditions ◽  
Physiological And Biochemical

Abstract Drought is a significant factor limiting crop production in arid regions while hawthorns (Crataegus sp.) are an important component of such region’s forests. Therefore, treatments that increase hawthorn drought resistance may also increase transplanting success. Thus, the physiological and biochemical responses of hawthorn seedlings to a factorial combination of different concentrations of silica nanoparticles (SNPs at 0, 10, 50 and 100 mg L−1) and three soil moisture treatments (without stress, moderate stress and severe stress) were investigated. Seedlings were irrigated with one of the four concentrations of SNPs for 45 days before exposing them to drought stress. Photosynthesis parameters, malondialdehyde (MDA), relative water content (RWC), membrane electrolyte leakage (ELI) as well as chlorophyll, carotenoid, carbohydrate and proline content were determined. At the end of the experiment, positive effects by SNP pre-treatment on physiological indexes were observed during drought stress. Under drought conditions, the effect of SNPs on photosynthetic rate and stomatal conductance was evident. Although the SNPs increased plant biomass, xylem water potential and MDA content, especially under drought conditions, RWC and ELI were not affected by the SNP pre-treatments. Seedlings pre-treated with SNPs had a decreased carbohydrate and proline content under all water regimes, but especially so under drought. Total chlorophyll content and carotenoid content did not change among the treatments. Generally, the findings imply that SNPs play a positive role in maintaining critical physiological and biochemical functions in hawthorn seedlings under drought stress conditions. However, more studies are needed before the physiological and biochemical basis of induced drought resistance can be determined.

scholarly journals Comparative transcriptome study of switchgrass (Panicum virgatum L.) homologous autopolyploid and its parental amphidiploid responding to consistent drought stress

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Peilin Chen ◽  
Jing Chen ◽  
Min Sun ◽  
Haidong Yan ◽  
Guangyan Feng ◽  
...  
Keyword(s):  
Drought Stress ◽  
Panicum Virgatum ◽  
Differentially Expressed ◽  
Drought Response ◽  
Sequencing Data ◽  
Short Term ◽  
Microrna Sequencing ◽  
Drought Resistant ◽  
Effects Of Drought ◽  
Physiological Tests

Abstract Background Newly formed polyploids may experience short-term adaptative changes in their genome that may enhance the resistance of plants to stress. Considering the increasingly serious effects of drought on biofuel plants, whole genome duplication (WGD) may be an efficient way to proceed with drought resistant breeding. However, the molecular mechanism of drought response before/after WGD remains largely unclear. Result We found that autoploid switchgrass (Panicum virgatum L.) 8X Alamo had higher drought tolerance than its parent amphidiploid 4X Alamo using physiological tests. RNA and microRNA sequencing at different time points during drought were then conducted on 8X Alamo and 4X Alamo switchgrass. The specific differentially expressed transcripts (DETs) that related to drought stress (DS) in 8X Alamo were enriched in ribonucleoside and ribonucleotide binding, while the drought-related DETs in 4X Alamo were enriched in structural molecule activity. Ploidy-related DETs were primarily associated with signal transduction mechanisms. Weighted gene co-expression network analysis (WGCNA) detected three significant DS-related modules, and their DETs were primarily enriched in biosynthesis process and photosynthesis. A total of 26 differentially expressed microRNAs (DEmiRs) were detected, and among them, sbi-microRNA 399b was only expressed in 8X Alamo. The targets of microRNAs that were responded to polyploidization and drought stress all contained cytochrome P450 and superoxide dismutase genes. Conclusions This study explored the drought response of 8X and 4X Alamo switchgrass on both physiological and transcriptional levels, and provided experimental and sequencing data basis for a short-term adaptability study and drought-resistant biofuel plant breeding.

Effects of drought stress on the water relations in Brassica species

1993 ◽  
Vol 73 (2) ◽  
pp. 525-529 ◽  
Author(s):  
Allen G. Good ◽  
James L. Maclagan
Keyword(s):  
Water Stress ◽  
Drought Stress ◽  
Osmotic Potential ◽  
Relative Water Content ◽  
Physiological Responses ◽  
Brassica Species ◽  
Leaf Osmotic Potential ◽  
Drought Conditions ◽  
Relative Water ◽  
Effects Of Drought

The physiological responses of different species of Brassica to induced drought stress were studied by analysing the relationships between relative water content, leaf water potential and leaf osmotic potential during the onset of drought stress. These data indicate that while there was a decrease in leaf osmotic potential with the onset of drought stress, this did not result from a net increase in solutes. Therefore, these genotypes of Brassica do not appear able to osmoregulate under these drought conditions. Key words: Brassica, drought, osmoregulation, water stress

Influence of Peg-induced Drought Stress on Antioxidant Components of Callus Tissue of Sainfoin (Onobrychis viciifolia Scop.) Ecotypes

2020 ◽  
Author(s):  
Ramazan Beyaz ◽  
Mustafa Yıldız
Keyword(s):  
Drought Stress ◽  
Callus Tissue ◽  
Stress Factors ◽  
Antioxidant Enzyme Activities ◽  
Ms Medium ◽  
Peg 6000 ◽  
Onobrychis Viciifolia ◽  
Stress Effects ◽  
Abiotic Stress Factors ◽  
Effects Of Drought

Background: Drought is one of the important abiotic stress factors that restrict plant development. Sainfoin is known to be relatively tolerant of drought. However, there are limited reports on the effects of drought stress on antioxidant components of Onobrychis species and/or ecotypes. Methods: To determine drought stress effects on antioxidant components of 4 sainfoin ecotypes (“Koçaþ”, “Malya”, “Altýnova” and “Ulaþ”), callus tissue was grown on MS medium enriched with 200 g l-1 PEG-6000. Result: Callus of the sainfoin ecotypes, cultured on a medium having 200 g l-1 PEG-6000, showed significant increases in antioxidant enzyme activities (SOD, CAT, GR (except in “Ulaþ” ecotype) and APX). However, the PEG induced increase in the accumulation of MDA and proline in callus tissue of all sainfoin ecotypes. The findings of the present study show that in terms of the increasing rate of antioxidant components under drought stress, the “Koçaþ” ecotype seemed to be the best.

scholarly journals Foliar application of melatonin alleviates the effects of drought stress in rice (Oryza sativa L.) seedlings

2021 ◽  
Vol 49 (3) ◽  
pp. 12417
Author(s):  
Parichart SILALERT ◽  
Wattana PATTANAGUL
Keyword(s):  
Drought Stress ◽  
Plant Growth ◽  
Enzyme Activities ◽  
Electrolyte Leakage ◽  
Relative Water Content ◽  
Foliar Application ◽  
Antioxidant Enzyme Activities ◽  
Rice Seedlings ◽  
Relative Water ◽  
Effects Of Drought

Melatonin (N-acetyl-5-methoxytryptamine) plays an essential role in abiotic stress in plants, but its mechanism in drought tolerance is unclear. To better understand the protective roles of melatonin against drought stress, we investigated the effect of foliar application with exogenous melatonin on plant growth, physiological responses, and antioxidant enzyme activities in rice seedlings under drought stress. Rice seedlings were grown for 21 days, and foliar sprayed with 0, 50, 100, 200, and 300 µM melatonin. The control plant was watered daily, while the others were subjected to drought stress by withholding water for seven days. The results showed that drought stress significantly reduced plant growth, relative water content, and chlorophyll content. Electrolyte leakage, malondialdehyde (MDA) content and hydrogen peroxide (H2O2) were also negatively affected by drought stress. Application of melatonin alleviated the effects of drought stress by increasing plant growth, improving relative water content and chlorophyll content, and decreasing electrolyte leakage, MDA, and H2O2. Foliar application with melatonin also increased antioxidant enzyme activities, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (GPX). In addition, melatonin also enhanced proline and total soluble sugar accumulation during drought stress. It is, therefore, suggested that foliar application with 100 µM melatonin was the most effective for reducing the adverse effects of drought stress in rice plants.

scholarly journals Nutrient Accumulation and Associated Root Characteristics in Response to Drought Stress in Tall Fescue Cultivars

HortScience ◽  
2001 ◽  
Vol 36 (1) ◽  
pp. 148-152 ◽  
Author(s):  
Bingru Huang
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Tall Fescue ◽  
Root Length ◽  
Festuca Arundinacea ◽  
Specific Root Length ◽  
Root Characteristics ◽  
Drought Conditions ◽  
Effects Of Drought ◽  
K Concentration

Drought is a major factor limiting the growth of turfgrasses in many areas. The functional relationship of drought stress and accumulation of various ions in turfgrasses is not well understood. The objective of this study was to investigate the effects of drought on root growth and accumulation of several major nutrients in three tall fescue (Festuca arundinacea Schreb.) cultivars varying in drought tolerance (Falcon II = Houndog V > Rebel Jr). Grasses were grown in well-watered or drying (nonirrigated) soil for 35 days in a greenhouse. Drought conditions limited total root length to a greater extent for `Rebel Jr' than for `Falcon II' and `Houndog V', while specific root length (SRL) was greater in `Falcon II' and `Houndog V' than in `Rebel Jr'. Concentrations of N, P, and Mg decreased, whereas those of K, Ca, and Fe increased, in shoots of drought-stressed plants of all three cultivars. Root N was not affected, but root P decreased in `Rebel Jr', and root K decreased in all three cultivars under drought conditions. Drought reduced the proportions of N and P in shoots and increased those in roots, while increasing the proportion of K in shoots and decreasing that in roots. During drought stress, both `Falcon II' and `Houndog V' maintained higher K concentration in shoots, and `Falcon II' in roots, than did `Rebel Jr', but `Rebel Jr' and `Houndog V' had higher Fe concentration in shoots than did `Falcon II'. The higher K and lower Fe accumulations in shoots could contribute to better drought tolerance of tall fescue cultivars.

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