Interaction Of Drought Stress Research Articles

The combined use of silicon and arbuscular mycorrhizal fungus mitigate the adverse effects of drought stress on Matthiola incana

Effects of the application of potassium silicate (PS) and an arbuscular mycorrhiza fungus (AMF) (Glomus mosseae) were investigated on alleviating the impacts of drought stress on Matthiola incana in a split-split-plot experiment in two consecutive years. The main plot was assigned to drought stress at three levels of irrigation (25%, 50%, 70%, of field capacity) comparing with control (100% of field capacity) and the sub-plots were assigned to AMF at two levels (0 and 200 g of fungi in pots) and sub-sub plots were assigned to potassium silicate (PS) at three levels (0, 200, and 400 ppm). The application of PS with fungus increased colonization percentage regardless of the drought stress level. Regarding the interaction of drought stress and PS, it was revealed that the application of 400 and 200 ppm of PS elevated the contents of chlorophylls a, b, and total at all drought stress levels. Also, deficit irrigation versus the normal irrigation increased malondialdehyde (MDA) content both in non-AMF and AMF-containing treatments. The lowest catalase (CAT) and peroxidase (POX) contents were obtained from the treatment of 400 ppm of PS, while the highest were related to the treatment of 0 ppm of PS. Proline content was reduced by the application of 200 g of AMF and 400 ppm of PS at moderate and severe (25% FC) drought stress levels. In general, at moderate and severe drought stress levels, some physiological traits were improved by the foliar application of 400 ppm PS and Glomus mosseae inoculation.

Melatonin-Induced Resilience Strategies against the Damaging Impacts of Drought Stress in Rice

Drought is a severe abiotic stress that imposes a serious threat to rice productivity. Although previous studies have found that melatonin can promote seed germination, the physiological regulation mechanism of drought tolerance in rice seed germination mediated by exogenous melatonin is still unclear. In order to overcome these challenges, polyethylene glycol 6000 (PEG6000) at concentrations of 20% and 35% was used to simulate osmotic stress. Rice seeds were treated with different concentrations of melatonin (i.e., 0, 20, 100, and 500 μM) to study the effects on germination characteristics, growth and development, superoxide dismutase (SOD) activity, peroxidase (POD) activity, catalase (CAT) activity, malondialdehyde (MDA) content, and soluble protein content. The results showed that the seed soaking treatment using melatonin at a concentration of 100 μM under drought stress effectively promoted the germination rate and improved the biomass of rice seed shoots and roots. Meanwhile, this treatment reduced MDA content to alleviate the oxidative damage of rice seeds caused by drought stress. The two-way ANOVA showed that the effect of single melatonin soaking treatment on rice seed germination was more significant than that of single drought stress and the interaction of drought stress and melatonin (p < 0.05). Using the membership function method, it was shown that the critical gradient of rice seeds under drought stress was 35%, and the critical treatment of interactive treatment was 35% + 100 μM. Through grey correlation analysis, it was found that germination rate (7 d) had the highest grey correlation with melatonin seed soaking treatment to evaluate the mitigation effect of melatonin on drought stress. This study provides a theoretical basis for light and simple cultivation technology for the dry direct seeding of rice.

Effect of foliar application of jasmonic acid and drought stress on yield and some agronomic and physiologic traits of quinoa (Chenopodium quinoa Willd) cultivars

Introduction Quinoa plant (Chenopodium quinoa Willd) is a grain- like crop with high nutritional values and resistant to abiotic stresses such as drought and salinity stress. Drought stress is one of major stresses, which had the undesirable effects on qualitative and quantitative yield of crops in arid and semi-arid regions of the world. On the other hand, Jasmonate (Jasmonic acid), are a new plant growth regulator that plays an important role in increase the resistance of plants to environmental stresses such as drought stress. That's why this experiment aims to investigate the impact of drought stress and foliar application Jasmonic acid on yield and some agronomic and physiologic characteristics of Quinoa cultivars. Material and methods This experiment was carried out in split factorial design based on randomized complete block design with three replications in Kerman agricultural research and education center (Joupar station) during 2018. The main factor was included non-stress (normal irrigation) and drought stress (based on 60% and 90% of usable soil moisture discharge) and foliar application of JA in three levels (0, 1 and 2 mg/l) and varieties (Giza1, Titicaca, Q29) as factorial arranged in sub factor. The measured traits were seed yield, inflorescence number in plant, seed 1000 weight, biological yield, plant height, harvest index, relative water content and chlorophyll index. Results and discussion The results showed that drought stress reduced the seed yield and some agronomic and physiologic traits of Quinoa. The application of JA, especially concentration of 2 mg/L improved these traits compared to the control treatments. The highest seed yield and biological yield were obtained from interaction of normal irrigation and 2 mg/l JA and Titicaca cultivar by 3316 and 13265 kg/ha, respectively. The lowest seed yield and biological yield related to interaction of drought stress and non-application of JA and Giza1 cultivar by 1682 and 7733 kg/ha, respectively. The highest plant height was achieved from the interaction of Titicaca cultivar under non-stress conditions and application of 2 mg/l JA by 142.4 cm. The highest chlorophyll leaf index (SPAD index) was observed under non stress conditions and spraying of 1 mg/l JA in Giza1 by 58.8. Conclusions According to the result of this research, it can be suggested that JA as a growth regulator, can increase seed yield and productivity of quinoa cultivars, especially Titicaca cultivar through the reducing the negative effect of drought stress and improving plant growth

Corn (Zea mays L.) Physiology and Yield Affected by Plant Growth Regulators Under Drought Stress

It is important to find methods, which may improve corn physiology, including nitrogen (N) metabolism, and yield production under drought stress. The use of plant growth regulators (PGR) is among the methods, which has been found effective on the alleviation of drought stress on corn physiology and yield. However, in this research, some new PGR, which has been rarely investigated and may improve plant nitrogen (N) under drought stress including (A) control, (B) 6-benzyl adenine (10,000 mg/L), (C) proline (2.5 ml/L), (D) glutamine (1 ml/L), (E) B + C, (F) B + D, (G) B + C + D, and (H) superoxide dismutase (2.5 ml/L) were proposed and examined on corn (genotype Single Cross 640) physiology and yield components under field conditions. The experiment was a split plot on the basis of a completely randomized block design with three replicates, and in addition to PGR (subplots) the main plots (drought stress) based on 70 (D1), 90 (D2) and 110 mm (D3) of evaporation from an evaporating pan were examined. Different corn physiology- and yield-related components including relative water (RW) and proline contents (Pro), weight of 100 grains (100GW), number of grains per corn (NGC), biological yield (BY), corn fresh yield (CFY), and grain yield (GY) were determined. According to the results, corn physiology and yield components were significantly affected by drought stress as Pro increased and RW and yield-related components decreased. However, interestingly the use of PGR (treatment G) significantly improved corn physiology and yield components by increasing RW (to a maximum of 63.81%), CFY (from a minimum of 80,542 kg/ha at control to a maximum of 100,263 kg/ha), and BY (from a minimum of 49,842 kg/ha at control to a maximum of 62,277 kg/ha). Although the effect of PGR was not statistically significant on GY, treatment G resulted in a 2500-kg increase compared with control. The interaction of drought stress and PGR significantly affected different corn physiology- and yield-related components except NGC and BY. The most effective PGR treatment on the alleviation of drought stress on corn physiology and yield production was treatment G containing 6-benzyl adenine, proline, and glutamine. It is possible to improve corn physiology and yield production under drought stress using the PGR tested in this research.

Effects of Palm Leaf Biochar on the Availability of Soil Nutrients, Leaf Nutrient Concentration, and Physiological Characteristics of Melon Plants (Cucumis melo L.) Under Drought Stress

To investigate the effect of palm leaf biochar on the element absorption and reduction of drought stress effects in melon plants, an experiment was conducted using a split plot in a randomized complete block design with three replications in two successive years. The main plot contained three levels of drought stress (60%, 85%, and 100% water requirement) and the subplot contained four levels of biochar (0, 150, 300, and 450 g per plant). The results revealed that biochar application reduced the effect of drought stress and thus proline content in plants. Application of 300 g biochar per plant with 100% water requirement increased total chlorophyll by 131% compared to control. The treatment of 450 g biochar per plant with 100% water requirement increased chlorophyll a and b and leaf nitrogen (N), potassium (K), calcium (Ca), and manganese (Mn) content by 169%, 127%, 58%, 65%, 44%, and 48%, respectively, compared to control. The treatment of 450 g biochar per plant increased phosphorus (P) and magnesium (Mg) content of leaves by 20% and 31%, respectively, in comparison with control. The interaction of drought stress and biochar indicated that the treatment of 450 g biochar per plant with 60% of water requirement increased plant iron, zinc, and copper by 60%, 44%, and 66%, respectively, compared to the biochar-free treatment with 100% water requirement. Addition of 450 g biochar per plant and irrigation with 60% of water requirement increased soil N, P, and K by 150%, 13%, and 75%, respectively, compared to the biochar-free treatment with 100% water requirement. The results indicated that the use of biochar can be a successful strategy for improving water use efficiency and reducing drought stress in melon plants.

Seed quality, water use efficiency and eco physiological characteristics of Lallemantia (Lallemantia sp.) species as effected by soil moisture content

This study investigated the effect of drought stress on the yield, water use efficiency (WUE), physiology, and seed quality of two species Lallemantia sp. Field experiments with three irrigation regimes were carried out in a split plot factorial in a randomized complete block design with three replications. Treatments included irrigation after 40 %, 60 %, and 100 % depletion of available soil water (ASW) (I40, I60, and I100, respectively) as main plots and Lallemantia species L. iberica (M. Bieb.) Fisch. & C. A. Mey. (S1) and L. royleana Benth. in Wall (S2) as subplots. Increment in depletion of ASW (I40 to I100) resulted in progressively less chlorophyll a content (Chl­ a), open stomata percentage (OS), and leaf area index (LAI). The highest Chl­ a and LAI were found to be 0.0087­ mg g−1, and 2.68 mg g−1 leaf mass in I40 treatment, respectively, while closed stomata percentage (CS) increased significantly as drought stress increased. The results of this experiment indicated that the appropriate yield of production was obtained in plots which were fully irrigated (I40) for all species of Lallemantia; however, the WUE increased as drought stress increased. The interaction of drought stress, Lallemantia species with grain yield and WUE was significant.

Phaseolus vulgaris genome possesses CAMTA genes, and phavuCAMTA1 contributes to the drought tolerance

Calmodulin-binding transcription activators (CAMTAs) are a family of transcription factors that play an important role in plants' response to the various biotic and abiotic stresses. The common bean (Phaseolus vulgaris L.) is one of the most important crops in the world and plays a pivotal role in sustainable agriculture. To date, the composition of CAMTA genes in genomes of Phaseolus species and their role in resistance to drought stress are not known. In this study, five PhavuCAMTA genes were characterized in common bean genome through bioinformatics analysis, the morphological and biochemical response of 23 Ph.vulgaris genotypes to different levels of drought stress were evaluated and the expression patterns of PhCAMTA1 in the leaf tissues of sensitive and tolerant genotypes were analysed. Gene structure, protein domain organization and phylogenetic analyses showed that the CAMTAs of Phaseolus were structurally similar and clustered into three groups as other plant CAMTAs. Genotypes showeda differential response to drought stress. Thus, the plant height, number of nodes and flower, total chlorophyll and total protein content, and activity of antioxidant enzymes (ascorbate peroxidase and catalase) in plants significantly influenced by genotype and drought stress interaction. Moreover, the resistant and susceptible genotypes were identified according to three-dimensional plots and the expression patterns of PhavuCAMTA1 gene were studied using real-time quantitative polymerase chain reaction. The results of the present study serve as the basis for future functional studies on the Phaseolus CAMTA family.

Evaluation of Drought Stress and Buried in Sand on Yield Components of Canola (Brassica napus L.) and Soil Properties

Drought is one of the most important environmental stresses that can impair plant growth and crop production. The purpose of Resent paper is to determine the effects of drought stress and Buried by sandon yield, yield components of canola (Brassica napusL.) as well as soil properties. The research was investigated in crop year 2013-14 in the field of Educational Research Institute of University of Zabol. Experiment split-plot in randomized complete block design with three replications. The main plot was drought stress in three levels including; 50, 100 and 150 mm evaporation from evaporation pan and sand buried quantities was considered as the sub – plot in three levels; control, 100 and 200 t/ha. The highest of grain yield (460.87 kg/ha) was obtained from treatment 200 t/hadue to Buried by sand. The result shownthat yield was increased in comparison to the control treatment of about 29.61 percent. The maximum soil temperature shows in treatments of 100mm and 150 mm respectively 27/5co and 28/3co evaporation from pan evaporation and the lowest soil temperatures in 50 mm from pan evaporation treatment was obtained 25/3c° .Using sand storm, the soil temperature decreased and the highest soil temperature (28/2c°) was observed in control treatment. The interaction of drought stress and sand storm showed that the highest grain yield in drought stress 50 mm evaporation and the application of sand storm 200 t/ha. This was indicates that the positive effect of sand to reduce evaporation. Keywords: Evaporation; Sand buried; Soil temperature; Seed yield

Interaction of drought and 5-aminolevulinic acid on growth and drought resistance of Leymus chinensis seedlings

Leymus chinensis is a dominant grass species in the Inner Mongolia steppes owing to its high vegetative productivity, good palatability for cattle, and abundant horizontally creeping rhizomes. Drought is generally regarded as one of the main environmental issues that is becoming a daunting challenge to the growth of plants, and ultimately results in land degradation. Drought stress influences plant growth and development by modulating physiological and biochemical events; however, some growth substances such as 5-aminolevulinic acid (5-ALA) show potential to ameliorate the damaging effects of drought. The objective of this study was to evaluate the response and mechanism of L. chinensis seedlings under drought stress, the effects of 5-ALA application, and the interaction of drought stress and 5-ALA application. Healthy and uniform-size seeds of L. chinensis were collected in a natural community of the Ecological Experimental Station in the Xilingole grassland. A potting experiment was carried out to determine the influence of exogenously applied 5-ALA at various concentrations (10mg/L, 50mg/L, and 100mg/L) under different soil water regimes (50% and 80% soil relative water content) on the morphological and physiological attributes of L. chinensis plants from June to November 2014. The seeds were grown in a biochemical incubator, and then the seedlings were transferred to pots. Water and Hoagland nutrient solution was applied to ensure an adequate nutrient supply at 5-day intervals. When seedlings attained a height of 18–21cm, 5-ALA was applied at different concentrations. Water spray was applied to L. chinensis plants as a control treatment. A second and third spray of 5-ALA was applied at 1-day intervals to exploit the full potential of 5-ALA application. Simultaneously, drought stress treatment was imposed using 50% soil relative water content; 80% soil relative water content was treated as the control. Therefore, there were eight treatments with three replications established in a random complete block design. The sampling for morphological, physiological, and biochemical attributes was conducted after 15days of drought stress, respectively. The results showed that 5-ALA could promote the growth of L. chinensis seedlings, including plant height, leaf area, plant water content, biomass, root activity, and photosynthetic pigments (chlorophyll a, chlorophyll b, and carotenoid), under a soil relative water content of 80%. Among all concentrations, 10mg/L 5-ALA proved to have the best effect on growth. Drought stress (50% soil relative water content) hampered plant growth. However, treatments of 5-ALA ameliorated the damaging effect of drought stress on seedlings, and improved the morphological index, biomass, plant water content, root activity, photosynthetic pigments, osmotic adjustments, and antioxidase activities viz. peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and ascorbate (APX), but reduced malondialdehyde (MDA) content and electrical conductivity. Among all concentrations, 50mg/L 5-ALA proved to have the best effect under drought stress. In summary, 5-ALA application improved the performance of L. chinensis by modulating growth and other morphological and physiological traits. However, the effect of 5-ALA on L. chinensis was concentration-dependent. Furthermore, significant interactions between drought stress and 5–ALA treatment (at a given spraying concentration) were observed with respect to leaf area, leaf width, fresh weight, root activity, chlorophyll b, carotenoids, MDA, proline, soluble protein, SOD, APX, and GR.

Effect of osmotic drought stress on germination indicators of eight monogerm genotypes of sugar beet

In order to investigate the effect of osmotic stress on germination indicators of eight genotypes of sugar beet, a factorial experiment was done in a randomized complete block design on 2011 with three replications. In this study indicators Coefficient of velocity of germination, Germination rate index, Final germination percentage, Mean germination time, Germination speed and Mean daily germination were evaluated. The results showed that the drought conditions all traits had significant difference at 1% probability level. According to result, there were significant difference between all evaluated genotypes except Mean daily at 1% and 5 probability level. Interaction of Drought stress × genotype was insignificant for all traits. Genotype 3 with an average of 9.67 percent had the highest percentage of germination, and genotype 1 with a mean of 78.66 percent had the lowest percentage of germination. Drought stress reduced the 10.99 % GI, 4.62% CVG, 47.85% MDG and 6.66% GS,

Interaction of drought stress and UV-B radiation - impact on biomass production and flavonoid metabolism in lettuce (Lactuca sativa L.)

The response of plants to stress such as UV-radiation or drought highly depends on the species, cultivar, plant organ, developmental stage, and furthermore, is influenced by ecophysiological interactions. Drought stress as well as UV irradiation are the most adverse factors for plant growth and productivity. In the present study, the interactive effect of UV-B and drought stress on biomass, primary and secondary metabolites, and mediated enzyme activity of phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) was investigated in lettuce (Lactuca sativa L.). It was found that biomass production decreased in response to both stressors, while dry matter, total phenolic contents and the flavonol quercetin were not significantly affected by UV-B and drought stress, neither solely nor in combination. In contrast, anthocyanins and luteolin accumulated only in response to drought stress. However, the precursor amino acid proline as well as the activity of PAL increased under conditions of increased UV-B and water deficit. Thus, the present results deduce that both stressors acted either synergistically or to some extent antagonistically in terms of inducing plant protective mechanisms.

210 Effects of Salt and Water Stress on the Growth and Photosynthesis Rate of Bell Pepper (Capsicum annuum L.)

Salt and water stress affect in a significant way most common horticultural crops in northwest Mexico, where bell pepper, hot pepper, and tomato are the most important vegetable crops. Growth rate (GR) and physiological traits in bell pepper were analyzed under salt and drought stress. Two cultivars of bell pepper, `Hungarian Yellow' (HY) and `Sta. Fe Grande' (SG), were evaluated. GR in both cultivars was decreased by salt and drought stress interaction. Salt concentration in the irrigation water affected the amount of dry matter in the plant tissue. Relative growth ratio (RGR), net assimilation ratio (NAR), leaf area ratio (LAR), and photosynthesis rate (Pn) decreased in a correlated amount to the salt NaCl content in the experiment (0, 80, and 160 mm). Differences in the RGR under salt and drought stress between SG and HY were significant. The observed decrease in RGR was explained by NAR and LAR, where RGR was more affected by NAR than LAR. Similarly, the decrease in NAR was explained by C/F and Pn, indicating that NAR was more affected by Pn than C/F. The difference in observed NAR between both cultivars was understood by difference in C/F. Finally, a high relation of C/F in SG cultivar under salt and drought stress was caused by a physiological use of photosynthetic products, causing a significant decrease in NAR in the cultivar HY. This difference in NAR was found to be the factor that affected RGR in both cultivars.

Effects of drought and CO2 enrichment on competition between two old-field perennials.

We studied the effects of drought stress and CO2 enrichment on the competition between Aster pilosus Willd. (aster, C3) and Andropogon virginicus L. (broomsedge, C4) under two CO2 concentrations (350 and 650 μl l-1 CO2 ) and two water treatments (well-watered and water-limited). Although broomsedge is the more drought-tolerant species, this did not increase its competitive ability against aster under drought conditions. With CO2 enrichment, aster was a stronger competitor than broomsedge and comprised 75% of above-ground pot biomass in both water treatments. CO2 enrichment also increased aster survival when competing with broomsedge under extreme drought conditions. Although drought stress and CO2 enrichment interacted to affect the two species in different ways, there was no interaction of drought stress and competition; aster was a stronger competitor than broomsedge under CO2 enrichment in both well-watered and water-limited conditions. With future increases in the atmospheric CO2 concentration, aster may delay broomsedge dominance in old-field communities.

Field evaluation of an acid rain-drought stress interaction

Various methods have been proposed to simulate natural field conditions for growing agricultural crops while controlling conditions to study specific environmental effects. This report briefly describes the use of moveable rain exclusion shelters (10·4 m × 40·9 m) to study the results of the interaction of acid rain and drought stress on corn and soybean yields. The rain exclusion shelters are constructed of galvanized pipe framing and covered with polyethylene film. Movement is automated by a rain switch to protect crops from ambient rainfall and to treat them with simulated acid rain The facility simulates a real environment with respect to variables such as solar exposure, wind movement, dew formation, and insect exposure, while allowing careful control of moisture regimes. Soybeans and corn were treated with average rainfall amounts, and with one-half and one-quarter of these rainfall amounts (drought stress) at two levels of rainfall acidity, pH 5·6 and 3·0. While drought stress resulted in considerable yield reduction for Amsoy and Williams soybeans, no additional reduction in yield was observed with rainfall of pH 3·0, as compared to rainfall of approximately pH 5·6. Similar results were observed for one corn cultivar, Pioneer 3377. For one year of the study however, yield of B73 × Mo17 (corn) was reduced 3139 kg ha −1 by the most severe drought, and an additional 1883 kg ha −1 by acid rain of pH 3·0, as compared to the control (pH 5·6). Yield reduction from acidic rain was considerably less at full water rates, resulting in a significant pH by drought stress interaction. However, during the second year of the experiment, no pH effect or drought by pH interaction was observed for this cultivar. The reason for the difference in the two years was not identified.