scholarly journals Ecophysiological Responses of Calcicole Cyclobalanopsis glauca (Thunb.) Oerst. to Drought Stress and Calcium Supply

Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 667 ◽  
Author(s):  
Liang Xue ◽  
Huadong Ren ◽  
Wei Long ◽  
Xiuhui Leng ◽  
Jia Wang ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Drought Stress ◽  
Water Deficit ◽  
Water Status ◽  
Karst Region ◽  
Drought Treatment ◽  
High Calcium ◽  
Mda Content ◽  
Ecophysiological Responses ◽  
Cyclobalanopsis Glauca

Water deficit and high calcium (Ca2+) content and are two typical soil characteristics in the Karst region. However, the problem of whether high Ca2+ in Karst calcareous soil could increase drought tolerance in calcicole plants has not been solved. We investigated the ecophysiological responses of Cyclobalanopsis glauca (Thunb.) Oerst. cuttings to short-term drought stress and Ca2+ application. Drought stress (10% PEG-6000) markedly reduced relative water content (RWC) and water potential (WP), and enhanced the levels of reactive oxygen species (ROS) production (H2O2 and O2•−) and malondialdehyde (MDA) content in C. glauca leaves. Under drought treatment, exogenous Ca2+ application (20 mM CaCl2) markedly increased the RWC and WP, and reduced the H2O2, O2•−, and MDA content. Furthermore, water deficit induced a significant increase in the activities of antioxidant enzymes such as peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), and glutathione peroxidase (GPX), and increased the accumulation of osmoregulation substances. External Ca2+ alleviated drought-induced oxidative stress and osmotic stress with further increased activities of antioxidant enzymes, and enhanced the accumulation of osmoregulation substances. In addition, exogenous Ca2+ treatment alleviated the reduction of the photosynthesis rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and chlorophyll content (SPAD), and further increased water use efficiency (WUE) under drought stress. This study confirms that exogenouos Ca2+ application induces improvements in the water status, osmotic adjustment, antioxidant defense, and photosynthesis efficiency of C. glauca under drought stress.

scholarly journals Diurnal and Seasonal Mapping of Water Deficit Index and Evapotranspiration by an Unmanned Aerial System: A Case Study for Winter Wheat in Denmark

2021 ◽  
Vol 13 (15) ◽  
pp. 2998
Author(s):  
Vita Antoniuk ◽  
Kiril Manevski ◽  
Kirsten Kørup ◽  
Rene Larsen ◽  
Inge Sandholt ◽  
...  
Keyword(s):  
Drought Stress ◽  
Winter Wheat ◽  
Water Deficit ◽  
Land Surface ◽  
Crop Production ◽  
Field Experiments ◽  
Root Zone ◽  
Potential Evapotranspiration ◽  
Water Status ◽  
Balance Model

Precision irrigation is a promising method to mitigate the impacts of drought stress on crop production with the optimal use of water resources. However, the reliable assessment of plant water status has not been adequately demonstrated, and unmanned aerial systems (UAS) offer great potential for spatiotemporal improvements. This study utilized UAS equipped with multispectral and thermal sensors to detect and quantify drought stress in winter wheat (Triticum aestivum L.) using the Water Deficit Index (WDI). Biennial field experiments were conducted on coarse sand soil in Denmark and analyses were performed at both diurnal and seasonal timescales. The WDI was significantly correlated with leaf stomatal conductance (R2 = 0.61–0.73), and the correlation was weaker with leaf water potential (R2 = 0.39–0.56) and topsoil water status (the highest R2 of 0.68). A semi-physical model depicting the relationship between WDI and fraction of transpirable soil water (FTSW) in the root zone was derived with R2 = 0.74. Moreover, WDI estimates were improved using an energy balance model with an iterative scheme to estimate the net radiation and land surface temperature, as well as the dual crop coefficient. The diurnal variation in WDI revealed a pattern of the ratio of actual to potential evapotranspiration, being higher in the morning, decreasing at noon hours and ‘recovering’ in the afternoon. Future work should investigate the temporal upscaling of evapotranspiration, which may be used to develop methods for site-specific irrigation recommendations.

scholarly journals Changes in Carbon Partitioning and Accumulation Patterns during Drought and Recovery for Colonial Bentgrass, Creeping Bentgrass, and Velvet Bentgrass

2006 ◽  
Vol 131 (4) ◽  
pp. 484-490 ◽  
Author(s):  
Michelle DaCosta ◽  
Bingru Huang
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Water Status ◽  
Creeping Bentgrass ◽  
Carbon Partitioning ◽  
Perennial Grasses ◽  
Species Variation ◽  
Carbohydrate Accumulation ◽  
Drought Treatment ◽  
Drought Duration

Efficient carbon distribution and utilization may enhance drought survival and recovery ability for perennial grasses. The objectives of this study were to examine changes in carbon partitioning and carbohydrate accumulation patterns in shoots and roots of colonial bentgrass (Agrostis capillaris L.), creeping bentgrass (A. stolonifera L.), and velvet bentgrass (A. canina L.) in response to drought and re-watering following drought, and to determine whether species variation in drought tolerance and recuperative potential is related to differences in the patterns of carbon partitioning and accumulation. The experiment consisted of three treatments: 1) well-watered control; 2) drought, irrigation completely withheld for 18 days; and 3) drought recovery, a group of drought-stressed plants were re-watered at the end of the drought treatment (18 days). Drought tolerance and recuperative ability of three species was evaluated by measuring turf quality and leaf relative water content. These parameters indicated that velvet bentgrass was most drought tolerant while colonial bentgrass had highest recuperative ability among the three species. Plants were labeled with 14CO2 to determine carbon partitioning to shoots and roots. Carbohydrate accumulation was assessed by total nonstructural carbohydrate (TNC) content. The proportion of newly photosynthesized 14C partitioned to roots increased at 12 days of drought compared to the pre-stress level, to a greater extent for velvet bentgrass (45%) than for colonial bentgrass (35%) and creeping bentgrass (30%). In general, the proportion of 14C was highest in roots, intermediate in stems, and lowest in leaves at 12 days of drought treatment for all three bentgrass species. As drought duration and severity increased (18 days), 14C partitioning increased more in leaves and stems relative to that in roots for all three species. Stem TNC content was significantly greater for drought-stressed plants of colonial bentgrass and velvet bentgrass compared to their respective well-watered control plants, whereas no differences in stem TNC content were observed between drought-stressed and well-watered creeping bentgrass. Our results suggest that increased carbon partitioning to roots during initial drought stress represented an adaptive response of bentgrass species to short-term drought stress, and increased carbon partitioning and carbohydrate accumulation in stems during prolonged period of drought stress could be beneficial for rapid recovery of turf growth and water status upon re-watering.

scholarly journals Effects of drought stress on antioxidant enzymes in common bean (Phaseolus vulgaris L.) seedlings

2021 ◽  
pp. 873-878
Author(s):  
Zhengong Yin ◽  
Xianxin Meng ◽  
Qiang Wang ◽  
Yifan Guo ◽  
Shuhong Wei ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Drought Stress ◽  
Common Bean ◽  
Physiological Mechanism ◽  
Resistant Variety ◽  
Efficient Production ◽  
Severe Drought ◽  
Common Beans ◽  
Drought Treatment ◽  
Effects Of Drought

Drought is one of the most severe environmental constraints which reduces common bean production worldwide. Exploration of the physiological mechanism of common bean under drought stress is important for the efficient production and variety selection of common beans. In the present study, non-droughtresistant variety (Longyundou10) and drought-resistant variety (Longyundou17) were identified to elucidate the effects of drought stress on antioxidant system of common beans at seedling stage. Under drought stress, APX and SOD activities showed a single peak curve that first increased and then decreased, and the dynamic changes of CAT and POD activities were more complicated. Under different levels of drought treatment, the average values of APX, SOD, CAT and POD activities of common bean were found to be higher than those of normal water conditions, and the average values were the highest under severe drought stress, indicating that these antioxidant enzymes were stimulated under drought stress. Bangladesh J. Bot. 50(3): 873-878, 2021 (September) Special

scholarly journals Exogenous Application of Proline and Salicylic Acid can Mitigate the Injurious Impacts of Drought Stress on Barley Plants Associated with Physiological and Histological Characters

2020 ◽  
Vol 12 (5) ◽  
pp. 1736 ◽  
Author(s):  
Khaled A. A. Abdelaal ◽  
Kotb A. Attia ◽  
Salman F. Alamery ◽  
Mohamed M. El-Afry ◽  
Abdelhalim I. Ghazy ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Antioxidant Enzymes ◽  
Drought Stress ◽  
Grain Yield ◽  
Chlorophyll Concentration ◽  
Stem Length ◽  
Hordeum Vulgare L ◽  
Drought Treatment ◽  
Growing Seasons ◽  
Relative Water

Barley is a very important crop worldwide and has good impact in preserving food security. The impacts of 10 mM proline and 0.5 mM salicylic acid were evaluated on water stressed barley plants (Hordeum vulgare L. Giza126). Salicylic acid and proline treatments led to increased stem length, plant dry weights, chlorophyll concentration, relative water content, activity of antioxidant enzymes, and grain yield under drought stress. Nevertheless, lipid peroxidation, electrolyte leakage (EL), superoxide (O2·−), and hydrogen peroxide (H2O2) significantly decreased in treated barley plants with proline and salicylic acid in both growing seasons as compared with drought treatment only, which caused significant decrease in stem length, plant dry weights, chlorophyll concentration, activity of antioxidant enzymes, as well as biological and grain yield. These results demonstrated the importance of salicylic acid and proline as tolerance inducers of drought stress in barley plants.

scholarly journals Enhancement of proline content and antioxidant enzyme activities induced by drought stress in maize (Zea mays L.) by application of compost

2020 ◽  
Vol 13 (7) ◽  
pp. 2978-2990
Author(s):  
Atalaèsso Bokobana ◽  
Outendé Toundou ◽  
Komi Odah ◽  
Koffi S.S. Dossou ◽  
Koffi Tozo
Keyword(s):  
Zea Mays ◽  
Antioxidant Enzymes ◽  
Drought Stress ◽  
Water Deficit ◽  
Sandy Soil ◽  
Zea Mays L ◽  
Proline Content ◽  
Sub Saharan Africa ◽  
Antioxidant Enzyme Activities ◽  
Sub Saharan

In sub-Saharan Africa, soil degradation and recurrent droughts are major obstacles to a sustainable agriculture. This study aimed at investigating the effect of compost addition to soil on proline content and activities of the antioxidant enzymes [catalase (CAT), ascorbate peroxidase (APX)] in maize plants, under drought stress conditions. The test was carried out in 20L plastic pots containing either sandy soil or sandy soil with the fertilizer, under natural conditions. The water deficit was induced at male blooming and milky grain stages. Plant irrigation was done by successive weighing of the pots during which the control is reduced to the same weight corresponding to 70% of the useful water reserve (UWR), while the stressed treatment maintains the water content at 30% of the UWR for 10 days. At the end of the stress period, the proline content, the CAT and APX activities in the leaves were determined through a spectrophotometry. The results show an important accumulation of proline and increase in enzymatic activity induced by water deficit in plants grown on compost (p = 0.00000 at p < 0.05). This study provides evidence for a beneficial effect of compost application in enhancing drought tolerance of maize.Keywords: Drought stress; compost; proline; antioxidant enzymes; Zea mays L.

scholarly journals Physiological Responses of Handeliodendron bodinieri (Levl.) Rehd. to Exogenous Calcium Supply under Drought Stress

Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 69
Author(s):  
Xiuhui Leng ◽  
Liang Xue ◽  
Jia Wang ◽  
Sheng Li ◽  
Zhiling Yang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Physiological Responses ◽  
Soluble Sugar ◽  
H2o2 Production ◽  
Endemic Plant ◽  
Production Rates ◽  
Adaptation Mechanism ◽  
High Calcium ◽  
Mda Content ◽  
Exogenous Calcium

The soils in karst regions, with carbonate rocks as the background material, are characterized by two main factors, drought and high calcium levels. Handeliodendron bodinieri (Levl.) Rehd is an endemic plant species in this area of China. However, few studies have been carried out on the adaptation mechanism of H. bodinieri to drought and high calcium soil. To reveal the physiological responses of H. bodinieri to exogenous calcium under drought stress, 10% PEG-6000 was used to simulate drought stress, and the effects of exogenous calcium at different concentrations on the physiology of H. bodinieri seedlings under drought stress were studied. The results showed that drought stress significantly reduced the relative water content and water potential of H. bodinieri seedlings. Malondialdehyde (MDA) content, O2− and H2O2 production rates significantly increased under drought stress. The addition of exogenous calcium significantly reduced MDA content and O2− and H2O2 production rates. Moreover, peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), ascorbic acid peroxidase (APX) and glutathione peroxidase (GPX) activities increased significantly under drought stress. At the same time, the accumulation of osmotic regulators such as soluble sugar, betaine and free proline also increased significantly. The addition of exogenous calcium further increased the activity of antioxidant enzymes and the accumulation of osmotic regulatory substances. Consequently, the oxidative stress and osmotic stress induced by drought decreased. Finally, exogenous calcium enhanced the photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) of H. bodinieri under drought stress and significantly improved water use efficiency (WUE). This study confirmed that the application of exogenous calcium can enhance the water condition, photosynthetic capacity, osmotic regulation and antioxidant capacity of H. bodinieri under drought stress. Of the treatments, the 10 mmol·L−1 CaCl2 treatment is more likely to improve survival of H. bodinieri under drought tolerance. This study provides an important reference for describing the adaptation mechanism and appropriate conservation of H. bodinieri under drought and high calcium conditions.

scholarly journals Morphological, physiochemical and antioxidant responses of Maclura pomifera to drought stress

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alireza Khaleghi ◽  
Rohangiz Naderi ◽  
Cecilia Brunetti ◽  
Bianca Elena Maserti ◽  
Seyed Alireza Salami ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Drought Stress ◽  
Water Deficit ◽  
Recovery Period ◽  
Soluble Sugars ◽  
Field Capacity ◽  
Complete Recovery ◽  
Soluble Carbohydrates ◽  
Drought Period ◽  
Maclura Pomifera

AbstractDrought is one of the most important environmental factor limiting the growth of woody and non woody plants. In the present paper, we aimed to explore the performance of Maclura pomifera under a prolonged drought period followed by re-watering. M. pomifera plants were exposed to four different watering regimes (100%, 75%, 50% and 30% of the field capacity (FC)) for three weeks and then rewatered. The exposure to drought affected physiological, morphological and biochemical traits of M. pomifera. Leaf area, relative water content and water potential of leaf decreased in parallel with increased water deficit. Malondialdehyde content increased along with the drought stress experiment. Soluble carbohydrates (sucrose, glucose and fructose) accumulated during drought stress, but decreased after 22 days of water deficit in severe stressed plants (30% FC). Proline and mannitol, two compatible osmolytes, were higher in drought stresses plants than in control plants. Additionally the activity of antioxidant enzymes (SOD, APX, DHAR and GR) resulted affected by drought stress. In the recovery period, the physiological parameters as well as the proline content recovered at control levels, whereas soluble sugars, mannitol and total activity of antioxidant enzymes remained slight higher than in control plants, presumably to allow plants a complete recovery after stress. Our results suggest that M. pomifera has a good adaptive response to drought stress, probably corresponded to decreasing oxidative injury by induction of the antioxidant system and accumulation of stable and protective osmolytes such as proline and mannitol at higher rates.

scholarly journals Silver nanoparticles improve growth and protect against oxidative damage in eggplant seedlings under drought stress  

2021 ◽  
Author(s):  
Nadiyah M. Alabdallah ◽  
Md. Mahadi Hasan ◽  
Abdalrhaman M. Salih ◽  
S.S. Roushdy ◽  
Aisha S. Al-Shammari ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Drought Stress ◽  
Crop Production ◽  
Negative Impact ◽  
Growth Parameters ◽  
Low Cost ◽  
Dry Mass ◽  
Chl A ◽  
Mda Content ◽  
The Impact

Drought stress is a significant abiotic stressor that has a negative impact on crop production and global food security systems. Drought stress was applied to eggplant seedlings with various field capacities (FC), 80% FC as control, 50% FC, 35% FC, and 20% FC. AgNPs were synthesised from green chemical methods, whereas different concentrations of AgNPs (0, 0.1, 0.2, 0.5 µmol) were applied exogenously on drought-stressed eggplants. Drought stress decreased the growth parameters (plant height, fresh mass, dry mass, leaf area), photosynthetic pigments (Chl a, Chl b, carotenoids), and protein content while increased the proline, hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), malondialdehyde (MDA) content, and activity of the antioxidant enzymes, i.e., superoxide dismutase (SOD) and catalase (CAT). AgNPs restricted proline accumulation and reduced H<sub>2</sub>O<sub>2,</sub> MDA content by upregulating the antioxidant enzymes. Overall, the current study’s findings indicated that AgNPs are an effective eco-friendly and low-cost application for plant growth under drought stress, with the potential to mitigate the impact of drought on plants.

scholarly journals Differential responses of antioxidants and dehydrin expression in two switchgrass (Panicum virgatum) cultivars contrasting in drought tolerance

2018 ◽  
Author(s):  
Yiming Liu ◽  
Guofu Hu ◽  
Guoqiang Wu ◽  
Guodao Liu ◽  
Hengfu Huan ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Panicum Virgatum ◽  
Limiting Factor ◽  
Drought Treatment ◽  
Drought Tolerant ◽  
Genes Expression ◽  
Relative Water ◽  
Mda Content ◽  
Leaf Relative Water Content

AbstractDrought stress is a major limiting factor for plant growth and development in many regions of the world. This study was designed to investigate antioxidant metabolism and dehydrin expression responses to drought stress in two switchgrass cultivars (drought tolerant Alamo, and drought sensitive Dacotah) contrasting in drought tolerance. The plants were subjected to well-watered [100% evapotranspiration (ET)] or drought stress (30%-50% ET) conditions for up to 24 d in growth chambers. Drought stress decreased leaf relative water content (RWC), increased leaf electrolyte leakage (EL), leaf malondialdehyde (MDA) content in two cultivars, but Alamo exhibited higher leaf RWC level, lower leaf EL and MDA when compared to Dacotah at 24 d of drought treatment. Drought stress also increased superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activities in two cultivars, Alamo had relatively higher SOD, CAT and APX activities and greater abundance of SOD and APX isozymes than Dacotah at 24 d of drought treatment. Alamo had higher abundance of 55 KDa and 18 KDa dehydrin accumulation than Dacotah under drought treatment. Relative genes expression level of PvCAT1, PvAPX2, PvERD and PvPIP1;5 in Alamo were significantly higher than Dacotah at 24 d of drought treatment. These results suggest that increase in antioxidant enzymes and accumulation of dehydrin were highly related with switchgrass drought tolerance. Antioxidant enzyme activity, isozyme expression and dehydrin abundance could provide a useful screening tool to identify relative drought tolerance in switchgrass cultivars.

scholarly journals Growth and Physiology of Two Psammophytes to Precipitation Manipulation in Horqin Sandy Land, Eastern China

Plants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 244
Author(s):  
Juanli Chen ◽  
Xueyong Zhao ◽  
Xinping Liu ◽  
Yaqiu Zhang ◽  
Yayong Luo ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Drought Stress ◽  
Stress Resistance ◽  
Proline Content ◽  
Free Proline ◽  
Horqin Sandy Land ◽  
Community Succession ◽  
Sandy Land ◽  
Mda Content ◽  
Precipitation Reduction

The availability of water is the critical factor driving plant growth, physiological responses, population and community succession in arid and semiarid regions, thus a precipitation addition-reduction platform with five experimental treatments, was established to explore the growth and physiology of two psammophytes (also known as psammophiles) to precipitation manipulation in Horqin Sandy Land. Changes in coverage and density were measured, and antioxidant enzymes and osmoregulatory substances in both of the studied species were determined. Investigation results showed that the average vegetation coverage increased with an increasing precipitation, and reached a maximum in July. Under the −60% precipitation treatment, Tribulus terrestris accounted for a large proportion of the area, but Bassia dasyphylla was the dominant species in the +60% treatment. T. terrestris was found to have higher a drought stress resistance than B. dasyphylla. From days 4 to 7 after rainfall, B. dasyphylla under precipitation reduction showed obvious water stress. The malondialdehyde (MDA) content of B. dasyphylla was higher than that of T. terrestris, but that of B. dasyphylla had the lower relative water content (RWC). The MDA content in the precipitation reduction treatments of the two studied species was higher than that in the precipitation addition treatments from days 4 to 10. Peroxidase (POD) and superoxide dismutase (SOD) activity and the soluble proteins and free proline content of T. terrestris were higher than those of B. dasyphylla. The free proline content of T. terrestris and B. dasyphylla increased with increasing drought stress. Our data illustrated that T. terrestris had a higher drought stress resistance than B. dasyphylla, which was correlated with the augmentation of some antioxidant enzymes and osmoregulatory substance. The adaptive mechanism provides solid physiological support for an understanding of psammophyte adaptation to drought stress, and of community succession or species manipulation for desertified land restoration.

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