Physiological responses of Agriophyllum squarrosum and Setaria viridis to drought and re-watering

AbstractDrought resistance of psammophyte determines survival and growth, but their responses to drought are not well understood. We conducted a pot experiment to study how physiological characteristics respond to drought and rehydration. We found that watering to 60–65% of field capacity (the control) provided more water than was required by Agriophyllum squarrosum and its leaves became yellow and slightly wilted. The total chlorophyll content and Fm (maximum fluorescence after dark adaptation) in control were lower than in the drought treatment, and both decreased after rehydration. With increasing drought duration and intensity, the relative water content (RWC), chlorophyll content, Fm, and the quantum efficiency of photosystem II (Fv/Fm) of Setaria viridis decreased, but malondialdehyde and membrane permeability increased. During the late drought, the activities of three antioxidant enzymes in A. squarrosum increased to prevent membrane lipid peroxidation; for S. viridis, only peroxidase and superoxide dismutase activities increased. After rehydration, RWC of both species increased, but Fv/Fm of A. squarrosum and Fm of S. viridis did not recover under severe drought. Our research illustrated that A. squarrosum is better adapted to arid environment than S. viridis, but the high soil moisture content is not conducive to normal growth of A. squarrosum.

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Physiological Responses of Agriophyllum Squarrosum and Setaria Viridis to Drought and Re-watering

10.21203/rs.3.rs-182119/v1 ◽

2021 ◽

Author(s):

Juanli Chen ◽

Xueyong Zhao ◽

Yuqiang Li ◽

Yongqing Luo ◽

Yaqiu Zhang ◽

...

Keyword(s):

Membrane Permeability ◽

Chlorophyll Content ◽

Field Capacity ◽

Membrane Lipid ◽

Severe Drought ◽

Setaria Viridis ◽

Drought Treatment ◽

Drought Duration ◽

Drought Period ◽

Agriophyllum Squarrosum

Abstract The drought resistance of psammophytes determines their survival and growth under natural conditions or after transplanting. However, their responses to drought are not well understood. Agriophyllum squarrosum is a pioneer psammophyte in Horqin sandy land’s vegetation community, and Setaria viridis is the climax species. We conducted a pot experiment with both species to study how their physiological characteristics respond to drought and rehydration. We found that watering to 60 and 65% of field capacity (the control) provided more water than was required by A. squarrosum, and its leaves became yellow and slightly wilted. The total chlorophyll content and Fm (maximum fluorescence after dark adaptation) were lower than in the drought treatment, and both decreased after rehydration. With increasing drought duration, the chlorophyll content and Fm of A. squarrosum under moderate and severe drought first increased and then decreased, malondialdehyde levels and membrane permeability increased, but the quantum efficiency of photosystem II (Fv/Fm) decreased. With increasing drought duration and intensity, the relative water content (RWC), chlorophyll content, Fm, and Fv/Fm of S. viridis decreased, but malondialdehyde levels and membrane permeability increased. During the late drought period, levels of A. squarrosum’s three antioxidant enzymes increased to prevent membrane lipid peroxidation; for S. viridis, only peroxidase and superoxide dismutase levels increased. After rehydration, RWC of both plants increased, but the chlorophyll content decreased. Fv/Fm of A. squarrosum and Fm of S. viridis did not recover after severe drought. Our results provide insights into psammophyte adaptation to drought stress to support ecological restoration and reconstruction.

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Effects of drought at different periods of wheat development on the leaf photosynthetic apparatus and productivity

Regulatory Mechanisms in Biosystems ◽

10.15421/021961 ◽

2019 ◽

Vol 10 (4) ◽

pp. 406-414

Author(s):

V. V. Morgun ◽

O. O. Stasik ◽

D. A. Kiriziy ◽

O. G. Sokolovska-Sergiienko ◽

N. M. Makharynska

Keyword(s):

Soil Moisture ◽

Chlorophyll Content ◽

Stem Elongation ◽

Flag Leaf ◽

Photosynthetic Apparatus ◽

Field Capacity ◽

Crop Productivity ◽

Drought Treatment ◽

Drought Impact ◽

Grain Productivity

The problem of drought impact on crop productivity is especially relevant for the leading cereal – wheat, since significant cultivation areas of this crop are located in risky farming zones. The aim of our studies was to compare the peculiarities of drought impact during the period of vegetative growth and reproductive development on the chlorophyll content, activity of chloroplast antioxidant enzymes, the rate of carbon dioxide gas exchange and transpiration as well as productivity of the wheat plants. The studies were carried out on bread winter wheat plants (Triticum aestivum L.) of the Astarta and Natalka varieties grown in a pot experiment. The plants were watered daily to maintain the soil moisture level in the pots in the range 70–60% of field capacity. Drought treatment involving decrease in soil moisture to 30% of the field capacity was applied to some of the plants at late stem elongation stage (BBCH 37-45) and to other plants at heading-anthesis (BBCH 59-65) while control plants were watered as usual. After 7 days of drought, the watering of treated plants was resumed to maintain the soil moisture at the level of control plants until the harvest. The penultimate leaf at the late stem elongation stage and flag leaf at the heading–anthesis period were used for measurements of photosynthetic apparatus response to drought. Plants of both varieties treated at stem elongation stage showed lower decline in the photosynthetic activity, chlorophyll content and grain productivity than those treated at heading-anthesis. The results obtained indicated that photosynthetic apparatus of wheat has a higher drought tolerance at the stem elongation stage than during the heading-anthesis stage. Furthermore, plants stressed at the stem elongation stage revealed better compensatory growth of lateral productive shoots due to superior supply of plants with assimilates after drought termination. Astarta variety had a more drought-tolerant photosynthetic apparatus and higher grain productivity in both well-watered and drought conditions as compared to Natalka variety. The differences between varieties were more contrasting when drought was applied at heading-anthesis.

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The role of calcium in drought stress response induced through antioxidant activity in oil palm (Elaeis guineensis Jacq.) seedlings

E-Journal Menara Perkebunan ◽

10.22302/iribb.jur.mp.v89i1.425 ◽

2021 ◽

Vol 89 (1) ◽

Author(s):

Endah NURWAHYUNI ◽

Eka Tarwaca Susila PUTRA

Keyword(s):

Drought Stress ◽

Oil Palm ◽

Elaeis Guineensis ◽

Essential Element ◽

Field Capacity ◽

Severe Drought ◽

Enzymatic Antioxidants ◽

Drought Treatment ◽

Sod Activity ◽

Effects Of Drought

Oil palm productivity in Indonesia faces challenges related to drought that occur during the dry season. Calcium is an element that plays a role in determining the response of plant resistance to drought through biochemical activity. This study aims to determine the contribution of calcium in biochemical mechanisms involving various antioxidants. The treatment was arranged in factorial of 3 x 4 in a split-plot design. The first factor was calcium dosage, which consisted of 0 g (control/without calcium), 0.04 g, 0.08 g, and 0.12 g of calcium per plant. The second factor was the intensity of drought stress, referred as the Fraction of Transpirable Soil Water (FTSW) at 1 (control/field capacity), 0.35 (moderate drought), and 0.15 (severe drought) with a week duration of intensity. Calcium was applied in a ring placement on four-month-old seedlings planted in 40 x 40 cm polybags with alfisol soil planting medium and given drought treatment two months later for three weeks. The results showed that calcium could induce plant response to drought through the increase in superoxide dismutase (SOD) activity, the decrease in hydrogen peroxide (H₂O₂) concentration, and the decrease in malondialdehyde (MDA) concentration. The study concluded that calcium is an essential element used to reduce the effects of drought on oil palm seedlings through the change of biochemical activities regulated by enzymatic antioxidants.

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Comparative Proteomics of Root Apex and Root Elongation Zones Provides Insights into Molecular Mechanisms for Drought Stress and Recovery Adjustment in Switchgrass

Proteomes ◽

10.3390/proteomes8010003 ◽

2020 ◽

Vol 8 (1) ◽

pp. 3 ◽

Cited By ~ 2

Author(s):

Zhujia Ye ◽

Sasikiran Reddy Sangireddy ◽

Chih-Li Yu ◽

Dafeng Hui ◽

Kevin Howe ◽

...

Keyword(s):

Mass Spectrometry ◽

Drought Stress ◽

Molecular Mechanisms ◽

Root Zone ◽

Root Apex ◽

Root Tip ◽

Leaf Water Content ◽

Severe Drought ◽

Proteomics Data ◽

Drought Treatment

Switchgrass plants were grown in a Sandwich tube system to induce gradual drought stress by withholding watering. After 29 days, the leaf photosynthetic rate decreased significantly, compared to the control plants which were watered regularly. The drought-treated plants recovered to the same leaf water content after three days of re-watering. The root tip (1cm basal fragment, designated as RT1 hereafter) and the elongation/maturation zone (the next upper 1 cm tissue, designated as RT2 hereafter) tissues were collected at the 29th day of drought stress treatment, (named SDT for severe drought treated), after one (D1W) and three days (D3W) of re-watering. The tandem mass tags mass spectrometry-based quantitative proteomics analysis was performed to identify the proteomes, and drought-induced differentially accumulated proteins (DAPs). From RT1 tissues, 6156, 7687, and 7699 proteins were quantified, and 296, 535, and 384 DAPs were identified in the SDT, D1W, and D3W samples, respectively. From RT2 tissues, 7382, 7255, and 6883 proteins were quantified, and 393, 587, and 321 proteins DAPs were identified in the SDT, D1W, and D3W samples. Between RT1 and RT2 tissues, very few DAPs overlapped at SDT, but the number of such proteins increased during the recovery phase. A large number of hydrophilic proteins and stress-responsive proteins were induced during SDT and remained at a higher level during the recovery stages. A large number of DAPs in RT1 tissues maintained the same expression pattern throughout drought treatment and the recovery phases. The DAPs in RT1 tissues were classified in cell proliferation, mitotic cell division, and chromatin modification, and those in RT2 were placed in cell wall remodeling and cell expansion processes. This study provided information pertaining to root zone-specific proteome changes during drought and recover phases, which will allow us to select proteins (genes) as better defined targets for developing drought tolerant plants. The mass spectrometry proteomics data are available via ProteomeXchange with identifier PXD017441.

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DEHYDRIN PROFILES OF SOME IRANIAN MELON VARIETIES (Cucumis melo L. Merr) UNDER DROUGHT STRE SS CONDITIONS

Acta Scientiarum Polonorum Hortorum Cultus ◽

10.24326/asphc.2019.6.8 ◽

2019 ◽

Vol 18 (6) ◽

pp. 75-84

Author(s):

Alireza Motallebi-Azar ◽

István Papp ◽

Anita Szegő

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Water Content ◽

Water Status ◽

Field Capacity ◽

Total Protein Content ◽

Severe Drought ◽

Molecular Weights ◽

Potential Marker ◽

Relative Water

Dehydrins are proteins that play a role in the mechanism of drought tolerance. This study aimed at establishing dehydrin profile and accumulation in four local melon varieties of Iran: Mino, Dargazi, Saveii, and Semsori, as well as in a commercial variety Honeydew. Plants were treated with drought stress by adjusting the soil water content to 75, 50, 40, 30 and 20% of field capacity (FC) by withholding water. Water status of plants was monitored based on the seedling fresh weight (FW) and relative water content of leaves (RWC). Total protein content was extracted, then heat-stable protein (HSP) fraction was isolated for each variety and water stress treatment. After SDS-PAGE of HSP, Western blotting analysis was carried out with Anti-dehydrin rabbit (primary) and Goat anti rabbit (secondary) antibodies. ANOVA results showed that with decreasing FC below 75%, FW and RWC decreased, but these changes significantly varied among genotypes. On the basis of FW and RWC data under different drought stress treatments, the following drought-tolerant ranking was established: Mino > Dargazi > Saveii and Honeydew > Semsori, from tolerant to sensitive order. Results of Western blot analysis showed that expression of some proteins with molecular weights of 19–52 kDa was induced in the studied varieties under drought stress (% FC). Expression level of the dehydrin proteins in different varieties was variable and also depending on the drought stress level applied. However, dehydrin proteins (45 and 50 kDa) showed strong expression levels in all varieties under severe drought stress (20% FC). The abundance of dehydrin proteins was higher in tolerant varieties (Mino and Dargazi) than in moderate and drought sensitive genotypes. Consequently, dehydrins represent a potential marker for selection of genotypes with enhanced drought tolerance.

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Function Analysis of Drought Resistance Related Gene TaGAPCs and TaWRKYs in Wheat

10.21203/rs.3.rs-565097/v1 ◽

2021 ◽

Author(s):

Qiuzhu Wang ◽

Lin Zhang ◽

Shushen Yang

Keyword(s):

Transcription Factors ◽

Drought Stress ◽

Function Analysis ◽

Severe Drought ◽

Primary Metabolism ◽

Wild Type ◽

Drought Treatment ◽

Biological Regulation ◽

Wheat Seedlings ◽

Differential Genes

Abstract Backgrounds: Wheat (Triticum aestivum L.) is one of the most important food crops in the world. It faces various abiotic stresses during its growth. Drought is one of the main factors limiting the growth and development of wheat. Severe drought stress will Lead to a decline in wheat production. Cytoplasmic glyceraldehyde-3-phosphate dehydrogenase (GAPC) is an important member of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) family, which is widely present in plant cytoplasm. Plants play an important role in the process of primary metabolism and stress resistance.Result: In this study, a comparative transcriptomic analysis of the TaGAPCs-RNAi strain of Changwu 134 and the wild-type wheat seedlings of Changwu 134 under natural drought conditions was carried out. A total of 30067 differentially expressed genes were screened in RNAi strains and wild-type strains, of which 19,959 genes were up-regulated in RNAi strains and 10,108 genes were down-regulated in transcription. GO analysis shows that differential genes are mainly enriched in biological regulation, cellular processes, metabolic processes, and responses to stimuli. KEGG analysis showed that the differential genes were mainly concentrated in the biosynthesis of phenylpropane, plant hormone signal transduction and flavonoid biosynthesis pathways. By analyzing the expression levels of differential transcription factors, the significantly down-regulated transcription factor WRKY family member TaWRKY2 / 22/28/29/33/40/47/52 in wheat was screened out. The TaWRKY28/33/40/47 gene silencing line was successfully obtained using the barley stripe mosaic virus (BSMV-VIGS) technology. The plants with TaWRKY28/33/40/47 gene silenced were subjected to natural drought treatment, and physiological and biochemical index tests were carried out. The results showed that the growth status of gene-silenced plants was worse than that of wild-type plants, and the relative water content and chlorophyll content decreased. The content of MDA, H2O2 and superoxide anion increases, the activity of antioxidant enzymes (SOD, POD, CAT) decreases, and the content of proline decreases. Conclusion: The results showed that TaGAPCs regulates the expression of some TaWRKYs transcription factors, activates antioxidant pathways, enhances tolerance of wheat to drought stress.

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Lipid remodelling plays an important role in wheat (Triticum aestivum) hypoxia stress

Functional Plant Biology ◽

10.1071/fp19150 ◽

2020 ◽

Vol 47 (1) ◽

pp. 58 ◽

Cited By ~ 1

Author(s):

Le Xu ◽

Rui Pan ◽

Meixue Zhou ◽

Yanhao Xu ◽

Wenying Zhang

Keyword(s):

Triticum Aestivum ◽

Oxygen Deficiency ◽

Normal Growth ◽

Triticum Aestivum L ◽

Growth Conditions ◽

Membrane Lipid ◽

Hypoxia Stress ◽

Phosphatidic Acids ◽

Hypoxia Treatment ◽

Lower Expression

Membrane lipid remodelling is one of the strategies that plants have developed to combat abiotic stress. In this study, physiological, lipidomic and proteome analyses were conducted to investigate the changes in glycerolipid and phospholipid concentrations in the wheat (Triticum aestivum L.) cultivars CIGM90.863 and Seri M82 under hypoxia treatment. The growth of CIGM90.863 remained unaffected, whereas Seri M82 was significantly stunted after 8 days of hypoxia treatment. The concentrations of all lipids except lysophosphatidylglycerol were significantly higher in the leaves of Seri M82 than in CIGM90.863 under normal growth conditions. The lipid profile changed significantly under hypoxia stress and varied between genotypes for some of the lipids. Phosphatidic acids remained unchanged in Seri M82 but they were gradually induced in CIGM90.863 in response to hypoxia stress because of the higher phospholipase D expression and lower expression of diglycerol kinase and phosphatidate phosphatases. In contrast, digalactosyldiacylglycerol content was highly stable in CIGM90.863 following hypoxia treatment, although it decreased significantly in Seri M82. Phosphatidylglycerol and lipoxygenase showed a stronger and faster response in CIGM90.863 than in Seri M82 under hypoxia stress. Different membrane lipid adjustments in wheat under oxygen deficiency conditions could be partly responsible for the differing tolerance of Seri M82 and CIGM90.863. This study will help us to better understand how wheat tolerates hypoxia stress by regulating lipid remodelling.

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Effects of Drought and Rehydration on the Physiological Responses of Artemisia halodendron

Water ◽

10.3390/w11040793 ◽

2019 ◽

Vol 11 (4) ◽

pp. 793

Author(s):

Juanli Chen ◽

Xueyong Zhao ◽

Yaqiu Zhang ◽

Yuqiang Li ◽

Yongqing Luo ◽

...

Keyword(s):

Chlorophyll Fluorescence ◽

Drought Stress ◽

Membrane Permeability ◽

Chlorophyll Content ◽

Physiological Responses ◽

Severe Drought ◽

Native Plant ◽

Chlorophyll Fluorescence Parameters ◽

Artemisia Halodendron ◽

Effects Of Drought

Artemisia halodendron is a widely distributed native plant in China’s Horqin sandy land, but few studies have examined its physiological responses to drought and rehydration. To provide more information, we investigated the effects of drought and rehydration on the chlorophyll fluorescence parameters and physiological responses of A. halodendron to reveal the mechanisms responsible for A. halodendron’s tolerance of drought stress and the resulting ability to tolerate drought. We found that A. halodendron had strong drought resistance. Its chlorophyll content first increased and then decreased with prolonged drought. Variable chlorophyll fluorescence (Fv) and quantum efficiency of photosystem II (Fv/Fm) decreased, and the membrane permeability and malondialdehyde increased. When plants were subjected to drought stress, superoxide dismutase (SOD) activity degraded under severe drought, but the activities of peroxidase (POD) and catalase (CAT) and the contents of soluble proteins, soluble sugars, and free proline increased. Severe drought caused wilting of A. halodendron leaves and the leaves failed to recover even after rehydration. After rehydration, the chlorophyll content, membrane permeability, SOD and CAT activities, and the contents of the three osmoregulatory substances under moderate drought began to recover. However, Fv, Fv/Fm, malondialdehyde, and POD activity did not recover under severe drought. These results illustrated that drought tolerance of A. halodendron resulted from increased enzyme (POD and CAT) activities and accumulation of osmoregulatory substances.

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Dark Island heath (Ninety-mile Plain, South Australia). V. The water relationships in heath vegetation and pastures on the Makin sand

Australian Journal of Botany ◽

10.1071/bt9570151 ◽

1957 ◽

Vol 5 (2) ◽

pp. 151 ◽

Cited By ~ 22

Author(s):

RL Specht

Keyword(s):

Soil Moisture ◽

Balance Sheet ◽

South Australia ◽

Field Capacity ◽

Severe Drought ◽

Soil Moisture Storage ◽

Drought Conditions ◽

Moisture Storage ◽

Medicago Sativa L ◽

Soil Moisture Status

Heath vegetation shows a major flush of growth during the mediterraneantype summer season, a time when calculations of the soil moisture storage by the techniques of Thornthwaite (1948) or Prescott, Collins, and Shirpurkar (1952) indicate that severe drought conditions should oocur. Monthly observations on the moisture status of the Makin sand under heath vegetation and, for comparison, under various pastures are therefore recorded. The problems of obtaining an accurate water balance-sheet for such a heterogeneous vegetation as the heath are discussed. Difficulties in the use of the various techniques for measuring soil moisture in sand, which has a low pF of 1.85 at field capacity, are enumerated. The following relationships were found between the evapotranspiration index (Itr = Etr / Ew0.75) and the available water (W). These data were calculated for 6 ft of sand. (i) Heath vegetation (10–14 years old) log (2.4–Itr) = 0.420–0.0383 W (ii) Heath vegetation (burnt) log (2.4–Itr) = 0.461–0.0380 W (iii) Oenothera odorata Jacq. pasture log (2.4–Itr) = 0.395–0.0269 W (iv) Medicago sativa L. pasture log (2.4–Itr) = 0.390–0.0270 W (v) Ehrharta calycina Sm. pasture log (2.4–Itr) = 0.400–0.0339 W From these equations the mean monthly quantities of rainfall which may be stored in 6 ft of sand under the various treatments described were calculated. Drought conditions are shown to occur in December and January, but are relieved in the later months of summer. Even if the stored moisture below 8 ft is considered, the soil moisture status would be expected to be just sufficient to maintain the vegetation in a "dormant" state, and yet the major growth of the heath vegetation occurs at this time. The calculated mean annual values of Itr range from 0.53 to 0.60 for these perennial communities. Close approximations to the actual soil moisture status can be obtained by substituting these values for K in Prescott's formula for potential evaporation, i.e. Etr = K x Ew0.75. Supplementary data on transpiration, growth, and the root systems of the pastures are also included.

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Regionalization and Spatiotemporal Variation of Drought in China Based on Standardized Precipitation Evapotranspiration Index (1961–2013)

Advances in Meteorology ◽

10.1155/2015/950262 ◽

2015 ◽

Vol 2015 ◽

pp. 1-18 ◽

Cited By ~ 25

Author(s):

Xiongfei Liu ◽

Shixin Wang ◽

Yi Zhou ◽

Futao Wang ◽

Wenjun Li ◽

...

Keyword(s):

Southern China ◽

Central China ◽

Tibet Plateau ◽

Severe Drought ◽

Standardized Precipitation Evapotranspiration Index ◽

Spatiotemporal Variations ◽

Drought Duration ◽

Mk Test ◽

Tree Edge ◽

Edge Removal

China is considered to be one of the most drought prone countries. This study is dedicated to analyzing the regionalization and spatiotemporal variations of drought based on the Standardized Precipitation Evapotranspiration Index, which covers the period 1961–2013 across 810 stations in China. Using Spatial “K”luster Analysis by Tree Edge Removal method, China was divided into eight regions: southwest (SW), northeast (NE), north (N), southeast (SE), Yangtze River (YR), northwest (NW), central China (C), and Tibet Plateau (TP). The spatiotemporal variations of drought characteristics indicated that the drought count in NE and C was generally high. Southern China and NW had suffered long drought duration and extreme severity. The MK test results show that stations with significant drying trends mainly locate in SW, N, NW, and C. The severe drought frequency was very high in 1990s and 2000s. Furthermore, more attention should be paid to abnormal less precipitation in summer and abnormal high temperature in spring in SW, NE, N, and C. Besides, abnormal less precipitation is the main factor of drought in SE and YR in whole year. This study is anticipated to support the water resources management, and to promote the realization of environmental protection and agricultural production.

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