Distinct growth and physiological responses of Arabidopsis thaliana natural accessions to drought stress and their detection using spectral reflectance and thermal imaging

2017 ◽  
Vol 44 (3) ◽  
pp. 312 ◽  
Author(s):  
Karel Klem ◽  
Kumud B. Mishra ◽  
Kateřina Novotná ◽  
Barbora Rapantová ◽  
Petra Hodaňová ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Drought Stress ◽  
Leaf Area ◽  
Thermal Imaging ◽  
Spectral Reflectance ◽  
Stomatal Closure ◽  
Substantial Reduction ◽  
Co2 Assimilation ◽  
Physiological Processes ◽  
Relative Water

Reduced growth and stomatal closure are the two main responses of plants to drought stress. The extent to which these processes are connected and whether different genotypes prefer one over the other remains unclear. To understand the genotype-specific interconnections of these two processes and evaluate potential utilisation of this knowledge for drought tolerance phenotyping, six natural accessions of Arabidopsis thaliana (L.) Heynh. were exposed to drought stress for 10 days. Projected leaf area of rosette, light-saturated CO2 assimilation rate (Amax), relative water content (RWC), leaf temperature (thermal imaging), and spectral reflectance were measured through the course of induced drought stress. Three types of acclimation were identified: (i) growth not affected but Amax significantly reduced, (ii) both growth and Amax significantly reduced, and (iii) growth significantly reduced but only small decrease in Amax. Within the last type, the smallest decline in RWC was evident. These results show that a substantial reduction in leaf area may cause a decline in transpiration that enables maintenance of both RWC and physiological processes. Both non-invasive thermal imaging and spectral reflectance measurements proved reliable tools for tracking drought-induced changes in Amax and RWC across all accessions tested and thus are effective tools for phenotyping stress tolerance.

scholarly journals Isolation, purification and characterization of an ascorbate peroxidase from celery and overexpression of the AgAPX1 gene enhanced ascorbate content and drought tolerance in Arabidopsis

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jie-Xia Liu ◽  
Kai Feng ◽  
Ao-Qi Duan ◽  
Hui Li ◽  
Qing-Qing Yang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Ascorbate Peroxidase ◽  
Drought Resistance ◽  
Stomatal Closure ◽  
High Survival ◽  
Gene Encoding ◽  
Sds Page ◽  
Relative Water ◽  
New Evidence

Abstract Background Celery is a widely cultivated vegetable abundant in ascorbate (AsA), a natural plant antioxidant capable of scavenging free radicals generated by abiotic stress in plants. Ascorbate peroxidase (APX) is a plant antioxidant enzyme that is important in the synthesis of AsA and scavenging of excess hydrogen peroxide. However, the characteristics and functions of APX in celery remain unclear to date. Results In this study, a gene encoding APX was cloned from celery and named AgAPX1. The transcription level of the AgAPX1 gene was significantly upregulated under drought stress. AgAPX1 was expressed in Escherichia coli BL21 (DE3) and purified. The predicted molecular mass of rAgAPX1 was 33.16 kDa, which was verified by SDS-PAGE assay. The optimum pH and temperature for rAgAPX1 were 7.0 and 55 °C, respectively. Transgenic Arabidopsis hosting the AgAPX1 gene showed elevated AsA content, antioxidant capacity and drought resistance. Less decrease in net photosynthetic rate, chlorophyll content, and relative water content contributed to the high survival rate of transgenic Arabidopsis lines after drought. Conclusions The characteristics of APX in celery were different from that in other species. The enhanced drought resistance of overexpressing AgAPX1 in Arabidopsis may be achieved by increasing the accumulation of AsA, enhancing the activities of various antioxidant enzymes, and promoting stomatal closure. Our work provides new evidence to understand APX and its response mechanisms to drought stress in celery.

Hydrogen sulfide mediates ion fluxes inducing stomatal closure in response to drought stress in Arabidopsis thaliana

2017 ◽  
Vol 419 (1-2) ◽  
pp. 141-152 ◽  
Author(s):  
Zhuping Jin ◽  
Zhiqing Wang ◽  
Qingxia Ma ◽  
Limin Sun ◽  
Liping Zhang ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Hydrogen Sulfide ◽  
Drought Stress ◽  
Stomatal Closure ◽  
Ion Fluxes

scholarly journals 278 Gas Exchange and Water Relations of Diverse Tall Fescue Cultivars in Response to Drought Stress

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 490C-490
Author(s):  
Bingru Huang ◽  
Hongwen Gao
Keyword(s):  
Drought Stress ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Stomatal Closure ◽  
Photochemical Efficiency ◽  
Physiological Factors ◽  
Relative Water

To investigate shoot physiological responses to drought stress of six tall fescue (Festuca arundinacea) cultivars representing several generations of turfgrass improvement, forage-type `Kentucky-31', turf-type `Phoenix', `Phoenix', and `Houndog V', and dwarf-type `Rebel Jr` and `Bonsai' were grown in well-watered or drying soil for 35 days in a greenhouse. Net photosynthetic rate (Pn), stomatal conductance (gs), transpiration rate (Tr), relative water content (RWC), and photochemical efficiency (Fv/Fm) declined during drought progression in all cultivars, but the time and the severity of reductions varied with cultivars and physiological factors. Pn, RWC, gs, and Tr decreased significantly for `Rebel Jr', `Bonsai', and `Phoenix' when soil water content declined to 20% after 9 days of treatment (DOT) and for `Falcon II', `Houndog V', and `Kentucky-31' when soil water content dropped to 10% at 15 DOT. A significant decrease in Fv/Fm was not observed in drought-stressed plants until 21 DOT for `Rebel Jr', `Bonsai', and `Phoenix' and 28 DOT for `Houndog V', `Kentucky-31', and `Falcon II'. The decline in Pn was due mostly to internal water deficit and stomatal closure under short-term or mild drought-stress conditions. After a prolonged period of drought (35 DOT), higher Pn in `Falcon II', `Houndog V', and `Kentucky-31' could be attributed to their higher Fv/Fm.

scholarly journals Evaluation of drought and UV radiation impacts on above-ground biomass of mountain grassland by spectral reflectance and thermal imaging techniques

Beskydy ◽  
2016 ◽  
Vol 9 (1-2) ◽  
pp. 21-30 ◽  
Author(s):  
Kateřina Novotná ◽  
Karel Klem ◽  
Petr Holub ◽  
Barbora Rapantová ◽  
Otmar Urban
Keyword(s):  
Drought Stress ◽  
Uv Radiation ◽  
Biomass Production ◽  
Thermal Imaging ◽  
Spectral Reflectance ◽  
Canopy Temperature ◽  
Stress Factors ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Mountain Grassland

Drought represents one of the major factors limiting productivity of managed and natural ecosystems. Under natural field conditions drought is often associated with other stress factors such as high temperature and UV radiation, which may result in enhancement or vice versa alleviation of drought impact. Remote sensing methods have a large potential to evaluate impacts of drought on plant production at regional scale. The main objective of this study was to analyse the potential of ground-based measurement of spectral reflectance and thermal imaging for monitoring the impacts of drought and UV radiation on above-ground biomass production of mountain grassland ecosystem. Experimental rain-out shelters were used to manipulate incident precipitation and UV radiation for 7 weeks (May–July). A canopy spectral reflectance, thermal images, and total above-ground biomass were determined at the end of drought and UV treatment. Results show that drought led to a significant reduction of above-ground biomass, particularly under ambient UV radiation. In contrary, UV had only negligible effect on biomass production. Canopy temperature as well as selected spectral reflectance indices showed significant response to drought stress and also significant relationships to above-ground biomass. However, the relationship between canopy temperature and above-ground biomass is modified by UV radiation. Best prediction of changes in biomass caused by drought stress was provided by vegetation index NDVI.

scholarly journals Physiological, Growth, and Biomass Attributes in Populus deltoides L. (clones G-48 and Kranti) Influenced by Water Stress

2013 ◽  
Vol 39 (5) ◽  
Author(s):  
Munna Singh ◽  
Aradhna Kumari ◽  
Krishan Kumar Verma
Keyword(s):  
Leaf Area ◽  
Populus Deltoides ◽  
Agronomic Traits ◽  
Field Capacity ◽  
Co2 Assimilation ◽  
Plant Performance ◽  
Stem Cuttings ◽  
Full Field ◽  
Co2 Diffusion ◽  
Relative Water

Six-week-old uniform cottonwood seedlings (clones G-48 and Kranti) were raised from stem cuttings and subjected under two different water regimes (full and half field capacity) up to 60 days under open field conditions. The higher and lower regulations of physiological responses were triggered in case these seedlings irrigated up to their full and half-field capacities. The enhanced A value was observed from 13–19 and 12–14 μmol m-2s-1 in clones G-48 and Kranti after subjecting them under irrigation to the level of full field capacity. The withdrawal of irrigation to the level of half field capacity could reduce these values (≤50%), significantly. The decreased CO2 assimilation during drought stress was found to be correlated with decline in transpiration, largely regulated by stomatal dynamics to restrict CO2 diffusion, which also impaired carboxylation. Upon experiencing drought, the progressive loss in maximum quantum yield of photosystem II photochemistry (Fv/ Fm) and CO2 assimilation was found to be correlated with the loss in transpiration in both these clones. Consequently, the study reveals that irrigation to the level of half field capacity for a period of 60 days impaired agronomic traits viz., plant height, number of leaves, leaf area expansion, specific leaf area, relative water content, biomass, and harvest index, significantly. It also concludes susceptibility of clones G-48 and Kranti toward drought in relation to plant performance (i.e., CO2 assimilation, Fv/Fm, and biomass yield).

scholarly journals Enhanced tolerance to drought stress resulting from Caragana korshinskii CkWRKY33 in transgenic Arabidopsis thaliana

2020 ◽  
Author(s):  
Zhen Li ◽  
Fengping Liang ◽  
Tianbao Zhang ◽  
Na Fu ◽  
Xinwu Pei ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Drought Stress ◽  
Stress Responses ◽  
Soluble Sugar ◽  
Survival Rates ◽  
Wrky Transcription Factor ◽  
Water Soluble ◽  
Caragana Korshinskii ◽  
Group I ◽  
Relative Water

Abstract Background: It is well known that WRKY transcription factors play important roles in plant growth and development, defense regulation and stress responses.Results: In this study, a WRKY transcription factor, WRKY33, was cloned from Caragana korshinskii. A sequence structure analysis showed that it belonged to the Group-I type. Subcellular localization experiments in tobacco epidermal cells showed the presence of CkWRKY33 in the nucleus. Additionally, CkWRKY33 was overexpressed in Arabidopsis thaliana. A phenotypic investigation revealed that compared with wild-type plants CkWRKY33-overexpressing transgenic plants had higher survival rates, as well as relative water, soluble sugar, proline and peroxidase contents, but lower malondialdehyde contents, following a drought stress treatment.Conclusions: This suggested that the overexpression of CkWRKY33 led to an enhanced drought-stress tolerance in transgenic A. thaliana. Thus, CkWRKY33 may act as a positive regulator involved in the drought-stress responses in Caragana korshinskii.

Leaf morphology, photochemistry and water status changes in resprouting Quercus ilex during drought

2005 ◽  
Vol 32 (2) ◽  
pp. 117 ◽  
Author(s):  
Karen Peña-Rojas ◽  
Xavier Aranda ◽  
Richard Joffre ◽  
Isabel Fleck
Keyword(s):  
Drought Stress ◽  
Quercus Ilex ◽  
Structural Characteristics ◽  
Water Status ◽  
Stomatal Closure ◽  
Severe Drought ◽  
Clear Cut ◽  
Leaf Mass Area ◽  
Relative Water ◽  
Moderate Drought

Functional and morphological (structural) characteristics of Quercus ilex L. leaves under drought stress were studied in the forest and in a nursery. We compared undisturbed individuals (controls) with resprouts emerging after clear-cut or excision. When soil water availability was high, gas-exchange was similar in resprouts and controls, despite higher midday leaf water potential, midday leaf hydration and relative water content (RWC). In moderate drought, stomatal closure was found to limit photosynthesis in controls, and in severe drought non-stomatal limitations of photosynthesis were also greater than in resprouts. Leaf structure and chemical composition changed under drought stress. Leaves tended to be smaller in controls with increasing drought, and resprouts had larger leaves and lower leaf mass area (LMA). The relationship between nitrogen (N) content and LMA implied lower N investment in photosynthetic components in controls, which could be responsible for their increased non-stomatal limitation of photosynthesis. Changes were more apparent in leaf density (D) and thickness (T), components of LMA. Decreases in D were related to reductions in cell wall components: hemicellulose, cellulose and lignin. In resprouts, reduced D and leaf T accounted for the higher mesophyll conductance (gmes) to CO2 measured.

scholarly journals Activation of the ABA Signal Pathway Mediated by GABA Improves the Drought Resistance of Apple Seedlings

2021 ◽  
Vol 22 (23) ◽  
pp. 12676
Author(s):  
Chenlu Liu ◽  
Hongtao Wang ◽  
Xiuzhi Zhang ◽  
Fengwang Ma ◽  
Tianli Guo ◽  
...  
Keyword(s):  
Drought Stress ◽  
Stomatal Conductance ◽  
Stomatal Closure ◽  
Carbon Dioxide Concentration ◽  
Closure Rate ◽  
Relative Water ◽  
Leaf Tissues ◽  
Mda Content ◽  
Relative Electrical Conductivity ◽  
Exogenous Treatment

Drought seriously affects the yield and quality of apples. γ-aminobutyric acid (GABA) plays an important role in the responses of plants to various stresses. However, the role and possible mechanism of GABA in the drought response of apple seedlings remain unknown. To explore the effect of GABA on apple seedlings under drought stress, seedlings of Malus hupehensis were treated with seven concentrations of GABA, and the response of seedlings under 15-day drought stress was observed. The results showed that 0.5 mM GABA was the most effective at relieving drought stress. Treatment with GABA reduced the relative electrical conductivity and MDA content of leaves induced by drought stress and significantly increased the relative water content of leaves. Exogenous GABA significantly decreased the stomatal conductance and intercellular carbon dioxide concentration and transpiration rate, and it significantly increased the photosynthetic rate under drought. GABA also reduced the accumulation of superoxide anions and hydrogen peroxide in leaf tissues under drought and increased the activities of POD, SOD, and CAT and the content of GABA. Exogenous treatment with GABA acted through the accumulation of abscisic acid (ABA) in the leaves to significantly decrease stomatal conductance and increase the stomatal closure rate, and the levels of expression of ABA-related genes PYL4, ABI1, ABI2, HAB1, ABF3, and OST1 changed in response to drought. Taken together, exogenous GABA can enhance the drought tolerance of apple seedlings.

scholarly journals Genetic control and combining ability of flag leaf area and relative water content traits of bread wheat cultivars under drought stress condition

Genetika ◽  
2013 ◽  
Vol 45 (2) ◽  
pp. 351-360 ◽  
Author(s):  
Ahmad Golparvar
Keyword(s):  
Drought Stress ◽  
Water Content ◽  
Leaf Area ◽  
Genetic Control ◽  
Bread Wheat ◽  
Combining Ability ◽  
Relative Water Content ◽  
Flag Leaf ◽  
Mean Square ◽  
Relative Water

In order to compare mode of inheritance, combining ability, heterosis and gene action in genetic control of traits flag leaf area, relative water content and grain filling rate of bread wheat under drought stress, a study was conducted on 8 cultivars using of Griffing?s method2 in fixed model. Mean square of general combining ability was significant also for all traits and mean square of specific combining ability was significant also for all traits except relative water content of leaf which show importance of both additive and dominant effects of genes in heredity of these traits under stress. GCA to SCA mean square ratio was significant for none of traits. Results of this study showed that non additive effects of genes were more important than additive effect for all traits. According to results we can understand that genetic improvement of mentioned traits will have low genetic efficiency by selection from the best crosses of early generations. Then it is better to delay selection until advanced generations and increase in heritability of these traits.

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