scholarly journals Responses of physiological activities and lateral root anatomical structure of Cercis glabra to waterlogging stress

2020 ◽  
Vol 48 (3) ◽  
pp. 1573-1584
Author(s):  
Jie LUO ◽  
Long-Yi YUAN
Keyword(s):  
Electric Conductivity ◽  
Lateral Root ◽  
Lateral Roots ◽  
Antioxidant Enzyme Activity ◽  
Anatomical Structure ◽  
Proline Content ◽  
Free Proline ◽  
Waterlogging Stress ◽  
Casparian Strip ◽  
Mda Content

Cercis glabra is a colour-leaf tree with excellent ornamental value, whereas its physiological and morphological responses to waterlogging stress are still unclear. A potted study was conducted to determine the effects of waterlogging stress on antioxidative enzymes (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)), lipid peroxidation (in terms of malondialdehyde (MDA) content), relative electric conductivity, and osmotic substance (free proline) of leaves and aerenchyma, lignification, suberization and Casparian strip of lateral roots of C. glabra. The result showed that the SOD, POD, and CAT activity and free proline content of C. glabra were significantly increased by the different degrees of waterlogging stress compared with the non-waterlogged treatment at 8 and 12 days, and the MDA content and relative electric conductivity of C. glabra leaves were significantly increased under the different degrees of waterlogging stress compared to the non-waterlogged treatment at 16 days, and the degrees of change increased among treatments was ranked as total waterlogged > semi-waterlogged > shallow waterlogged. The lateral roots of C. glabra not only formed developed aerenchyma in the cortex but also formed suberization and Casparian strip in the endodermis under semi-waterlogged treatment at 16 days. These results implied that C. glabra had a certain tolerance to waterlogging stress, which was associated with the increasing antioxidant enzyme activity and osmotic adjustment substance content, and with the formation of aerenchyma, suberization and Casparian strip in the lateral root to adapt to the waterlogged environment.

Evaluation of Azadirachtin on Arthrospira plantensis Gomont growth parameters and antioxidant enzymes

2020 ◽  
Vol 56 ◽  
pp. 8
Author(s):  
Hatice Tunca ◽  
Ali Doğru ◽  
Feray Köçkar ◽  
Burçin Önem ◽  
Tuğba Ongun Sevindik
Keyword(s):  
Enzyme Activity ◽  
Growth Parameters ◽  
Arthrospira Platensis ◽  
Proline Content ◽  
Enzyme Analysis ◽  
Free Proline ◽  
Sod Activity ◽  
Pesticide Pollution ◽  
Antioxidant Parameters ◽  
Mda Content

Azadirachtin (Aza) used as insecticide due to inhibiting growth of insects and preventing them from feeding on plants. To understand the effects of contamination of this insecticide on phototrophs, and to determine the responses of these organisms against these insecticides are extremely important in understanding how the ecosystem is affected. In this study, chlorophyll-a amount, OD 560 and antioxidant parameters (total SOD, APX, GR, Proline, MDA and H2O2) were determined in order to understand the effect of Aza on Arthrospira platensis Gomont. Aza was applied between 0–20 μg mL−1 concentrations for 7 days in the study. Enzyme analysis was conducted at the end of the 7th day. There was a statistically significant decrease in the absorbance of OD560 and the chlorophyll-a content in A. platensis cultures exposed to the Aza (0–20 μg mL−1) during 7 days due to the increase in pesticide levels. SOD activity decreased at 8, 16 and 20 μg mL−1 concentrations; GR enzyme activity showed a significant decrease compared to the control at a concentration of 20 μg mL−1. APX activity did not change significantly compared to control. The MDA content increased significantly at 16 and 20 μg mL−1 concentrations. The H2O2 content significantly increased at 12, 16 and 20 μg mL−1 concentrations (p < 0.05) while the free proline content decreased at 4 μg mL−1 concentration (p < 0.05). As a result, regarding the Aza concentrations used in this study may be a step to prevent pesticide pollution in the environment.

Probable sites for passive movement of ions across the endodermis

1971 ◽  
Vol 49 (1) ◽  
pp. 35-38 ◽  
Author(s):  
E. B. Dumbroff ◽  
D. R. Peirson
Keyword(s):  
Fluorescence Microscopy ◽  
Mass Flow ◽  
Lateral Root ◽  
Lateral Roots ◽  
Passive Movement ◽  
General Picture ◽  
Effective Barrier ◽  
Casparian Strip ◽  
Endodermal Cells ◽  
The Relationship

The endodermis, with its associated Casparian strip, is generally believed to act as an effective barrier to the passive movement of ions from the cortex to the xylem in young roots. However, several workers have suggested that the functional integrity of the endodermis might be somewhat impaired with the emergence of branch roots from the pericycle, thus providing pathways for the mass flow of water and ions into the stele. The present work was undertaken to examine the validity of this hypothesis.Sections of lateral roots embedded in glycol methacrylate were stained and examined by fluorescence microscopy, and a general picture of the relationship between branch root development and concomitant changes in the endodermis emerged. The endodermal cells of the parent root were found to maintain a continuous, unbroken, suberized layer over the surface of a very young lateral root, but with continued elongation there is a period when formation of the Casparian strip lags behind division of endodermal cells. It appears likely that, at this stage, water and ions can enter the stele of the parent root by mass flow.

Study of Uranium Accumulation Mechanism and Physiological Responses of Eichhornia crassipes and Pistia stratiotes

2014 ◽  
Vol 1073-1076 ◽  
pp. 142-146
Author(s):  
Shi You Li ◽  
Qing Peng Wei ◽  
Shui Bo Xie ◽  
Ying Jiu Liu ◽  
Zheng Yan
Keyword(s):  
Antioxidant Enzymes ◽  
Proline Content ◽  
Pistia Stratiotes ◽  
Free Proline ◽  
Concentration Effects ◽  
Hydroponic Experiment ◽  
Accumulation Mechanism ◽  
Mda Content ◽  
Uranium Accumulation ◽  
Accumulation Ability

A hoagland solution hydroponic experiment was carried out to study the short-duration (8 d) accumulation ability of uranium byEichhornia crassipesandPistia stratiotesunder different uranium concentration. Effects on antioxidant enzymes (SOD, CAT, POD) activity, malondialdehyde (MDA) and free proline content ofE.crassipesandP.stratiotesunder uranium stress were discussed. The results show the activity of antioxidant enzymes is increased under 0.1~1 mg·L-1uranium stress, MDA content is at lower level indicated that antioxidant enzymes play an important role in alleviating lipid peroxidation induced by uranium stress. Under 5mg·L-1uranium stress, the antioxidant enzymes activity ofE.crassipesis at higher level and MDA content is lower,nevertheless, theP.stratiotesis just the opposite, indicating thatE.crassipestolerated higher concentrations thanP.stratiotes. The activity of antioxidant enzymes is inhibited under higher concentration (20 mg·L-1and 50 mg·L-1) uranium stress. As an important osmoregulation material, free proline content of both plants is more than the contrast.

Changes in antioxidant systems in sunflower partial resistant and susceptible lines as affected by Sclerotinia sclerotiorum

Biologia ◽  
2013 ◽  
Vol 68 (5) ◽  
Author(s):  
Robab Davar ◽  
Reza Darvishzadeh ◽  
Ahmad Majd
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Biochemical Parameters ◽  
Proline Content ◽  
Antioxidant Systems ◽  
Guaiacol Peroxidase ◽  
Free Proline ◽  
Resistant Line ◽  
Necrotrophic Pathogen ◽  
Host Pathogen Interaction ◽  
Mda Content

AbstractSunflower, Helianthus annuus L., is a major oil-seed crop widely cultivated throughout the globe. White mold, caused by necrotrophic pathogen Sclerotinia sclerotiorum (Lib.) de Bary, is a common and widespread disease of sunflower. Changes in various physiological activities such as production of malondialdehyde (MDA) as the main end product of lipid peroxidation, enzymatic and non-enzymatic activities and proline content, were investigated in leaves and stems of sunflower lines either resistant or susceptible to S. sclerotiorum. The results showed accumulation of high amount of free proline in the leaves of the resistant line. S. sclerotiorum invasion resulted in increase in the MDA content in both lines compared to the controls. Superoxide dismutase, ascorbate peroxidase and guaiacol peroxidase activities significantly increased in the stem and leaves of inoculated lines. In the resistant line, Sclerotinia infection significantly induced catalase (CAT) activity both in the stem and leaves of contaminated plants. The activity of CAT was significantly decreased in susceptible line. Based on our results the activity of antioxidant enzymes was much pronounced in sunflower resistant line than in susceptible one. Studied lines showed distinctive activity considering different biochemical parameters, which may point to further directions in exploring host-pathogen interaction and lead to selection and production of new lines to achieve an improvement of plant adaptation to pathogen.

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.

Penconazole and calcium ameliorate drought stress in canola by upregulating the antioxidative enzymes

2020 ◽  
Vol 47 (9) ◽  
pp. 825 ◽  
Author(s):  
Maryam Rezayian ◽  
Vahid Niknam ◽  
Hassan Ebrahimzadeh
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Antioxidative Enzymes ◽  
Proline Content ◽  
Fresh Weight ◽  
Negative Effects ◽  
Mda Content ◽  
Effects Of Drought

The aim of this research was to gauge the alternations in the lipid peroxidation and antioxidative enzyme activity in two cultivars (cv. RGS003 and cv. Sarigol) of canola under drought stress and drought tolerance amelioration by penconazole (PEN) and calcium (Ca). Plants were treated with different polyethylene glycol (PEG) concentrations (0, 5, 10 and 15%) without or with PEN (15 mg L–1) and Ca (15 mM). The Ca treatment prevented the negative effects of drought on fresh weight (FW) in RGS003 and Sarigol at 5 and 15% PEG respectively. Ca and PEN/Ca treatments caused significant induction in the proline content in Sarigol at 15% PEG; the latter treatment was accompanied by higher glycine betaine (GB), lower malondialdehyde (MDA) and growth recovery. Hydrogen peroxide (HO2) content in Sarigol was proportional to the severity of drought stress and all PEN, Ca and PEN/Ca treatments significantly reduced the H2O2 content. PEN and PEN/Ca caused alleviation of the drought-induced oxidative stress in RGS003. RGS003 cultivar exhibited significantly higher antioxidative enzymes activity at most levels of drought, which could lead to its drought tolerance and lower MDA content. In contrast to that of Sarigol, the activity of catalase and superoxide dismutase (SOD) increased with Ca and PEN/Ca treatments in RGS003 under low stress. The application of PEN and Ca induced significantly P5CS and SOD expression in RGS003 under drought stress after 24 h. Overall, these data demonstrated that PEN and Ca have the ability to enhance the tolerance against the drought stress in canola plants.

Lateral root formation and nutrients: nitrogen in the spotlight

2021 ◽  
Author(s):  
Pierre-Mathieu Pélissier ◽  
Hans Motte ◽  
Tom Beeckman
Keyword(s):  
Signaling Pathways ◽  
Root System ◽  
Root Development ◽  
Lateral Root ◽  
Molecular Mechanisms ◽  
Root Formation ◽  
Lateral Roots ◽  
Nutrient Use Efficiency ◽  
Lateral Root Formation ◽  
Lateral Root Development

Abstract Lateral roots are important to forage for nutrients due to their ability to increase the uptake area of a root system. Hence, it comes as no surprise that lateral root formation is affected by nutrients or nutrient starvation, and as such contributes to the root system plasticity. Understanding the molecular mechanisms regulating root adaptation dynamics towards nutrient availability is useful to optimize plant nutrient use efficiency. There is at present a profound, though still evolving, knowledge on lateral root pathways. Here, we aimed to review the intersection with nutrient signaling pathways to give an update on the regulation of lateral root development by nutrients, with a particular focus on nitrogen. Remarkably, it is for most nutrients not clear how lateral root formation is controlled. Only for nitrogen, one of the most dominant nutrients in the control of lateral root formation, the crosstalk with multiple key signals determining lateral root development is clearly shown. In this update, we first present a general overview of the current knowledge of how nutrients affect lateral root formation, followed by a deeper discussion on how nitrogen signaling pathways act on different lateral root-mediating mechanisms for which multiple recent studies yield insights.

scholarly journals Salinity Stress Affects Photosynthesis, Malondialdehyde Formation, and Proline Content in Portulaca oleracea L.

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 845
Author(s):  
Helena Hnilickova ◽  
Kamil Kraus ◽  
Pavla Vachova ◽  
Frantisek Hnilicka
Keyword(s):  
Salt Stress ◽  
Water Potential ◽  
Co2 Concentration ◽  
Co2 Assimilation ◽  
Proline Content ◽  
Portulaca Oleracea ◽  
Control Group ◽  
Malondialdehyde Formation ◽  
Salinity Levels ◽  
Mda Content

In this investigation, the effect of salt stress on Portulaca oleracea L. was monitored at salinity levels of 100 and 300 mM NaCl. At a concentration of 100 mM NaCl there was a decrease in stomatal conductance (gs) simultaneously with an increase in CO2 assimilation (A) at the beginning of salt exposure (day 3). However, the leaf water potential (ψw), the substomatal concentration of CO2 (Ci), the maximum quantum yield of photosystem II (Fv/Fm), and the proline and malondialdehyde (MDA) content remained unchanged. Exposure to 300 mM NaCl caused a decrease in gs from day 3 and a decrease in water potential, CO2 assimilation, and Fv/Fm from day 9. There was a large increase in proline content and a significantly higher MDA concentration on days 6 and 9 of salt stress compared to the control group. After 22 days of exposure to 300 mM NaCl, there was a transition from the C4 cycle to crassulacean acid metabolism (CAM), manifested by a rapid increase in substomatal CO2 concentration and negative CO2 assimilation values. These results document the tolerance of P. oleracea to a lower level of salt stress and the possibility of its use in saline localities.

Formation of lateral root meristems is a two-stage process

Development ◽  
1995 ◽  
Vol 121 (10) ◽  
pp. 3303-3310 ◽  
Author(s):  
M.J. Laskowski ◽  
M.E. Williams ◽  
H.C. Nusbaum ◽  
I.M. Sussex
Keyword(s):  
Lateral Root ◽  
Lateral Roots ◽  
Initial Period ◽  
Subsequent Stage ◽  
Root Initiation ◽  
Root Meristems ◽  
Lateral Root Initiation ◽  
Cell Layers ◽  
Stage Process ◽  
Pericycle Cells

In both radish and Arabidopsis, lateral root initiation involves a series of rapid divisions in pericycle cells located on the xylem radius of the root. In Arabidopsis, the number of pericycle cells that divide to form a primordium was estimated to be about 11. To determine the stage at which primordia are able to function as root meristems, primordia of different stages were excised and cultured without added hormones. Under these conditions, primordia that consist of 2 cell layers fail to develop while primordia that consist of at least 3–5 cell layers develop as lateral roots. We hypothesize that meristem formation is a two-step process involving an initial period during which a population of rapidly dividing, approximately isodiametric cells that constitutes the primordium is formed, and a subsequent stage during which meristem organization takes place within the primordium.

Stressed Response of Submerged Elodea nattalii under Eutrophication Growth Conditions

2012 ◽  
Vol 610-613 ◽  
pp. 229-234
Author(s):  
Han Feng Xiong ◽  
Qi Ling Tan
Keyword(s):  
Superoxide Dismutase ◽  
Enzyme Activity ◽  
Aquatic Plants ◽  
Nutrient Concentration ◽  
Growth Conditions ◽  
Antioxidant Enzyme Activity ◽  
Metabolic Responses ◽  
Concentration Increase ◽  
Time Period ◽  
Mda Content

Eutrophication in water bodies affects the growth of aquatic plants. In this study, we conducted static experiments to better understand the metabolic responses of Elodea nattalii under eutrophication conditions. The nitrogen (N) and phosphorous (P) levels in tissue, malondiadehyde (MDA), and activities of three antioxidases (peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT)) of Elodea nattalii cultured at different nutrient levels (oligotropher, mesotropher, eutropher, and hypertrophics) were investigated. The results showed that with nutrient concentration increase, N and P contents of Elodea nattalii increased. The MDA content improved with nutrient increase. the POD activity initially increased and later decreased. CAT and SOD activities decreased during the experimental time period. These finding suggested that changes in stem the increase of antioxidant enzyme activity can be served as the indicators of the response of Elodea nattalii to eutrophication conditions.

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