scholarly journals Physiological and Biochemical Changes under Salinity and Drought Stress in Ricebean [Vigna umbellata (Thunb.) Ohwi and Ohashi] Seedlings

Author(s):  
Kousik Atta ◽  
P. Chettri ◽  
A. K. Pal

Aims: To study the effect of iso-osmotic potentials of drought and salinity during seedling growth stage in ricebean. Study Design: Completely randomised design. Place and Duration of Study: The lab experiment was conducted during the year of 2017- 2018 and 2018-2019 in ricebean variety Bidhan 1 at Department of Plant Physiology, Bidhan Chandra Krishi Viswavidyalaya, Kalyani, Nadia, West Bengal, India. Methodology: For studying the effect of iso-osmotic potential of salinity and drought stress, the solutions of NaCl and PEG 6000 with -0.2, -0.4 and -0.8 MPa osmotic potential were used and the experiment was conducted in sand culture using modified Hoagland solution [1] under laboratory condition of diffused light, at around 80±1% relative humidity (R.H.) and at a temperature of 28±1°C. Results: All the biochemical parameters under study, in general were adversely affected by the both stress with the effects being more drastic as the intensity of stress increased. The highest intensity of salinity stress was found to produce more adverse effects than drought in respect of RLWC, leaf chlorophyll as well as protein content in leaves of ricebean in the present experiment. While the content of soluble sugar, starch and phenol in the leaf were more drastically affected by drought stress. Conclusion: The drought stress was found to register more drastic effects on seedling growth as compared to iso-osmotic potential of salinity stress, especially, at the highest intensity of stress in ricebean cultivar Bidhan 1.

Author(s):  
Kousik Atta ◽  
Jahnavi Sen ◽  
Pravachan Chettri ◽  
Anjan Kumar Pal

Background: Salinity and drought are the major abiotic stresses and both can cause osmotic imbalances. Drought stress directly results in osmotic stress whereas salinity problem firstly disrupts the water balance and eventually induces ion toxicity which results in cyto-toxicity, metabolic impairment, nutrient imbalance and finally poor crop growth and yield. The co-ordinated up-regulation or constitutive expression of antioxidative system in plants is the main defense in plant against these stresses and thus the present experiment was undertaken to study the antioxidant responses under drought and salinity stress at seedling stage in ricebean (Bidhan 1). Methods: For studying the effect of iso-osmotic potential of salinity and drought stress solutions of NaCl and PEG 6000 with -0.2 MPa (50mM NaCl and 10% PEG), -0.4 MPa (100 mM NaCl and 12% PEG) and -0.8 MPa (200mM NaCl and 18% PEG) osmotic potential were used. The experiment was done in the laboratory of Department Plant Physiology, Bidhan Chandra Krishi Viswavidyalaya (BCKV), Mohanpur, Nadia and West Bengal in the year 2017-18 and 2018-19. Result: Under moderate to high intensity of osmotic stresses the leaf proline content decreased. The mild and medium stress treatments induced much higher activity of GPOX and APX in the leaf which then decreased somewhat as the intensity of stress increased. The experiment showed that drought stress was found to produce more drastic effects on seedling growth in ricebean as compared to the salinity stress at iso-osmotic potentials.


Author(s):  
P. Chettri ◽  
Kousik Atta ◽  
A. K. Pal

Aims: The aim of this study was to investigate the effect of iso-osmotic potentials of drought and salinity on physiological parameters of grass pea seedlingsas well as to compare varietal responses. Study Design: Completely randomized design. Place and Duration of Study: In the years 2017-2018 and 2018-2019, laboratory research on grass pea varieties BK-14 and Pratik was conducted in the Department of Plant Physiology, Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal, India. Methodology: The effect of iso-osmotic potential of salinity and drought stress was studied using NaCl (50, 100 and 200 mM ) and PEG 6000 (10, 12 and 18%) solutions with -0.2, -0.4, and -0.8 MPa osmotic potential, and the experiment was carried out in sand culture using modified Hoagland solution under diffused light, at about 80±1% relative humidity (R.H.) and a temperature of 22±1oC. Data on different physiological and biochemical parameters were recorded after ten days of seedling growth in sand culture. Statistical analysis was performed on the mean data in all cases following completely randomized design (CRD) by application of INDOSTAT version 7.1 software. Results: The germination of grass pea seeds was more severely affected by drought stress than salinity. Both stresses had a negative impact on most of the parameters studied except for leaf proline and sugar The impact became  more pronounced as the severity of the stress increased. The highest intensity of drought stress was found to be more detrimental to leaf protein and relative water content in BK 14, while Pratik was more drastically affected by the highest level of salinity. Drought was found to have a significant negative impact on leaf starch in both the grass pea varieties. The highest concentration of PEG led to a remarkable increase in leaf proline. Conclusion: The mild to moderate levels (-0.2 and -0.4 MPa)  of stress did not produce much severe effects on the grass pea seedlings, but the highest intensity of stress with an osmotic potential of -0.8 MPa mostly produced drastic effects. There were varietal differences in response to two abiotic stresses. In general, drought stress was found to cause more negative effects on seedling than iso-osmotic potential of salinity stress.


2018 ◽  
Vol 5 (03) ◽  
Author(s):  
ARADHNA KUMARI ◽  
IM KHAN ◽  
ANIL KUMAR SINGH ◽  
SANTOSH KUMAR SINGH

Poplar clone Kranti was selected to assess the morphological, physiological and biochemical responses under drought at different levels of water stress, as it is a common clone used to be grown in Uttarakhand for making paper and plywood. The cuttings of Populus deltoides L. (clone Kranti) were exposed to four different watering regimes (100, 75, 50 and 25% of the field capacity) and changes in physiological and biochemical parameters related with drought tolerance were recorded. Alterations in physiological (i.e. decrease in relative water content) and biochemical parameters (i.e. increase in proline and soluble sugar content and build-up of malondialdehyde by-products) occurred in all the three levels of water stress, although drought represented the major determinant. Drought treatments (75%, 50% and 25% FC) decreased plant height, radial stem diameter, harvest index, total biomass content and RWC in all the three watering regimes compared to control (100% FC). Biochemical parameters like proline, soluble sugar and MDA content increased with severity and duration of stress, which helped plants to survive under severe stress. It was analyzed that for better wood yield poplar seedlings should avail either optimum amount of water (amount nearly equal to field capacity of soil) or maximum withdrawal up to 75% of field capacity up to seedling establishment period (60 days). Furthermore, this study manifested that acclimation to drought stress is related with the rapidity, severity, and duration of the drought event of the poplar species.


Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 65
Author(s):  
Changchang Shao ◽  
Honglang Duan ◽  
Guijie Ding ◽  
Xianying Luo ◽  
Yuanhong Fu ◽  
...  

In recent years, global forests have been facing an increase in tree mortality owing to increasing droughts. However, the capacity for plants to adjust their physiology and biochemistry during extreme drought and subsequent recovery is still unclear. Here, we used 1.5-year-old Pinus massoniana Lamb. seedlings and simulated drought conditions to achieve three target stress levels (50%, 85%, and 100% loss of stem hydraulic conductivity (PLC)), followed by rehydration. Needle water status, gas exchange, and biochemical parameters were assessed during drought and recovery. The results showed that drought had significantly negative impacts on needle water status and gas exchange parameters, with gas exchange declining to 0 after PLC85 was achieved. Soluble protein concentration (SPC), soluble sugar concentration (SSC), malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, and needle water-use efficiency showed fluctuations. The activity of antioxidant enzymes and the values of osmotic regulators were then gradually decreased as the physiological and biochemical functions of seedlings were disturbed. Seedlings showed a stronger ability to recover from PLC50 than PLC85 and PLC100. We conclude that the physiological and biochemical recovery of P. massoniana seedlings is more likely to be inhibited when plants experience increasing drought stress that induces 85% and greater loss of hydraulic conductance.


2021 ◽  
Author(s):  
Shifa Xiong ◽  
Yangdong Wang ◽  
Yicun Chen ◽  
Ming Gao ◽  
Yunxiao Zhao ◽  
...  

Abstract Background: Quercus fabri Hance, Quercus serrata Thunb, Quercus acutissima Carruth, and Quercus variabilis BL are four Chinese oak species commonly used for forestation. In recent years, with the global warming caused by the greenhouse effect, seedlings in mountainous areas after afforestation often suffer seasonal drought stress, which seriously affects their survival and growth. In order to ensure the survival of seedlings, we need to select oak species with strong drought resistance. Therefore, we first need to understand the differences in drought resistance of the four oak tree species at the seedling stage, and comprehensively evaluate their drought resistance capabilities by studying the changes in the physiological and biochemical characteristics of the seedlings under continuous drought and rehydration conditions.Methods: The four oak seedlings were divided into drought-rewatering treatment group and normal watering control group. For the seedlings of the drought-rewatering treatment group, drought stress lasting 31 days was used, and then re-watering and recovering for 5 days. The water parameters, osmotic adjustment substance content, antioxidant enzyme activity and photosynthesis parameters of the seedlings in the two groups were measured every 5 days. Principal component analysis, correlation analysis and membership function were used to analyze the physiological and biochemical characteristics of the seedlings of the four oak in two groups.Results and conclusions: Compared with the control group, the relative water content, water potential, net photosynthetic rate, transpiration rate, and stomatal conductance levels of the four oaks all showed a downward trend under continuous drought stress, and showed an upward trend after rehydration. The soluble protein, soluble sugar, proline, peroxidase, superoxide dismutase and catalase content of the four oaks increased first and then decreased under drought stress, and then increased after rehydration. The content of glycine betaine and malondialdehyde continued to increase, and gradually decreased after rehydration. The weight of each index was calculated by PCA, and then the comprehensive evaluation of each index was carried out through the membership function method. The drought resistance levels of the four oak species were as follows: Q. serrata > Q. fabri > Q. variabilis > Q. acutissima.


HortScience ◽  
2019 ◽  
Vol 54 (3) ◽  
pp. 492-498 ◽  
Author(s):  
Qi Wang ◽  
Rui Zhao ◽  
Qihang Chen ◽  
Jaime A. Teixeira da Silva ◽  
Liqi Chen ◽  
...  

Herbaceous peony is a perennial flowering plant with strong environmental adaptability and may be a good candidate for culture in arid areas. In this study, the physiological and biochemical responses of two herbaceous peony cultivars to different soil moisture gradients in pots were assessed by analyzing changes in 13 stress-related indices. The drought damage index (DDI) and the contents of malondialdehyde (MDA), soluble sugar, proline, and abscisic acid (ABA) generally increased as drought stress intensified, whereas leaf relative water content (LRWC) decreased, and the contents of soluble protein, indole-3-acetic acid (IAA), the ratio of IAA and ABA, and the activities of four antioxidant enzymes fluctuated. For the leaves, a positive correlation was found between DDI and superoxide dismutase (SOD), MDA, soluble sugar, proline, ascorbate peroxidase (APX), and ABA, but it was negatively correlated with LRWC, peroxidase (POD), and catalase (CAT). In fibrous roots, DDI was positively correlated with MDA, soluble sugar, proline, soluble protein, and ABA but was negatively correlated with SOD, CAT, APX, and IAA/ABA. Principal component analysis and subordinate functions were used to evaluate drought resistance of the two cultivars, with ‘Karl Rosenfield’ showing greater resistance to drought than ‘Da Fu Gui’.


Author(s):  
Thắng Thanh Trần

Peanut is am essential legume and has many uses, such as producing oil, food, and fodder. However, with the negative effects of climate change, drought is one especially of the important issues that reduce the yield of peanut. Thus, in this study, the impact of drought stress on the peanut growth was investigated by using PEG-6000 to block pathways of water movement. The changes in morphological, physiological, and biochemical during the peanut growth under drought were analyzed. In the drought condition (-2 bar), the germination time of seed increased but the percentage of germination seeds decreased by approximately 50% compared to control. Besides, the shoot height, the number of leaves, the total leaf area, root length, and fresh weight were lower than that of control. Drought stress made the formation quickly of secondary xylem and phloem. Also, the process of lignification in the phloem parenchyma cell increased. These cell walls were much thicker than those in the control root. In the drought stress, the physiological and biochemical analysis showed that the content of chlorophyll a, leaf relative water content, and starch content reduced significantly in comparison to control. Similarly, the photosynthetic intensity, the activity of cytokinin, and gibberellin decreased. The reverse pattern can be seen in the content of carotenoid, epicuticular wax, proline, and total soluble sugar, respiratory intensity, the activity of catalase, auxin, and ABA activity.


1974 ◽  
Vol 52 (6) ◽  
pp. 1357-1362 ◽  
Author(s):  
Irwin A. Ungar

Studies on the germination of Hordeum jubatum seeds indicate that they were highly tolerant of salinities up to 1.0%, with little reduction in germination. Each increase in salt concentration did, however, delay the time of germination. Seedling growth proved to be more sensitive than germination to salinity stress, with newly germinated plants showing a decrease in size with each salinity increment. Results of growth studies were similar to those in germination tests; plants decreased in size with decreased osmotic potential of the salt solution. The germination stage and later periods of active growth were nearly equal in their ability to withstand salinity stress.


Author(s):  
Phuong Thi Bach Vu ◽  
Hong Thi Anh Pham ◽  
Phuong Ngo Diem Quach

In this study, NaCl at varrious concentrations of 4 – 10 g/L was used to investigate the salt tolerance of in vitro shoot cuttings of Chrysanthemum indicum. Morphological, physiological and biochemical changes during the response of shoot cuttings in the salinity stress were analyzed. NaCl at 6 g/L reduced the development of shoot cuttings. Under salinity stress conditions, there have just a little reduction of the chloroplast in parenchymal cells near the midrib of leaf before they turn brown and die. Besides, carotenoid, starch content, and photosynthesis intensity were decreased. In contrast, respiration rate, proline and total soluble sugar content, and the activity of IAA and gibberellin were strongly increased. The application of IAA 0.25 mg/L, zeatin 0.1 mg/L and GA3 0.1 mg/L improved the shoot development in the salinity stress condition. Shoots in MS medium supplemented with BA 0.2 mg/L, NAA 2 mg/L and NaCl 6 g/L grow better in salinity stress condition.


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