scholarly journals Exogenous Abscisic Acid Alleviates Harmful Effect of Salt and Alkali Stresses on Wheat Seedlings

Author(s):  
Xiaoyu Li ◽  
Shuxin Li ◽  
Jinghong Wang ◽  
Jixiang Lin

Exogenous hormones play an important role in plant growth regulation and stress tolerance. However, little is known about the effect of exogenous abscisic acid (ABA) on wheat seedlings under salt and alkali stresses. Here, a pot experiment of saline and alkaline stresses (0 and 100 mmol/L) in which ABA water solution (0, 50 and 100 μmol/L) was sprayed on wheat seedlings was conducted to study the alleviative effectiveness of ABA on salt and alkali stresses. After spraying ABA (50 μmol·L−1), shoot biomass increased 19.0% and 26.7%, respectively. The Na+ content in shoots reduced from 15-fold and 61.5-fold to 10-fold and 37.3-fold in salt and alkali stresses, compared to controls. In addition, proline and organic acid synthesis in shoots also reduced significantly, but the soluble sugar content increased under alkali stress. A high concentration of ABA (100 μmol·L−1) had no significant effects on biomass and ion content in wheat seedlings under both stresses. In conclusion, foliar application of ABA with moderate concentration could effectively accelerate shoot growth of salt-induced wheat seedlings by adjusting the levels of ions and organic solutes.

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1916
Author(s):  
Iwona Ledwożyw-Smoleń ◽  
Sylwester Smoleń ◽  
Stanisław Rożek ◽  
Włodzimierz Sady ◽  
Piotr Strzetelski

Despite wide prevention programmes, iodine deficiency remains a substantial problem in various populations around the world. Consumption of crop plants with increased iodine content may help supply additional amounts of that element in a daily diet. The aim of the work was to evaluate the efficiency of iodine biofortification of potato tubers. Soil application of KI and foliar application of KIO3 in doses up to 2.0 kg I ha−1 were tested in a three-year field experiment. Biomass, yield as well as dry matter, iodine, starch, and soluble sugar content in potato tubers were analyzed. No negative effect of tested methods of iodine application on potato yield or dry matter content was observed. Both soil and foliar application of iodine allowed to obtain potato tubers with increased content of that element with no decrease of starch or sugar content. The highest efficiency of iodine biofortification was noted for foliar spraying with KIO3 in a dose of 2.0 kg I ha−1. The obtained level of iodine in 100 g of potatoes could be sufficient to cover up to 25% of Recommended Daily Allowance for that element. The findings of the study indicate that potatoes biofortified with iodine can become an additional source of I in a daily diet.


2014 ◽  
Vol 665 ◽  
pp. 543-546
Author(s):  
Hui Qin Liu ◽  
Gao Feng Shen ◽  
Yi Liu ◽  
Qin Xu ◽  
Hui Ping Liu ◽  
...  

In order to explore phytoremediation and physiological effect of plant to heavy metal, physiological and biochemical changes of tall fescue seedlings were comparatively analyzed when they were contaminated by lead at different times and concentrations. The results showed that: At three lead concentrations, superoxide dismutase (SOD) and peroxidase (POD) activity in tall fescue increased initially and then decreased overall with stress times. Change of POD is slower. It indicated that lead can rapid induce tall fescue protecting enzyme activity at low concentrations or in a short period. Malondialdehyde (MDA) contents were positively correlated with stress time and stress concentrations, which indicated that with the increase of stress concentration and time, membrane lipid peroxidation strengthen. Changes of chlorophyll total concentration increased first and then decreased at low concentration (500 and 1000 mg·L-1), and continued to decline at high concentration. It indicated tall fescue may adapt low lead stress by increasing chlorophyll to, and lose regulation at high concentrations.Proline content decreased initially and then increased with time at 500,1000 mg·L-1, however, it was opposite at 1500 mg·L-1. They were higher than controls, indicating that osmotic adjustment ability enhanced after lead stress. Changes of soluble sugar content were down - up - down with times at three concentrations, eventually they reduced significantly. Therefore, in the process of lead stress, changes of physiological characteristics in tall fescue showed their actively adapt and resistance at low stress, and tolerance and injury at high stress.


2019 ◽  
Vol 136 ◽  
pp. 06001
Author(s):  
Jing Sun ◽  
Aihui Li ◽  
Qianhe Jing ◽  
Yingying Huang ◽  
Jiaxi Han ◽  
...  

A pot experiment was conducted to study the effects of different concentrations of chitosan solutions (0, 1, 2, 4, 6 g/L) on soluble sugar content in Prunus davidiana seedlings. The result showed that there was no significant difference of the soluble sugar content in roots, stems, leaves and shoot in P. davidiana seedlings between at 1 g/L concentration and the control. All concentration treatments were reduced the soluble sugar content in roots and stems of P. davidiana seedlings compared with the control. On the contrary, all concentration treatments were improved the soluble sugar content in leaves and shoot of P. davidiana seedlings compared with the control and the concentration treatment of 2 g/L and 4 g/L was at a higher level. All concentration treatments were improved the content in relative conductivity of blade in P. davidiana seedlings and the concentration treatment of 4 g/L was at a higher level. On the contrary, all concentration treatments were reduced the content in soil conductivity. Therefore, the chitosan solutions concentration of 2 g/L and 4 g/L concentration was beneficial to soluble sugar content in P. davidiana seedlings. On the contrary, high concentration of chitosan solutions was not good for soluble sugar content.


2018 ◽  
Vol 4 (01) ◽  
pp. 105-112
Author(s):  
N. B. Singh ◽  
Nimisha Amist

In the present study we compared the effects of allelochemical with water stress (WS) on growth, biochemical parameters and responses of antioxidative enzymes in wheat seedlings. The wheat seedlings were treated with 0.5, 1.0 and 1.5 mM concentrations of cinnamic acid (CA) with and without water stress by withholding water supply for 5 days. Leaf water status, photosynthetic pigments, protein content, amount of proline and nitrate reductase (NR) and antioxidant enzymes activities were examined. CA resulted in reduction of seedling height with drastic decrease in stressed seedlings. The combined treatments CA+WS further decreased the seedling height. The same result was registered for seedlings dry weight, relative water content and pigment and protein contents. Total soluble sugar content and nitrate reductase activity were variedly affected under all treatments. Proline content and lipid peroxidation increased. Activity of superoxide dismutase increased significantly (less than 0.05) while catalase P activity was lower in all treatments. Ascorbate peroxidase and guaiacol peroxidase activities were higher as compared with catalase which showed protection of wheat seedlings from oxidative stress. Water stress elevated the toxic effect of allelochemical.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Fereshteh Yousefi ◽  
Zohreh Jabbarzadeh ◽  
Jafar Amiri ◽  
MirHassan Rasouli-Sadaghiani ◽  
Ali Shaygan

Abstract Objective This experiment was conducted to investigate the effects of foliar spray of polyamines on some morphological and physiological characteristics of rose. Materials and methods Experimental variants involved the type (putrescine, spermidine and spermine) and concentration (0 mM, 1 mM, 2 mM and 4 mM) of polyamines. In this research, the plant height, number of leaves and shoots, leaf area and thickness, fresh and dry weight of leaf and stem, the content of anthocyanin, soluble sugar, phenol and antioxidant capacity were measured 2 weeks after the end of experiment. Results Results indicated that among all polyamine types, putrescine has the highest effect on the morphological characteristics. Among different concentrations of polyamines, the concentration of 1 mM resulted in the highest increase in shoot fresh and dry weight. Putrescine application at 2 mM and 4 mM concentrations increased soluble sugar content. In the present study, polyamine treatment reduced the content of anthocyanin, phenol and antioxidant capacity. Conclusions It can be cocluded that application of polyamines improved some morphological and physiological traits in various ways.


2020 ◽  
Vol 44 (2) ◽  
pp. 191-201
Author(s):  
Nesrin Colak ◽  
Petr Tarkowski ◽  
Faik Ayaz

Heavy metal stress adversely affects plant growth and productivity worldwide. Alleviating the stress effect through the exogenous use of various chemical substances has become an interesting area of study in the field of plant stress tolerance. As a thiol compound, the cysteine derivative N-acetylcysteine (N-acetyl- L-cysteine, NAC) is the precursor of glutathione synthesis and a potent ROS scavenger with powerful antioxidant and free radical scavenging capabilities. This study investigated the effects of heavy metals (Cd, Hg and Pb, 100 ?M) on accumulation of soluble sugars and polyamine content in roots and shoots of wheat seedlings, the water potential and proline content in shoots and the role of NAC in protection against heavy metal toxicity. The addition of 1 mM NAC significantly increased root content of glucose, fructose and sucrose in varying degrees (avg. 1.34-, 1.20- and 1.51-fold, respectively) in comparison with heavy metals alone. The treatments led to a significant reduction of sugar content in shoots. Water potential values were highly correlated with proline and sugar content in wheat seedling shoots. Heavy metal stress significantly reduced polyamine content in both plant parts. The addition of NAC increased polyamine content in seedlings in comparison with heavy metals alone in both roots and shoots. These results suggest that NAC may protect plants from oxidative stress damage in heavy metal stress, and this enhancement of stress tolerance seems to involve soluble sugar and polyamine biosynthesis.


2021 ◽  
Vol 233 ◽  
pp. 01108
Author(s):  
Renyan Liao ◽  
Yinsong Xu

A pot experiment was used to study the effects of different concentrations of salt (100, 200, 300 mmol/L) stress on the photosynthetic physiology and antioxidant enzyme activities of Solanum photeinocarpum. The results showed that NaCl of 100 and 200 mmol/L could significantly improve the contents of chlorophyll a, chlorophyll b and carotenoid in S. photeinocarpum. However, under different concentrations of salt stress, there was no significant difference in the amount of total chlorophyll in S. photeinocarpum. Besides, as the salt stress increased, the net photosynthetic rate, stomatal conductance, CO2 concentration of intercellular and transpiration rate of S. photeinocarpum gradually decreased, when the concentration of NaCl was 300 mmol/L, reached the lowest value. With the increase of salt stress, the POD activity, CAT activity and soluble sugar content of S. photeinocarpum increased first and then decreased, reaching the highest when the concentration of NaCl was 100 mmol/L. Therefore, S. photeinocarpum had a certain salt tolerance, low concentration of NaCl (≤ 200 mmol/L) stress could promote its growth, but high concentration (> 200 mmol/L) could inhibit its growth.


2011 ◽  
Vol 39 (1) ◽  
pp. 41 ◽  
Author(s):  
Feng XU ◽  
Shuiyuan CHENG ◽  
Jun ZHU ◽  
Weiwei ZHANG ◽  
Yan WANG

The flavonoid content determines the quality of Ginkgo biloba that can be increased by using of plant growth regulators. The objective of study was to observe the effect of 5-aminolevulinic acid (ALA), a key precursor in the biosynthesis of porphyrins and a new plant growth regulator, on photosynthetic rate, chlorophyll and soluble sugar content, flavonoid accumulation, and flavonoid enzyme activity in G. biloba leaves. The ginkgo seedlings were grown in greenhouse conditions under low levels (10 and 100 mg l-1) of foliar application of ALA. Photosynthetic rates of leaves increased significantly at day 4 in response to both ALA concentrations and remained elevated as compared to control for further 12 days. Chlorophyll and soluble sugar contents were significantly increased by day 4 and continued to increase by day 16; however, Chl a/b ratio remained unchanged. Total polyphenols, flavonoids, and anthocyanins, phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS) and chalcone isomerase (CHI) activities were increased from day 4 to 16 after ALA treatment. The increase in chlorophyll and soluble sugar contents, and activities of flavonoid enzymes (PAL, CHS and CHI) were likely to be closely associated with improvement of the accumulation of total polyphenols, flavonoids, anthocyanins and advance of leaf quality by ALA treatment. Foliar treatment with a low concentration of ALA therefore, might provide a useful means of improving pharmacological properties of G. biloba leaves.


2011 ◽  
Vol 23 (2) ◽  
pp. 119-123 ◽  
Author(s):  
Renata Wojciechowska ◽  
Iwona Kowalska

The effect of foliar application of urea, Mo and BA on nitrate metabolism in lettuce leaves in the spring and summer-autumn seasons‘Melodion’ butter lettuce was grown on rockwool slabs in a film tunnel in the spring and summer-autumn seasons. The following experimental factors were investigated: foliar application with a solution of urea (1%), Mo (1 mg dm-3) and benzyladenine (5 mg BA dm-3) and light conditions in the film tunnel (films covering two parts of the tunnel differed in light permeability for PAR radiation). The nitrate metabolism was studied before application, three days after treatment and on the harvest day (seven days after application). Higher light intensity stimulated nitrate reductase activity, ammonium ions and soluble sugars, while fewer nitrates were observed in lettuce leaves. In the spring season, the least nitrate ions occurred as a consequence of urea + Mo nutrition, and when BA was added in the summer-autumn. Moreover, a positive effect on soluble sugar content was also observed when BA was used. In the spring, BA stimulated nitrate and nitrite reductase activities in the leaves of lettuce that had received less light.


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