• Journal of Plant Biology
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• v.37 no.3
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• pp.301-308
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• 1994

The individual and combined effects of acidic rain, Mg deficiency (-Mg) and Al surplus (＋Al) on the growth of shoots and roots of pitch pine seedlings and the effect of humic substances (Lit) on Al toxicity were investigated. The growth of height and dry matter were not significantly less for pitch pine seedlings sprayed with simulated acid rain (SAR) of pH 3.5 than for those sprayed with SAR of pH 5.6. But treatments of Al and ＋Al-Mg in soil solution reduced the growth of seedlings in terms of height of shoots, and dry matter of shoots or roots. Effect of Mg deficiency on the growth of seedlings was apparent only when Al was treated simutaneously. The growth of seedlings, regardless of rain pH, decreased in the following order: control=-Mg>Lit＋Al>＋Al>＋Al-Mg. Treatments of Al and ＋Al-Mg in soil solution reduced the total length of secondary and teritary roots of seedlings regardless of rain pH, and decreased in the following order: the primary root

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.1
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• pp.57-61
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• 1999

This study measured the soaking effects of two brassinosteroids(BRs), homobrassinolide(hBR : 225, 23S-homobrassinolide) and epibrassinolide(epiBR : 22R, 23R. 24R-$2{\alpha}$, $3{\alpha}$, 22, 23-Tetrahydroxy-B-homo-7-oxa-$5{\alpha}$-ergostan-6-one) on the germination of two rice cultivars, 'Milyang 23' and 'Naepungbyeo' exposed to simulated acid rain(SAR). The results suggested that promoting effect of two BRs on alleviating damage to SAR would be attributed to the promotion of plant growth, root elongation, and particularly germination rate of both cultivars. Eight organic acids were determined by HPLC. Succinic acid acetic acid in 'Milyang 23' under SAR were highest among eight organic acids.

• Korean Journal of Weed Science
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• v.31 no.2
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• pp.152-159
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• 2011

The effects of simulated acid rain (SAR) on fatty acid composition and biochemical defense responses of plant was investigated. Garden balsam (Impatiens balsamina L.) was exposed to four pH levels (5.6, 4.0, 3.0, 2.0) of SAR and placed in the growth chambers for 2 weeks. SAR drastically inhibited chlorophyll content of garden balsam. The level of $H_2O_2$ was significantly increased by SAR. As pH levels decreased from 5.6 to 2.0, the ratio of unsaturated to saturated fatty acids of garden balsam was increased. Changes of three major polyamines (putrescine, spermidine and spermine) of garden balsam leaves were observed. All of the polyamine contents were increased with SAR. Catalase activities of the plant affected by SAR were increased as the pH decreased. The results indicate that the application of SAR generates oxidative stresses from the garden balsam and retards the plant growth significantly. A biochemical protect mechanism might be activated to neutralize the oxidative stresses generated through SAR.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.159-163
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• 2005

This study was conducted to investigate the effect of simulated acid rain (SAR) on growth and antioxidant system in french marigold (Tagetes patula L.). Plants were subjected to four levels of SAR (pH 5.6, 4.0, 3.0, 2.0) in the growth chambers for 2 weeks. SAR decreased both plant height and plant dry weight of french marigold. As the pH levels decreased from 5.6 to 2.0, the content of MDA highly increased linearly. The ratios of dehydroascorbate/ascorbate and oxidized glutathione/reduced glutathione were significantly increased with decreasing pH levels. The enzyme (superoxide dismutase, ascorbate peroxidase etc.) activities of the plant affected by SAR were increased as the pH decreased. Based on the results, SAR caused oxidative stress in french marigold and resulted in significant reduction in plant growth. Biochemical protection responses might be activated to prevent the plant from damaging effects of oxidative stress generated in SAR.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.382-386
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• 2005

To investigate the effects of simulated acid rain (SAR) on growth and biochemical defense responses of plant, garden balsam (Impatiens balsamina L.) was subjected to four levels of SAR based on pH (5.6, 4.0, 3.0, 2.0) and placed in the growth chambers for 2 weeks. SAR drastically inhibited both height and dry weight of garden balsam. The content of total carotenoid was tended to decrease, but the level of malondialdehyde was significantly increased by SAR. As the pH levels decreased from 5.6 to 2.0, the content of dehydroascorbate and oxidized glutathione of the plant were significantly increased. The enzyme (superoxide dismutase, ascorbate peroxidase etc.) activities of the plant affected by SAR were increased as the pH decreased. The results indicate that garden balsam may receive oxidative stresses by the application of SAR and by which the plant growth can be significantly retarded. A biochemical protective mechanism might be activated to nullify the oxidative stresses generated through SAR.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.889-894
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• 2005

This experiment was carried out to investigate the effects of simulated acid rain (SAR) in the shoot growth and internal structure of Arabidopsis thaliana. In the shoot growth, the plants treated with SAR (pH 3.0) for 15 days showed no morphological change compared to the control plants. Some change was observed in the internal structure of the stems: the epidermis and cortex tissues of the stems treated with SAR were partly damaged. The plants treated with SAR showed no noticeable difference compared to the control plants, but morphological changes were observed in the leaf. The leaves of the plants treated with SAR showed many white necrotic spots on the part of upper epidermis. A light microscopic examination of the leaves with necrotic spots showed that the upper epidermis was severely compressed with the damaged cuticle layer and the mesophyll cells were also damaged and compressed. However, noticeable structural change of vascular bundle cells was not observed.

• Journal of Korean Society of Forest Science
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• v.77 no.1
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• pp.43-52
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• 1988

One-year-old seedlings of Ginkgo biloba were treated with various simulated acid rains(pH 2.0, pH 3.0, pH 9.0 and pH 5.0) to examine the effects of simulated acid rain on the chemical properties of the tested soil. The seedlings were grown in a pot($4500cm^3$)containing one of three different soils(nursery soil, mixed soil and sandy soil). Simulated acid rain was made by diluting sulfuric and nitric acid solution($H^1SO^4$ : $HNO^3$ =3 : 1, V/V) with tap water and tap water(pH 6.4), and treated by 5mm each time for three minutes during the growing seasons(April to October 1985). Acid rain treatments were done three times per week to potted seedlings by spraying the solutions. The chemical properties of potting media were compared among three soil types as well as among the various pH levels. The results obtained in this study were as follows : 1. Exchangeable calcium and magnesium contents and base saturation of the soil decreased with decreasing pH levels of acid rain, and their decreasing rates were as follows : sandy soil was the highest, followed by mixed and nursery soils, However, exchangeable aluminum content rather increased as the pH levels decreased. 2. Available phosphate in the soil decreased as the pH levels of acid rain decreased. Its content increased in nursery soil, compared with those before acid gain treatment, Gut decreased in mined and sandy soils. 3. Soil sulfate and nitrate contents increased remarkably as the pH levels decreased, and the only significant difference in the sulfate was found among the pH levels. Soil sulfate content was the highest in nursery soil, followed by mixed and sandy soils.

• Korean Journal of Environmental Agriculture
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• v.13 no.2
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• pp.175-182
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• 1994

The experiment was performed to investigate the effects of simulated acid rain of several pH levels (2.0, 3.0, 4.0, and 5.0) on growth, injury, pigment compositions and leaf surface morphology of the seedlings of Amaranthus tricolor L. by foliar application. The growth of the tops and roots was markedly retarded below pH 3.0 and speck spots appeared on the leaf. Seven different peaks were detected by the absorption spectra of pigments of the leaf. But cv. Early splendor did not show the peaks at 473nm and 535nm, and nor did cv. Tricolor show the peaks at 476nm and 546nm. The pigment composition of leaves was affected by strong acid rain. As pH levels decreased, chlorophyll content increased. Leaf surface was eroded by acid rain, and leaf surface tissues were broken down and collapsed at the lower pH levels.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.56-60
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• 1997

In order to investigate the relationships between the responses of four crops (rice, soybeans, potatoes, and red pepper) to acid rain, the simulated acid rain(SAR) of pH 1.8, 2.3, and 2.8 and normal rain of pH 6.0 were applied from 30 days after emergence to harvest at the two-week interval for rice, soybeans and red pepper and at a week interval for potatoes. SAR of pH 1.8 and 2.3 caused brown spots in the leaves of rice, soybeans, and red pepper and the damages were severer as the pH of SAR lowered, while no visual damages were observed in potatoes. The SARs did not affect chlorophyll content of rice and potatoes, while chlorophyll content of soybeans and red pepper decreased as the pH of SAR lowered. Photosynthetic activity was not significantly different among the pHs of SAR in rice, while decreased as pHs of SAR lowered from pH 2.8 to 1.8 in soybeans, potatoes, and red pepper. Yield of rice, soybeans, and potatoes was not affected by the pHs of SAR, but in red pepper the length, diameter, and weight of a fruit, the number of fruits per plant, and total matured fruit yield decreased as the pHs of SAR lowered. In rice and potatoes visual damages caused by SAR did not correlated with other observed traits. However, visual damages were negatively correlated with chlorophyll content and photosynthetic activity of soybeans and photosynthetic activity and yield of red pepper.

• Journal of Korean Society of Forest Science
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• v.82 no.4
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• pp.337-346
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• 1993

Experiments were performed to find out the effects of simulated acid rain(SAR) of pH 4.0 or pH 2.5 for 12 weeks on stomatal resistance, wettability and anatomical changes in Quercus acutissima and Ginkgo biloba seedlings. As a control, distilled water with a pH 6.5 was also sprayed. Stomatal resistance of Q. acutissima and of G. biloba remarkably increased after exposure to SAR. SAR increased the wettability of Q. acutissima leaves measured with water blue solution and of G. biloba leaves measured by leaf contact angle method. Anatomical changes in the leaves of Q. acutissima affected by SAR were the partial damage of epidermis and parenchymatous cells. Scanning electron microscopical observation showed that the number of trichomes in the leaves of Q. acutissima treated with SAR markedly decreased and the erosion of epicuticular wax was significant. No distinct damage was found in the G. biloba leaves at pH 4.0, while epidermis and vascular tissue were collapsed at pH 2.5. No significant alteration of surface structures in this tree species was observed.