• Rapid Communication in Photoscience
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• v.1 no.1
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• pp.21-24
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• 2012

Influence of gamma rays on the cyanobacterium Synechocystis sp. PCC 6803 cells was investigated in terms of a bidirectional hydrogenase, which is encoded by hoxEFUYH genes and responsible for biohydrogen production. Irradiated cells revealed a substantial change in stoichiometry of photosystems at one day after gamma irradiation at different doses. However, as evaluated by the maximal rate of photosynthetic oxygen evolution, maximal photochemical efficiency of photosystem II, and chlorophyll content, net photosynthesis or photosynthetic capacity was not significantly different between the control and irradiated cells. Instead, transcription of hoxE, hoxH, or lexA, which encodes a subunit of bidirectional hydrogenase or the only transcriptional activator, LexA, for hox genes, was commonly enhanced in the irradiated cells. This transcriptional enhancement was more conspicuously observed immediately after gamma irradiation. In contrast, hydrogenase activities were found to somewhat lower in the irradiated cells. Therefore, we propose that transcription of hox genes should be enhanced by gamma irradiation in a LexA-mediated and possibly photosynthesis-independent manner and that this enhancement might not induce a subsequent increase in hydrogenase activities, probably due to the presence of post-transcriptional and/or post-translational regulatory mechanisms.

• The Plant Pathology Journal
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• v.36 no.5
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• pp.476-490
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• 2020

The parasitic weed, Orobanche crenata, is one of the most devastating constraint for faba bean production in Mediterranean regions. Plant host defense induction was reported as one of the most appropriate control methods in many crops. The aim of this study was to elucidate the effect of salicylic acid (SA) and indole acetic acid (IAA) on the induction of faba bean resistance to O. crenata under the field and controlled experimental conditions. Both hormones were tested on two contrasting faba bean genotypes: Giza 843 (partially resistant to O. crenata) and Lobab (susceptible) at three different application methods (seed soaking, foliar spray, and the combination of both seed soaking and foliar spray). Soaking seeds in SA or IAA provided the highest protection levels reaching ~75% compared to the untreated control plants. Both elicitors limited the chlorophyll content decrease caused by O. crenata infestation and increased phenolic compound production in host plants. Phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase activities were stimulated in the host plant roots especially in the susceptible genotype Lobab. The magnitude of induction was more obvious in infested than in non-infested plants. Histological study revealed that both SA and IAA decreased the number of attached O. crenata spikes which could be related to specific defense responses in the host plant roots.

• Journal of Korean Society for Atmospheric Environment
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• v.3 no.1
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• pp.13-26
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• 1987

One-year-old seedlings of Ginkgo biloba, potted in three different soils (nursery soil, mixed and sandy soil), were treated with simulated acid rain (pH 2.0, 3.0, 4.0 and 5.0) and tap water (control, pH 6.4) during the growing seasons (1985. 4. 28 - 1985. 10. 19) to examine the effects of acid rain on growth and physiological characteristics, and the relations between seedling growth and physiological characteristics. The results obtained in this study were as follows: 1. The effects of soil types on the total, top and root dry weight per seedling were significant at 5% level, and those of the pH of the rain treated at 1% level. The total dry weight of the pH 3.0 sub-plots was the highest for nursery soil, while for mixed and sandy soils, those of the control and the pH 5.0 sub-plots were the highest, respectively. 2. The leaf surface areas of pH 2.0 sub-plots severely decreased after July, but those of other sub-plots were not affected. The correlations between growth and leaf surface area differed among soil-types, however, the highest positive correlation was found in September. 3. The injured leaf rate increased with decreasing pH levels of acid rain. Highly negative correlations between growth and injured leaf rate were found. 4. The lower the pH level of acid rain treated was, the more the chlorophyll content was measured at the beginning of treatment, and the more severely it decreased at late growing season. A negative correlations were found in August, September and Octobfer. 5. The photosynthetic ability decreased rapidly after July with decreasing pH levels. A highly positive correlation between growth and photosynthetic ability was found in August.

• Journal of Microbiology and Biotechnology
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• v.26 no.9
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• pp.1542-1550
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• 2016

This is the first report that paromomycin, an antibiotic derived from Streptomyces sp. AG-P 1441 (AG-P 1441), controlled Phytophthora blight and soft rot diseases caused by Phytophthora capsici and Pectobacterium carotovorum, respectively, in chili pepper (Capsicum annum L.). Chili pepper plants treated with paromomycin by foliar spray or soil drenching 7 days prior to inoculation with P. capsici zoospores showed significant (p < 0.05) reduction in disease severity (%) when compared with untreated control plants. The disease severity of Phytophthora blight was recorded as 8% and 50% for foliar spray and soil drench, respectively, at 1.0 ppm of paromomycin, compared with untreated control, where disease severity was 83% and 100% by foliar spray and soil drench, respectively. A greater reduction of soft rot lesion areas per leaf disk was observed in treated plants using paromomycin (1.0 μg/ml) by infiltration or soil drench in comparison with untreated control plants. Paromomycin treatment did not negatively affect the growth of chili pepper. Furthermore, the treatment slightly promoted growth; this growth was supported by increased chlorophyll content in paromomycin-treated chili pepper plants. Additionally, paromomycin likely induced resistance as confirmed by the expression of pathogenesis-related (PR) genes: PR-1, β-1,3-glucanase, chitinase, PR-4, peroxidase, and PR-10, which enhanced plant defense against P. capsici in chili pepper. This finding indicates that AG-P 1441 plays a role in pathogen resistance upon the activation of defense genes, by secretion of the plant resistance elicitor, paromomycin.

• 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.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.112-117
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• 2011

This research was conducted to determine the effect of the pre-treatment of mulberry charcoal on the salt tolerance response in Kentucky bluegrass 'Perfection'. As this results, 400 mM NaCl treatment reduced turf growth such a fresh and dry weight, and induced physiological damages like decreased chlorophyll content and increased electrolyte leakage. The pre-treatment of mulberry charcoal, however, mitigated those growth and physiological responses associated with NaCl stress, regardless of the concentrations of charcoal solution. Furthermore, it was observed that higher K ion concentration by mulberry charcoal pre-treatment reduced Na ion in shoot. This research suggests to be a possibility of planting turf grasses in reclaimed land or higher salt accumulated area using a mulberry charcoal treatment.

• Journal of Microbiology and Biotechnology
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• v.20 no.7
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• pp.1134-1139
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• 2010

This study explored the chronic effects of different doses of the triazole fungicide tebuconazole on the growth, and metabolic and enzymatic functions of the filamentous paddy field cyanobacterium, Westiellopsis prolifica Janet. The growth of the cyanobacterium was determined by an estimation of the change in pigment contents. Chlorophyll-a, carotenoids, and accessory pigments such as phycocyanin, allophycocyanin, and phycoerythrin were shown to decline over a 16-day period by a factor of 92%, 93%, 83%, 95%, and 100%, respectively, with increasing doses of the fungicide. Metabolic and enzymatic activities were also adversely affected. Over the 16 days, a gradual rise in total phenol content was recorded when Westiellopsis prolifica Janet was treated with 60 ppm of the fungicide, despite the reduction in carbohydrates, proteins, and amino acids by 96%, 92%, and 90%, respectively. Moreover, the enzymes nitrate reductase (NR), glutamine synthetase (GS), and succinate dehydrogenase (SDH) also registered reductions of 93%, 90%, and 98%, respectively. This study indicates that tebuconazole, although an important fungicide used extensively in rice fields, exhibits an inhibitory effect on the growth and metabolic activities of Westiellopsis prolifica Janet and hence possibly on other varieties as well.

• Ocean and Polar Research
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• v.23 no.4
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• pp.389-394
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• 2001

During austral summer 1998 we examined the impacts of artificial UV-B and solar radiation on chlorophyll a content and fresh weight of four species of Antarctic red algae namely, Georgiella confluens, Iridaea cordata, Pantoneura plocamioides and Porphyra endiviifolium. These subject species were taken in consideration of clear demarcations of their vertical distribution and classified as shallow water group (Iridaea and Porphyra) and deep water group (Georgiella and Pantoneura). When irradiated with artificial UV-B at the irradiance of $2.0Wm^{-2}$ the shallow water inhabitants were much more resistant than the algae from deep water the fresh weight of which was reduced by 40-50% relative to control apart from loss of pigmentation. Direct solar radiation was lethal to the deep water group with a sign of complete bleaching whereas the shallow water group did not show any change in the physiological parameters. We were unable to discriminate difference in the algal sensitivity between UV-filtered and UV-transparent treatments since samples tested were either all unaffected or dead. Spectrophotometric measurements of methanolic extracts revealed a strong absorption peak in the UV range in the shallow water group of algae, Iridaea and Porphyra, but not in the deep water counterparts. Species difference in sensitivity to artificial UV-B and solar radiation is discussed in relation to biochemical and morphological characteristics and the role of the radiation in the algal vertical distribution is suggested from ecological perspective.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.2
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• pp.61-66
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• 2015

In this study, manufacture of kitchen garden soil and its application on the growth of Lettuce has been performed. The optimal ratio of various raw materials for pH, total nitrogen, phosphate, cations, and salt content was found to be 49 : 35 : 10 : 5 : 1(w/w) in peatmoss, livestock manure, cocopeat, zeolite, and microbial fertilizer, respectively. In the growth experiment using Lettuce, the manufactured soil obtained 21% & 20% increase in leaf length and width, 17% increase in chlorophyll, and 22% in biomass, compared to the control.

• Current Research on Agriculture and Life Sciences
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• v.15
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• pp.1-5
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• 1997

The purpose of this study was to determine the inheritance of chlorosis under low temperature at seedling stage of rice. The expression of chlorosis among 21 rice cultivars treated at $18^{\circ}C$ showed in one Tongil type cultivar, Milyang 23, and two Indica type cultivars, IR 36 and Dular. The sign of chlorosis was not appeared in all of the japonica type cultivars under the same treatment. The reduction of chlorophyll content under the low temperature was differed from varietal group and cultivars. The $F_2$ population from a cross between Toyohatamochi and Dular segregated 3:1 ratio for normal and white phenotypes of third leaf. From the result, it was suggested that the chlorosis was controlled by a single recessive gene. The chlorosis rice detected from this study will be used as a good material for the genetic study related to photosynthetic ability of rice.