• 방사선산업학회지
• /
• 제9권3호
• /
• pp.119-126
• /
• 2015

In Shinjeong-dong of Jeongeup, there are three government-supported research institutes and an RFT industrial complex which is currently being established. Increased human activities can affect flora and fauna as a man-made pressure onto the region. As a baseline study, status of exotic plants was investigated prior to a full operation of the RFT industrial complex. A total of 54 species and 1 variety of naturalized or introduced plants were found in the study area. Among them, three species (Ambrosia artemisifolia var. elatior, Rumex acetocella and Aster pilosus) belong to 'nuisance species', and four species(Phytolacca americana, Iopomoea hederacea, Ereechtites hieracifolia and Rudbeckia laciniata) to 'monitor species' designated by the ministry of Environment. Some of naturalized trees and plants were intentionally introduced in this area, while others naturally immigrated. Physalis angulata seemes to immigrate in the study area in the form of mixture with animal feeds as its distribution coincided with the transportation route of the animal feeds. Liquidambar styraciflua is amenable to the ecological investigation on the possible expansion of the species to the nearby Naejang National Park as its leave shape and autumn color are very similar to those of maple trees. The number of naturalized plants around the RFT industrial complex will increase with an increase in floating population, in human activities in association with constructions of factories and operations of the complex. The result of this study provides baseline data for assessing the ecological change of the region according to the operation of the RFT industrial complex.

• Journal of Plant Biology
• /
• 제26권2호
• /
• pp.91-99
• /
• 1983

The formation of chlorophyll-protein complexes (CP-complexes) during the greening of rape cotyledons (Brassica napus cv. Yongdang) was investigated by the SDS-polyacrylamide gel electrophoresis. The total chlorophyll content and Chl a/b ratio were also determined. In addition, the effects of dark treatment on the CP-complex patterns during greening have been examined with respect to their photosynthetic electron transport activity. Greening has brought about the increasein total chlorophyll content and the decrease in Chl a/b ratio, but there have been no changes in Chl a/b ratio after 24 hrs of greening. The light-harvesting chlorophyll a/b-protein complex (LHCP-complex0 was predominant during the initial greening period. Thereafter, the amout of chlorophyll a-protein complex (CP I-complex) was gradually increased. Twenty-four-hr dark treatment immediately after illumination for 6 hrs and 12 hrs resulted in the increase of the Chl a/b ration and the CP I complex, otherwise the decrease of the LHCP-complex. The LHCP/CP I ratio was gradually decreased with further greening, and appeared no change after 48 hrs illumination. The investigation of the photosynthetic electron transport activity indicated that photosystem (PS) II activity (H2Olongrightarrowp-PD*＋FeCy**) did not change, but the activity of PS I was increased suddenly due to the dark treatment. The data suggests that the increase of CP I-complex may result in that of P-700, that is, the increase of PS I activity.

• Journal of Plant Biotechnology
• /
• 제38권4호
• /
• pp.278-284
• /
• 2011

The CCR4-CAF1-NOT complex-mediated degradation of mRNA is a fundamental aspect of gene regulation in eukaryotes. We herein examined the role of AtCAF1 in the innate immune and wound responses of plants. Our results showed that overexpression of AtCAF1 significantly downregulated the transcript level of EFR but not FLS2 and BRI1, as well as abolished up-regulated expression pattern of EFR in response to wounding. Consistently, Agrobacteriummediated transient expression of GUS was highly enhanced in the transgenic plants overexpressing AtCAF. Furthermore, JA responsive genes were down-regulated by overexpression of AtCAF, causing the transgenic plants overexpressing AtCAF more susceptible to necrotrophic fungal pathogen, Botrytis cinerea. These results suggest that The CCR4-CAF1-NOT complex-mediated degradation of mRNA negatively regulates wounding-mediated disease resistance in Arabidopsis thaliana.

• Journal of Plant Biology
• /
• 제33권4호
• /
• pp.237-242
• /
• 1990

Geographical distribution of diploid plant with AA genome (2n=16) and allotetraploid with AABB genome (2n=34) of Scilla scilloides Complex from Korea has been studied. The composition and frequencies of B chromosomes ere also investigated. Plants with AABB genome were predominant over AA genome plants. A mixed population of AA and AABB genome plants was found for the first time. Aneuploid plants have not been found. Chromosomes of AA genome were composed of three pairs of metacentric, two pairs of submetacentric, two pairs of subtlocentric and one pair of telocentric chromosomes, whereas BB genome was four pairs of metacentric and five pairs of subtelocentric chromosomes. B chromosomes were classified into two categories, isochromosome (F) and chromosome fragment (f). The frequencies of B chromosomes were 43% in AA genome plants and 44% in AABB genome plants. The number of B chromosome ranged from 1 to 3 and 1 to 7 in AA and AABB genome plants, respectively. B chromosome combinations were F and F+f in AA genome plants and F, F+f and f in AABB genome plants.

• Journal of Plant Biology
• /
• 제36권1호
• /
• pp.97-104
• /
• 1993

The lipid composition of thylakoid membranes was compared between mesophyll and bundle sheath chloroplasts of maize. According to mild-denaturing gel electrophoresis, mesophyll thylakoids contained both PS I complex and PS II light-harvesting chlorophyll-protein complex(LHCP), while those of bundle sheath cells contained mainly PS I complex. The amount of lipids per mg chlorophyll was higher in bundle sheath thylakoids than in mesophyll. The major polar lipid classes were monogalactosyldiacylglycerol(MGDG), digalactosyldiacylglycreol, sulfolipid and phosphatidylglycerol (PG) in both tissues. Linolenic acid(18 : 3), linoleic acid(18 : 2) and palmitic acid(16 : 0) were the main fatty acyl components, with higher ratio of unsaturated to saturated fatty acids in bundle sheath thylakoids, suggesting these membranes are more fluid. The most striking difference in lipid composition between the two kinds of tissues was the practical absence of trans- 3-hexadecenoic acid(16 : 1t) in PG of bundle sheath thylakoids. This fatty acid is known to be involved in the association of LHCP as oligomeric form. More than 80% of MGDG molecular species was 18 : 3, 18 : 3, demonstrating that maize is a typical 18 : 3 plant. Therefore, the possibility of the functional relationships between the lamella structure, and thus the distribution of photosystems, and MGDG molecular species was excluded.

• Mycobiology
• /
• 제48권3호
• /
• pp.233-239
• /
• 2020

A small-spored Alternaria was found from black spots of storaged Koerle pear (Pyrus sinkiangensis), one of the economically important fruit in Xinjiang province, China. The morphology is similar to A. limoniasperae but obviously different in secondary conidiophores and conidial septa. A phylogenetic analysis using sequence datasets of ITS, GAPDH, TEF1, RPB2, Alt a1, OPA10-2, and EndoPG genes revealed that it belonged to the Alternaria alternata complex group. Pathogenicity tests illustrated that the fungus was the causal pathogen of black spot on Koerle pear fruit.

• 식물병연구
• /
• 제23권2호
• /
• pp.89-98
• /
• 2017

Ralstonia solanacearum species complex (RSSC) causes bacterial wilt, and it is one of the most important soil-borne plant pathogenic bacteria. RSSC has a large host range of more than 50 botanical families, which represent more than 200 plant species, including tomato. It is difficult to control bacterial wilt due to following reasons: the bacterial wilt pathogen can grow inside the plant tissue, and it can also survive in soil for a long period; moreover, it has a wide host range and biological diversity. In most previous studies, scientists have focused on developing biological control agents, such as antagonistic microorganisms and botanical materials. However, biocontrol attempts are not successful. Plant-derived metabolites and extracts have been promising candidates to environmentally friendly control bacterial wilt diseases. Therefore, we review the plant extracts, essential oils, and secondary metabolites that show potent in vivo antibacterial activities (in potted plants or in field) against tomato bacterial wilt, which is caused by RSSC.

• Molecules and Cells
• /
• 제40권10호
• /
• pp.773-786
• /
• 2017

The loss of green coloration via chlorophyll (Chl) degradation typically occurs during leaf senescence. To date, many Chl catabolic enzymes have been identified and shown to interact with light harvesting complex II to form a Chl degradation complex in senescing chloroplasts; this complex might metabolically channel phototoxic Chl catabolic intermediates to prevent oxidative damage to cells. The Chl catabolic enzyme 7-hydroxymethyl Chl a reductase (HCAR) converts 7-hydroxymethyl Chl a (7-HMC a) to Chl a. The rice (Oryza sativa) genome contains a single HCAR homolog (OsHCAR), but its exact role remains unknown. Here, we show that an oshcar knockout mutant exhibits persistent green leaves during both dark-induced and natural senescence, and accumulates 7-HMC a and pheophorbide a (Pheo a) in green leaf blades. Interestingly, both rice and Arabidopsis hcar mutants exhibit severe cell death at the vegetative stage; this cell death largely occurs in a light intensity-dependent manner. In addition, 7-HMC a treatment led to the generation of singlet oxygen ($^1O_2$) in Arabidopsis and rice protoplasts in the light. Under herbicide-induced oxidative stress conditions, leaf necrosis was more severe in hcar plants than in wild type, and HCAR-overexpressing plants were more tolerant to reactive oxygen species than wild type. Therefore, in addition to functioning in the conversion of 7-HMC a to Chl a in senescent leaves, HCAR may play a critical role in protecting plants from high light-induced damage by preventing the accumulation of 7-HMC a and Pheo a in developing and mature leaves at the vegetative stage.

• 식물분류학회지
• /
• 제51권2호
• /
• pp.115-132
• /
• 2021

Seven species and two varieties belonging to the genus Boehmeria Jacq. (Urticaceae) are known to be distributed in Korea. Among them, B. spicata, B. tricuspis, and B. tricuspis var. unicuspis were subjected to an external morphological study. Among the individuals believed to exhibit variations in the leaf shape, B. gracilis and B. silvestrii were newly recognized. Unlike related taxa, B. gracilis has middle leaves with an elliptic, broadly elliptic, ovate, or broadly depressed ovate shape, a regular and serrulate-dentate margin, and an unlobed and short caudate or cuspidate apex. Boehmeria silvestrii has middle leaves with 5-angled ovate, orbicular ovate or broadly ovate shapes, and 3- or 5-lobed and caudate apices. Therefore, we assigned the corresponding names 'Top-geo-buk-kko-ri' and 'Cham-geo-buk-kko-ri'. Meanwhile, the B. spicata complex (B. gracilis, B. silvestrii, B. spicata, and B. tricuspis var. unicuspis) is very closely related in terms of the morphological characters, whereas B. tricuspis exhibits no relationship. Furthermore, because the scientific name and type specimen of B. tricuspis var. unicuspis (Pul-geo-buk-kko-ri) are problematic, the correct name B. paraspicata Nakai and corresponding holotype are presented. Additionally, lectotypes of B. gracilis and B. silvestrii are newly designated here. A taxonomic treatment, descriptions, a key, photographs, type specimens, and leaf variation images of the B. spicata complex are provided in this study.

• 한국대기환경학회지
• /
• 제13권6호
• /
• pp.427-437
• /
• 1997

Complex terrain which is rather typical topographic character in Korea would greatly influence the dispersion of air pollutant. In this study, we investigated how the complex terrain in the vicinity of the coal-fired plant affects the air dispersion modeling results by using several US EPA models: SCREEN, CTSCREEN, ISCLT3, ISCST3, and RTDM. Screening analysis was followed by long-term analysis, and the plume movement over the terrain was precisely tracked for selected cases. Screening analysis revealed that the highest concentration of sulfur dioxide occurs at the downwind distance of 1.3 km under the unstable conditions with weak winds. However, this highest level of $SO_2$ could be raised by 4 times even in the presence of a hill of 170 m at a distance of 2 to 3 km. Seasonal and annual average concentrations predicted with the ISCLT3, ISCST3, and RTDM models showed a rapid incrase of $SO_2$ levels in front of the high mountains which are located more than 15 km away fromt the source. The highest concentrations predicted with ISCST3 were significantly higher than those with ISCLT3 and RTDM mainly because ISCST3 chooses simple-terrain model calculations for receptors between stack height and plume height. Although the highest levels under the stable conditions were usually found in the areas beyond 15 km or more, their absolute values were not so high due to enough dispersion effects between the source and the receptors.