• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.4
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• pp.326-333
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• 2003

Transgenic rice plants expressing a Bacillus subtilis protoporphyrinogen oxidase (Protox), the last shared enzyme of the porphyrin pathway in the expressed cytoplasm or the plastids, were compared with non-trangenic rice plants in their growth characteristics such as tiller number, plant height, biomass, and yield. Transgenic rice plants of $\textrm{T}_3$ generation had 8 to 15 % and 25 to 43% increases in tiller number compared to non-transgenic rice plants at 4 and 8 weeks after transplanting(WAT); similar values were observed for $\textrm{T}_4$ generation at 4 and 8 WAT. However, the plant height in both $\textrm{T}_3$ and $\textrm{T}_4$ generations was similar between transgenic rice plants and non-transgenic rice plants at 4 and 8 WAT. Transgenic rice plants had 13 to 32% increase in above-ground biomass and 9 to 28% increase in grain yield compared to non-transgenic rice plants, demonstrating that biomass and yield correlate with each other. The increased grain yield of the transgenic rice plants was closely associated with the increased panicle number per plant. The percent of filled grain, thousand grains and spikelet number per panicle were similar between transgenic and non-transgenic rice plants. Generally, the growth and yield of transgenic generations ($\textrm{T}_2$, $\textrm{T}_3$, and $\textrm{T}_4$) and gene expressing sites (cytoplasm-expressed and plastid-targeted transgenic rice plants) were similar, although they slightly varied with generations as well as with gene expressing sites. The transgenic rice plants had promotive effects, indicating that regulation of the porphyrin pathway by expression of B. subtilis Protox in rice influences plant growth and yield.

• Molecules and Cells
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• v.42 no.9
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• pp.637-645
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• 2019

Effector-triggered immunity (ETI) is an effective layer of plant defense initiated upon recognition of avirulence (Avr) effectors from pathogens by cognate plant disease resistance (R) proteins. In rice, a large number of R genes have been characterized from various cultivars and have greatly contributed to breeding programs to improve resistance against the rice blast pathogen Magnaporthe oryzae. The extreme diversity of R gene repertoires is thought to be a result of co-evolutionary history between rice and its pathogens including M. oryzae. Here we show that Pii is an allele of Pi5 by DNA sequence characterization and complementation analysis. Pii-1 and Pii-2 cDNAs were cloned by reverse transcription polymerase chain reaction from the Pii-carrying cultivar Fujisaka5. The complementation test in susceptible rice cultivar Dongjin demonstrated that the rice blast resistance mediated by Pii, similar to Pi5, requires the presence of two nucleotide-binding leucine-rich repeat genes, Pii-1 and Pii-2. Consistent with our hypothesis that Pi5 and Pii are functionally indistinguishable, the replacement of Pii-1 by Pi5-1 and Pii-2 by Pi5-2, respectively, does not change the level of disease resistance to M. oryzae carrying AVR-Pii. Surprisingly, Exo70F3, required for Pii-mediated resistance, is dispensable for Pi5-mediated resistance. Based on our results, despite similarities observed between Pi5 and Pii, we hypothesize that Pi5 and Pii pairs require partially distinct mechanisms to function.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2004.10a
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• pp.61-62
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• 2004

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• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.3
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• pp.157-165
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• 2017

Being a staple food for more than half of the population of the world and South Korea, rice is an important crop. For the past 20 years, global paddy rice cultivation area and production have shown an annual growth of 0.46% and 1.61%, respectively. Global rice consumption for food and processing has increased by 1.37% and 3.68%, respectively. Due to the main reason for such increasing human population, it is expected that from 439 million tons in 2010, additional 116 million tons will be needed in 2035. Global rice imports and exports have doubled in the last 20 years. However, in spite of such increment, global rice exports in 2013 were 8.4% of the total production. It is thought that rice protection policies in the producing countries are the main reason for such small scale of rice trading. In the past 5 years, India recorded the largest growth rate in rice exports (51.4%), whereas China showed the largest growth rate in imports (61.0%). For global utilization of milled rice during the same period, approximately 79.4% was used as food, 7.2% as animal feeds, and 1.4% for processing. Regionally, Asia has shown a similar pattern to the global rice usage, whereas utilization for processing in America, for food in Africa, and for animal feed in Europe was relatively higher than the global rice usage. Korea's cultivation area and production since the last 5 years, are 0.5% and 0.8% of those of the world, respectively. Its annual rice export is approximately 3,000 tons, which is 0.01% of the global rice export. Korea's rice utilization is high for food and low for feed and for processing relative to global rice utilization. Therefore, a review must be conducted to increase Korea's utilization of rice for processing and for feed production.

• Proceedings of the Korean Society of Crop Science Conference
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• 2004.04a
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• pp.72-73
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• 2004

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.83.1-83
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• 2003

Rice seedling disease is one of major problems in water-seeded rice. This disease is known to be caused by several pathogen such as Pythium, Achlya, and Fusarium species. However, seedling disease of rice in water-seeded rice in Korea is not extensively studied. Pythium species have been isolated from Seosan, Yeoju, Icheon areas using Pythium selective media and their pathogenicity was investigated. All of the Pythium isolates showed strong pathogencity causing seedling emergence reduction in water-seeded rice. Seedling emergence was reduced to 0∼9％ at 10 days after inoculation of 23 Pythium isolates compared to 60％ of noninoculated control in a growth chamber. However, Fusarium species did not cause seedling emergence reduction in water-seeded rice. In contrast, when no water added into water agar or soil, the pathogen caused seedling rot two weeks after planting. These results indicate that Pythium species is a cause of seedling disease in water-seeded cultivation areas in Korea.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.64-64
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• 2020

Bakanae disease, caused by several Fusarium species, imposes serious limitations to the productivity of rice across the globe. The incidence of this disease has been shown to increase, particularly in major rice-growing countries. Thus, the use of high resistant rice cultivars offers a comparative advantage, such as being cost effective, and could be preferred to the use of fungicides. In this research, we used a tropical japonica rice variety, Zenith, a bakanae disease resistant line selected as donor parent. A RIL population (F_8:9) composed of 180 lines generated from a cross between Ilpum and Zenith was used. In primary mapping, a QTL was detected on the short arm of chromosome 1, covering about 3.5 Mb region flanked by RM1331 and RM3530 markers. The resistance QTL, qBK1^Z, explained about 30.93% of the total phenotype variation (PVE, logarith of the odds (LOD) of 13.43). Location of qBK1^Z was further narrowed down to 730 kb through fine mapping using additional RM markers, including those previously reported and developed by Sid markers. Furthermore, there is a growing need to improving resistance to bakanae disease and promoting breeding efficiency using MAS from qBK1^Z region. The new QTL, qBK1^Z, developed by the current study is expected to be used as foundation to promoting breeding efficiency with an enhanced resistance against bakanae disease. Moreover, this study provides useful information for developing resistant rice lines carrying single or multiple major QTLs using gene pyramiding approach and marker-assisted breeding.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.1-14
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• 2024

High soil salinity is the most severe threat to global rice production as it causes a significant decline in rice yield. Here, we investigated the effects of various plant extracts on rice plant stress associated with high salinity. Additionally, we examined various physiological and biochemical parameters such as growth, photosynthetic activity, chlorophyll content, and lipid peroxidation - in rice plants after treatment with selected plant extracts under salt stress conditions. Of the 11 extracts tested, four - soybean leaf, soybean stem, moringa (Moringa oleifera), and Undaria pinnatifida extracts - were found to effectively reduce salt stress. A reduction of only 3-23% in shoot fresh weight was observed in rice plants under salt stress that were treated with these extracts, compared to the 43% reduction observed in plants that were exposed to stress but not given plant extract treatments (control plants). The effectiveness varied with the concentration of the plant extracts. Water content was higher in rice plants treated with the extracts than in the control plants after 6 d of salt stress, but not after 4 d of salt stress. Although photosynthetic efficiency (Fv/Fm), electron transport rate (ETR), and the content of pigments (chlorophyll and carotenoid) varied based on the types and levels of stress and the extracts that the rice plants were treated with, generally, photosynthetic efficiency and pigment content were higher in the treated rice compared to control plants. Reactive oxygen species (ROS), such as superoxide radicals, hydrogen peroxide (H₂O₂), and malondialdehyde (MDA), increased as the duration of stress increased. ROS and MDA levels were lower in the treated rice than in the control plants. Proline and soluble sugar accumulation also increased with the duration of the stress period. However, proline and soluble sugar accumulation were lower in the treated rice than in the control plants. Generally, the values of all the parameters investigated in this study were similar, regardless of the plant extract used to treat the rice plants. Thus, the extracts found to be effective can be used to alleviate the adverse effects of stress on rice crops associated with high-salinity soils.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.5-6
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• 2002

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.7-8
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• 2002