• Journal of Microbiology and Biotechnology
• /
• 제25권7호
• /
• pp.1119-1128
• /
• 2015

1-Aminocyclopropane-1-carboxylate (ACC) deaminase, which is encoded by some bacteria, can reduce the amount of ethylene, a root elongation inhibitor, and stimulate the growth of plants under various environmental stresses. The presence of ACC deaminase activity and the regulation of ACC in several rhizospheric bacteria have been reported. The nitrogen-fixing Pseudomonas stutzeri A1501 is capable of endophytic association with rice plants and promotes the growth of rice. However, the functional identification of ACC deaminase has not been performed. In this study, the proposed effect of ACC deaminase in P. stutzeri A1501 was investigated. Genome mining showed that P. stutzeri A1501 carries a single gene encoding ACC deaminase, designated acdS. The acdS mutant was devoid of ACC deaminase activity and was less resistant to NaCl and NiCl₂ compared with the wild-type. Furthermore, inactivation of acdS greatly impaired its nitrogenase activity under salt stress conditions. It was also observed that mutation of the acdS gene led to loss of the ability to promote the growth of rice under salt or heavy metal stress. Taken together, this study illustrates the essential role of ACC deaminase, not only in enhancing the salt or heavy metal tolerance of bacteria but also in improving the growth of plants, and provides a theoretical basis for studying the interaction between plant growth-promoting rhizobacteria and plants.

• Mycobiology
• /
• 제47권4호
• /
• pp.473-482
• /
• 2019

Rice blast disease, caused by the ascomycete fungus Magnaporthe oryzae, is one of the most important diseases in rice production. PAS (period circadian protein, aryl hydrocarbon receptor nuclear translocator protein, single-minded protein) domains are known to be involved in signal transduction pathways, but their functional roles have not been well studied in fungi. In this study, targeted gene deletion was carried out to investigate the functional roles of the PAS-containing gene MoPAS1 (MGG_02665) in M. oryzae. The deletion mutant ΔMopas1 exhibited easily wettable mycelia, reduced conidiation, and defects in appressorium formation and disease development compared to the wild type and complemented transformant. Exogenous cAMP restored appressorium formation in ΔMopas1, but the shape of the restored appressorium was irregular, indicating that MoPAS1 is involved in sensing the hydrophobic surface. To examine the expression and localization of MoPAS1 in M. oryzae during appressorium development and plant infection, we constructed a MoPAS1:GFP fusion construct. MoPAS1:GFP was observed in conidia and germ tubes at 0 and 2 h post-infection (hpi) on hydrophobic cover slips. By 8 hpi, most of the GFP signal was observed in the appressoria. During invasive growth in host cells, MoPAS1:GFP was found to be fully expressed in not only the appressoria but also invasive hyphae, suggesting that MoPAS may contribute to disease development in host cells. These results expand our knowledge of the roles of PAS-containing regulatory genes in the plant-pathogenic fungus M. oryzae.

• Journal of Microbiology and Biotechnology
• /
• 제23권1호
• /
• pp.22-28
• /
• 2013

Xo2276 is a putative transcription activator-like effector (TALE) in Xanthomonas oryzae pv. oryzae (Xoo). Xo2276 was expressed with a TAP-tag at the C-terminus in Xoo cells to enable quantitative analysis of protein expression and secretion. Nearly all TAP-tagged Xo2276 existed in an insoluble form; addition of rice leaf extracts from a Xoosusceptible rice cultivar, Milyang23, significantly stimulated secretion of TAP-tagged Xo2276 into the medium. In a T3SS-defective Xoo mutant strain, secretion of TAPtagged Xo2276 was blocked. Xo2276 is a Xoo ortholog of Xanthomonas campestris pv. vesicatoria (Xcv) AvrBs3 and contains a conserved DNA-binding domain (DBD), which includes 19.5 tandem repeats of 34 amino acids. Xo2276- DBD was expressed in E. coli and purified. Direct in vitro recognition of Xo2276-DBD on a putative target DNA sequence was confirmed using an electrophoretic mobility shift assay. This is the first study measuring the homologous expression and secretion of Xo2276 in vitro using rice leaf extract and its direct in vitro binding to the specific target DNA sequence.

• 한국육종학회지
• /
• 제42권2호
• /
• pp.151-156
• /
• 2010

The mutants of sugary-2 (su-2), floury (flo), shrunken-1 (shr-1), and dull-1 (du-1) were crossed to waxy (wx) to produce $F_2$ seeds. Chi-square analysis on the segregating ratio of the $F_2$ seeds revealed that flo, su-2, and shr-1 were independently transmitted with wx, while wx was epistatic over du-1. The floury and sugary-2 were crossed to Hwasunchalbyeo, a waxy variety, and then the $F_4$ of floury-waxy and sugary-2-waxy seeds were developed, respectively. As the parents phenotypes of sugary-2 and floury, the grains of these two lines showed lower hardness and grain weight than normal grain of Hwacheongbyeo. For alkali digestive value (AVD), the sugary-2-waxy showed lower ADV than Hwacheongbyeo. For the gel consistency of grain flours, the floury was medium like Hwacheongbyeo, while those of the sugary-2, floury-waxy, and sugary-2-waxy were soft like Hwasunchalbyeo. The amylose contents in the grains of the sugary-2 and floury were decreased to ~15% whereas that of Hwacheongbyeo was 19.1%. All the lines showing waxy endosperm (Hwasunchalbyeo, floury-waxy, and sugary-2-waxy) showed less than 4% amylose contents. Interestingly, the free sugar content in the brown rice was increased to 9.27% in the sugary-2-waxy, showing transgressive segregation phenomenon where the free sugar contents in its parents, sugary-2 and Hwasunchalbyeo, were 5.98% and 3.98% respectively. Also, the floury-waxy showed transgressive segregation phenomenon, containing 6.15% of free sugar content in the grains.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 추계학술대회
• /
• pp.268-268
• /
• 2022

Protein is a major nutrient of food and has long been studied for nutritional and utility value. Among them, rice protein is attracting attention because of its hypoallergenic characteristics and nutritional value. Mutant DM225 with increased protein content was selected by EMS treatment on the weed rice Dharial. QTL analysis of Protein content was carried out using BC₂F₂ populations derived from a cross between "Hanareum2" as a recurrent parent and "DM225" as a donor parent. The protein content of populations was between 5~11%, with an average of 7.7%. To identify QTLs related to Protein content, 117 KASP markers(polymorphic ratio: 15%) showing polymorphisms between the parents were genotyped for the BC₂F₂ population. One QTL was detected between markers SK07 06 and SK07_10 on chromosome 7(LOD: 28.1). This QTL explained 71.4% of the phenotypic variance for Protein content. This QTL will be useful for protein-related rice breeding program.

• Applied Biological Chemistry
• /
• 제47권1호
• /
• pp.61-66
• /
• 2004

신선찰거대배아미, 화청거대배아미 및 남풍거대배아미 등 거대배 돌연변이 계통 쌀 3종류 및 일반미의 70% 에탄올 추출물을 제조하여, 이들의 항산화 활성 및 항변이원성을 비교 검정하였다. 거대배아미 추출물의 항산화 활성은 DPPH radical 및 Fenton 반응에 의해서 유도되는 hydroxy radical의 소거활성, hypoxanthine/xanthine oxidase system에서 생성되는 활성산소종인 superoxide radical의 소거활성, linoleic acid자동산화에 대한 지질 과산화 억제활성 및 토끼 적혈구 막지질의 과산화 억제활성 둥으로써 검정하였으며, 항변이원성은 E. coli PQ 37 균주를 사용하여 화학적 변이원 mitomycin C에 대한 변이원성 억제효과를 SOS chromotest에 의해서 검정하였다. 일반미 품종에 비해서 거대배아미 품종의 항산화 활성 및 항변이원성이 모두 높았으며, 거대배아미 품종 중에서는 남풍거대배아미가 가장 효과적인 경향이 있었다. 남풍거대배아미의 DPPH radical, superoxide radical과 hydroxyl radical 소거활성, 그리고 지질과산화 억제활성은 일반미보다 각각 2.3배, 3.3배, 1.7배 및 2.5배 정도까지 더 높았다.

• 한국작물학회지
• /
• 제60권2호
• /
• pp.146-152
• /
• 2015

본 연구는 국내 조생종 벼 품종들과 농촌진흥청 국립식량과학원에서 육성된 자포니카(Oryza sativa L. ssp. Japonica)의 조생 다수성 품종인 남일 돌연변이 계통인 중모1024의 등숙기 고온내성을 비교 평가하여 등숙기 고온내성의 기초자료를 얻고자 수행하였다. 본 연구를 통하여 국내 조생종벼 품종들 중 대봉, 운광, 및 만안과 돌연변이 계통인 중모 1024가 고온에서 상대적으로 양호한 고온내성을 가지고 있는 것으로 평가되었으며. 특히 중모1024는 다른 공시품종들에 비하여 상당히 양호한 고온내성을 가진 것으로 평가되었다. 본 연구의 주요 결과는 등숙기간 동안 고온에 의하여 현미의 길이와 너비가 감소하였으며, 현미 너비의 감소율이 현미 길이의 감소율에 비하여 평균 4배 이상 높았다. 이러한 결과로 보아, 등숙기간 동안 고온에 의하여 현미의 길이보다는 너비가 더 많은 영향을 받는다고 사료된다. 등숙기간 동안 고온에 의해 가장 문제가 되는 완전미율과 미숙립율을 공시품종들간 비교 평가한 결과, 상대적으로 중모 1024, 태봉, 운광 및 만안이 고온에서 높은 현미완전미율을 보였으며, 상대적으로 적온에서 낮은 현미완전미율을 보인 품종들이 상대적으로 고온에 의한 현미완전미율 감소율이 적온에서 높은 현미완전미율을 보인 품종들에 비해 낮았다. 또한, 다른 공시품종들에 비하여 고온내성이 양호한 중모 1024는 고온에서도 좋은 쌀 외관품위와 안정적 수확성 향상을 위한 육종모재로서 유용형질을 교배를 통해 고품질 벼의 보완을 위해 이전할 수 있는 것이 용이할 것으로 사료된다.

• Interdisciplinary Bio Central
• /
• 제2권4호
• /
• pp.13.1-13.8
• /
• 2010

The National BioResource Project of Japan is a governmental project to promote domestic/international research activities using biological resources. The project has 27 biological resources including three cereal resources. The core center and sub-center which historically collected the cereal resources were selected for each cereal program. These resources are categorized into several different types in the project; germplasm, genetic stocks, genome resources and database information. Contents of rice resources are wild species, local varieties in East and Southwest Asia & wild relatives, MNU-induced chemical mutant lines, marker tester lines, chromosome substitution lines and other experimental lines. Contents of wheat resources are wild strains, cultivated strains, experimental lines, rye wild and cultivated strains; EST clones and full-length cDNA clones. Contents of barley resources are cultivar and experimental lines, core collection, EST/cDNA clones, BAC clones, their filters and superpool DNA. Each resource is accessible from the online database to see the contents and information about the resources. Links to the genome information and genomic tools are also important function of each database. The major contents and some examples are presented here.

• 한국작물학회지
• /
• 제36권3호
• /
• pp.197-203
• /
• 1991

화청벼와 IR24의 수정란에 N-methyl-N-nitros-ourea(MNU)를 처리하여 여러 종류의 배란 및 배 돌연변이체를 유기하였다. 그 결과는 다음과 같이 요약된다. 1. 변이체들에 대한 외관특성, SEM 검경 특성 및 amylose 함량 분석을 통하여 각각 dull, 찰성, 심백, 분질, sugary, shrunken, 유색종피 변이체들로 명명하였다. 2. 변이체들 중에서는 심백 변이체들의 비율이 74.8%로 가장 높았다. 3. 47320(dull)을 제외한 모든 변이 형질은 단순열성 돌연변이인 것으로 나타났다.

• 생명과학회지
• /
• 제20권1호
• /
• pp.22-26
• /
• 2010

벼의 적색 종피 표현형질은 Rc 혹은 Rd 그리고 RdRc 두 개의 복수유전자에 의하여 결정된다. 본 연구에서는 종피에 색소가 있는 돌연변이 벼 7계통을 벼 표현형 돌연변이 군들로부터 분리하였다. 이들 종피색의 돌연변이 형질을 조사한 결과 두 개의 변이체가 갈색의 종피형질을 가졌으며 네 개의 변이체가 적색의 종피형질을 가졌다. 그리고 한 개의 변이체는 종피에 색깔이 없었다. 수확 후 종자의 종피색 표현형질에 관한 정밀조사를 실시한 결과 두개의 갈색종피 돌변이체는 Rc 유전자형 이었으며 네개의 적색종피 돌변이체는 RdRc 유전자형이었다. 또한 종피에 색깔이 없는 한 개의 돌변이체가 Rd 유전자형이었다. 이들 중 동일한 종피색깔을 나타내는 돌연변이 개체들이 단일 돌연변이 개체의 후손인지 여부를 판명하기 위하여 돌변이체들의 초형과 농업형질을 조사한 결과 동일 종피색 돌변이체들의 형질이 서로 상이하므로 각각 서로 다른 돌연변이 계통들로 확인되었다. 그리고 이들 종피색깔 돌연변이들은 초형, 분얼 특징, 임성과 수량성 등을 포함한 농업형질들이 정상 벼의 농업형질들보다 대체로 빈약하고 또한 높은 탈립성을 보였다. 이러한 종피색과 관련된 돌연변이 벼 유전자원은 안토시아닌과 폴리페놀이 풍부하므로 병충해 저항성 품종과 환경스트레스 내성 품종의 육종에 필요할 뿐만 아니라 종피의 색깔을 결정하는 유전자들의 기능을 밝히는 데 중요한 자료로 사용될 것이다.