• Journal of Applied Biological Chemistry
• /
• 제44권4호
• /
• pp.159-162
• /
• 2001

Plant stress incurred by flooding was studied in terms of oxidative stress, using greened rice seedlings subjected to a complete submergence followed by re-exposure to air under illumination ($30W/m^2$). It appeared that shoot tissues of the seedlings suffered oxygen deficiency during the flooding treatment, pertinent to the general concept. Interestingly enough, however, membrane peroxidation in shoots was enhanced by the submergence, as assessed by the content of 2-thiobarbituric acid-reactive substances (TBARS), and the re-aeration resulted in a rapid reduction of TBARS content. Such pattern of response was also seen in the change in the steady state level of $H_2O_2$. In contrast, superoxide dismutase and glutathione reductase that are involved in the detoxifying processes of superoxide in plant cells were significantly activated only during the re-aeration. These results allowed us to suggest the followings as a working hypothesis. Photorespiration-linked production of $H_2O_2$ may largely contribute to the increase in $H_2O_2$ level as well as TBARS production in shoots during the submergence. An abrupt re-supply of $CO_2$ by the re-aeration brings the photosynthetic apparatus back to full operation, suppressing photorespiration and probably causing a momentary, excess formation of superoxide and its dismutation product through side reaction, which gives rise to activating substrate-inducible antioxidative enzymes.

• Applied Biological Chemistry
• /
• 제39권1호
• /
• pp.84-88
• /
• 1996

벼의 생육 단계별 brassinolide의 검정을 위하여 HPLC 형광분석법을 개발하였다. 형광분석에 민감한 1-cyanoisoindole-2-m-phenylboronic acid를 o-phthalaldehyde와 m-phenylbornic acid 및 KCN과 반응시켜 합성하여 brassinolide의 1, 2-diol과 유도체화 시켰다. Brassinolide $1\;{\mu}g$에 대한 1-cyanoisoindole-2-m-phenylboronic acid의 brassinolide boronate의 형성정도는 $20\;{\mu}g$에서 90% 이상의 유도체화를 보였고 형광검출법에 의한 brassinolide의 검출한계는 0.16 ng이었다. 벼의 생육단계별 brassinolide는 분얼기 및 신장기에서는 검출이 되지 않았으며 유수형성기에는 $0.8\;{\mu}g$(생체 10g)이 그리고 출수개화기에는 $0.2\;{\mu}g$(생체 10g)이 검출되었다.

• Applied Biological Chemistry
• /
• 제41권4호
• /
• pp.228-234
• /
• 1998

An adaptive measure of photosynthetic cells to a condition identified with a reduction of cellular energy charge, caused by water deficit-induced impairment of photosynthetic ATP production, was investigated using hydroponically cultured rice seedlings. Water stress treatment of the seedlings resulted in a marked decrease in cellular ATP level, a significant increase in the content of NAD(H) and concurrent decrease in that of NADP(H) in shoots, which accompanied a decrease in the activity of NAD kinase (EC 2.7.1.23) that specifically converts NAD(H) to NADP(H). The decline in the enzyme activity was particularly evident in the $Ca^{2+}/calmodulin-dependent$ kinase, the major form of NAD kinase in plants, whereas the level of active calmodulin remained unchanged during water deficit. The ratio of $NADP^+$ to NADPH was maintained nearly constant and no increases were seen in the level of $H_2O_2$ and the activities of $superoxide/H_2O_2-detoxifying$ enzymes in shoots stress-treated for two days. Based on these results, it may be suggested that rice plants take a strategy to cope with an adverse situation of limited photophosphorylation created by water deficit in that cells facilitate ATP production through glycolysis and oxidative phosphorylation; in doing so, rice cells suppress NAD kinase activity, consequently up-sizing the NAD(H) pool at the expense of the NADP(H) pool. Several parameters associated with the stress symptoms are also of implicative that there is no overproduction of superoxide radical or the related active oxygen at least in rice seedlings.

• 한국육종학회지
• /
• 제42권2호
• /
• pp.129-138
• /
• 2010

Total phenolic content, total anthocyanin content and antioxidant activity were analyzed from rice samples collected in Korea, Japan and China. The results showed that the total phenolic content and free-radical scavenging activity differed significantly in these rice lines. The correlation between content and activity was subsequently investigated. The results showed that in black rice, anthocyanin was the major phenolic component and that both phenolic content and anthocyanin content were closely correlated with free-radical scavenging activity. Reverse Phase High Performance Liquid Chromatography (RP-HPLC) data showed that cyanidin-3-O-glucoside and peonidin-3-O-glucoside composed about 90% of the total anthocyanin content in black rice and in red rice. In the red rice extract, the total phenolic content produced a high correlation coefficient with antioxidant activity but correlated very poorly with the total anthocyanin content. The $OD_{458}$ and the $OD_{500}$ values which represent the proanthocyanidin content of the rice extract, produced high correlation coefficients with antioxidant activity and total phenolic content. These results suggest that the $OD_{458}$ and the $OD_{500}$ values can be used to evaluate the quality of red rice. In addition, based on the data obtained, a competitive accumulation model of anthocyanin and proanthocyanidin in black and red rice was proposed.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2000년도 춘계 학술대회지
• /
• pp.254-255
• /
• 2000

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2000년도 추계 학술대회지
• /
• pp.93-94
• /
• 2000

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2004년도 추계학술발표회
• /
• pp.94-95
• /
• 2004

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2004년도 춘계 학술대회지
• /
• pp.108-109
• /
• 2004

• 한국유기농업학회지
• /
• 제18권2호
• /
• pp.199-208
• /
• 2010

벼 유기재배와 관행재배의 쌀 수량 및 품질의 비교를 조사하기 위하여 벼 병충해의 발생정도를 반남과 노안의 벼 포장에서 실시하였다. 본 시험의 결과를 요약하면 다음과 같다. 1. 본 시험에서 벼 병충해 방제는 노안지역 관행재배는 2회, 반남지역 관행재배는 4회 실시하였으며 유기재배는 노안, 반남지역 모두 2회 실시하였다. 포장에서 벼 병해충은 줄무늬잎마름병, 잎도열병, 이삭도열병, 잎집무늬마름병, 흰잎마름병, 혹명나방, 멸구류가 주로 발생하였다. 벼 병해충 중 잎도열병, 이삭도열병, 혹명나방은 관행재배보다 유기재배에서 발생이 많았다. 2. 벼 생육상황은 간장이나 수장은 관행재배에 비해 유기재배에서 약간 짧은 경향이었다. 노안지역은 유기재배의 경우 관행재배에 비해 주당수수는 0.6개 정도 많았으나 수당입수, 등숙비율, 정현비율, 현미 천립중이 낮았다. 반면 반남지역은 유기재배의 경우 관행재배에 비해 주당수수는 0.8개 정도 적었으나 수당입수와 등숙비율은 높았고 정현비율은 낮았다. 전체 수량은 유기재배가 관행재배에 비해 노안지역은 84% 수준이고, 반남지역은 94% 수준이었다. 3. 쌀의 품위는 노안지역과 반남지역 두 지역 모두 완전립율이 관행재배보다 유기재배에서 낮은 경향을 보였다. 쌀의 품질은 반남지역의 경우 유기재배시 기비로 사용한 질소가 관행재배에 비해 많아서 늦게 비효가 발현되어 이삭도열병, 혹명나방 피해가 발생하여 관행재배에 비해 단백질, 취반미 윤기치값이 낮았다. 반면 노안지역의 경우 유기재배시 기비로 사용한 질소가 관행재배에 비해 적어서 관행재배보다 단백질, 백도, 취반미 윤기치값 등에서 양호하게 나타났다.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 춘계학술대회
• /
• pp.106-106
• /
• 2022