Symposia / S3-3 : Role of a novel photosystem 2-associated carbonic anhydrase in photosynthetic carbon assimilation in Chlamydomonas reinhardtii

박연일(Youn Il Park),(J . Karlsson),(I . Rojdestvenski),(N . Pronina),(V . Klimov),(G . Oquist),(G . Samuelsson) 한국생화학분자생물학회 (구 한국생화학회) 1999 생화학분자생물학회 춘계학술발표논문집 Vol.- No.-

고온 스트레스를 받은 밀 엽록체에서 광합성능과 엽록소 형광의 관계

박연일(Youn Il Park),박민철(Min Chul Park),홍영남(Young Nam Hong) 한국식물학회 1994 Journal of Plant Biology Vol.37 No.1

Correlative changes between photosynthetic O_2 exchange rates and room temperature Chl fluorescence were investigated in wheat (Triticum aestivum L.) chloroplasts treated with high temperature for 5 min. With increaseing treatment temperature, photosynthetis O_2 evolution rate mediated by PSⅡ was decreased, showing 50% inhibition at 38℃ (Ⅰ_50). But PSⅠ activity measured by O_2 uptake rates was stimulated as a function of increasing temperature. Dark level fluorescence (Fo)-temperature (T) analysis showed that florescence rising temperature( T_r), critical temperature (T_c), and peak temperature (T_p) was 38, 43, and 52℃, respectively. Quenching analysis of Chi fluorescnece showed that both the oxidized fraction of plastoquinone (qQ) and the degree of thylakoid membrane energization (qNP) increased up to 40℃ and then declined dramatically. These results suggest that T_r is correlated with temperature showing a 50% inhibition of photosynthesis and under mild high temperature stress, qNP is worth regarding as indicator for heat-induced damage of photosynthesis.

Mannose 처리된 배추 잎의 무기인산 감소에 따른 비광화학성 소산의 증가

박연일(Youn Il Park),서계홍(Kye Hong Suh),홍영남(Young Nam Hong) 한국식물학회 1991 Journal of Plant Biology Vol.34 No.4

Limitation of photosynthesis in detached Chinese cabbage (Brassica campestris L.) leaves was induced by feeding of mannose (25 mM) for 12 h in the light, and changes in the basic thylakoid functions under this condition were investigated. The acid soluble phosphate content and CO_2 uptake rate was decreased by 66% and 67%, respectively. However, the starch content was increased by 24% compared to those of controls. From the fast induction curves of chlorophyll fluorescence, dark level fluorescence (F_O) slightly increased while intermediate plateau fluorescence level (F_I) to peak level fluorescence (F_P) transient was significantly decreased with a slight decrease in the F_O-to-F_I transient. This data means that reduction of secondary electron acceptor of PSⅡ (Q_B) might be more severely inhibited than that of primary electron acceptor of PSⅡ (Q_A) by decrease in phosphate level. The strong decline of (F_V)_m//F_m ratio suggests that efficiency of excitation energy capture by PSⅡ was decreased markedly. The quenching of F_O (qO), an indicator of state transition, was also occurred over the slow induction kinetics of chlorophyll fluorescence. From quenching analysis, fluorescence was dominantly quenched by nonphotochemical quenchings (qE+qT). These results showed that the capture and transfer efficiency of excitation energy to PSⅡ reaction center in thylakoid was decreased with the decline of leaf phosphate level, and that the state transition was occurred during the induction of photosynthesis under these conditions.

청록색광에 색성적응된 Anacystis niduland 의 상전이 증가

박연일,양덕조,홍영남 ( Youn Il Park,Duck Jo Yang,Young Nam Hong ) 생화학분자생물학회 1994 BMB Reports Vol.27 No.2

Photoacclimation of Anacystis nidulans toward blue-green light was investigated in terms of sensitivity of state transition. Ratio of phycobilin/chlorophyll and maximal photosynthetic rates of A. nidulans grown in blue-green light increased 7.6 and 1.5 times as large as those of white light-grown cells, respectively, but there was no apparnnt change in the energy transfer efficiency from phycocyanin to chlorophyll. The magnitude of state transition of blue-green light grown cells under preferential excitation of photosystem I by red light ($gt;630 ㎚) was increased by 38% in comparision with that of white-light grown cells. Uncoupler, m-chlorophenylhydrazone, and protein kinase inhibitor, 5`-p-fluorosulfonylbenzoyladenosine, severely inhibited the state 2 transition, but ATP synthase inhibitor, N,N`-dicyclohexylcarbodiimide, did the state 1/2 transitions. These results suggest that state transition in A. nidulons should be regulated by redox state of plastoquinone, and photoacclimation to blue-green light is related to the increased senstitivity of state transition.

산전 초음파로 진단된 태아 수신증의 생후 경과 관찰

박연진,문순정,배종우,이범하,김진일,Park, Youn Jin,Mun, Soon Jung,Bae, Chong Woo,Lee, Bum Ha,Kim, Jin Il 대한소아청소년과학회 2002 Clinical and Experimental Pediatrics (CEP) Vol.45 No.10

목 적: 산전초음파 검사로 진단되는 태아기 기형 중 수신증이 많은 비율을 차지하고 있으나, 출생 후 대부분이 무증상이나 이에 대한 예후의 판단에 자연 경과의 관찰은 중요하다. 이에 저자들은 산전 초음파로 진단된 신생아 수신증의 추적 관찰을 통하여, 그 원인 질환의 빈도와 그에 따른 자연 경과를 알아보고자 하였다. 방 법: 1992년 4월부터 11월까지 경희대학교병원에서 산전 초음파 검사로 수신증으로 진단 받고 출생 후 3-7일 내에 실시한 초음파 검사에서 수신증으로 진단된 23명의 신생아(36 renal units)를 대상으로 수신증의 원인을 분석하고, 이중 신우요관이행부 폐색과 기질적 병변이 없었던 경우의 수신증은 12-24개월 동안 추적 관찰하여 경과를 관찰하였다. 결 과 : 23명의 신생아 중 수신증은 양측인 경우가 12명, 우측 4명, 좌측 7명이었으며, 그 원인 질환으로는 기질적 병변이 없는 경우가 16례(44%), 신우요관 이행부 폐색이 14례(39%), 방광요관역류가 3례(8%) 였으며, 다낭성이형성신, 방광요관 역류와 요관협착을 동반한 신우요관이행부 폐색, 방광요관역류를 동반한 요관방광이행부 폐색이 각각 1례씩이었다. 추적 관찰한 출생 후 수신증의 정도는 이환 된 30개의 신장 중 경증인 경우가 26례(87%), 중등증인 경우가 4례(13%)로 대부분이 경증으로 나타났으며, 추적 관찰기간 12-24개월 동안 수신증이 자연 소실된 예는 6례(20%), 수신증이 호전중인 경우는 15례(50%), 수신증이 악화되어 기저 질환 수술 후 호전된 경우는 2례(7%), 추적 관찰 실패한 경우는 7례(23%)였다. 자연 소실되거나 호전 중인 수신증은 처음 진단 시 경증 19례, 중등증 2례였으며, 악화되어 수술을 시행한 경우는 처음진단 시 경증 1례, 중등증 1례였다. 결 론 : 산전 초음파 진단으로 수신증을 보인 경우, 기질적 원인으로 가장 많은 원인은 신우요관이행부 폐색 이었으며, 출생 시 경증으로 진단된 수신증은 자연 호전되거나 소실되는 경우가 많으나, 추적 관찰 시 악화되어 수술이 필요한 경우도 있으므로 장기간에 걸친 주의 깊은 추적 관찰이 필요하다고 하겠다. Purpose : Hydronephrosis constitutes a great portion of fetal anomalies screened by prenatal sonogram. The present authors made an attempt to access its natural courses through follow up neonatal hydronephrosis diagnosed by prenatal sonogram. Methods : The study was composed of 23 neonates(36 renal units) who were diagnosed with hydronephrosis through prenatal sonogram screening and confirmed 3-7 days after birth with sonographic evaluation at Kyung Hee University Hospital. The neonates were closely monitored for 12-24 months with renal sonogram, diuretic renogram, intravenous pyelography(IVP) and voiding cystoureterography(VCUG). Results : The underlying diseases were composed of 16 cases(44%) of functional abnormalities, 14 cases(39%) of ureteropelvic junction(UPJ) obstruction, three cases(8%) of vesicoureteral reflux (VUR) and on case each of multicystic dysplastic kidney, UPJ obstruction with ureteral stenosis and ureterovesical junction(UVJ) obstruction with VUR. The degree of hydronephrosis was divided into three classes according to its severity. In 30 renal units with UPJ obstruction and functional abnormalities, 26(87%) showed mild hydronephrosis, while four(13%) were moderate. During the follow up period, six cases(20%) showed natural resolution of hydronephrosis, 15 cases(50%) showed improvement while two cases(7%) were aggravated with improvement only after surgery of the underlying disease. The cases which showed natural resolution were all mild hydronephrosis at diagnosis and the cases which underwent surgery due to continuous aggravation were mild one case and moderate one case. Conclusion : Those with cases of mild hydronephrosis show rapid natural improvement. On the other hand, in some cases, follow up monitoring reveal aggravation of the situation, emphasizing the necessity for thorough follow up for a long period of time.

고온 스트레스가 Anacystis nidulans 의 광합성에 미치는 영향

박연일,양덕조,홍영남 ( Youn Il Park,Duck Jo Yang,Young Nam Hong ) 한국하천호수학회 1993 생태와 환경 Vol.26 No.1

4Effects of high temperature stress on the photosynthesis of Anacystis nidulans were investigated by using the measurements of oxygen exchange rates and room temperature chlorphyll fluorescence. With increasing pretreated-temperature for 5 min, oxygen evolution rates of A. nidulans were increased up to 50˚C , and then rapidly decreased. Especially, the oxygen evolution rates were inhibited by 50˚C(I_50) at 53˚C. These inhibition of photosynthesis by high temperature were caused by the restrictions of PS II activites. Hydroxylamine could not restore the oxygen evloution rates of PS II in A. nidulans pretreated with high temperature at 53˚C for 5 min. Ca^2+ pretreatment before temperature treatment for 5 min at 53˚C prevented PS II function from high temperature stress. Constant fluorescence level(Fo)-temperature curves showed the increase of F_O level with increaing heating temperature. However, Ca^2+ prevented increase of F_O from heat treatment. From the analysis of fast induction kinetics of room tenpe-rature chlorophyll fluorescence, F_O level was increased by 79%, but variable fluroescence(Fv) was declined by 24% in 53˚C treated A. nidulans as compared to controls. Ca^2+ pretreatment also inhibited both the increase of F_O and the decrease of Fv levels induced by high temperature stress. Frnm above results, it was concluded that the inhibition of PS II function in A. nidulans by high temperature stress was resulted from the restrictions of PS II reaction center rather than the malfunction of oxygen evolution complex or the strucutral changes of photosyntheic thyakoid membranes.

자외선-B 스트레스에 대한 담배 잎의 광합성 능의 변화

이혜연 ( Hae Youn Lee ),박연일 ( Youn Il Park ),홍영남 ( Young Nam Hong ) 韓國環境農學會 2007 한국환경농학회지 Vol.26 No.3

Synechocystis sp. PCC 6803의 에너지 대사 결함 돌연변이 균주에서의 Poly(3-hydroxybutyrate) 축적량 증진

김수연,최강국,박연일,박영목,양영기,이영하,Kim Soo-Youn,Choi Gang Guk,Park Youn Il,Park Young Mok,Yang Young Ki,Rhee Young Ha 한국미생물학회 2005 미생물학회지 Vol.41 No.1

본 연구에서는 남세균인 Synechocystis sp. PCC 6803 (Syn6803)을 대상으로 transposable element Tn5를 이용하여 획득된 1,200여 돌연변이주로부터 모균주에 비하여 PHB 축적량이 크게 증진된 균주를 선별하고, Tn5 삽입에 의해 결함을 나타낸 유전자를 확인함으로써 Syn6803에서의 PHB 생합성에 영향을 주는 세포내 생리학적 요인을 조사하고자 하였다. 모균주인 야생형 균주의 경우 질소원이 제한된 $BG11_0$ 배지에서의 PHB 생합성량이 건체량의 $4\%$ (w/w) 수준인데 반하여, $10-34\%$의 생합성량을 보이는 25개의 돌연변이 균주를 얻을 수 있었다. Inverse PCR을 이용하여, 선별된 돌연변이 균주내 돌연변이가 일어난 유전자를 조사한 결과, 아직까지 그 기능이 규명되지 않은 유전자가 대부분이었으나, NADH-ubiquinone oxidoreductase, O-succinylbenzoic-CoA ligase 또는 photosystem II PsbT protein과 같이 광합성과 호흡에 관여하는 유전자에 돌연변이가 일어난 4 균주와 histidine kinase가 결여된 1균주가 확인되었다. 이들 균주를 대상으로pulse-amplitude modulated fluorometer를 이용하여 세포내 $NAD(P)H/NAD(P)^+$비를 측정한 결과, 에너지 대사 흐름의 차단에 의해 세포내의 $NAD(P)HNAD(P)^+$비가 모균주에 비하여 현저하게 높은 것으로 나타났다. 이는 잉여의 전자로 포화된 세포, 즉 NAD(P)H에 의해 환원적 상태를 유지하고 있는 세포의 경우 PHB 축적 이 증진될 수 있음을 시사한다. 이러한 사실은 인위적으로 광합성과 호흡 관련 유전자가 제거되어 $NAD(P)H/NAD(P)^+$비가 높아진 것으로 알려진 다수의 Syn6803 돌연변이 균주들을 대상으로 PHB 생합성량을 조사한 결과로부터 재확인되었다. Photoautotrophic bacteria are promising candidates for the production of poly(3-hydroxybutyrate) (PHB) since they can address the critical problem of substrate costs. In this study, we isolated 25 Tn5-inserted mutants of the Synechocystis sp. PCC 6803 which showed enhanced PHB accumulation compared to the wild-type strain. After 5-days cultivation under nitrogen-limited mixotrophic conditions, the intracellular levels of PHB content in these mutants reached up to $10-30\%$ of dry cell weight (DCW) comparable to $4\%$ of DCW in the wild-type strain. Using the method of inverse PCR, the affected genes of the mutants were mapped on the completely known genome sequence of Synechocystis sp. PCC 6803. As a result, the increased PHB accumulation in 5 mutants were found to be resulted from defects of genes coding for NADH-ubiquinone oxidoreductase, O-succinylbenzoic-CoA ligase, photosystem II PsbT protein or histidine kinase, which are involved in photosystem in thylakoid inner membrane of the cell. The values of $NAD(P)H/NAD(P)^+$ ratio in the cells of these mutants were much higher than that of the wild-type strain as measured by using pulse-amplitude modulated fluorometer, suggesting that PHB synthesis could be enhanced by increasing the level of cellular NAD(P)H which is a limiting substrate for NADPH-dependent acetoacetyl-CoA reductase. From these results, it is likely that NAD(P)H would be a limiting factor for PHB synthesis in Synechocystis sp. PCC 6803.

저선량 γ선 조사가 고추의 광합성과 광 스트레스 경감에 미치는 효과

이혜연,백명화,박순철,박연일,김재성,Lee, Hae-Youn,Baek, Myung-Hwa,Park, Soon-Chul,Park, Youn-Il,Kim, Jae-Sung 한국환경농학회 2002 한국환경농학회지 Vol.21 No.2

고추 종자에 저선량 $\gamma$선을 조사시킨 고추 식물체의 생육과 광합성 능 및 광 스트레스 반응에 미치는 영향을 조사하였다. 저선량 4 Gy가 조사된 고추 식물체에서 광합성에 의한 산소발생이 대조구에 비해 1.5배정도 높은 것으로 나타났다. 고추 잎에 900 ${\mu}mol/m^2/s$의 빛의 세기로 광저해를 4시간 유도하였을 때 최대 광합성능 (Pmax)이 대조구의 경우 20%정도 감소되는 반면 4 Gy 조사구는 3% 정도의 감소를 보였다. Fv/Fm는 광저해가 진행됨에 따라 감소되는 경향을 보이며 대조구의 경우 4시간 처리시 Fv/Fm 값이 50% 정도 감소되는 것을 볼 수 있었다. 반면 4 Gy 조사구는 Fv/Fm값이 대략 37%정도 감소되어 대조구에 비해 광 스트레스에 대해 덜 민감한 것으로 나타났다. Fo는 광저해가 진행됨에 따라 거의 변화가 없었으며 대조구나 4 Gy조사구 사이의 차이도 거의 없는 것으로 나타났다. 광계II의 광양자 수율인 $\Phi_{PSII}$과 광계II 반응중심에 의한 여기 포획률을 나타내주는 1/Fo-1/Fm 또한 광저해가 진행됨에 따라 감소되었으며 4시간을 처리했을 경우 각각 대조구는 47%, 4 Gy 조사구는 30%의 감소를 볼 수 있었다. 비광화학적 소멸인 NPQ는 광저해가 진행됨에 따라 감소되는 경향을 보였으나 대조구와 4 Gy 조사구간에 차이는 없는 것으로 나타났다. 이러한 결과를 볼 때 종자의 종피를 투과한 저선량의 $\gamma$선이 식물의 광합성을 증대시키고 동시에 광 스트레스에 대한 저해를 감소시키는 것으로 보인다. The effect of low dose $\gamma$ radiation on photosynthesis and the reduction of photoinhibition in red pepper plant was investigated. The seedling height leaf width and leaf length of pepper were stimulated in plants grown from seeds irradiated with the low dose of 4 Gy. The $O_2$ evolution in the 4 Gy irradiation group was 1.5 times greater than in the control. To investigate the effect of low dose $\gamma$ radiation on response to high light stress, photoinhibition was induced in leaves of pepper by illumination of high light (900 $\mu mol/m^2/s$). Pmax was decreased with increasing illumination time by 20% in the control, while hardly decreased in the 4 Gy irradiation group. The photochemical yield of PSII, estimated as Fv/Fm, was decreased with increasing illumination time by 50% after 4 hours while Fo did not change. However, Fv/Fm in the 4 Gy irradiation group was decreased by 37% of inhibition, indicating that the photoinhibition was decreased by the low dose $\gamma$ radiation. Changes in the effective quantum yield of PSII, $\Phi_{PSII}$, and 1/Fo-1/Fm, a measure of the rate constant of excitation trapping by the PSII reaction center, showed similar pattern to Fv/Fm. And NPQ was decreased after photoinhibitory treatment showing no difference between the control and the 4 Gy irradiation group. These results showed the positive effect of low dose $\gamma$ radiation on the seedling growth and the reduction of photoinhibition.

산전 초음파로 진단된 태아 수신증의 생후 경과 관찰

박연진,문순정,배종우,이범하,김진일 대한소아과학회 2002 小兒科 Vol.45 No.10