• BMB Reports
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• 제50권7호
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• pp.343-344
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• 2017

Plants are able to recognize even small changes in surrounding temperatures to optimize their growth and development. At warm temperatures, plants exhibit diverse architectural adjustments, including hypocotyl and petiole elongation, leaf hyponasty, and reduced stomatal density. However, it was previously unknown how such warm temperatures affected the early stages of seedling development. In our recent study, we demonstrated that the RNA-binding protein, FCA, is critical for sustaining chlorophyll biosynthesis during early seedling development, which is a prerequisite for autotrophic transition at warm temperatures. FCA plays a dual role in this thermal response. It inhibits the rapid degradation of protochlorophyllide oxidoreductases (PORs) that mediate chlorophyll biosynthesis. In addition, it induces the expression of POR genes at the chromatin level, which contributes to maintaining functional enzyme levels. Our findings provide molecular basis for the thermal adaptation of chlorophyll biosynthesis during the early stages of seedling development in nature.

• 생물환경조절학회지
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• 제20권4호
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• pp.311-319
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• 2011

본 연구는 칼륨의 독성에 따른 배추의 생육과 생리적 특성 그리고 형태적 변화를 관찰하기 위하여 수행하였다. 100mM의 칼륨 농도 처리구까지 전체적인 생육이 증가한 반면, 600mM 처리구에서 생육이 가장 저조하였다. 칼륨 처리 농도가 높을수록 N, P, K, 함량은 증가하였지만 Ca, Mg, Na 함량은 감소하는 경향을 보였으며 미량원소, Fe, Mn, Zn의 경우 100mM의 처리구에서 가장 높은 함량을 나타내었다. 생체중당 Chl a, b와 carotenoid 함량은 600mM에서 가장 많이 증가하였으나 증가한 엽록소 함량에 비해 광합성효율($F_v/F_m$)은 처리구간에 차이가 없었고 $CO_2$ 동화율은 오히려 감소하였다. 이는 칼륨 과다에 의한 삼투스트레스의 결과로 기공의 퇴화와 $CO_2$ 동화능력과 밀접한 관계가 있는 것을 형태학적 관찰로 확인되었다. Total free amino acid의 경우 100mM 처리구까지 칼륨 처리 농도가 증가함에 따라 증가한 반면 600mM에서 급격히 감소하였다. 따라서 본 실험에서의 배추는100mM의 칼륨 농도까지는 긍정적인 효과가 있는 것으로 판단되었다.

• 한국연초학회지
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• 제17권1호
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• pp.20-26
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• 1995

This study was carried out to obtain the basic data which include the change of the photosynthetic rate and protein content according to growth stage in the process of senescence of tobacco plant The photosynthetic rate was the maximum with 26.31$\mu$mol.CO2/m2.sec and stomatal resistance was the minimum with 0.2552cm/sec at 15th days after leaf emergence. However, after 50 days the photosynthesis was very little occurred. During leaf developments the number of chloroplast was increased and reached at the maximum at 25th days after emergence of leaf, thereafter, it was decreased gradually. The content of protein increased continuously and showed the highest value at 15th days after leaf emergence. The degradation rate of soluble protein was more rapid than that of insoluble protein at early stage of senescence. The range of decrement in the insoluble protein was low at late stage of senescence. The content of Rubisco, the key enzyme of photoamthesis, corresponded to about 50% of soluble protein and reached to the maximum at 150 days after leaf emergence. As the senescence progressed, the content of large subunit(UV) of Rubisco showed a tendency to decrease more rapidly than that of small subunit(SSU). The total amount of amino acids was the highest at 15th days after leaf emergence.

• 한국잡초학회지
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• 제1권1호
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• pp.57-68
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• 1981

수도묘(水稻苗)의 Butachlor(2-chloro-2',6'-diethyl-N-(carboxymethyl) acetanilide) 흡수특성(吸收特性)과 약해발생가구(藥害發生機構)를 밝히어 Butachlor의 안전사용(安全使用)에 도움을 주고자 시도(試圖)되었다. 수도품종(水稻品種) '만석(萬石)'(수원(水原)264호(號))을 사용(使用)하여 제(第)6, 7여기(葉期)까지 수경재배(水耕栽培)한 후 Butachlor를 0, 1.8, 3.6, 7.2, 10.8 또는 14.4ppm 되도록 처리(處理한) 수경액(水耕液)으로 1, 2, 4일간(日間) 생육(生育)시킨 경우와 Butachlor 처리(處理) 후(後) 정상수경액(正常水耕液)으로 교체(交替)하고 6일간(間生) 생장(生長)시킬 경우 약해(藥害)의 진전(進展) 또는 회복과정중(恢復過程中)에 일어나는 수도(水稻)의 Butachlor 흡수(吸收)에 따른 생장반응(生長反應), 수분흡수(水分吸收), 양분흡수(養分吸收), 기공(氣孔) 개폐(開閉), 질산환원효소(窒酸還元酵素)(Nitrate reductase)의 생합성(生合成) 및 분해작용(分解作用)의 변화(變化)를 검정(檢定)했고 Butachlor의 세포구성물질(細胞構成物質)들에 대한 흡착특성(吸着特性)을 비교(比較)하였으며 그 결과(結結)는 다음과 같이 요약(要約)된다. 1. 수도묘(水稻苗)의 Butachlor의 흡수(吸收)는 처리농도(處理濃度) 및 기간(期間)에 비례(比例)하여 거의 직선적(直線的)으로 증가(增加)하였다. 2. Butachlor는 지상부(地上部) 생육(生育)보다는 뿌리생육(生育)을, 지상부(地上部) 생체중(生體重) 및 출엽(出葉)보다는 초장(草長)의 생육(生育)을 더욱 저해(沮害)하였으며, 처리종료(處理終了) 후(後) 지상부(地上部) 생체중(生體重)과 출엽(出葉)은 조속(早速)히 회복(恢復)되었으나 초장(草長) 및 뿌리생체중(生體重) 생장(生長)은 4일(日) 이후(以後) 회복세(恢復勢)를 보였다. 3. Butachlor는 뿌리의 수분흡수(水分吸收)를 처리농도(處理濃度) 비례(比例)하여 곧 저해(沮害)하였고, 그 결과(結果) 엽면(葉面) 기공(氣孔)의 저항(低抗)을 증가(增加)시켰으며, 처리종료(處理終了) 후(後)에는 수분흡수력(水分吸收力)은 곧 회복(恢復)되었으나 기공(氣孔)의 개도(開度)는 서서히 회복(恢復)되었다. 4. Butachlor는 처리(處理) 전(前) 후(後) 수도묘(水稻苗)의 $NH_4^+$, $K^+$ 및 $Ca^{++}$ 같은 양(陽)이온의 흡수(吸收)에는 영향(影響)하지 않았으나 $NO_3^-$의 흡수(吸收)를 뚜렷이 저해(沮害)했고, 7.2 ppm의 고종도(高濃度)에서는 인산(燐酸)의 흡수(吸收)도 저해(沮害)했다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.149-149
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• 2017

The RING (Really Interesting New Gene) finger proteins are known to play crucial roles in various abiotic stresses in plants. In this study, we report on RING finger E3 ligase, ${\underline{O}ryza}$ ${\underline{s}ativa}$ ${\underline{s}alt$-, ${\underline{A}BA}$- and ${\underline{d}rounght}$ stress-${\underline{i}nduced}$ RING finger ${\underline{p}}rotein{\underline{1}}$ gene (OsSAD1). In vitro ubiquitination assay demonstrated that unlike OsSAD1, a single amino acid substitution ($OsSAD1^{C168A}$) of the RING domain showed no E3 ligase activity, supporting the notion that the activity of most E3s is specified by a RING domain. Result of Yeast-Two hybridization, In vivo protein degradation assay supports that OsSAD1 interacting with 3 substrate, OsSNAC2, OsGRAS44 and OsPIRIN1, and mediates proteolysis of 3 substrates via the 26S proteasome pathway. Subcellular localizations of OsSAD1 while approximately 62% of transient signals were detected in cytosol, 38% of signals were showed nucleus. However, transiently expression of OsSAD1 was detected in cytosol 30% while as 70% of nucleus under 200 mM salt treated rice protoplasts. Results of bimolecular fluorescence complementation (BiFC) showed that two nucleus-localized proteins (OsSNAC2 and OsGRAS44) interacted with OsSAD1 in the both cytosol and nucleus. Heterogeneous overexpression of OsSAD1 Heterogeneous overexpresssion of OsSAD1 in Arabidopsis exhibited sensitive phenotypes with respect to Salt-, mannitol-responsive seed germination, seedling growth. In ABA conditions, OsSAD1 overexpression plants showed highly tolerance phenotypes, such as root length and stomatal closure. Our findings suggest that the OsSAD1 may play a negative regulator in salt stress response by modulating levels of its target proteins.