• 한국초지조사료학회지
• /
• 제42권4호
• /
• pp.222-228
• /
• 2022

This study was conducted to investigate the effect of waterlogging stress on the physiological response and growth characteristics of the five Italian ryegrass varieties. For all varieties, the germination rate of seed decreased by 10-15% as the waterlogging period increased, but the waterlogging stress treatment after the early seedling stage increased the growth of shoot and root length. Photosynthetic activity (Fv/Fm) according to waterlogging stress treatment decreased in all vareity, and Florida 80 showed the least decrease with 1.5%. Waterlogging stress treatment was found to reduce the accumulation of reactive oxygen species (malondialdehyde, MDA) and the activities of antioxidant enzymes. These results suggest that other mechanisms may be involved in the defense mechanism of Italian ryegrass against waterlogging stress, such as promoting root growth to escape from waterlogging stress, in addition to the antioxidant enzyme system.

• ALGAE
• /
• 제39권1호
• /
• pp.17-30
• /
• 2024

Red macroalga Pyropia yezoensis is a high valuable cultivated marine crop. Its acclimation to cold stress is especially important for long cultivation period across winter in coasts of warm temperate zone in East Asia. In this study, the response of P. yezoensis thalli to low temperature was analyzed on physiology and transcriptome level, to explore its acclimation mechanism to cold stress. The results showed that the practical photosynthesis activity (indicated by Φ_PSII and qP) was depressed and pigment allophycocyanin content was decreased during the cold stress of 48 h. However, the F_v/F_m and non-photochemical quenching increased significantly after 24 h, and the average growth rate of thalli also rebounded from 24 to 48 h, indicating a certain extent of acclimation to cold stress. On transcriptionally, the low temperature promoted the expression of differentially expressed genes (DEGs) related to carbohydrate metabolism and energy metabolism, while genes related to photosynthetic system were depressed. The increased expression of DEGs involved in ribosomal biogenesis and lipid metabolism which could accelerate protein synthesis and enhance the degree of fatty acid unsaturation, might help P. yezoensis thallus cells to cope with cold stress. Further co-expression network analysis revealed differential expression trends along with stress time, and corresponding hub genes play important roles in the systemic acquired acclimation to cold stress. This study provides basic mechanisms of P. yezoensis acclimation to cold temperature and may aid in exploration of functional genes for genetic breeding of economic macroalgae.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 추계학술대회
• /
• pp.57-57
• /
• 2022

In many areas of the world, salt damage and drought have had a negative impact on human survival due to a decrease in agricultural productivity. For instance, about 50% of agricultural land will be affected by salt damage by 2050. Biostimulants such as plant extracts can not only increase the nutrient utilization efficiency of plants, but also promote plant growth and increase resistance to abiotic or biotic stress. Therefore, the objective of this study was to determine how selected plant extracts might reduce levels of stress caused by drought and salt and to better understand the physiological response mechanisms of rice plants. In this study, we used Soybean leaves, Soybean stems and Allium tuberosum, Allium cepa, Hizikia fusiforme, and Gracilaria verrucosa extracts were used. These extracts had been used in previous studies and were found to be effective. The materials were dried in a dry oven at 50℃ for 5 days and ground using a blender. Each 50 g of materials was put in 1 L of distilled water, stirred for 24 hours, filtered using 4 layers of mirocloth, and then concentrated using a concentrator. Rice (cv. Hopumbyeo) seeds were immersed and germinated, and then sown in seedbeds filled with commercial soil. In drought experiments, three rice seedlings at 1 week after seeding was transplanted into 100 ml cups filled with commercial soils and grown until the 4-leaf stage. For this experiment, the soil weight in a cup was equalized, and water was allowed to become 100% saturated and then drained for 24 hours. Thereafter, plant extracts at 3% concentrations were applied to the soils. For NaCl treatments, rice plants at 17 days after seeding were treated with either 100 mM NaCl or plant extracts at 1%+ 100 mM NaCl combinations in the growth chamber. Leaf injury, relative water content, photosynthetic efficiency, and chlorophyll contents were measured at 3, 5, and 6 days after treatments. Shoot fresh weight of rice under drought conditions increased 28-37% in response to treatments of Soybean leaf, Soybean stem, Allium tuberosum, Allium cepa, Hizikia fusiforme, and Gracilaria verrucosa extracts at 3% when compared with control plants. Shoot fresh weight of rice subjected to 100 mM NaCl treatments also increased by 6-24% in response to Soybean leaf, Soybean stem, Allium tuberosum, Allium cepa, Hizikia fusiforme, and Gracilaria verrucosa extracts at 3% when compared with control plants. Compared to the control, rice plants treated with these six extracts and subjected to drought conditions had significantly higher relative water content, Fv/Fm, total chlorophyll and total carotenoids than control plants. With the exception of relative water contents, rice plants treated with the six extracts and subjected to salt stress (100 mM NaCl treatments) had significantly higher Fv/Fm, total chlorophyll and total carotenoids than control plants. However, the type of extract used did not produce significant difference in these parameters. Thus, all the plant extracts used in this study could mitigate drought and NaCl stresses and could also contribute substantially to sustainable crop production.

• 한국토양비료학회지
• /
• 제43권3호
• /
• pp.400-406
• /
• 2010

서리태콩 (Glycine max Merr. var Seoritae)에서 광원에 따른 엽의 광합성 변화를 구명하기 위하여 콩의 제 1복엽이 완전 전개되었을 때 3일 동안 빛을 차단한 후 UV-B 와 일반광에 노출시켜 색소 함량과 엽록소 형광반응의 변화를 측정하였다. 암처리에서 엽록소 함량은 감소하고, 일반 광에서 회복하였다. 카로티노이드와 안토시아닌 함량은 UV-B 조사한 처리구에서 증가하였다. 엽록소 형광분석을 이용한 광합성 능률을 분석한 결과, 암처리가 진행 됨에 따라 Fv/Fm, F'v/F'm, ${\Phi}_{PSII}$ 및 NPQ는 감소하였다. 모든 변수들은 일반광에 노출되면서 회복하였으나 UV 처리한 것은 암처리 72시간의 수치와 큰 변화가 없었다. 이를 통하여 암처리 48시간 경과함으로 엽록체가 에티오플라스트로 전환되며, 일반광을 조사하였을 시 광합성 관련 광계가 복구되지만, UV-B의 강한 광이 조사되었을 때 광계가 회복되지 못하는 것으로 사료되었다.

• 한국환경복원기술학회지
• /
• 제17권4호
• /
• pp.57-67
• /
• 2014

The vigor condition of trees is an important indicator for the management of urban forested area. But difficulties in how to assess the tree vigor condition still remain. Previous efforts were limited in the 1) measurement of single indicator rather than using multiple indices, 2) purpose-oriented measurement such as for air-pollution effect or specific pathological symptom, and 3) ordinal-scale evaluations by field crews 4) despite human errors based on his/her experiences or prior knowledge. Therefore, this study attempted to develop a quantitative and objective methodology for assessing tree vigor condition, by measuring multiple modules and building the profile inventory. Furthermore, the possibility and limitations were discussed in terms of schematic frames describing tree vigor condition. The vigor condition of 56 flowering cherry plants in urban park were assessed by in-situ measurements of following eight items; growth of crown(Gc), growth of shoots, individual tree volume(Vol), plant area index, woody area index, leaf area index, leaf chlorophyll content(Lc) and leaf water content(Lw). For validation, these measurements were compared with the ranks of holistic tree vigor condition, which were visually assessed using a 4-point grading scale based on the expert's knowledge. As a result, the measures of each evaluation item successfully highlighted a variety of aspects in tree vigor condition, including the states of both photosynthetic and non-photosynthetic parts. The variation in the results depending on evaluated parts was shown within an individual tree, even though the broad agreement among the results was found. The result of correlation analysis between the tested measurements and 4-point visual assessment, demonstrated that the state of water-stressed foliage of the season (Lw) or the development of plant materials since sapling phase (Vol) could be better viewed from the outer appearance of trees than other symptoms. But only based on the visual assessment, it may be difficult to detect the quality of photosynthesis (Lc) or the recent trend in growth of trees (Gc). To make this methodology simplified for the broad-scale application, the tested eight measurements could be integrated into two components by principal component analysis, which was labelled with 'the amount of plant materials' and 'vigor trend', respectively. In addition, the use of these quantitative and multi-scale indicators underlies the importance of assessing various aspects of tree vigor condition, taking into account the response(s) on different time and spatial scale of pressure(s) shown in each evaluated module. Future study should be advanced for various species at diverse developing stages and environment, and the application to wide areas at a periodic manner.

• 한국환경과학회지
• /
• 제25권4호
• /
• pp.473-481
• /
• 2016

We examined the effects of ocean acidification (OA) and eutrophication on the physiology of a red alga, Gracilariopsis chorda, using specimens collected at Wando Island, Korea, in July of 2015. The samples were transported to a laboratory and placed on growth media for treatments involving low or high levels of ammonium ($4{\mu}M$ or $60{\mu}M\;NH_4{^+}$) and low or high pH(7.5 or 8.2). The control treatment used filtered seawater (pH 8.2 and $4{\mu}M\;NH_4{^+}$). All experiments were conducted at $20^{\circ}C$ and under a lighting intensity of $80{\mu}mol\;photons\;m^{-2}\;s^{-1}$, with or without an injection of $CO_2$ (pH 7.5). In addition, we calculated rates of respiration under darkness, at a pH of 7.5 and $60{\mu}M\;NH_4{^+}$. Fluctuations in pH as well as the evolution of photosynthetic oxygen and $NH_4{^+}$ uptake rates were monitored for 6 h. The greatest increase in pH levels, from 7.50 to 8.65, occurred in response to $60{\mu}M\;NH_4{^+}$, whereas the largest decrease, from 7.50 to 7.42, was associated with elevated respiration rates. At a pH of 7.5, rates of oxygen evolution were higher (236% saturation) for samples treated with $60{\mu}M\;NH_4{^+}$ than for the control (121% saturation). Ammonium uptake was highest at pH 7.5 and $60{\mu}M\;NH_4{^+}$, with a rate of $0.526{\pm}0.002{\mu}mol\;g^{-1}\;FW\;h^{-1}$, followed in order by the treatments of $pH\;8.2/60{\mu}\;NH_4{^+}$, $pH\;7.5/4{\mu}M\;NH_4{^+}$, and the control ($pH\;8.2/4{\mu}M\;NH_4{^+}$). We speculated that the rates of photosynthesis and $NH_4{^+}$ uptake could be enhanced at a higher ammonium concentration and lower pH because $CO_2$ concentrations were increased through greater photosynthetic activity. Therefore, these findings suggest that the physiology of G. chorda populations can be improved by the interaction of optimized $CO_2$ concentrations and an adequate supply of essential nutrients such as ammonium.

• 한국작물학회지
• /
• 제57권2호
• /
• pp.106-112
• /
• 2012

본 연구는 $CO_2$농도와 온도가 상승함에 따라 인삼의 생육반응 및 광합성 특성의 변화를 알아보기 위해 실험하였다. 유리 온실 안에 대조구(대기중 $CO_2$ 농도)와 $CO_2$ + 온도상승구(750-800 ppm, $2^{\circ}C$ 상승)로 나누어 비교하였으며 다음과 같다. 1. 인삼의 개엽율은 1년생 인삼을 이식한 후 1주일 이후인 4월 6일에 $CO_2$ + 온도상승구의 개엽율이 대조구보다 더 높았다. 그러나 최종 개엽율은 $CO_2$ + 온도상승구간 차이가 없었다. 2. 꽃이 나오는 시기는 대조구보다 $CO_2$ + 온도상승구가 3일 빨랐고, 열매관찰시기와 열매 성숙시기는 대조구와 $CO_2$ + 온도상승구간 차이가 없었다. 3. 인삼의 줄기길이는 대조구보다 $CO_2$ + 온도상승구에서 길었고, 잎수는 대조구보다 $CO_2$ + 온도상승구에서 많았다. 4. 지하부 생량무게는 대조구와 $CO_2$ + 온도상승구간 차이가 없었다. 5. 광합성은 모두 대조구보다 $CO_2$ + 온도상승구가 높았다. 대조구 내에서는 년도별 광합성이 차이가 있었다. 하지만 $CO_2$ + 온도상승구에는 1년생과 2년생 간 차이가 없었다. 6. 증산률은 대조구와 $CO_2$ + 온도상승구에서 모두 년생간 차이가 있었다. 1년생은 대조구보다 $CO_2$ + 온도상승구가 높았고, 2년생은 대조구와 $CO_2$ + 온도상승구간 차이가 없었다. 7. 수분이용효율은 대조구와 $CO_2$ + 온도상승구에서 모두 1년생과 2년생간 차이가 있었다. 1년생은 대조구와 $CO_2$ + 온도상승구간 차이가 없었고, 2년생은 대조구 보다 $CO_2$ + 온도상승구가 높았다. 이상으로 볼 때 지구온난화는 인삼의 생육과 생리 생태학적 반응에 다소 긍정적인 영향을 준다.

• 한국해양학회지:바다
• /
• 제14권2호
• /
• pp.118-126
• /
• 2009

저서규조류는 하구역 먹이망을 이해하는 데 중요한 생물로서 그들의 광생리 특성에 따라 일차생산력이 크게 변화한다. 본 연구에서는 단기간 온도 변화가 저서규조류 4종(Navicula sp., Nitzschia sp., Cylindrotheca closterium, Pleurosigma elongatum)의 광합성 반응에 미치는 영향을 Diving PAM을 이용한 엽록소 형광 분석법으로 측정하여 광생리 특성을 분석하였다. 6개의 온도 조건(10, 15, 20, 25, 30, $35^{\circ}C$)에서 2시간 간격으로 24시간 동안 엽록소 형광을 측정하여 P-I 곡선을 도출하였다. 제2광계의 유효양자수율($\Phi_{PSII}$)은 대부분의 종에 있어서 온도가 증가함에 따라 감소하였으며, 상대 최대 전자전달율(rETRmax)은 최적 온도까지 증가한 후 급격하게 감소하였다. 최대 빛이용 효율($\alpha$)은 다른 광합성 매개변수에 비해 온도에 덜 민감하였으나, 높은 온도에서는 감소하였으며, 광포화 계수($E_K$)는 상대 최대 전자전달율의 반응과 매우 유사하였다. 종별 광생리 특성을 분석한 결과, Navicula sp.와 Cylindeotheca closterium가 광생리적 조절을 통하여 단시간의 온도 변화에 광순응하는 것을 확인할 수 있었다.

• 한국자원식물학회지
• /
• 제36권2호
• /
• pp.172-180
• /
• 2023

후박나무 묘목의 효율적인 생산을 위해 시비농도에 따른 간장, 근원경, 묘목품질지수, 광합성 반응 측정으로 생장과 생리적 특성을 조사하고 적정 용기묘 생산에 적합한 시비량을 확인하였다. 광합성 특성은 대조구에 비해 시비처리구에서 순광합성속도(A), 순간증산효율(ITE), 내재적 수분이용효율(WUEi), 최대카르복실화속도(Vcmax) 등 높았다. 특히, 시비 농도는 활발한 가스교환을 통해 비교적 높은 A, Vcmax 보였던1000 mg/L과 기공개폐 기작의 조절로 광합성 반응기작을 향상시킨500 mg/L가 적정 수준의 시비로 실험 결과를 보였다. 생장량 또한 대조구보다 시비처리구에서 묘목의 품질지수 등 통계적으로 높은 것으로 나타났다. 특히, 1000 mg/L은 근원경, 간장이 처리구 중 가장 큰 특징을 보였으며, 잎, 줄기, 전체 건중량, 역시 다른 처리구들에 비해 통계적으로 높았고, 묘목의 품질을 나타내는 H/D율 및 T/R율도 건전한 수준인 것을 볼 수 있었다. 500 mg/L 역시 양호한 생육 특성을 보여 경제성을 고려한다면 한 가지 선택지가 될 수 있다고 여겨진다. 그러나 2000 mg/L의 경우, 근원경의 감소로 H/D율은 높아졌고, 지상부에 비해 지하부로의 물질분배가 저조하여 T/R율 역시 증가하는 형태적 특성과 비용 저감을 위한 경제성을 고려하였을 때 2000 mg/L의 시비농도는 과하다고 판단된다. 따라서 후박나무 용기묘의 시비는 500 mg/L 혹은 1000 mg/L이 경제적으로나 식물의 형태적으로 가장 이상적인 시비량이라고 판단된다.

• 생명과학회지
• /
• 제16권3호
• /
• pp.485-492
• /
• 2006

광합성세균인 Rhodobacter sphaeroides의 PrrBA two-component system은 산소분압의 변화에 따라 광합성 유전자의 발현을 조절하는 주요한 조절계 중 하나이다. PrrBA two-component system은 PrrB histidine kinase와 PrrA response regulator로 구성되어 있는데, PrrB의 N-말단 transmembrane 도메인은 신호인지 도메인으로서, 여섯 개의 transmembrane helix가 세 개의 periplasmic loop와 두 개의 cytoplasmic loop을 형성하고 있다. 그 중 세 번째, 네 번째 transmembrane helix와 두 번째 periplasmic loop가 산화/환원 인지 기능에 있어 중요한 역할을 할 것이라고 제안되었다. 본 연구에서는, 두 번째 periplasmic loop와 그 인접 부위에서의 돌연변이 (Asp-90, Gln-93, Leu-94, Leu-98, Asn-106)에 의해 PrrB의 인지 기능에 있어 심각한 결함이 생기는 것을 증명하였고, 이는 이 아미노산들이 PrrB의 산화/환원 인지 기능에 연관되어 있을 수 있다는 것을 보여준다. PrrB의 돌연변이 형태 (D90E, D90N, D90A)가 대장균에서 과발현되어서 affinity chromatography에 의해 정제되었고, 정제된 단백질의 자가인산화 반응이 측정되었다. PrrB D90N 변이형태는 PrrB wild-type보다 높은 자가인산화 활성을 가지는 반면에, PrrB D90E 변이형태는 PrrB wild-type보다 낮은 자가인산화 활성을 나타내었다. 그리고 D90A 변이형태는 PrrB의 자가인산화 활성이 매우 약화되었다.