Drought stress represents a major threat to global agricultural productivity, particularly affecting cereal crops such as Sorghum bicolor (L.) Moench. This study investigated the role of silicon (Si) in alleviating drought-induced oxidative stress through the modulation of antioxidant enzyme activities in sorghum seedlings. Using a drought-tolerant Sudanese cultivar (cv. Gadambalia), plants were treated with sodium silicate (1.67 mM) and subjected to osmotic stress via sorbitol treatment. Hydrogen peroxide (H₂O₂) levels were significantly elevated under drought stress, reaching 3.48-fold and 8.00-fold increases in shoots and roots, respectively. Si application substantially reduced H₂O₂ accumulation to 1.95-fold and 3.81-fold in shoots and roots. Enzyme activity analysis revealed that ascorbate peroxidase (APX) remained relatively stable across treatments, while catalase (CAT) showed a sparing effect under Si application. Peroxidase (POD) activity remained elevated in Si-treated plants under stress, indicating maintained antioxidant defense capacity. These results demonstrate that Si mitigates drought-induced oxidative stress not only through enzymatic regulation but primarily by reducing primary ROS generation, thereby enhancing plant stress tolerance and growth performance under water-deficit conditions.

본 연구는 생식생장기 가뭄 스트레스의 강도가 밀의 지상부 생리반응, 지하부의 형태학적 발달 및 종실수량에 미치는 영향을 구명하고자 수행되었 다. 포장실험은 경남 진주시 대곡면에 위치한 경상국립대학교 부속농장에서 2024년 10월부터 2025년 6월까지 산파한 앉은뱅이밀을 이용하여 실시였다. 밀의 생식생장기에 비가림시설(rainout shelter)을 설치하여 대조구(open field), 약한발(-0.5±0.2 MPa), 강한발(-1.2±0.2 MPa)처리를 하였다. 가뭄 스트레스에 의해 등숙기 초장은 대조구 대비 약한발과 강한발 처리에서 각각 8.8, 5.7% 감소였으나, 엽면적지수는 유의한 차이가 없었다. 등숙기 지엽(flag leaf)의 광합성 속도는 대조구 대비 약한발과 강한발에서 각각 33.0, 31.3%, 기공전도도는 각각 40.0, 43.3% 감소하였다. 지하부의 경우, 토양수분 확보에 필요한 분얼당 뿌리 길이는 가뭄 스트레스 처리구가 대조구에 비해 출수기에 증가하는 방향으로 가뭄에 대한 반응을 보였다. 종실 수량과 수확지수는 강한발 처리구에서 대조구 대비 각각 24.3%, 42.9% 감소하여 가뭄에 의한 수량감소 효과가 컸다. 따라서 봄철 가뭄은 밀의 뿌리발달은 증가시키나 광합성속도 감소와 지상부의 발달 저하를 초래하고 수량 감소를 일으킬 수 있으며 그 영향은 가뭄 스트레스 정도에 따라 다르게 나타난다.

To study the effects of external ethanol pretreatment on growth and drought tolerance in alfalfa, 21-day-old plants were pretreated with ethanol at 0-1000 mM for 4 days and then subjected to drought stress for 9 days. Ethanol pretreatment significantly enhanced plant survival under drought conditions, with the highest survival rate observed in the 250 mM treatment. In contrast, fresh weight and dry weight were not significantly affected by ethanol pretreatment. Relative water content was increased 7.15% at 250 mM ethanol treatment compared to 0 mM ethanol treatment. Chlorophyll content decreased compared to the control, while carotenoid content remained unchanged. total soluble carbohydrate content was reduced by ethanol pretreatment. Hydrogen peroxide (H2O2) levels were maintained only in plants treated with 250 mM ethanol, whereas lower and higher concentrations resulted in significantly decreased H2O2 content. These results suggest that ethanol pretreatment does not affect alfalfa growth, but significantly improves survival rate under drought conditions by maintenance of relative water content. Furthermore, it suggests that chemical priming using ethanol pretreatment could be applied as a method to improve drought tolerance of alfalfa plants.

본 연구는 배추의 내건성 평가지표 개발을 위해 엽록소 형광 이미지 파라미터, 형태 및 생리적 특성을 활용 하여 유묘기 배추의 건조 스트레스 후 회복을 평가하였다. ‘불암3호’와 ‘휘파람’ 두 품종을 이용하여, 5일동안 단수 처리 후 재관수 후, 12일간 회복기간을 가졌다. 건조 스트레스는 엽면적, 생체중, 엽수분함량을 감소시켰으나, 건물 함량은 증가하였다. 순광합성률, 증산률, 기공전도도는 건조 스트레스에 따라 유의하게 감소하였고, 엽육세포 내의 CO2 농도는 증가한 뒤 회복기에 점차 감소하여, 이는 광합성 제한요인이 기공적 요인(stomatal limitation)에서 비 기공적 요인(non-stomatal limitation)으로 전환된 것으로 판단하였다. 엽록소 형광 파라미터 중 Fv/Fm과 Fv/Fo는 건 조 스트레스에 따라 감소하였으나, 재관수 후 점차 회복되어 광계II의 가역적 광저해(photoinhibition)를 나타냈다. 회복 양상은 품종 간에 차이를 나타냈고, ‘불암3호’는 생육과 광합성 지표에서 빠른 회복을 보였으며, ‘휘파람’은 회복속도는 느리지만 광화학적 안정성이 더 크게 나타냈다. CF 파라미터는 형태적 및 생리적 특성과 높은 상관관 계를 보였고, 건조 스트레스 및 회복 평가에 있어 객관적이고 신뢰할 수 있는 평가지표로서 활용 가능성을 나타냈으 며, 이는 고속대량 피노타이핑(High-throughput phenotyping) 기술을 활용한 내건성 품종 선발 및 육성에 기여할 수 있을 것으로 판단된다.

본 연구는 건조 스트레스 조건에서 글루탐산의 경엽처리가 마늘의 생장, 광합성 특성 및 생리활성 반응에 미치는 영향과 적정 농도를 구명하고자 하였다. 건조 스트레스 처리 후 글루 탐산(Glu; 10, 80, 169mg·L-1)을 각각 7일 간격으로 2회 엽면 살포 하였다. 글루탐산 처리 시 마늘의 광합성 속도, 기공전도 도, 세포내 CO2 농도 및 증산속도는 무처리 대비 증가하였고, 1회차 처리시 효과가 높았다. 광합성 속도는 무처리 대비 평균 20－40% 이상 증가하였고, Glu80 처리가 가장 높았다. 항산 화 효소 활성 분석 결과 1회차 처리시 APX, CAT 및 SOD 활 성은 Glu80 처리가 가장 높았고, 무처리 대비 평균 30% 정도 높은 활성을 보였다. MDA 함량과 근활력을 측정한 결과 Glu80 처리가 Glu를 엽면살포 하지 않은 건조 처리와 유의한 차이를 보였다. 마늘의 생육 특성은 전반적으로 증가하는 경 향을 보였으며, 구중은 Glu80 처리가 11.1g으로 무처리 8.5g 에 비해 가장 무거웠다. 따라서, 건조스트레스 조건에서 글루 탐산 경엽 처리는 마늘의 생육, 광합성 특성 및 항산화 효소 활 성을 증대시켜 스트레스 피해를 완화하였고, 적정 농도는 80mg·L-1으로 판단된다.

Italian ryegrass (Lolium multiflorum Lam.) is one of the most widely grown winter forage crops in Korea, but its yields are known to be greatly affected by drought that occur frequently in spring. This study aimed to compare the growth and tolerance response characteristics to drought stress in several Italian ryegrass varieties cultivated in Korea. Twenty-day-old Italian ryegrass was subjected to drought treatment for 4 days, and then the growth and physiological responses of the plants were compared. Drought stress reduced leaf length, fresh weight, and dry weight in all Italian ryegrass varieties compared to the control. In addition, chlorophyll content was significantly decreased in all varieties treated with drought stress, but Fv/Fm was significantly decreased only in Winter hawk. For H2O2 and malondialdehyde (MDA) contents, Winter hawk showed the highest increase and New dawn showed the least increase. In terms of relative water content (RWC), New dawn showed the least decrease and Winter hawk showed the greatest decrease. These results indicate that New dawn is relatively drought-tolerant and Winter hawk is a drought-sensitive variety, indicating that each variety of Italian ryegrass has different drought tolerance mechanisms, which may provide basic insight for the development of tolerant varieties in the future.

Drought is one of the environmental factors inhibiting plant productivity and growth, leading to oxidative damage. This study aims to identify the role of sodium hydrosulfide (NaHS) as a hydrogen sulfide (H2S) donor in drought stress tolerance in Brassica napus. Drought-induced stress symptoms appeared eight days after treatment, showing wilted leaves and a significant reduction of leaf water potential. Drought-induced increase of lipid peroxidation was significantly reduced by NaHS application. NaHS-treated plants mitigated stress symptoms under drought conditions by reducing hydrogen peroxide (H2O2) content, confirmed with H2O2 localization in situ. Furthermore, NaHS promotes photosynthetic activity by maintaining chlorophyll and carotenoid content, thereby supporting plant growth under drought conditions. Pyrroline-5-carboxylate and proline contents were significantly increased by drought but further enhanced by NaHS treatment, indicating the important roles of proline accumulation in drought stress tolerance. In conclusion, this study provides valuable insight into the roles of NaHS in alleviating drought stress by reducing oxidative stress and promoting proline accumulation. Therefore, NaHS may serve as an effective strategy to enhance crop production under drought-stress conditions.

본 연구는 관수조건에 따른 지피식물의 생육특성을 파악하고 수분 스트레스 후 생육 회복력을 평가하 기 위하여 수행되었다. 지피식물로 많이 사용되는 초본류 4종을 대상으로 피복의 목적을 달성할 수 있 는 적정 식재간격을 도출하였으며, 또한 관수처리 유형에 따른 생육 및 피복률의 변화를 분석하였다. 식물마다 피복효과를 달성하기 위한 적정 식재간격에 차이가 있었다. 돌단풍은 30～35cm, 송엽국은 30～40cm간격, 꽃잔디는 40cm이상, 돌나물은 20cm미만의 식재간격이 효과적이다. 관수처리에 따른 생육특성을 분석한 결과 관수가 지속적으로 이루어지면 초장이 길지만 처리기간 동안 생육의 변화는 거의 없었다. 피복률은 관수처리와 식물에 따라 차이가 있다. 송엽국과 돌단풍은 무관수 20일 후 관수가 이루어지면 피복률도 회복되었으며, 꽃잔디는 관수가 이루어지고 나서 시간이 경과된 후에 피복률을 회복하였다. 피복이 전체적으로 이루어진 이후에는 토양 수분부족에 의한 피복률의 변화가 거의 없었 으나 피복 초기에 수분이 공급되지 않으면 피복에 어려움이 있다. 꽃잔디, 송엽국, 돌단풍은 일정기간 무관수가 지속되더라도 다시 관수가 이루어지면 회복이 될 수 있다. 즉 식물관리에 있어서 종 마다 차이 는 있으나 관수관리가 중요하며, 일정기간 무관수 후 관수가 이루어지면 생육이 회복될 수 있다.

The Republic of Korea reclaimed land to increase its food self-sufficiency rate, but the yield was reduced due to abnormal climate. In this study, it was hypothesized that rapid and continuous monitoring technology could help improve yield. Using the vegetation index (VI) analysis, the drought stress index was calculated and the drought stress for corn grown in Hwaong, Saemangeum, and Yeongsan River reclaimed tidal land was predicted according to drying treatment. The vegetation index of corn did not decrease during the last 20 days of irrigation when soil moisture rapidly decreased, but decreased rapidly during the 20 days after irrigation. The reduction rate of the vegetation index according to the drying treatment was in the order of Saemangeum>Yeongsan River>Hwaong reclaimed tidal land, and normalized difference vegetation index (NDVI) decreased by approximately 50% in all reclaimed tidal lands, confirming that drought stress occurred due to the decrease in moisture content of the leaves. In addition, structure pigment chlorophyll index (SIPI) and photochemical reflectance index (PRI), which are calculated based on changes in light use efficiency and carotenoids, were reduced; drought stress caused a decrease in light use efficiency and an increase in carotenoid content. Therefore, vegetation index analysis was confirmed to be effective in evaluating and predicting drought stress in corn growing on reclaimed tidal land corn.

To understand antioxidant enzyme response of two contrasting Arundinella hirta ecotypes to drought stress, drought-tolerant Youngduk and drought-sensitive Jinju-1, were comparatively analyzed changes in the enzymatic activities of peroxidase (POD), ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR). Two ecotypes, drought-tolerant Youngduk and drought-sensitive Jinju-1 were subjected to drought stress by withholding water for 12 days. ROS accumulation level and electrolytic leakage were significantly increased in both A. hirta ecotypes by drought stress treatment but less in Youngduk than Jinju-1. The RWC significantly decreased in both the drought stress-treated ecotypes as compared to control, but less in Youngduk than Jinju-1. Soluble sugar and protein content were increased more in drought stress-treated Youngduk as compared to Jinju-1. The activities of antioxidant enzymes such as SOD, CAT, POD, APX, and GR increased significantly in both the drought stress-treated ecotypes Youngduk and Jinju-1 as compared to control. The increase in antioxidant enzyme activity level was more prominent in drought stress-treated Youngduk as compared to Jinju-1. Taken together, these results suggest that Youngduk was more tolerant to drought stress than Jinju-1, and seem to indicate that tolerance of A. hirta to drought stress is associated with increased activity of antioxidant enzymes.

살리실산은 식물의 생장 및 발달, 항산화 방어기작, 광합성 작용 그리고 생물적 및 비생물적 스트레스 조건에서 다양한 생리적 기능을 조절하는 물질로 알려져 있다. 본 연구에서는 고온･건조 스트레스 조건에서 살리실산 경엽처리가 고추의 생육, 광합성 특성 및 항산화효소 활성에 미치는 영향을 구명 하고자 하였다. 광합성 특성 측정결과 광합성 속도, 기공전도 도 및 증산 속도가 증가하였고, 3회차 처리에서 가장 높았다. 세포내 MDA와 H2O2 함량은 살리실산 3회차 처리에서 현저 하게 감소하는 경향을 보였다. APX, CAT, POD 및 SOD 활 성이 현저하게 증가하였으며, 무처리 대비 최대 247, 318, 55 및 54% 증가하였다. 고추의 생육 특성은 무처리구와 유의한 차이를 보이지 않았으나, 상품 수량은 15% 정도 증가하였다. 이러한 결과들을 종합해 볼 때, 살리실산의 경엽처리는 고추 의 광합성 특성과 항산화효소 활성을 증진시켜 고온･건조 스트 레스에 의한 피해 경감에 긍정적 효과를 유발함을 확인하였다

Drought stress is a condition that occurs frequently in the field, it reduces of the agricultural yield of field crops. The aim of the study was to screen drought-adapted genotype of Italian rye grass. The experiments were conducted between the two Italian ryegrass (Lolium multiflorum L.) cultivars viz. Hwasan (H) and Kowinearly (KE). The plants were exposed to drought for 14 days. The results suggest that the morphological traits and biomass yield of KE significantly affected by drought stress-induced oxidative stress as the hydrogen peroxide (H2O2) level was induced, while these parameters were unchanged or less affected in H. Furthermore, the cultivar H showed better adaptation by maintaining several physiological parameter including photosystem-II (Fv/Fm), water use efficiency (WUE) and relative water content (RWC%) level in response to drought stress. These results indicate that the cultivar H shows improved drought tolerance by generic variation, improving photosynthetic efficiency and reducing oxidative stress damages under drought stress. These findings can be useful to the breeder and farmer for improving drought tolerance in Italian rye grass through breeding programs.

The objective of this study was to determine effects of phosphorus on lignification and carbohydrate metabolism in Kentucky bluegrass under drought stress. Drought stress was induced by reducing of water to plants in pots. Two types of phosphorus were applied as potassium phosphate (PO4 3-; P) or potassium phosphonate (PO3 3-; PA) in drought-stressed plants. Drought had significant negative effects on plant growth, as revealed by reduced biomass of shoot. Drought-induced increase of lignin content was concomitant with the increase of phenylalanine ammonia-lyase (PAL). Soluble sugar content was highly increased but fructan content was largely decreased by drought stress. However, the application of phosphorus was efficient to ameliorate the adverse effects of drought. PA application improved reduced shoot growth and relative water content, and inhibited lignification synthesis with a reduction of PAL activity. P or PA application maintained soluble sugar and fructan content at similar levels to controls under drought stress. These results indicate that phosphorus application may mitigate the drought stress by inhibiting the lignification and promoting the fructan assimilation.

The objective of this study was to determine phosphorus effects on drought stress-induced oxidative stress in Kentucky bluegrass. Drought stress was induced by reducing of water to plants in pots. Two types of phosphorus were applied as potassium phosphate (P) or potassium phosphonate (PA). Application of phosphorus was efficient to ameliorate the adverse effects of drought. Osmotic potential, total chlorophyll and carotenoid content were significantly decreased by drought stress, but was relieved by P or PA application. Superoxide (O2 •−) concentration was significantly increased more than 14-fold under drought-stressed plants, was accompanied with increase of hydrogen peroxide (H2O2) and lipid peroxidation (MDA). However, malondialdehyde (MDA) was much less in P or PA applied plants under drought stress condition. Activities of catalase (CAT), ascorbate peroxidase (APX) and guaiacol-peroxidase (GPX) were largely increased by drought stress and its increase rate was much higher in P or PA applied plants except APX. These results indicate that drought stress-induced oxidative stress is alleviated by P or PA application due to the increase of activities of antioxidant enzymes.

본 연구는 케일(Brassica oleracea L. var. acephala)의 노지 재배 시, 생육 초기에 노출될 수 있는 건조 스트레스 조건에서 Glutamate (Glu)의 스트레스 경감 및 생육 회복 효과를 구명하기 위해 실시하였다. 건조 조건(D)에 노출된 케일에 5㎛ Glu 용액을 경엽처리하였다(D+Glu). Glu 처리 전 및 처리 후 4, 8일 차(0, 4, 8DAT)의 생육과 엽록소 함량을 측정하고 식물 체내의 ABA와 Glu, Pro의 함량을 분석하여 정상 환경 및 D, D+Glu 처리구 간의 비교를 실시하였다. 엽록소 함량의 경우, 8DAT에서 D+Glu 처리구는 일정한 수준을 유지한 반면에, D처리구는 14% 감소하였다. 엽면적으로 대표되는 생장 또한 D+Glu 처리구가 D 처리구에 비해 높게 나타났다. 또한 4, 8일차의 ABA 함량이 D 처리구에서 D+Glu 처리구에 비해 44.13, 49.18% 높게 나타났으며, 체내 아미노산 대사 및 건조저항성 지표인 Glu, Pro 함량은 D 처리구에 비해 D+Glu 처리구에서 보다 높은 수준을 유지하였다. 이러한 결과를 통해, Glu 처리에 의해 건조 스트레스가 경감되고 생육이 회복될 수 있다고 판단된다.