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.

선행연구를 통해 침수에 대해 저항성과 감수성을 나타내는 야생콩계통을 선발하고 난 뒤 이들 자원들간 지상부 및 지하부 특성을 분석하였고, 유전자의 발현량도 비교 분석하였다. 1. 연구결과, 침수에 대해 저항성을 나타낸 ‘CW11598’과 감수성을 나타낸 ‘CW11948’는 알코올 발효를 촉매하는 PDC와 ADH효소의 활성을 조절하는 mRNA 발현량에서 차이를 보였다. 감수성계통에서 PDC와 ADH 활성을 조절하는 유전자 모두 침수처리에서 무처리보다 유전자 발현량이 감소하였고, 저항성계통해서는 침수처리에서 오히려 무처리보다 이들 유전자의 발현량이 증가하였다. 이런 침수스트레스 대체 경로의 차이는 감수성계통에서 침수처리 무처리보다 줄어든 LSA, TRL 및 RSA로 나타났다. 2. 식생지수 NDVI와 PRI 모두 감수성계통이 침수처리에서 무처리 대비 크게 감소하였다. 하지만 저항성계통에는 LSA는 침수처리와 무처리간 차이가 없었고, 식생지수 NDVI와 PRI도 침수처리와 무처리간 차이를 보이지 않았다. 하지만 TRL와 RSA는 침수처리에서 무처리보다 감소한 것으로 조사되었다.

본 연구는 유채 6 품종(‘선망’, ‘탐미’, ‘탐라’, ‘내한’, ‘영산’,‘한라’)에 대해 개화기 침수처리(무처리, 3, 6, 9, 12일)에 따른유채 품종별 개화기 습해반응을 평가하고자 수행하였다. 침수3일 처리구는 무처리구와 비교해 유채 6 품종의 생육에 차이가 없으나, 침수 4~9일 처리구에서는 꽃봉오리 정단부 꺾임현상이 심하게 나타났다. 특히 ‘내한’과 ‘영산’ 유채는 침수 9일처리구에서 꽃봉오리 정단부 꺾임현상이 나타나 침수처리에강한 반응을 보였다. 전반적으로 유채는 개화기에 토양 침수가 4일 이상 지속되면 꽃봉오리 정단부 꺾임, 안토시아닌 과다형성, 도복, 개화기 연장, 및 등숙 지연 등 생식생장기 생육에 큰 영향을 주었다. 또한 유채는 개화기에 침수 스트레스가6일 이상 지속되면 주당협수, 협당립수, 결실율, 및 천립중이현저하게 감소하였고, 각각의 수량구성요소 감소는 최종적으로 종실수량 감소로 이어졌다. 무처리구 대비 침수 6일 처리구에 대한 품종별 종실수량을 보면 ‘선망’(54%), ‘탐미’(35%),‘탐라’(33%), ‘내한’(78%), ‘영산’(70%), 및 ‘한라’(32%)로 나타났다. 하지만 침수처리에 따른 종자의 지방산 조성에는 큰변화가 없었다. 전반적으로 공시된 6 품종 중에서는 ‘영산’ 유채가 개화기 내습성이 강한 품종으로 나타났다.

The study was performed to explore the molecular changes in the vegetative stage (3-and 5-leaf) of sorghum under waterlogging stress. A total of 74 differentially expressed protein spots were analyzed using LTQ-FT-ICR MS. Among them, 12 proteins were up-regulated and 3 proteins were down-regulated. Mass spectrometry (MS) results showed that about 50% of the proteins involved in various metabolic processes. The level of protein expression of malate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase related to carbohydrate metabolic process increased in both 3 and 5-leaf stage under waterlogging stress. These proteins are known to function as antistress agents against waterlogging stress. The expression of oxygen-evolving enhancer protein 1 protein related to photosynthesis was slightly increased in the treated group than in the control group, however the expression level was increased in the 5-leaf stage compared to the 3-leaf stage. Probable phospholipid hydroperoxide glutathione peroxidase protein and superoxide dismutase protein related to response to oxidative stress showed the highest expression level in 5-leaf stage treatment. This suggests that the production of reactive oxygen species by the waterlogging stress was the most abundant in the 5-leaf treatment group, and the expression of the antioxidant defense protein was increased.

This research was conducted to evaluate methods of enhancing the waterlogging resistance of soybean plant. Thus, we applied seven types of plant growth regulators (PGRs) to soybean plants and exposed them to waterlogged conditions for a total of 14 days. To evaluate stress resistance, we monitored plant growth characteristics data such as height, chlorophyll content, and chlorophyll fluorescence for 28 days after the initial waterlogging (14 days under waterlogging conditions and 14 days after waterlogging). According to the results, plant height was significantly increased by gibberellin A4 (GA4) treatment compared to the control treatment and waterlogging-only treatment. However, we could not detect plant height owing to plant death when we applied abscisic acid (ABA). Except for GA4 and ABA treatments, plant heights slightly decreased in all treatments compared to the waterlogging-only treatment. The chlorophyll content and chlorophyll fluorescence showed a similar tendency among PGR treatments. The chlorophyll content and chlorophyll fluorescence were significantly increased by ethephon and kinetin treatments 28 days after waterlogging compared to the waterlogging-only treatment. Consequently, kinetin and ethephon treatments induced more resistant phenotypes in soybean plants during or after exposure to waterlogging conditions.