Salinity is a major abiotic stress for crop plants that cause reduced food production. The application of plant growth-promoting microorganisms can improve the adaptability of plants to biotic and abiotic stresses. Therefore, in the current study, we aimed to enhance the mitigation effects of artificially applied rhizobacterium Klebsiella variicola AY13 on salinity stress in Trifolium repens L. The results suggested that AY13 innately produced indole-3-acetic acid and accelerated the morphological adaptation of T. repens to salt stress conditions. Furthermore, AY13 promotes a Trp-dependent pathway for indole-3-acetic acid (IAA) production, as adding L-tryptophan (L-Trp) increased IAA production in pure culture. AY13 improved plant growth by maintaining relative water content and minimizing water loss in excised leaves. Moreover, AY13 inoculation significantly reduced the endogenous levels of abscisic acid and antioxidants such as glutathione and catalase. These results suggest that AY13 plays a crucial role in reprogramming stress-related metabolism and enhancing plant stress tolerance.

Sulfur is an essential element in plants, including amino acids, vitamin synthesis, and acting as an antioxidant. However, the interaction between endogenous sulfur and proline synthesis has not been yet fully documented. White clover (Trifolium repens L.) is known as a species highly sensitive to sulfate supply. Therefore, this study aimed to elucidate the role of sulfur in regulating proline metabolism in relation to ammonia detoxification and hydrogen peroxide (H2O2) accumulation in white clover. The detached leaves of white clover were immersed in solution containing different concentration of sulfate (0, 10, 100, and 1000 mM MgSO4). As MgSO4 concentrations were increased, the concentration of H2O2 increased up to 2.5-fold compared to control, accompanied with H2O2 detection in leaves. Amino acid concentrations significantly increased only at higher levels (100 and 1000 mM MgSO4). No significant difference was observed in protein concentration. Proline and Δ1-pyrroline-5-carboxylate (P5C) concentrations slightly decreased at 10 and 100 mM MgSO4 treatments, whereas it rapidly increased over 1.9-fold at 1000 mM MgSO4 treatment. Ammonia concentrations gradually increased up to 8.6-fold. These results indicate that exogenous sulfur levels are closely related to H2O2 and ammonia synthesis but affect proline biosynthesis only at a higher level.

Molybdenum (Mo) in rhizosphere influences sulfate assimilation as well as a number of other physiological aspects. In this study, the activity of key enzymes in sulfate assimilatory pathways, such as ATP sulfurylase (ATPs), adenosine 5'-phosphosulphate reductase (APR), as well as the responses of reactive oxygen species (ROS), were analyzed to elucidate the metabolic and physiological effects of external Mo supply to detached leaves of Trifolium repens L. Mo supply with a range from 1 mM to 40 mM depressed the activity of ATPs throughout the entire time course. In the leaves exposed to 1 mM Mo, a continuous decrease in the activity of ATPs was confirmed by Native-PAGE. The APR activity was also declined by Mo treatment. The accumulation of H2O2 and O2 were not significant up to 10 mM Mo, whereas a remarked accumulation was detected under 40 mM Mo supply. The data suggest that an external supply of Mo has an inhibitory effect on sulfate assimilation, and induces oxidative stress only at an extremely high concentration.

화이트 클로버에서 마이코라이자 접종이 가뭄스트레스와 관련된 생리학적 요인들을 조사하기 위하여, 마이코라이자 접종 (AM) 또는 비접종구에서 정상관수 (WW) 또는 가뭄 스트레스 처리 (DS)하여 7일동안 주기적으로 잎 수분포텐셜, 상대수분함량, 건물중, 광합성효율, 증산, 기공전도성, 프롤린 및 암모니아 함량을 각각 측정하였다. 모든 조사항목에서 정상적인 관수조건 (대조구)에서는 전 시험기간 중 변화가 매우 적었으며, 마이코라이자 접종에 의한 변화도 매

본 시험은 화이트클로버 California Ladino(대조품종), Seminole, Sonja, Milo, Rinendel, Alberta 및 Sona 7품종을 축산기술연구소 대관령지소(표고 800m)와 남원지소(표고 450m)에서 각각 난괴법 3반복으로 수행하였다. 화이트 클로버의 엽색은 대조품종 Ladino와 Seminole을 제외하고 모두 연녹색이었고 엽폭도 대형이었다. 내한성은 대조품종인 Ladino 보다 좋은 품종은 Seminole로서 85.

This study was designed to investigate the effects of antagonistic microorganism, Bacillus subtilis, on the growth of forage seedlings in repeated cultivation soils and unrepeated cultivation soils. The field experiment was wnducted in pots in a vinyl hou

This study was conducted to investigate the effect of antagonistic bacteria and pathogenic fungi on growth and yields of white clover(Trifo1iurn repens L.) in continuous cropping soil(CCS) and non-continuous cropping soil(NCCS). The gowth experiment of wh

The esterase isozyme in tissue of wild legume plants were separated by horizontal starch gel electrophoresis. Extracts used in this study were prepared from fully expanded young leaf, cotyledon and radicle of seedling and root-nodule of Glycine sola, Vign

The more N fertilizer, the more grass proportion (58 8, 240 kg N/ha) and the less white clover (Trifolium repens) (6 %, 240 kg N) under grazing utilization. The proportion of white clover was maintained about 27 % at 60 kg N/ha/yr and weed proportion was

화이트 클로버의 배축, 잎, 미숙배 유래의 embryogenic callus에 식물 binary vector인 pBI121을 포함하는 A. tumefaciens LBA4404를 접종하여 효과적으로 화이트 클로버를 형질전환시켰다. A. tumefaciens를 이용한 화이트 클로버의 형질전환은 acetosyringone을 사용함으로써 품종간의 차이가 없이 배발생 캘러스에서 16-19%를 보였다. 재분화 식물체의 PCR 및 Northern 분서글 통하여 형질 전환된 화이트 클로버의 염색체내에 GUS 유전자가 안정되게 도입되었고 식물체내에서 mRAN로 발현됨을 확인하였다. 또한, GUS 유전자가 식물체내에서 단백질로 발현됨을 확인하기 위하여 형질 전환되어진 화이트 클로버부터 단백질을 추출하고 분광분석법에 의하여 GUS의 활성을 측정하였으며, 시료간에 약간의 차이는 있으나 유의적인 GUS 활성을 확인하였다.