Oilseed rape is known to crop having low nitrogen use efficiency (NUE) but requires high levels of N fertilizer. NUE is associated with N remobilization from source to sink organ, consequently affects seed yield. Remobilization of leaf N is also related to transport of C/N metabolites in phloem. However, interaction between seed yield and phloem transport was not fully documented. In response to seed yield, N and C metabolites and their transport into seed from bolting to pod filling stage investigated in two contrasting genotypes (Capitol and Pollen) cultivated under ample (HN) or limiting nitrate (LN) supply. Seed yield was significantly reduced in N limitation and its reduction rate was much lower in Capitol than in Pollen compared to HN treated plants. Amino acid and protein content was higher in Capitol than in Pollen at bolting stage. They gradually decreased during plant development but not significant between two cultivars and/or two treatments. Glucose, fructose and sucrose content were 1.8-,1.6- or 1.25-fold higher in LN condition than in HN condition, respectively. Amino acid and sucrose content in phloem were largely higher in Capitol than in Pollen under LN condition. These results indicate that the higher seed yield might be related to greater transport ability of amino acid and sucrose in phloem under LN condition.

본 연구는 비만 모델동물 랫드에서 식이 내 오메가 6와 3 지방산 비율(n-6/n-3 0, 4:1, 15:1, 30:1)이 지질대사의 생화학적 메카니즘을 구명하였다. 혈액 중성지방은 대조군과 비교할 때 n-6/n-3 비율 4:1, 15;1, 30:1 처리군에서 22.21%, 총콜레스테롤 20.60%, LDL-C 52.96%, 혈당 15.71%, ALT 11.97%, AST 9.13%, 인슐린 37.57%, 렙틴 45.98% 낮아졌으나, HDL-C 28.38%, 인지질 80.39% 증가하였고, 특히 4:1 처리군에서 가장 큰 효과가 나타났다. 간 조직에서 SREPB-1α, SREPB-2 mRNA는 대조군과 비교할 때 n-6/n-3 비율 처리군에서 하향조절 하였으나 PPARs 그리고 지방조직의 LPL-mRNA는 상향조절 하였다. 간 조직에서 지방세포의 크기는 n-6/n-3 비율 30:1, 대조군, 15:1, 4:1 순서로 낮아졌고, 지방조직에서 지방세포의 크기는 대조군, 30:1, 15:1, 4:1 순서로 낮았다. 결과는 비만 모델동물 랫드에서 오메가 6와 오메가 3 지방산 비율, 특히 4:1을 함유하는 식이를 급여하면 혈액 유해 지질, 간 기능 효소, 렙틴, 인슐린, 간과 지방조직의 유전자 발현 조절을 통하여 건강을 유지할 수 있다는 새로운 사실을 발견하였다.

To investigate C and N metabolisms in response to potassium-deficient stress during regrowth of Italian ryegrass(Lolium multiflorum L.), C and N metabolites were analyzed at day 0 (cutting date), 6, 12 and 24 days after defoliation. K-sufficient (control,

This study was aimed to observe dose-response effects of squid liver oil enriched in n3 polyunsaturated fatty acids(n-3 PUFA) on the metabolism of streptozotocint(STZ)-induced diabetic rats. In this experiment, 24 STZ-induced diabetic male rats of Sprague Dawley strain were divided into 4 groups and fed for 4 weeks with basal diet(0%). 33%,67% and 100% squid liver oil(SLO) of total fat content, and 6 normal rats were fed with 0% SLO diet at the same time. The results obtained were as follows: 1. Rat group fed with 33% SLO diet showed the least body weight loss and changes in blood glucose, while ones of 100% SLO diet showed the highest level. 2. Serum total protein and ratio of albumin to globulin of all the groups were below the standard level, but did not show significantly different among diet groups. 3. Serum creatinine concentration of all the groups were stayed whthin normal range, but BUN were 3 to 4 times higher than normal rats. BUN concentration of rats fed with 0% and 33% SLO diet was significantly lower than those of others. 4. Total-cholesterol level of serum increased in all the groups except 33% SLO diet, but since HDL-chol, levels and TG concentration went up with an incerase of SLO in the diets, the ratio of HDL-chol. to total-chol, of rats fed with 67% and 100% SLO diet showed higher than those with 0%, and 33% SLO, and TG concentration of rats fed with 67% and 100% SLO diet decreased significantly.

To investigate of C and N metabolisms in response to phosphorus-deficient stress during regrowth of Italian ryegrass (Lolium multiflorum L.), C and N metabolites were analyzed at 0, 6, 12 and 24 days after defoliation. P-sufficient (control, +P) and P-absent (-P) nutrient solutions were applied from 7 days before defoliation, and continued for one cycle of 24 day-regrowth period. During 24 days of regrowth, dry matter of regrowing shoots and remaining tissues were not significantly different between +P and -P treatment. In remaining stubble, 70% to 91 % decline of the initial level (at day 0) in all C compounds occurred during the first 6 days of regrowth. Initial amounts of nitrate and amino acids in roots were significantly higher in the +P medium. Nitrate contents in stubble in the +P medium significantly decreased for the first 12 days and then rapidly recovered, while that of the -P medium continuously decreased until day 24. Amino acids in stubble in the P medium were continuously increased during the whole regrowth period. Soluble proteins in stubble in the +P medium also largely fell down (46.0% of the initial) for only the first 6 days, however the decline in the -P medium continued until day 12. In regrowing shoots, the accumulation of C compounds was significantly higher, while that of N compounds except amino acids was largely lower in the -P medium. These results showed a stimulation of carbohydrate synthesis and a compensatory utilization of organic reserves occurred to support regrowth under P-deficient condition.