Study On Relationship Between Enzymes Activity Of Organic Nitrogen Reutilization And Nitrogen Use Efficiency During Later Growth Period Of Oilseed Rape

As important oil crops with traditional cultivation advantages, oilseed rape has been more and more focused in recent years. Low use efficiency of nutrients is become a limitation factor for oilseed rape production development, along with higher and higher of fertilization amount. Low use efficiency of nitrogen (N) is one of the most important factor in crop production, and closely relation to N application and N metabolic in plant tissues. To further investigate regulation function of proteolytic enzymes (PE), glutamine synthetase (GS), glutamate synthaserape (GOGAT) for N reuse and N efficiency during later growth period of oilseed rape. Two oilseed rape (2and6) was used as plant materials with normal N application and deficiency N application, through painting specific enzymes inhibitors (PE inhibitor, GS inhibitor, GOGAT inhibitor) of organic N metabolisms on leaf and silique during later growth period, to study on effect mechanisms of specific inhibitor on N reuse and N efficiency. It will provide scientific basis for further inspecting physiological mechanisms of N metabolic in oilseed rape, and further improving its N efficiency. The main results showed as follows1Seed yield was decreased by treatments of enzyme inhibitors, and significant decreased in GOGAT inhibitor treatment. Seed yield of inhibitor treatment was lower than control, especially appeared in GOGAT inhibitor treatment (GOGAT inhibitor painted on silique) of number2variety. Seed yield of normal N application is higher than deficiency application. Biomass yield of2variety was higher than6variety under the same N application level, regardless painting enzyme inhibitor or not. There are few effect of enzyme inhibitor on silique number, seed number per silique, seed thousand weight. Silique number and seed number per silique can be increased by higher N application level, but few influenced on seed thousand weight.2Enzyme inhibitor treatments can significantly effect on redistribution of N from vegetative organs to reproductive organs and N metabolic. N content in2variety leaf of GS inhibitor treatment was significantly lower than control under deficiency N application condition. N content in6variety leaf of PE inhibitor treatment was significantly lower than control. Seed and plant total N of normal N application was higher than deficiency N application. Seed and plant total N of enzyme inhibitor treatment was lower than control under normal N application condition, seed and plant total N of2variety can be significantly decreased by GOGAT inhibitor treatment. N redistribution proportion and amount from vegetative organs to seed can be decreased by enzyme inhibitor treatment. N redistribution proportion and amount to seed of2variety can be significantly decreased by GOGAT inhibitor treatment.3. Inhibitors can reduce the absorption efficiency and the use efficiency of oilseed rape. Normal N conditions on the2species of GOGAT to deal with the absorption efficiency are very significantly lower. Normal N under the conditions of the2species inhibitors, N use efficiency is lower than that of the control PE (leaves smear protease inhibitors) and GOGAT processing effects on achieve a significant level. Conditions of N stress on the2varieties PE, GS (blades smear the glutamine synthetase inhibitor) treatment of N use efficiency are lower than the control treatment, but the difference was not significant; while the GOGAT processing N use efficiency was significantly low in the CK. In summary, GOGAT can significantly affect plant N use efficiency and absorption efficiency.4. Normal N conditions, the2variety of the PE, GS and GOGAT processing the proportion of N loss was significantly higher than the CK. The GOGAT processing to achieve a significant level, N loss ratio slightly higher than the6varieties PE, GS and GOGAT processing the control treatment. N stress conditions, the proportion of N loss from the control treatment are lower than other treatments in addition to the6varieties GS handling the proportion of N loss was significantly higher than outside the control treatment, other differences between treatments were not significant.5.The highest contribution to the proportion of leaf N on grain and pod, the average contribution of80%or more. Normal for the conditions of N and N stress on the2varieties the GOGAT deal with the proportion of leaf N contribution and contribution are very significantly lower than the control treatment. Under N stress conditions, the contribution ratio and the contribution of the varieties of the CK in the6leaf N was significantly lower than other enzyme inhibitors.6.Compared with the control treatment, PE inhibitor treatment under the conditions of free amino acids and soluble sugar content in the phloem showed a downward trend. Glutamine content decreased in the phloem under the GS inhibitor treatment conditions, the increase in soluble sugar content; GOGAT inhibitor treatment under the conditions of L-glutamine in the phloem and soluble sugar content increased.7IAA and ABA content in plant tissues can be affected by enzyme inhibitor treatment. IAA content in leaf of the two varieties (2and6variety) was increased by PE, GS and GOGAT inhibitor treatment, IAA content in silique of the two varieties was decreased under normal N condition, and increased under deficiency N condition. Compared with control treatment, ABA content in leaf of the two varieties was increased by PE, GS and GOGAT inhibitor treatment under normal N condition, while decreased under deficiency N condition. Compared with control treatment, ABA content in silique of the two varieties was increased by PE, GS and GOGAT inhibitor treatment under normal N condition, while decreased of6variety, ABA content in silique of the two varieties was increased under deficiency N condition.