Study On The Change Rule Of Vegetative Storage Proteins In Poplar

Based on one-year-old 797 poplar (P. deltoides×P. euramericana) seedlings, the content of vegetative storage protein, dissociative amino acid, nitrate, endogenetic hormones and activity of enzyme (reductase, glutamine synthetase, endopeptidase, peroxidaseone ) in different tissues in poplar during annual growth cycle (especial during germination in spring and leaf fall in autumn)were studied in this paper, the result of VSPs anuual dynamic change, fraction of VSPs and regulation mechanism of nitrogen accumulation degradation were carried out, in order to offer foundations for cultivating high efficacy utilization poplar by transgene technology. We can draw satisfactorily conclusion as follows from our results: 1. A mass of protein were accumulated in trees in the stage of over wintering. The total content of protein distributing in tree's cortex, xylem and roots follows such a sequence: cortex>xylem>roots. The total content of protein declined sharply after bourgeoning in spring, and arrived at the bottom in 13th, April (one week after the leaves outspread).The decline range of protein in cortex is the biggest, the xylem second, roots thirdly, and each of their range is 65.6%,47.3% and 30.3% respectively. After then, the content changed following a conk line. 2. According to SDS-PAGE result, there are 4 types of storage protein in cortex (36 KD, 32 KD, 22 KD, 15 KD protein), 2 types of protein in roots(36 KD, 32KD), and 5 types of storage protein in xylem (97 KD, 42 KD, 38 KD, 32 KD, 18 KD protein). Also it is be made sure that several types of protein (19 KD, 18 KD, 16 KD protein) in cortex were temporary synthesized as special functionality protein. Protein in leaves is mainly used as temporary storeroom, and the changing rule of this protein may be related to the changes of "source/pool"in tree. 3. The N-metabolizing in poplar reached to the heartiest time in middle time of May and June and the late stage of October, then decline during defoliation. The accumulation and degradation of protein can be affected by the multi-action of nitrate absorbing and the enzyme which related with N metabolism directly. Amino acid metabolism can also affect nitrate absorbing in root. 4. The GA and CTK in leaves and cortex have a notably correlativity, and the same to JA and IAA. The high concentration of IAA, JA and GA can inhibit the bug's bourgeon, and control protein degradation. JA and ABA are related to the changes of some proteins compactly, and light and temperature may be the major factors affect the content of JA and ABA. The vegetative storage protein accumulation in fall may be directly related to the photoperiod, accommodation of N, temperature and water. 5. The accumulation and degradation of vegetative storage protein is an important approach of nitrogen utilization, the ecological countermeasure to active adapt to the environment changes, the crucial mechanism to maintain the ecology balance in poplar. The study on reuse of storage N can offer a possible way for study rule of N utilization thoroughly.