Cytological Research Of Vegetative Storage Proteins In Zizyphus Jujuba

Vegetative storage proteins (VSPs) is the main form of nitrogen storage in many deciduous trees during the winter. The type and distribution and seasonal changes of vegetative storage proteins in small roots and branchlets and leaves of Hupingzao, which was especial fruiter in Taigu of Shanxi Province, were investigated by light and electron microscope and phonologic record in the paper. The main conclusions were as follows:(1) The date of bud in Zizyphus jujuba was April12in2013. Flowering period was May25. Maturity was May25. The fallen leaves was October15.(2) The seasonal change of vegetative storage proteins of Zizyphus jujuba was obvious.The process of change could be divided into two stages which called degradation and accumulation. In the dormant period, the bark and xylem of branchlets accumulated abundance vegetative storage proteins. These proteins degraded gradually in the process of bud germination, and disappeared completely after new shoots sprouting. The degraded proteins provided important source of nitrogen to the growth of new shoots. In mid-May, the new shoots started to accumulate vegetative storage proteins with the growth of new shoots and leaves mature. The vegetative storage proteins began to be accumulated rapidly during leaf fall period, whose content ammounted the most in December. The dynamic change of vegetative storage proteins in roots of Zizyphus jujuba was similar to that of branches. But, the begining of degradation time of proteins in roots was earlier than that of branches, and the great accumulation in roots began later than that of branches. Moreover, the accumulation in roots was not as rich as in branches. The process of dynamic change in leaves of Zizyphus jujuba may be related to the growth activities of itself. The new leaves started to accumulate vegetative storage proteins during leaf growth period. The leaves began to degrade vegetative storage proteins during leaf fall period.(3) The vegetative storage proteins of Zizyphus jujuba have different forms such as homogeneous, floccular, granular, and conglobate. In the initial stage, the storage proteins were accumulated in large central vacuoles mainly with forms of homogeneous and floccular, while accumulated in numerous small vacuoles with other forms of granular and conglobate in dormant stage.(4) The cell of vegetative storage proteins in Zizyphus jujuba is similar to poplar.