Research Progress on the Relationship between Plant Microstructure and Ultrastructure Changes and its Tolerance
Yang Chunxue 1 Zhuo Lihuan 1,2 Liu Shenkui 1 1 Alkali Soil Natural Environmental Science Center (ASNESC), Northeast Forestry University, Harbin, 150040; 2 Shanghai Vocational and Technical College of Agriculture and Forestry, Shanghai, 201600
Plant morphological structure always adapts to the environment. Many environment factors make the stresses for the growth of plant and change the plant morphological structure. For example, the quantity of cortex layers of root reduces under drought stress, which makes it possible to shorten the transverse transportation distance of water. The amount of mitochondria in both root epidermis and cortex is found to increase under salt stress, which may be considered as a kind of energy supplement of osmotic adaption. The number and bulk of starch grains in chloroplast of stem cortex cells increases distinctively, which not only alleviate the shortage of energy in order to ensure normal life activity, but also raise the osmotic press which is beneficial for water absorbing and maintaining. Bushy epidermis hair or white wax can be easily observed on the leaves of some xerophil, the function of which might be decrease transpiration and reflex high light. In this paper, microstructure and ultrastructure changes in roots, stems and leaves under stresses were reviewed, and the relationship between these structure changes and plant tolerance was analyzed, which provides a useful information for the research of the tolerant mechanism and breed cultivation.