Class Integrin Protein And Tubulin Role In Plant Responses To Drought Stress

Plant is always effected by environmental stresses such as drought, cold and salt et.al. in the course of its life. Drought is the main reason of restricting the plant growth and its output in our country. Thereby, to explore the mechanisms of how plants response to drought stresses and how to improve the resistance of plants to drought stresses is of great significance. In this test, the suspension cell lines of Arabidopsis Thaliana and the root tips of Zea Mays L. were used as experimental materials to investigate the role of integrin-like protein, microtubule and their interaction in the responses of plant cells to drought stress. Results showed:1. Immuno-fluorescent localization studies, using a monoclonal antibody againstβ1 subunit of human integrin, showed that the integrin-like protein localized in the plasma membrane fraction in Arabidopsis suspension cells and both cell membrane and nucleus of maize root cells. And preliminary functional studies indicated that the integrin-like protein conglutinates the cell wall and plasma membrane. The ABA content of stressed Arabidopsis suspension cells (2.4-fold higher than that of control) increased significantly faster than that of cells treated by RGD and stressed simultaneously(1.5-fold higher than that of controlled cells). At the same time, RGD and osmotic stress make the ABA content increase 1-fold in maize root cells. However, the ABA content of drought stressed cell which was pretreated by RGD increased 6-fold. These results suggest that the integrin-like protein be involved in osmotic stress-induced ABA biosynthesis.2. The arranged pattern of microtubule changed obviously when cells were imposed to osmotic stress. More cortical microtubules arrays was observed in osmotic stressed cells than in control cells. In maize root cells, PEG treatment make the ABA content increase by 3 times; As oryzalin treatment, PEG treatment after pretreated by oryzalin increased the ABA content by less than 1 times; However, the ABA contents of cells treated by oryzalin after pretreatting by PEG was 4 times higher than the control cells. RT-PCR experiments showed that: A marked increase in the expression of Vp14 gene in PEG stressed maize roots; As oryzalin treatment, PEG treatment after pretreatting by oryzalin...