Regulation On Stomatal Movement Of Tube Seedlings Of Transgenic Populus Tomentosa Carr.

Populus tomentosa Carr. is a native species of section populus China. It plays an important role in the urban and rural environmental afforestation and industrial and agricultural material as its fast growth, the adaptability with the straight trunk and beautiful shapes. Rapid propagation of improved varieties through tissue culture is a widely used technology, however, the long-term growth of tube seedlings in high humidity, weak light, temperature, no wind conditions make its stomatal morphology and physiology significantly different from that of plants grown under natural conditions, this affacts the survival rate of transplanations of tube seedlings. With nail polish, the change of stomatal density, stomatal size, the daily variation of stomatal aperture, the daily variation of stomatal open percentage of the leaves'lower epidermis of tube seedlings and the 10 years plant of transgenic Populus tomentosa Carr. were compared, and the effect of wilting, H2O2, Ca2+, ABA, SA, ethrel, darkness, different concentrations of ABA in medium, different concentrations of CaCl2 in medium, tube seedlings grown in medium without sugar on stomatal aperture were studied, and analyzed the reason of abnormal stomatal behavior. It is important for the further understanding of the guard cells signal transduction pathways and the mechanisms of tube seedlings. The main results were as follows:1. Stomatal density of the leaves'lower epidermis of tube seedlings of transgenic Populus tomentosa Carr. was 255.10/mm2, stomatal density of the leaves'lower epidermis of the 10 years plant was 374.15/mm2, tube seedlings'stomatal density was less than that of the 10 years plant, there was a significant difference in stomatal density between tube seedlings and the 10 years plant.2. Stomata of the leaves'lower epidermis of tube seedlings of transgenic Populus tomentosa Carr. was 610.86μm2, stomata of the leaves'lower epidermis of the 10 years plant was 112.97μm2, tube seedlings'stomata was obviously larger than that of the 10 years plant, there was a significant difference in stomata between tube seedlings and the 10 years plant.3. Stomatal aperture of the leaves'lower epidermis of tube seedlings of transgenic Populus tomentosa Carr. was 60.53～92.17μm2, stomatal aperture of the leaves'lower epidermis of the 10 years plant was 16.70～18.74μm2, stomatal aperture in tube seedlings was greater than that in the 10 years plant.4. The changes of stomatal aperture of the leaves'lower epidermis of tube seedlings of transgenic Populus tomentosa Carr. was evident, the ratio of minimum and maximum was about 0.66:1, changes of stomatal aperture during 24 hours appeared wave crest, the two peaks of stomatal aperture were 9:00 and 15:00; the changes of stomatal aperture of the leaves'lower epidermis of the 10 years plant was not evident, the ratio of minimum and maximum was about 0.89:1, changes of stomatal aperture during 24 hours was steady and no evident fluctuation.5. Stomatal open percentage reached 100% in tube seedlings of transgenic Populus tomentosa Carr. during a day, a bimodal curve change was observed in stomatal open percentage of the 10 years plant.6. In vitro, wilting , H2O2 can reduce stomatal aperture, but not promote stomatal closing; the Ca2+, ABA, SA, ethrel can induce stomatal closing when their concentration were respectively 1mol?L-1,200μmol?L-1,0.1mmol?L-1,0.4%.7. In vivo, continuous darkness, ABA in medium can not promote stomatal closing when their concentration were 0.5mg?L-1~3mg?L-1; CaCl2 in medium can induce stomatal closing when their concentration were 37.8g?L; tube seedlings grown in medium without sugar compared with tube seedlings grown in medium with sugar, stomatal aperture of tube seedlings grown in medium without sugar was reduced, stomatal close percentage of tube seedlings grown in medium without sugar were 83%.