The Mechanism Of Phosphoinositide Signaling Pathway Involved In Pollen Germination And Pollen Tube Growth Of Picea Wilsonii, And The Ecophysiology Of Cell Wall In The Reed Leaves.

I The involvement of phosphoinositide signaling pathway in pollen germination and pollen tube growth of Picea wilsonii: Two potent inhibitors of phosphoinositide signaling pathway, neomycin and TMB-8, were used to investigate their influence on pollen tube growth and cell wall deposition in Picea wilsonii in relation to phosphoinositide signaling. Apart from inhibiting pollen germination and pollen tube growth, the tube morphology was largely influenced by the two inhibitors. The inhibition of phosphoinositide signaling pathway not only obviously disturbed the generation and maintenance of the tip-localized Ca2+ gradient, but also led to a heavy accumulation of callose at the tip region of Picea wilsonii pollen tubes. Fourier transform infrared (FTIR) analysis showed that the deposition of cell wall components such as carboxylic acid, pectins and other polysaccharides in pollen tubes was changed by the two inhibitors. The results obtained from immunolabeling with different pectin and arabinogalactan-protein (AGP) antibodies agreed well with FTIR results and further demonstrated that the generation and maintenance of the gradient of cross-linked pectins as well as the proportional distribution of AGPs in tube cell walls are essential for the pollen tube growth. These results strongly suggest that phosphoinositide signaling pathway mediates the processes of pollen germination and pollen tube growth in Picea wislonii and its inhibition can lead to abnormally growth by disturbing the tip-focused Ca2+ gradient and changing the deposition of cell wall components in pollen tube tips. Keywords: cell wall, phosphoinositide signaling pathway, Picea wislonii Mast, pollen tube.II The ecophysiological characteristics of cell wall structure in different reed ecotypes: We investigated the anatomical and chemical characteristics of the foliar vascular bundles in four ecotypes of common reed (Phragmites communis Trin.) inhabiting the desert region of northwest China: swamp reed (SR), low-salt meadow reed (LSMR), high-salt meadow reed (HSMR), and dune reed (DR). The cell walls of the vascular systems of all four ecotypes exhibited bright autofluorescence. Compared to SR, the three terrestrial ecotypes, LSMR, HSMR and DR, had higher percentages of bundle...