title: Initiation of dedifferentiation and structural changes in in vitro cultured petiole of Arabidopsis thaliana.
abstract: Although the method of tissue culturing has been used widely in practice for a long time, and there are numerous hypotheses to explain the dedifferentiation phenomenon in the tissue culturing, many details of mechanism of dedifferentiation remain unclear. In the study, dedifferentiation process is initiated in the residual procambium, followed by the procambium-derived cells and finally xylem parenchyma cells under the culturing of Arabidopsis thaliana petiole explants. The procambium may induce its derivative cells to undergo dedifferentiation, which in turn induce the xylem parenchyma cells to dedifferentiate. This phenomenon is very similar to the activity of interfascicular cambium induced by intrafascicular cambium in secondary growth of plant stems. In the present study, only the paired procambium-derived cells and xylem parenchyma truly underwent dedifferentiation, whereas the initial changes in the procambium simply recovered the inherent meristematic capacity of those cells. In transverse section of petiole of A. thaliana, parenchyma cells outside the vascular bundle did not participate in dedifferentiation and gradually disintegrated under the culture conditions. Obviously, the time for initiation and difficulty underlain for undergoing dedifferentiation are dependent on the differential degree and location of parenchyma cells in the petiole.
authors.affiliation: School of Life Science and Technology, Tongji University, 200092 Shanghai, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Feng
authors.forename: Guangchao
authors.initials: G
authors.lastname: Wang
authors.forename: Fei
authors.initials: F
authors.lastname: Li
authors.forename: Xiling
authors.initials: X
authors.lastname: Du
authors.forename: Jian
authors.initials: J
authors.lastname: Zhu
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000378:metabolism; D054337:Cell Dedifferentiation / Q000502:physiology*; D017403:In Situ Hybridization; D018515:Plant Leaves / Q000166:cytology* / Q000378:metabolism