Research On Giant Cell By Root-knot Nematode

In the promoter trap of giant cells by root-knot nematode Meloidogyne javanica, a promoterlessβ-glucuronidase(GUS) structure was introduced randomly into the tobacco genome. Selection were conducted for those GUS expression exclusively restricted within the galls in the transgenic tobaccos, and then these materials were used for key promoters trapping of giant cells which up-regulated in the galls.Four different methods were used to separate single giant cell from a gall, the results showed that all methods were useful ways of disuniting giant cells from galls. Single cell from galls were then proved to be giant cell. Our results implicated that these methods might be a useful way for the further research on the development, biochemistry and molecular biology of giant cells under single giant cell level.Under controlled condition, histopathological and histochemical observations on cell wall,sugar,protein,nuclei acid and calcium in giant cells have been done. The results show that giant cell have lots of saccharide,protein,nucleic acid and calcium. Results implied that the development of giant cell induced by root-knot nematode is in the level of single cell regulation which nematode choose, and involved lots of genes up-regulated or down-regulated in single normal cell. Root-knot nematodes use their stylet to inject specific compounds which may be secretions of esophagus gland into the initial feeding cell, then, giant cells were induced. Though histopathological ways, giant cells which was induced by root-knot nematode have some response under macro nutrition, which may have direct or indirect influence on nematode.Identification of root-knot nematodes of Achyranthes aspera L. collected form Xiamen University have been done by PCR[6]. The result showed that root-knot nematodes of Achyranthes aspera L. were composed of more than three genus. The predominant species were Meloidogyne incognita and Meloidogyne javanica.