Halophila (thellungiella Halophila) Genomic Library Construction And Proline Metabolism Related Gene Cloning And Screening

Arabidopsis thaliana is always best model plant for the research of the plantmolecular biology, but it is true glycophyte and can unclose less salt-toleranemechanisms. Recently, Thellungiella halophila(Salt Cress), a close-relative ofArabidopsis thaliana, which is been suggested and be developed as a new salttolerance model plant. Thellungiella halophila is a salt-tolerance crucifer with a shortlife cycle, small genome, and with high sequence similarity(about 90-95% on cDNAlevel), similar heredity characteristics and growth habits with Arabidopsis thaliana.So it is convenience for T. halophila to benefit from a lot of Arabidopsis thalianainformation data. The purpose of my research is to do some explorations on itssalt-tolerance mechanism of Thellungiella halophila as model halophyte.In plant, in order to enhance its salt-tolerane, it can absorb and accumulate lotsof inorganic salt ion (including Na⁺,K⁺,Ca²⁺,Mg²⁺,Cl^-,SO₄^2-,NO₃^- and soon). At the same time, it can synthesis many different kinds of organics. It hasalready been proved that the high-density of Proline accumulation has no inhibitingfunction towards some Erzymes in plant. On account of this, on the saltingconditions, the higher plants can accumulate a lot of Proline as its penetrant.As one of the most important osmoregulation actor, firstly,Proline plays a keyrole in the osmotic potential adjustment in plant cells. Secondly, Proline can preventNaCl from damaging the structure of biomacromolecule in cells. Thirdly, the highdissolubility and non-rejection capability of Proline can enlarge the solution volumnof the cell, so the concentration of salt will be diminished in cytoplasm and the saltstress will be relieved. Forthly, the accumulation of Proline could prevent thedehydrolysis from sap cavity in cytoplasm. Fifthly, the synthesis of plant chlorophyllwill be diminished under the salt stress, but the Proline can provide request ofchlorophyll synthesis.In this experimentation, we constructed the genomic library of Thellungiellahalophila(Salt Cress) successfully, and we cloned the genes(ThP5CS1, 2,ThP5CDH, ThPDH, ThERD5) of the metabolic pathway of Proline. It could help usto do the research in the new model plant. The more function of Proline will alse berevealed by these researches.