Central Asia Atriplex Salt Induced Genes Of Badh Cdna Cloning, Characterization And The Atriplex Centralasiatica Genome Library Construction

Certain higher plants (c. g. chenopodincLc and poaceae) synthesize and accumulate glycino betaine as a nontoxic osmoprotectant under saline or dry condition. It is generally believed that in addition to acting as an osmolyte to raise osmotic r)ressurc, glycine hetaine can stabilize enzymes and membranes against damage by high salinity. In higher plants, giycine betaine is synthesized in chioroplast via the pathway: choline be tai no al debydo gil yc inc hotai no. The Cirst step is catalyzed by choi inc monooxygenase(CMO), the second by hetai ne aidehyde dehydrogonase(BADII). According to the sequences of BADH eDNA that have been published in several other plants, two primers have been designed to amplify the Uragmcnt of BADH eDNA from Atriplex centralasiatica I i/in through RTCR (Reverse Transer i pt ion? Polymerase Chain Reaction). A 393 hp fragment was obtained, the sequence is very similar to the corresponding fragment of BADH eDNA of spinach and mountain spinach. The result of Southern blotting shows that the I3ADH gene may have only one copy. Northern blotting demonstrates that the level of BADH mRNA in the plant that had been treated by 250mM NaCI. .is 2 fold higher than the control 1)bfltS. it suggests t;hat the expression of BADI-l gene is induced by saline. Burthermore, using A EMBL3/Bam[II vector, A triplex cenlralasic,ticu I I/in genomic library was constructed, its titer is about 4 )( l0pfu/mi. The insertion fragment is about 16Kb. e genomic library will be used to screen the promoter of [3ADII gene.