Cloning And Analysis Of ZmVPP1 And ZmCRY1 Gene Related To Salt And Drought Tolerance In Maize (Zea Mays L.)

Maize is one of the most important cereal crops in the world, which production is limited under abitotic stresses like drought and salt. Cloning genes related to stress tolerence in maize not only shows theoretical meanings, but also benefits to practical application, providing potential candidate genes for improving stresses torlerance by genetic transformation in maize.Plant vacuolar pyrophosphatase is tonoplast membrane binding protein. It can decompose pyrophosphate and transport H+ into the vacuole. So it establish a transmemberane H+ gradient as an energy source of Na+/H+ antiporter. Overexpression of Arabidopsis AVP1 can improve plant salt tolerance and drought tolerance. So far, the VPP gene has been cloned in a variety of plant. Previous studies focused on the changes of physiological activity of pyrophosphatase and other physiological indicators under stress condition, but the tissue-specific expression and the promoter of VPP analysis in maize have not been reported. Plants cryptochrome (CRY) is a blue light receptor. Studies have shown that it can adjust hypocotyl elongation, and improve the ability of resistance to deep-seeding. So it maybe improve plant drought tolerance.Here, we isolated ZmVPP1 in maize and analized its expression profiles and fuctions. Then, we cloned completely cDNA of ZmVPP1 gene from maize through in silico cloning and made bioinformatics analysis.The main results were as follows.1. Cloning and sequence analysis of ZmVPP1 geneThe full length cDNA of ZmVPP1 was obtained by using homology cloning method, while the DNA of ZmVPP1 and the promoter region, 2200bp upstream of ATG initiation codon, was obtained from Maize Genetics and Genomics Database. It belonged to H_PPase superfamily (GenBank Number is cl11452). A promoter motif search of this region showed that there were motifs related to low temperature, abscisic acid, salicylic acid, jasmonic acid and others.2. Expression analysis of ZmVPP1 gene in maizeZmVPP1 was mainly expressed in mature leaves of maize but minor in the reproductive organs under normal growth conditions. ZmVPP1 was induced by dehydration, PEG, salt, low temperature and other conditions, but not by ABA. 3. Over-expression of ZmVPP1 in ArabidopsisThe over-expression vector 35S:3301-ZmVPP1 has been constructed and successfully transformed into Arabidopsis mediated by GV3101. Ten positive transformants have been obtained by PPT screening, and has been identified by PCR.4. In silico cloning of ZmCRY1 gene and bioinformatics analysisThe full length cDNA of ZmCRY1 gene was obtained through in silico cloning method. The results of bioinformatics analysis show that it encodes 699 amino acids and belongs to blue light receptor family, and showed high identity with other CRY in plant.