The Sequence Analysis Of Genes Related To Drought Stress Tolerance And Study On Their Applications In Maize

The sequence analyses were done about 9 groups of drought-resistant genes with about 1000 sequences related to osmoregulation and active oxygen metabolism in different organisms using bioinformatic tools. Based on the characteristics of these known drought-resistant genes, the possible drought-resistant genes in maize were explored, and then silicon cloning and further sequence analyses were conducted. The cloning, transfer, and expression of these new genes and their application in maize were also studied. The main results were as follows.1. The sequence composition and molecular weight of drought-tolerant genes are related not only to their functions but also to their original organisms. There are more differences among genes from the same origin with different functions than those from different origins with the same function. The lengths of mRNA and amino acids (AA) are similar in genes in from different organism with the same function and become longer from bacterium to plant to animal. The organisms with closer relative have the less difference in the length and these characteristics are strongly showed in higher organisms. The molecular weights of these genes and proteins vary, depending on the length. There are differences in G+C amounts among genes with different functions in the same species and among genes with the same function in different species. Bacteria could be divided into two groups, one containing genes with higher G+C content and the other one with lower G+C content. The G+C content in most animal genes is higher than that in plants. Other species have the opposite trends.2. The compositions of AA sequences in drought tolerance genes are strong consistency. In most drought tolerance genes, Ala and Leu have the highest content in the amino acids, and reach up to 9%. But Gly is of the highest content in Cu-SOD genes with an average content of 17.20%. Amino acids with the lowest content are Trp and Cys, and lower than 1% in most of genes. In most drought tolerance species, the contents of Ala, Gly, Ile, Leu, Ser and Val are considerably high, reaching up to 6%; the contents of Met, Tyr and His are considerably low, and are less than 2%. The contents of other amino acids are consistent with each other in the same group of genes, but vary a lot in different groups of genes.3. The preference of codon usage is various among genes or among organisms. The...