| Maize is an important foodstuff and fodder crops, and is also an more contributions about the genetics and breeding theory and technical. With the molecular biotechnology innovation and further improve, and the maize genome sequencing completed, functional genomics research has become a main theory basic which created corn germplasm resource and molecular breeding. Mutants are the most strait-forward and efficient materials to discover new genes and study gene functions. Mutator(Mu)elements are endogenous transposons with the highest transposition activity and Mutagenic ability, which has more easily obtained Mutagenic Mutant. It was an important strategy to carry out gene function research in maize functions genomics based on this material (transposon tagging).Photosynthesis is the basis of yield formation, and is the determining factor light energy utilization conversion of efficiency, is closely correlated determined by the chlorophyll content of leaves color variations. Leaf albino is leaf color variation extreme traits that was the ideal material related with leaf color variation relevant theoretical research, which could conduct chlorophyll (Chlorophyll, Chl) synthesis and decomposition, cell kernel cytoplasm interaction and photomorphogenesis etc. This research depended on establishing Mu-mediated mutagenesis mutant library, and this population were generated from seeds of crosses between the high active autonomous transposon elements MuDR donor parents(W22∷Mu)and the recipient parents Z31. Then we screened obviously Mutant phenotype and isolated flanking sequences of mutant phenotype, then we erected corresponding relation between Mutant phenotype and genes, at the same time we further analyzed albino mutation. Our results are mainly as follows:1. Constructed a large mutant library had more 1 500 mutant plants. The mutant plants major types included leaves mutations, important agronomic traits mutant, male and female ear mutations, seeds mutations and other mutations.2. The normal plants were self-pollinated to obtain M4 families that had 189 lines and 3 780 plants for screening albino mutations in the M3 family found albino mutation. We found 32 lines with leaf color phenotype, a total of 141 plants. In M4 families, the albino green degree of chlorophyll (SPAD value) relative value was 0, while SPAD values of the yellow and normal green plants were respectively 12.3 and 42.5. Chlorophyll content showed that chlorophyll content has decreased significantly between mutations and normal plants.3. All 41 albino seedlings were used for Mu-TAIL-PCR to obtain flanking sequences. Then we obtained 105 flanking sequences, among them the 35 flanking sequence were Mutator transposon elements, among which 15 sequences about 400~900 bp were non-redundant and bioinformatics analyzed. Bioinformatics analyzed 35 flanking sequences of contain MuTIR, DNA sequence alignment results revealed that 8 flanking sequences was multi-copy in the genome but 27 flanking sequences was single-copy. After removing duplicate sequences, 15 non-redundant flanking sequences insertion sites distribute in maize genome. Alignment 15 target sites found they have no homology and insertion sites vary widely distributed in 8 chromosomes among 10 chromosomes. 14 flanking sequences located in interior genes, 1flanking sequence was far from gene coding region, which showed that Mu elements could have specificity insertion into interior genes.4. Further BLAST analyzed 14 non-redundant Mu factor insertion into the target genes by Maizesequence, we discovered that related to electron transfer, protein synthesis, protein transport and localization, signal transduction, energy metabolism, and other physiological biochemical processes. In addition, some gene or protein functions were assumed or unknown. In the 15 non-redundant flanking sequence, there were six sites may be related to chlorophyll synthesis, and participated in five reactions or pathways chlorophyll synthesis and metabolic. |
PDF Full Text Request