신제품 개발에 있어서 제품의 잠재적 고장모드를 줄이기 위한 설계 노력은 매우 중요하며 이를 위해서는 체계적이고 혁신적인 신뢰성프로그램을 적용하는 것이 반드시 필요하다. 기업에서 동시공학을 기초로 한 건전한 신뢰성프로그램에 포함된 주요활동으로는 DFR(Design for Reliability), 신뢰성검증 및 물리적 해석활동 등이 있으며, 이 중 DFR은 제품 개발을 지원하는 첫 번째 과학적 신뢰성활동이다. 본 연구는 브레이크패드의 신뢰성을 향상시키기 위

Soybean [Glycine max (L.) Merr.] have a variety of flower colors which are controlled by six different genes (W1,W2,W3,W4,Wm, and Wp). Among these genes, mutation in W3 gene causes near white flowers in the background of w4 genotype whereas the genotype W3w4 does purple throat flowers. Earlier studies showed that dihydroflavonol 4-reductase1 (DFR1) gene was closely linked to the flower color variants for W3 locus. In order to find out the W3 gene responsible for w3 phenotype, we first, studied the candidate gene Glyma14g07940 (DFR1) which is having 100% similarity with DFR probe sequence. Sequence analysis of DFR1 between W3 and w3 soybeans showed one base substitution in exon 6 of w3 mutant soybean resulting in one amino acid change in the amino acid sequence. However, comparison of amino acid sequences of DFR proteins from various crop plants showed that there is no functional change in the protein. Besides, the promoter analysis showed that, 311 bp of indel was traced in 5’-upstream promoter region of DFR1 gene in the w3 mutant. Here, we show that the near white or purple throat phenotypes in G. max is associated with existence or nonexistence of indel at 5’- upstream promoter region and low or high expression of DFR1, respectively. These results suggest that w3 phenotype may be caused by certain regulator of DFR1 gene located near or distant from DFR1 in G. max. In further study, we need to check the correlation between promoter indel with W3 expression level through GUS analysis.

Flavonoids including anthocyanins provide flower and leaf colors and other derivatives that play diverse roles in plant development and interactions with the environment and dihydroflavonol 4-reductase (DFR) is part of an important step in the flavonoid biosynthesis pathway of anthocyanins. This study characterized 12 DFR genes of Brassica rapa and investigated their association with anthocyanin coloration, cold and freezing tolerance in several genotypes of B. rapa. Sequences of these genes were analyzed and compared with DFR gene sequences from other species and a high degree of homology was found. Constitutive expression of them in several pigmented and non-pigmented lines of B. rapa showed a correlation with anthocyanin accumulation only for BrDFR8 and 9. Conversely, BrDFR genes also showed responses to cold and freezing stress treatment in B. rapa. BrDFRs were also shown to be regulated by two transcription factors, BrMYB2-2 and BrTT8, contrasting with anthocyanin accumulation and cold and freezing stress. Thus, the above results suggest the association of these genes with anthocyanin biosynthesis and cold and freezing stress tolerance and might be useful resources for development cold and/or freezing resistant Brassica crops with desirable colors as well. The findings presented here may also help explore the molecular mechanism that regulates anthocyanin biosynthesis and its response to abiotic stress at the transcriptional level in plants.

Inactivation of the gene (DFR-A) coding for dihydroflavonol 4-reductase (DFR) involved in the anthocyanin biosynthesis pathway results in a yellow bulb color in onion (Allium cepa L.) and three inactive alleles have previously been identified in onion. Additionally, three active and six inactive DFR-A alleles were newly identified from extensive analyses of diverse onion germplasm. Presently, a yellow mutant containing a 171-bp deletion in the promoter region was identified and designated DFR-APD. Critically reduced transcription of this mutant allele and perfect co-segregation with color phenotypes in segregating populations were observed. Another yellow mutant (DFR-A5’DEL) containing a 518-bp deletion covering exons 1 and 2, which played important roles in DFR function, was identified. Meanwhile, both 2-bp and 4-bp insertions in the coding region leading to creation of pre-mature stop codons were also identified and designated DFR-AGT and DFR-A2AT, respectively. A 1-bp substitution mutation (DFR-AK48N) changing a positively charged lysine residue into a neutral asparagine was identified. This lysine residue, a NADPH binding site, was strictly conserved in other species. In addition, insertion of a leucine residue around substrate binding sites and catalytic triad was identified in several yellow accessions and was designated DFR-ATTA. Phylogenetic analysis of DFR-A alleles showed that all inactive alleles were independently derived from four different active alleles. In addition, the close relatedness and diversity of DFR-A mutants implied that all these mutations might have occurred after domestication of onions and had probably been maintained by artificial selection.