The asymmetric phospha-Michael addition of dialkyl phosphite to α,β-unsaturated carbonyl compounds by using an azetidine-derived dinuclear zinc catalyst was described. The catalyst was proved to be general and efficient for a broad spectrum of enones and α,β-unsaturated N-acylpyrroles. A series of phosphonate-containing compounds were generated with excellent enantioselectivities (up to 99% ee) and chemical yields (up to 99%) under mild conditions without using additives. The products were obtained with more than 95% ee for 23 examples of α,β-unsaturated carbonyl compounds. A positive nonlinear effect was observed and the possible mechanism was proposed.
Using RT-PCR and rapid amplification of cDNA ends, two new full-length cDNAs of SAD (TaSAD1 and TaSAD2) were obtained from a hardiest winter wheat cultivar (Mironovskaya808). Sequence comparison analysis showed that the deduced amino acid sequences of TaSAD1 and TaSAD2 had high similarity to those of other reported SAD proteins. They were also different each other by some substitutions, insertions and/or deletions involving single amino acid residues or motifs. Based on evolution analysis, it was clear that all SAD genes from Poaceae were closer than those from other genus such as Arabidopsis, Glycine, Triadica, Brassica, Sesamum and Bassia. All SAD genes clustered into two major groups in Poaceae. Meanwhile, TaSAD1 and TaSAD2 were clustered into different groups. The tertiary structure prediction indicated that both TaSAD1 and TaSAD2 proteins were a compact globular protein and their model structures almost were the same.
Anthocyanins are ubiquitous in Compositae and MYB regulates the expression of DFR and plays an important role in anthocyanin synthesis. Here, the regulation pathway that MYB protein of subgroup 6 in Compositae promotes dihydroflavonol reductase (DFR) expression was analyzed and verified by yeast one-hybrid experiment in Saussurea medusa. The results of the branch model and site model analysis revealed that MYB gene underwent purification selection, and the motif of bHLH protein [DE]Lx(2)[RK]x(3)Lx(6)Lx(3))R and anthocyanin-related motif ANDV underwent strong purification selection during evolution. DFR promoter analysis showed that there are MYB binding site (GAGTTGAATGG) and bHLH binding site (CANNTG) at the sense strand of 84–116 nucleotide residues from the start codon, and the two motifs are separated by 9–10 nucleotide residues, and this rule exists in DFR promoters of many Compositae plants. Yeast one-hybrid experiment proved that SmMYB1 can activate the promoter of SmDFR. Our results provide a reference for further functional studyof DFR gene in Compositae.
Anthocyanins are ubiquitous in Compositae and MYB regulates the expression of DFR and plays an important role in anthocyanin synthesis. Here, the regulation pathway that MYB protein of subgroup 6 in Compositae promotes dihydroflavonol reductase (DFR) expression was analyzed and verified by yeast one-hybrid experiment in Saussurea medusa. The results of the branch model and site model analysis revealed that MYB gene underwent purification selection, and the motif of bHLH protein [DE]Lx(2)[RK]x(3)Lx(6)Lx(3))R and anthocyanin-related motif ANDV underwent strong purification selection during evolution. DFR promoter analysis showed that there are MYB binding site (GAGTTGAATGG) and bHLH binding site (CANNTG) at the sense strand of 84–116 nucleotide residues from the start codon, and the two motifs are separated by 9–10 nucleotide residues, and this rule exists in DFR promoters of many Compositae plants. Yeast one-hybrid experiment proved that SmMYB1 can activate the promoter of SmDFR. Our results provide a reference for further functional studyof DFR gene in Compositae.
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