EC Number   |
General Information |
Reference |
|---|
   5.4.99.30 | evolution |
the Nicotiana tabacum UAM gene family consists of four members |
748489 |
| 5.4.99.30 | evolution |
the UAM gene family has three members in Oryza sativa |
748926 |
| 5.4.99.30 | malfunction |
Arabidopsis lines with reduced RGP1 and/or RGP2 expression are deficient in cell wall L-arabinose and exhibit severe developmental defects |
730599 |
| 5.4.99.30 | malfunction |
OsUAM3-knockdown plants grow normally, but show abnormal phenotypes in reproductive tissues, especially in terms of the pollen cell wall and exine. Pollen formation is abnormal in OsUAM3-KD plants, and KI-I2 staining for starch content shows that OsUAM3-KD pollen is abnormal and accumulates little starch. Low levels of arabinan in OsUAM3-KD pollen grains |
748926 |
| 5.4.99.30 | malfunction |
RNAi is used to downregulate OsUAM gene expression. This leads to a reduction of between 6 and 44% in the amounts of arabinofuranose in the cell wall, a decrease in the extent of substitution of the xylan backbone, and a reduction of between 25% and 80% in the ferulic acid or p-coumaric acid contents of the wall. Transgenic rice plants with a >25% reduction in arabinose content are dwarfed and infertile |
730565 |
| 5.4.99.30 | malfunction |
RNAi mutants of isozyme BdRGP1 result in large alterations in cell wall carbohydrate composition with significant decreases in cell wall arabinose content but with minimal change in plant stature. Real-time PCR analysis indicates that gene expression levels for BdRGP1, BdRGP2, and BdRGP3 are reduced in RNAi-RGP1 plants to 15-20%of controls. Cell wall arabinose content is reduced by 23-51%of control levels. No alterations in cell wall xylose and glucose content are observed. Corresponding decreases in cell wall ferulic acid and ferulic acid-dimers are observed. Additionally, cell wall 4-coumarates are decreased. The cell wall decrease in 4-coumarates corresponds to arabinose-coupled 4-coumarates. Xylanase-mediated digestibility of RNAi-RGP1 Brachypodium cell walls results in a near 2fold increase of released total carbohydrate. Cellulolytic hydrolysis of cell wall material is inhibited in leaves of RNAi-RGP1 mutants |
747867 |
| 5.4.99.30 | malfunction |
the NtUAMKD mutant, with all four isozymes knocked out, shows abnormal leaf development in the form of a callus-like structure and many holes in the leaf epidermis. A clear reduction in the pectic arabinan content is observed in the tissue of the NtUAM-KD leaf. The arabinose/xylose ratio in the xyloglucan-rich cell wall fraction is drastically reduced in NtUAM-KD |
748489 |
| 5.4.99.30 | more |
three-dimensional structure modeling of isozyme UAM1 |
747199 |
| 5.4.99.30 | physiological function |
isozyme OsUAM3 has a different function from that of isozymes OsUAM1 and OsUAM2i, sozyme UDP-arabinopyranose mutase 3 is required for pollen wall morphogenesis in Oryza sativa. L-Arabinose is one of the main constituents of cell wall polysaccharides such as pectic rhamnogalacturonan I, RG-I, glucuronoarabinoxylans and other glycoproteins. It is found predominantly in the furanose form rather than in the thermodynamically more stable pyranose form. UDP-L-arabinofuranose (UDP-Araf), rather than UDP-L-arabinopyranose (UDP-Arap), is a sugar donor for the biosynthesis of arabinofuranosyl (Araf) residues. UDP-arabinopyranose mutases (UAMs) interconvert UDP-Araf and UDP-Arap and are involved in the biosynthesis of polysaccharides including Araf |
748926 |
| 5.4.99.30 | physiological function |
the enzyme is involved in cell wall carbohydrate biosynthesis, the cell wall composition has a complex effect on digestibility of grass plants |
747867 |
