| Wheat is the main food crop for human beings.Improving the yield is an urgent problem as explosive growth of population and limited arable land.Dwarf gene is the key gene of high yield breeding.At present,there is a lack of research on dwarf genes in tetraploid wheat and the utilization of dwarf genes in breeding is limited.ANW16 G is a durum wheat carrying dwarf gene Rht 18,which is an important tetraploid dwarf gene resource.To date,the dwarfing mechanism of Rht 18 gene is not clear.Understanding the dwarfing mechanism of Rht 18 will be helpful for the further utilization of Rht 18 gene,which has practical significance for wheat breeding and production.In this study,tetraploid dwarf wheat(ANW16G)and its near isogenic line(LD222)were used as experimental materials.Metabonomics was studied by LC-MS and GCMS techniques.It is expected that the metabolites and metabolic pathways related to stem-node differentiation and stem-node elongation will be screened out in order to lay a foundation for explaining the dwarf mechanism of Rht18 gene and to provide a new perspective for elucidating the molecular mechanism of wheat dwarfing.It has certain significance for guiding wheat breeding and increasing yield.The main research results are as follows:1.There are nine categories of metabolites,including amino acids,sugars,nucleotides,organic acids,fatty acids,phosphoric acids,amines,polyols and others.A total of 55 different metabolites were screened based on P?0.05 and VIP>1,as well as the interactive permutation model.Under the condition of VIP>1.5,23 differential metabolites were screened.2.For the comparison group of RH-1 vs LD-1 and RH-2 vs LD-2,the unique differential metabolites were 33 and 23,respectively,which were differentially expressed at the stem node at jointing stage and the first stem node at heading stage,respectively.These metabolites were associated with stem node differentiation and stem node elongation,respectively.There were 11 different metabolites,which were related to stem node differentiation and stem node elongation.There were 11 different metabolites,which were related to stem node differentiation and stem node elongation,and jointly participated in plant height morphogenesis of dwarf wheat AMW16 G and high-stem control LD222.For the the comparison group of RH-1 vs RH-2 and LD-1 vs LD-2,there were 39 and 26 unique differential metabolites,which played an important role in the height morphogenesis of dwarf wheat and high stem wheat LD222,respectively.There were 23 different metabolites,which were co-involved in the plant height morphogenesis of dwarf and high-stalk wheat.Six differentially expressed metabolites were screened in all comparison groups,among which there were only three metabolites with VIP value greater than 1.5.They were ferulic acid,citric acid and ribose.Whether dwarf wheat or tall control,the contents of ferulic acid and citric acid were higher at jointing stage,but lower in heading stage,indicating that ferulic acid and citric acid mainly played a role in elongation of stem node at heading stage.However,compared with high-stem wheat,the contents of ferulic acid and citric acid were higher in RH-1 and lower in LD-1 at the elongation stage,and they were down-regulated in RH-2 and up-regulated in LD-2 at the heading stage,which further indicated that these two metabolites were associated with plant dwarfing of dwarf wheat ANW16 G.3.In comparison group RH-1 vs RH-2,a total of 28 differential metabolites were annotated to 31 metabolic pathways,mainly involved in arginine and proline metabolism,aminoacyl biosynthesis metabolism,aspartic acid and glutamate metabolism,etc.Among the 28 different annotated metabolites,10 different metabolites were up-regulated,accounting for 35.71% of the total,and 18 showed down-regulation,accounting for 64.29% of the total.In the comparison group LD-1 vs LD-2,a total of 29 differential metabolites were annotated to 34 metabolic pathways,mainly involved in the biosynthesis of aminoacyl,valine,leucine and isoleucine,as well as the degradation of valine,leucine and isoleucine.Of the 29 differential metabolites annotated,23 showed up-regulation,accounting for 79.31%,and 6 showed downregulation,accounting for 20.69%.In the comparison group of the RH-1 vs LD-1,26 different metabolites were annotated to 36 metabolic pathways,which were mainly involved in the metabolism of alanine,aspartate and glutamate,and the biosynthesis of aminoacyl,etc.Among the 26 differential metabolites,19 were up-regulated,accounting for 73.08%,and 7 were down-regulated,accounting for 26.92%.In the comparison group RH-2 vs LD-2,a total of 9 different metabolites were annotated to 19 metabolic pathways,mainly involved in aminoacyl biosynthesis,and so on.Among the 9 differential metabolites annotated,2 were up-regulated,accounting for 22.22%,and 7 showed down-regulated,accounting for 77.78%.One common metabolic pathways were obtained in the four comparison groups,namely phenylpropyl biosynthesis,which was associated with plant dwarfing of dwarf wheat ANW16 G. |
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