The Correlation Analysis Of Transcriptome And Proteome In Rice Ribless Dl2 Mutant

Vascular bundles mainly exist in the root, stem and leaf,which play an important role in supplying water, inorganic nutrients, sugar and amino acid, and keeping the shape of the plant organs. Vein are the main manifestation of vascular bundles. It is well-known that higher plant leaves consist of veins, mesophyll and epidermis and are the main organ of photosynthesis. As the representative of monocotyledon, rice is no exception. We have known that leaf vascular differentiation and venation pattern plays a key role in transporting nutrients and keeping the plantshape, which is an important agronomic trait. In the past years, with the in-depth research of leaf vascular development, we find many rice mutants which have defects in leaf vascular development, such as the rice dl2 mutant which displays drooping leaf. However, the molecular mechanism about the regulation of leaf vascular specification and development remains unclear. Therefore, understanding of the regulation of leaf vascular specification in rice can help to improve rice production through developing new genetic or management strategies. Therefore, in-depth research about the molecular mechanism of vein development has important theoretical significance and practical application value.Our research materials come from the mutant dl2 of Indica rice varieties‘N45-2’, and we mainly investigate the differential expression of dl2 mutant from transcription and protein levels. The main research results are as follows:①Differential expression of transcripts between wild-type and dl2 mutant by digital gene expression analysis:There are 15882 differentially expressed genes in dl2 mutant. Howener, we use Q value ≥0.8 and the absolute value of log2 ratio ≥ 1 as the threshold to judge the significance of gene expression difference at P<0.05. Finally, 98 differentially expressed genes were identified, among which 48 genes were upregulated and 50 genes were down-regulated. To validate the expression pro?les obtained by DGE, 20 differentially expressed genes were selected and verified by q RT-PCR, and results showed that the expression levels of q RT-PCR was similar to the DGE data, so we can surely conclude that our DGE analysis is reliable.② Differential expression of proteins between wild-type and dl2 mutant revealed by i TRAQ analysis:Only proteins which were identi?ed by three or more peptides and had >1.6-fold change were considered to be differentially expressed proteins in dl2. A total of 141 proteins showed a signi?cant difference(P<0.05) in the comparison, with which 94 up-regulated and 47 down-regulated proteins in dl2 mutant compared to WT leaves.③The result of concordance between transcript and protein levels:1) We matched 141 of differentially expressed proteins(DEPs) with 98 of differentially expressed m RNAs(DEGs), andonly two genes were sorted according to the more stringent criteria.2) We then generated a second list correlating the 141 of differentially expressed protein with the cognate m RNAs according to the less stringent criteria(ratio≥2, no Q value), and we got a positive correlation of r = 0.35.3) Compared the differentially proteins with all expressed m RNAs, we got the correlation of r = 0.088.4) Compared all the expressed protein with all expressed m RNAs, we got the correlation of r = 0.081.In conclusion, the correlation between m RNA and protein levels are modest.④Ten candidate proteins were selected from the differential expression of proteins, and we successfully constructed four over-expression vectors, and named them 35S::DL,35S::P02, 35S::M07, 35S::H05, which were genetically tranformed into calli of dl2 mutant, respectively. At present we abtained 35S::DL positive transgenic plants.⑤m RNA levels of DL in 35S::DL transgenic lines were analyzed by q RT-PCR, and the results showed that the expression level of DL Gene obviously increased.