Project description:A T-DNA insertion within RBP-L 3’UTR resulted in 10-25% expression level of RBP-L gene compared to wild-type. The reduced expression of RBP-L caused partial mis-localization of glutelin and prolamine RNAs and conferred other general growth defects including dwarfism, late flowering and smaller seeds. Transcriptome analysis showed that RBP-L knockdown greatly affected the expression of prolamine family genes and many genes invovled in essential biological pathways during plant development.
Project description:Two RBP-P mutants, P1MH and P3MH, carrying G401S and A252T point mutations, respectively, were obtained by TILLING studies (http://www.shigen.nig.ac.jp/rice/oryzabase). The A252T mutation site in P3MH lies within the linker sequence between the two RRM domains while the G401S substitutions in P1MH is located in the glycine-rich C-terminal region. Those mutations results in varying degrees of reduced RNA binding and/or protein-protein interactive properties of RBP-P. Transcriptome analysis on the dehulled 10-14 days old developing seeds from wild type, P1MH and P3MH mutants indicates that partial loss of RBP-P function caused the differential expression of storage protein genes and relevant genes involved in several essential biological processes during rice development.
Project description:Arsenic (As) contamination of rice grains affects millions of people worldwide. In this study, we found that sulfur application (20As+120S) decreased As concentration in rice grains by 44 % compared to grains without sulfur application (20As+0S). Importantly, sulfur application decreased arsenate [As(V)] and arsenite [As(III)] concentration in rice grains significantly, while there was no significant effect on dimethylarsenate (DMA) concentration. To elucidate the molecular basis of As accumulation in rice grains, we performed Illumina sequencing to acquire the differentially expressed genes induced by arsenate and sulfur treatments. By contrast with the control, the expression of 1,000 genes was found to be changed significantly, with 46 genes up-regulated and 954 genes down-regulated in grains grown in arsenate-contaminated soil (20As+0S). Between samples of control and arsenate together with sulfur treatment (20As+120S), 1,169 genes expressed significantly differently, with 16 genes up-regulated and 1,153 genes down-regulated. Sulfur application significantly changed the expression of genes involved in As metabolism in rice grains, significantly down-regulated phosphate transporter gene OsPT23 and aquaporin gene OsTIP4;2, while ABC transporter genes (OsABCG5, OsABCI7_2 and OsABC6) and phytochelatin synthase genes (OsPCS1, OsPCS3 and OsPCS13) were up-regulated. These results provide an insight into the molecular basis of how sulfur assimilation regulates As accumulation in rice grains.
Project description:High temperature markedly reduces the yields and quality of rice grains. To identify the mechanisms underlying heat stress-induced responses in rice grains, proteomic technique was used. Khao Dawk Mali 105 rice grains at the milky, doughy, and mature stages of development after flowering were treated at 40 °C for 3 days. Aromatic compounds were decreased in rice grains under heat stress. The protein abundance involved in glycolysis and tricarboxylic acid cycle, including glyceraldehyde 3-phosphate dehydrogenase and citrate synthase, was changed in milky and doughy grains after heat treatment; however, no changes in mature grains. The abundance involved in amino acid metabolism was increased in doughy grains, but decreased in milky grains. In addition, the abundance involved in starch and sucrose metabolism, such as starch synthase, ADP-glucose pyrophosphorylase, granule-bound starch synthase, and alpha amylase, was decreased in milky grains, but increased in doughy grains. A number of redox homeostasis-related proteins, such as ascorbate peroxidase and peroxiredoxin, were increased in developing rice grains treated with heat stress. These results suggest that in response to heat stress, the abundance of numerous proteins involved in redox homeostasis and carbohydrate biosynthetic pathways may play a major role in the development of KDML105 rice grains.
Project description:We performed Illumina sequencing to acquire the differentially expressed genes induced by arsenate and sulfur treatments. We found that sulfur (S) application reduced As concentration of rice grains harvested at 20 days after anthesis (DAA). By contrast with the control, the expression of 1001 genes were found to be significantly changed, 46 genes up-regulated and 954 genes down-regulated in the 20As grains. 1169 genes expressed significantly differently between the samples of control and 20As+120S, with 16 genes up-regulated and 1153 genes down-regulated. Among the differentially expressed genes (DEGs) regulated by As and S treatment, there were 10 DEGs encoding phosphate transporter, and 24 DEGs encoding aquaporin transporter. Some genes involved in As detoxification, such as ABC transporter, glutathione S-transferase and phytochelatin synthase were up-regulated by sulfur treatment. The results provide an insight into the molecular basis of how sulfur application regulates As accumulation in rice grains. Arsenic (As) was artificially added to soil with 20 mg/kg As (Na2AsO4.12H2O, 20As), another treatment was 20As+120S, sulfur (S) were supplied artificially with 120 mg/kg (Na2S2O3•5H2O) to the As-added soil (20As+120S).
Project description:We aimed to identify targets of miRNAs during wheat grain development by using degradome sequencing approach. Two degradome libraries were constructed from wheat grains. Verification of miRNA targets from two degradome libraries in developing wheat grains.
Project description:Endogenous small RNAs, including microRNAs (miRNAs) and short-interfering RNAs (siRNAs), function as posttranscriptional or transcriptional regulators in plants. miRNA function is essential for normal development and therefore likely to be important in the growth of the rice grain. To investigate the likely roles of miRNAs in rice grain development we carried out deep sequencing of the small RNA populations of rice grains. A total of 96,091 (including 23,867 reads from vegetative tissues) and 5,379,724 small RNA sequences that are longer than 17nt were generated. Approximately 94% of these small RNAs were 20-24nt in length. The majority of the small RNAs were singletons, indicating that rice genome has a very complex small RNA population, which is harder to be saturated. From these smal RNA sequences we found representatives of all 20 conserved plant miRNA families and evidence for changes in expression of miRNAs during rice grain development. Using an approach based on the presence of the miRNA and miRNA* sequences, we identified 51 novel, non-conserved rice miRNA families expressed in grains with functionally diverse predicted target genes. miRNA-guided cleavage was confirmed for a number of targets genes including ones with roles in sugar signalling and restoration of cytoplasmic male sterility. We identified a likely mirtron, indicating that plants can also use spliced introns as a source of miRNAs. Our sequencing results revealed four TAS3 loci; these all contain dual miR390 sites of which only the 3? site is cleaved. We also found a miRNA-like long hairpin generating phased 21nt small RNAs, strongly expressed in developing grains and show that these small RNAs act in trans to cleave target mRNAs. Keywords: high throughput pyrosequencing, small RNA, microRNA, grain development, rice