ABSTRACT: Endogenous ABA regulates sucrose transport and starch synthesis to regulate grain filling of dimorphic seeds under water stress in Cleistogenes songorica
Project description:RNAi mediated suppression of MADS29 severely affects seed set; the surviving seeds are smaller in size with reduced grain filling, abnormal starch grains and aberrant embryo development. To identify the affected pathways due to suppression of this transcription factor in the transgenic seeds, transcriptome analysis using microarray was carried out.
Project description:Favorable grain filling ability is crucial for seed development and plant yield1, with less fertilizer applying is the most urgent goals to meet the growing demands of green and safe food. However, the balance mechanism between grain filling and nutrient elements is still unclear so far. Here, we describe a gene GAF1, specially expressed in endosperm aleurone layer, encoding a phosphate transporter, positively controls rice grain filling and seed development and also contributes to phosphate balance was mapped in our study. To study the regulation pattern of GAF1, we performed the RNA-seq analysis of NIL-GAF1 and NIL-gaf1 at middle grain filling stage in seeds. The data shows that many pathways related to starch and sugar metabolism were enriched, and many starch synthesis related genes and phosphate response genes were up-regulated or down-regulated. These data further support that seed specific expressed GAF1 plays a key role in regulating both phosphate homeostasis and seed development. More importantly, overexpression of GAF1 can significantly improve grain filling and thus yield enhanced plant production in field.
Project description:RNAi mediated suppression of MADS29 severely affects seed set; the surviving seeds are smaller in size with reduced grain filling, abnormal starch grains and aberrant embryo development. To identify the affected pathways due to suppression of this transcription factor in the transgenic seeds, transcriptome analysis using microarray was carried out. Three biological replicates of MADS29 RNAi (silencing) lines and Wild Type PB1 (control) plants were used for microarray study
Project description:Cereal crops accumulate starch in seeds as an energy reserve. Sucrose synthase (SuSy) plays an important role in grain starch synthesis. In this study, ZmSUS1 was transformed into maize inbred line KN5585, and transgenic plants were obtained. Compared with the control, the content and activity of SuSy were significantly increased, the amylose content in mature seeds of transgenic maize increased by 41.1-69.2%, the total starch content increased by 5.0-13.5%, The 100-grain weight increased by 19.0-26.2% and the average diameter of starch granules increased by 10.8-17.2%. These results indicated that overexpression of ZmSUS1 can significantly improve the traits of maize kernels and obtain new lines with high amylose content. It was also found that ZmSUS1 may increase the amylose content by regulating the expression of Shrunken2 (Sh2) and Brittle2 (Bt2) which encodes endosperm ADP-glucose pyrophosphorylase (AGPase) size subunits, and the expression of Granule bound starchsynthase1 (GBSS1) and Starch synthase1 (SS1) which encodes starch synthase. This study proved the important role of ZmSUS1 in maize starch synthesis, and provided a new technology strategy for improving corn starch content and yield.
Project description:Barley (Hordeum vulgare) is one of the major food sources for humans and forage source for animal livestock. Barley endosperm is structured into three distinct cell layers: the starchy endosperm, which acts essentially as storage tissue for starch, the subaleurone, which is characterized by a high accumulation of endoplasmic reticulum (ER)-derived seed storage proteins (SSP) and finally the aleurone beside the seed coat with a prominent role during seed germination. Prolamins account for more than 50% of the total protein amount in mature seeds. Together with other seed storage proteins (SSPs) they are important for both grain quality and flour quality. Prolamins are synthesized on the rough ER, translocated into the ER lumen and accumulate in distinct, ER-derived protein bodies (PBs) that are most abundant in the SE. PB formation is regulated by the protein disulfide isomerase (PDI) that is involved in the disulfide transfer pathway. Here, we used laser microdisection (LMD) to characterize spatio-temporal molecular and morphological differences of the ER during barley endosperm development. We revealed by nanoLC-MS/MS proteomic analyses performed on whole seeds and collected tissues at different seed development stages that the protein level of the protein disulfide isomerase HvPDIL1-1 is spatio-temporally regulated in developing barley endosperm. Our microscopic studies showed that HvPDIL1-1 preferentially accumulates in SE, especially at 12 days after pollination (dap). HvPDIL1-1 re-localized from PBs to the protein matrix at the periphery of starch granules along grain filling process. Detailed analysis of SE proteome dynamics identified clusters of proteins with similar expression pattern as HvPDIL1-1, which were analysed in a protein-protein network. It revealed a strong functional interconnection between transcription and translation, protein folding and amino acid synthesis with sucrose and starch metabolism. Our data indicate a role of HvPDIL1-1 in the coordination of protein synthesis and prolamins deposition during grain filling processes in developing barley endosperm. These results are discussed in relation to the putative role of HvPDIL1-1 for cereal food end-product quality and recombinant protein production in cereal seeds.
Project description:We study the expression level change of candidate genes associated with seed filling in maize, through RNA-seq for maize seeds in different filling stages. The results show that the change of the expression of these candidate genes would lead to the change of grain filling trajectory.
Project description:A heat and drought tolerant rice cultivar (N22) was grown in the field under control and drought conditions during the dry season in 2013. Drought was applied during early grain filling and resulted in simultaneous heat stress, leading to reduced grain yield and quality. Total RNA was extracted from developing seeds under stress and control (fully flooded) conditions and RNA-seq analysis was performed. These samples are a part of a bigger experiment analysing the responses of three contrasting rice cultivars (N22, Dular, Anjali) to combined heat and drought stress including different organs (developing seeds, flag leaves, flowering spikelets) and developmental stages (early grain filling, flowering) at the transcriptomic level.
Project description:OsNF-YB1 is a transcription factor that plays important roles during rice grain filling. OsNF-YB1 is specifically expressed in aleurone layer of developing endosperm and OsNF-YB1 RNAi lines showed retardation in grain filling and produced small grains with chalky endosperm as well as the altered starch quality. To reveal the transcriptional regulatory framework of OsNF-YB1, we determined OsNF-YB1 DNA binding targets using chromatin immunoprecipitation coupled to high-throughput sequencing (ChIP-Seq). ChIP-Seq analysis detected 933 binding peaks distributed 743 neighbor genes. OsNF-YB1 directly regulates genes involved in nutrient transport including sugar and amino acids, and interestingly, different from the reported binding site of NF-Y complex, the GCC-box (a binding motif of ERF transcription factors) was enriched in the binding peaks of OsNF-YB1.