Project description:Different wheat cultivars may be classified as either winter or spring varieties depending on whether they require exposure to an extended period of cold in order to become competent to flower. Using a growth regime that mimics the conditions that occur during a typical winter in Britain, we wished to survey the genes that are involved in phase transition as well as those involved in cold-acclimation. Keywords: Time course
Project description:MicroRNAs (miRNAs) are single strand small non-coding RNAs that regulate target mRNAs at post-transcription level. Winter wheat (Triticum aestivum L.), is an important crop plant all over the world. Long term cold exposure (vernalization) is necessary for winter wheat transition from vegetative growth to reproductive growth, yet the involvement of miRNAs in these stages remains unknown. Therefore, we performed next generation sequencing of small RNAs profiles in crown tissues at three-leaf stage, winter dormancy stage, spring greenup stage and jointing stage.
Project description:The SSU Processome (sometimes referred to as 90S) is an early stable intermediate in the small ribosomal subunit biogenesis pathway of eukaryotes. Progression of the SSU Processome to a pre-40S particle requires a large-scale compaction of the RNA and release of many biogenesis factors. The U3 snoRNA is a primary component of the SSU Processome and hybridizes to the rRNA at multiple locations to organize the structure of the SSU Processome. Thus, release of U3 is prerequisite for the transition to pre-40S. Our lab proposed that the RNA helicase Dhr1 plays a crucial role in the transition by unwinding U3 and that this activity is controlled by the SSU Processome protein Utp14. How Utp14 times the activation of Dhr1 is an open question. Despite being highly conserved, Utp14 contains no recognizable domains, and how Utp14 interacts with the SSU Processome is not well characterized. Here, we used UV crosslinking and analysis of cDNA (CRAC) and yeast two-hybrid interaction to characterize how Utp14 interacts with the pre-ribosome. Moreover, proteomic analysis of SSU particles lacking Utp14 revealed that the presence of Utp14 is needed for efficient recruitment of the RNA exosome. Our analysis positions Utp14 to be uniquely poised to communicate the status of assembly of the SSU Processome to Dhr1 and possibly to the exosome as well.
Project description:To explore transcriptional regulations in common wheat cultivars Norstar (NO), Manitou (MA), and the near-isogenic lines (NIL) spring Norstar (SN) and winter Manitou (WM) during seasonal cold acclimation.
Project description:Mitoribosomes are essential for synthesis and maintenance of bioenergetic proteins. Here, we use cryoelectron microscopy (cryo-EM) to determine a series of the small mitoribosomal subunit (SSU) intermediates in complex with auxiliary factors, revealing a sequential assembly mechanism. The methyltransferase TFB1M binds to partially unfolded rRNA h45 that is promoted by RBFA, while the mRNA channel is blocked. This enables METTL15 binding that promotes further rRNA maturation and a large conformational change of RBFA. The new conformation allows initiation factor mtIF3 to already occupy the subunit interface during the assembly. Finally, the mitochondria-specific ribosomal protein mS37 outcompetes RBFA to complete the assembly with the SSU:mS37:mtIF3 complex that proceeds towards IF2 binding and translation initiation. Our results explain how the action of step-specific factors modulate the dynamic assembly of the SSU, and adaptation of a unique protein mS37 links the assembly to initiation to establish the catalytic human mitoribosome.
Project description:Different wheat cultivars may be classified as either winter or spring varieties depending on whether they require exposure to an extended period of cold in order to become competent to flower. Using a growth regime that mimics the conditions that occur during a typical winter in Britain, we wished to survey the genes that are involved in phase transition as well as those involved in cold-acclimation. Experiment Overall Design: We wished to study the profiles of expression of genes involved in both phase transition (vegetative to reproductive growth transition) and cold-acclimation. To that end we we exposed plants to a gradual, stepped decline in both temperature and light. We sampled plants at three time points (3 weeks post-germination, 5 weeks post germination and 9 weeks post germination). We took samples from two separate tissues (crown and leaf) to se whether responses were different. We used two biological reps for each time point and tissue. Control plants were exposed to a delined in day-length and light intensity, but not in temperature.