Project description:The degree of yellowing in tobacco leaves is an important indicator for determining the maturity and harvesting time of tobacco leaves. Reduction in chlorophyll is of utility for promoting the concentrated maturation of tobacco leaves and achieving mechanised harvesting and mining, and utilising tobacco yellow leaf regulatory genes is of great significance for the selection and breeding of tobacco varieties suitable for mechanised harvesting and the resolution of the molecular mechanisms controlling leaf colouration. In this study, the phenotypes of the yellow-leaf K326 and K326 varieties were analysed, and it was observed that the yellow-leaf K326 variety exhibited a distinct yellow leaf phenotype with a significant reduction in chlorophyll content. Subsequently, using a combination of BSA-seq, transcriptomic sequencing (RNA-seq), and proteomic sequencing approaches, we identified the candidate gene Nitab4.5_0008674g0010 that encodes dihydroneopterin aldolase as a factor associated with tobacco leaf yellowing. Finally, by measuring the folate content in K326 and Huangye K326, the folate content in Huangye K326 was observed to be significantly lower than that in K326, thus indicating that folate synthesis plays a crucial role in phenotypic changes in tobacco yellow leaves. This study is the first to use BSA-seq combined with RNA-seq and proteomic sequencing to identify candidate genes in tobacco yellow leaves. The results provide a theoretical basis for the analysis of the mechanism of tobacco yellow leaf mutations.
Project description:Primary objectives: The primary objective is to investigate circulating tumor DNA (ctDNA) via deep sequencing for mutation detection and by whole genome sequencing for copy number analyses before start (baseline) with regorafenib and at defined time points during administration of regorafenib for treatment efficacy in colorectal cancer patients in terms of overall survival (OS).
Primary endpoints: circulating tumor DNA (ctDNA) via deep sequencing for mutation detection and by whole genome sequencing for copy number analyses before start (baseline) with regorafenib and at defined time points during administration of regorafenib for treatment efficacy in colorectal cancer patients in terms of overall survival (OS).
Project description:1. Comparison of two near isogenic lines between which the genome differs only for the region of the leaf-yellowing QTL Y3-4 on chromosome III.<br> Experiment description: <br><br> The lines HIF404-Sha and HIF404-Bay were grown on 3 mM nitrate in growth chamber according to Loudet et al . (2002, TAG 104:1173-84) until phenotypic yellowing symptoms differed between them. Plants were collected 49 days after sowing.<br><br> 2. Comparison of sugar effect on the leaf senescence progress using three RIL from the Bay-0 x shahdara population that exhibited differential leaf yellowing symptoms.<br> Experiment description: The recombinant inbred lines RIL310 (hypersenescing and early-senescing), RIL232 (early--senescing) et RIL045 (late-senescing) were grown in petri dishes (4,7 mM Nitrogen, with (LNG) or without (LN) glucose 2% until some difference of Fv/Fm trait can be observed (Wingler et al. 2004, New Phytol, 161 : 781-789). Growth experiments were performed in A. Wingler lab, University College of London.
