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Existence of potent in vitro regeneration system is a prerequisite for efficient genetic transformation and functional genomics of crop plants. We know little about why only some cultivars in crop plants are tissue culture friendly. In this study, tissue culture friendly cultivar Golden Promise (GP) and tissue culture resistant DWRB91(D91) were selected as contrasting cultivars to investigate the molecular basis of regeneration efficiency. Multiomics studies involving transcriptomics, proteomics, metabolomics, and biochemical analysis were performed using GP and D91 callus to unravel the regulatory mechanisms. Transcriptomics analysis revealed 1487 differentially expressed genes (DEGs), in which 795 DEGs were upregulated and 692 DEGs were downregulated in the GP-D91 transcriptome. Genes encoding proteins localized in chloroplast and involved in ROS generation were upregulated in the embryogenic calli of GP. Moreover, proteome analysis by LC-MSMS revealed 3062 protein groups and 16989 peptide groups, out of these 1586 protein groups were differentially expressed proteins (DEPs). Eventually, GC-MS based metabolomics analysis also revealed the higher activity of plastids and alterations in key metabolic processes such as sugar metabolism, fatty acid biosynthesis, and secondary metabolism. Higher accumulation of sugars, amino acids and metabolites corresponding to lignin biosynthesis were observed in GP as compared to D91.Highlights:Multi omics analysis revealed chloroplast play crucial role in providing in vitro regeneration capability in contrasting genotypes

Rust fungi are plant pathogens that cause epidemics that threaten the production of important plant species, such as wheat, soy, coffee and poplar.Melampsora larici-populina(Mlp) causes the poplar rust and encodes at least 1 184 candidate effectors (CEs), however their functions are poorly known. In this study, we usedArabidopsisplants constitutively expressing CEs ofMlpto discover processes targeted by these fungal proteins. For this purpose, we sequenced the transcriptome and used mass spectrometry to analyse the metabolome ofArabidopsisplants expressing individually one of the 14 selected CEs and of a control line. We found 2 299 deregulated genes across the experiment. Among the down-regulated genes, the KEGG pathways “MAPK signaling pathway” and “Plant-pathogen interaction” were respectively over-represented in six and five of the 14 transgenic lines. Moreover, genes related to hormone response and defense were down-regulated across all transgenic lines are. We further observed that there were 680 metabolites deregulated in at least one CE-expressing transgenic line, with highly unsaturated and phenolic compounds enriched in up-regulated metabolites and peptides enriched among down-regulated metabolites. Interestingly, we found that transgenic lines expressing unrelated CEs had correlated patterns of gene and metabolite deregulation, while expression of CEs belonging to the same family deregulated different genes and metabolites. Taken together, our results indicate that the sequence of effectors and their belonging to families may not be a good predictor of their impact on the plant.ImportanceRust fungi are plant pathogens that threaten the production of important crops, including wheat, soy, coffee and poplar. Effectors are used by pathogens to control the host, however in the case ofMelampsora larici-populina, the causal agent of the poplar rust, and other rust fungi these proteins are poorly known. We usedArabidopsisplants expressing candidate effectors (CEs) ofMlpto better understand the interaction between this pathogen and its hosts. We found that expression of unrelated CEs led to similar patterns of gene and metabolite deregulation, while transgenic lines expressing CEs belonging to the same family showed different groups of different genes and metabolites deregulated. Thus, our results suggest that functional annotation of effectors based on sequence similarity may be misleading.

Rapid and reliable screening of SARS-CoV-2 is fundamental to assess viral spread and limit the pandemic we are facing. In this study we evaluated the reliability and the efficiency of a direct RT-QPCR method (without RNA extraction) using SeeGene Allplex™ 2019-nCoV RT-QPCR and the influence of swab storage media composition on further viral detection.We show that SeeGene’s assay provides similar efficiency as the RealStar® SARS-CoV-2 RT-PCR kit (Altona Diagnostics), and that RNA extraction is not necessary nor advantageous if samples are stored in UTM or molecular water but is recommended if samples are stored in saline solution and in Hanks medium.