The environmental conditions regulate plant growth and development. Here the impact of environment on BPM1 protein stability and the role of BPM1 in flowering time and abiotic stress is presented.

Most Croatian indigenous grapevine cultivars and vineyards are infected with a few dominant viruses. The goal of this study was to establish somatic embryogenesis as an efficient method for virus elimination from valuable Croatian cultivars and creating a reliable source of healthy plants. Somatic embryogenesis was induced from immature anthers and somatic embryogenesis-derived plantlets for seven indigenous cultivars were successfully regenerated. This procedure led to the elimination of viruses GFLV, GLRaV-1, GLRaV-3 and GFkV that were initially detected in the field-grown cultivars ‘Plavac mali’ and ‘Babica’ with an elimination success of at least 30%. The described method has the potential for production of virus-free rooted plantlets for all economically important cultivars or superior cultivar clones and for the establishment of a steady source of certified virus-free planting material.

During plant embryogenesis, regardless of whether it begins with a fertilized egg cell (zygotic embryogenesis) or an induced somatic cell (somatic embryogenesis), significant epigenetic reprogramming occurs with the purpose of parental or vegetative transcript silencing and establishment of a next-generation epigenetic patterning. To ensure genome stability of a developing embryo, large-scale transposon silencing occurs by an RNA-directed DNA methylation (RdDM) pathway, which introduces methylation patterns de novo and as such potentially serves as a global mechanism of transcription control during developmental transitions. RdDM is controlled by a two-armed mechanism based around the activity of two RNA polymerases. While PolIV produces siRNAs accompanied by protein complexes comprising the methylation machinery, PolV produces lncRNA which guides the methylation machinery toward specific genomic locations. Recently, RdDM has been proposed as a dominant methylation mechanism during gamete formation and early embryo development in Arabidopsis thaliana, overshadowing all other methylation mechanisms. Here, we bring an overview of current knowledge about different roles of DNA methylation with emphasis on RdDM during plant zygotic and somatic embryogenesis. Based on published chromatin immunoprecipitation data on PolV binding sites within the A. thaliana genome, we uncover groups of auxin metabolism, reproductive development and embryogenesis-related genes, and discuss possible roles of RdDM at the onset of early embryonic development via targeted methylation at sites involved in different embryogenesis-related developmental mechanisms.

Increases in environmental temperature are directly linked to the issue of climate change and are known to significantly disrupt plant growth and development. Studies of gene expression in plants commonly include RT‐qPCR but the reliability of the method depends on the use of suitable reference genes for data normalization. Despite this, no reference genes have been validated specifically for experiments in Arabidopsis thaliana employing treatments with elevated temperature. Here, ten genes were selected for expression stability analysis based on the screening of available literature and microarray data from temperature‐treated A. thaliana. Expression levels of candidate reference genes were measured in 12‐day‐old seedlings, rosette leaves and flower buds of 5‐week‐old A. thaliana plants exposed to five different temperatures (22°C, 27°C, 32°C, 37°C and 42°C) and their expression stabilities were assessed using four statistical algorithms (BestKeeper, geNorm, NormFinder and comparative ΔCq method). This study provides reliable reference genes for use in A. thaliana RT‐qPCR expression analyses employing elevated temperature treatments, namely OGIO and PUX7 in seedlings, UBC21 and PUX7 in leaves, TIP41 and UBC21 in buds, and TIP41 and UBC21 in all three tissues combined. Orthologues of these genes can be of potential use in less studied plants, especially agricultural species heavily affected by climate change.

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