The ability to control the timing of flowering is a key strategy for planning production in ornamental species such as azalea, however it requires a thorough understanding of floral transition. Floral transition is achieved through a complex genetic network and regulated by multiple environmental and endogenous cues. Dynamic changes between chromatin states facilitating or inhibiting DNA transcription regulate the expression of floral induction pathways in response to environmental and developmental signals. DNA methylation and histone modifications are involved in controlling the functional state of chromatin and gene expression.

Maritime pine (Pinus pinaster Aiton) grows in a range of different climates in the southwestern Mediterranean region and the existence of a variety of latitudinal ecotypes or provenances is well established. In this study, we have conducted a deep analysis of the transcriptome in needles from two P. pinaster provenances, Leiria (Portugal) and Tamrabta (Morocco), which were grown in northern Spain under the same conditions. An oligonucleotide microarray (PINARRAY3) and RNA-Seq were used for whole-transcriptome analyses, and we found that 90.95 % of the data were concordant between the two platforms. Furthermore, the two methods identified very similar percentages of differentially expressed genes with values of 5.5 % for PINARRAY3 and 5.7 % for RNA-Seq. In total, 6,023 transcripts were shared and 88 differentially expressed genes overlapped in the two platforms. Among the differentially expressed genes, all transport related genes except aquaporins were expressed at higher levels in Tamrabta than in Leiria. In contrast, genes involved in secondary metabolism were expressed at higher levels in Tamrabta, and photosynthesis-related genes were expressed more highly in Leiria. The genes involved in light sensing in plants were well represented in the differentially expressed groups of genes. In addition, increased levels of hormones such as abscisic acid, gibberellins, jasmonic and salicylic acid were observed in Leiria. Both transcriptome platforms have proven to be useful resources, showing complementary and reliable results. The results presented here highlight the different abilities of the two maritime pine populations to sense environmental conditions and reveal one type of regulation that can be ascribed to different genetic and epigenetic backgrounds.

Gnomoniopsis castaneae Tamietti (syn. G. smithogilvyi L.A. Shuttleworth, E.C.Y. Liew and D.I. Guest) is the causal agent of chestnut rot disease (Visentin et al. 2012). It has recently become known for being responsible for wood cankers on sweet chestnut, similar those caused by Cryphonectria parasitica on twigs and scions of sweet chestnut (Seddaiu et al. 2017). In November 2016, three samples of hybrid plants C. sativa x C. crenata showing chestnut blight symptoms such as bark coloration, were collected in a nursery in Asturias, northern Spain. Symptomatic branches were surface-sterilized in 98% ethanol for 30 s and dried on sterilized tissue paper, plated on potato dextrose agar (PDA) and incubated at room temperature with amnatural photoperiod (about 11 h light, 13 h dark). Fungal colonies different from C. parasitica were consistently isolated from affected bark after 5 days of incubation in two of the samples. Colonies were transferred on PDA and next incubated at 25º C with a natural photoperiod (1...

Pinus pinaster is a plant species of great ecological and economic importance. Understanding the underlying molecular mechanisms that govern the growth and branching of P. pinaster is crucial for enhancing wood production and improving product quality. In this study, we describe a simple methodology that enables the discovery of candidate genes in Pinus pinaster by transferring existing knowledge from model species like Arabidopsis thaliana and focusing on factors involved in plant growth, including hormonal and non-hormonal pathways. Through comparative analysis, we investigated the main genes associated with these growth-related factors in A. thaliana. Subsequently, we identified putative homologous sequences in P. pinaster and assessed the conservation of their functional domains. In this manner, we can exclude sequences that, despite displaying high homology, lack functional domains. Finally, we took an initial approach to their validation by examining the expression levels of these genes in P. pinaster trees exhibiting contrasting growth patterns. This methodology allowed the identification of 26 candidate genes in P. pinaster. Our findings revealed differential expression patterns of key genes, such as NCED3, NRT1.2, PIN1, PP2A, ARF7, MAX1, MAX2, GID1, AHK4, AHP1, and STP1, in relation to the different growth patterns analyzed. This study provides a methodological foundation for further exploration of these genes involved in the growth and branching processes of P. pinaster. This will contribute to the understanding of this important tree species and open new avenues for enhancing its utilization in sustainable forestry practices.