Catalpa bungei is an economically important tree with high-quality wood and highly valuable to the study of wood formation. In this work, the xylem microstructure of C. bungei tension wood (TW) was observed, and we performed transcriptomics, proteomics and Raman spectroscopy of TW, opposite wood (OW) and normal wood (NW). The results showed that there was no obvious gelatinous layer (G-layer) in the TW of C. bungei and that the secondary wall deposition in the TW was reduced compared with that in the OW and NW. We found that most of the differentially expressed mRNAs and proteins were involved in carbohydrate polysaccharide synthesis. Raman spectroscopy results indicated that the cellulose and pectin content and pectin methylation in the TW were lower than those in the OW and NW, and many genes and proteins involved in the metabolic pathways of cellulose and pectin, such as galacturonosyltransferase (GAUT), polygalacturonase (PG), endoglucanase (CLE) and β-glucosidase (BGLU) genes, were significantly upregulated in TW. In addition, we found that the MYB2 transcription factor may regulate the pectin degradation genes PG1 and PG3, and ARF, ERF, SBP and MYB1 may be the key transcription factors regulating the synthesis and decomposition of cellulose. In contrast to previous studies on TW with a G-layer, our results revealed a change in metabolism in TW without a G-layer, and we inferred that the change in the pectin type, esterification and cellulose characteristics in the TW of C. bungei may contribute to high tensile stress. These results will enrich the understanding of the mechanism of TW formation.

Stone fruits (Prunus spp.) occupy a pivotal position in global fruit production due to their significant nutritional profile and distinctive organoleptic characteristics. Contemporary orchard systems are undergoing transformation through innovative cultivation approaches, notably high-density dwarfing systems, greenhouse cultivation, agri-tech integration, and simplified management. As a crucial agronomic component in modern stone fruit cultivation, rootstock systems confer multi-benefits including enhanced environmental resilience, improved scion productivity, superior fruit quality, controlled vigor, and dwarfing capacity. While the majority of European apple orchards have transitioned to dwarfing rootstock systems, achieving substantial gains in productivity and profitability, stone fruit cultivation lags significantly due to the key gaps in prunus rootstock development, including genetic complexity, extended evaluation cycles, clonal propagation barriers, and limited research programs. Urgent innovation is required to address these challenges in rootstock breeding to meet the demand of sustainable stone fruit production. This review systematically examines strategic breeding objectives and innovative molecular methodologies in prunus rootstock development, with particular emphasis on marker-assisted selection and genomic prediction technologies. We provide a comprehensive synthesis of breeding achievements across major commercial rootstock cultivars, while proposing forward-looking research strategies incorporating CRISPR-based genome editing and multi-omics approaches. The synthesized insights establish a theoretical pathway for advancing rootstock genetic improvement and sustainable orchard management practices in stone fruit cultivation systems.

Partial desiccation treatment (PDT) is an effective technology for promoting the germination and conversion of conifer somatic embryos (SEs). PDT, as a drought stress, induces intensive physiological responses in phospholipid metabolism, which are not well understood in the conifer SEs. Here, we integrated lipidomics, transcriptomics and proteomics analyses to reveal the molecular basis of lipid remodeling under PDT in Picea asperata SEs. Among the 82 lipid molecular species determined by mass spectrometry, phosphatidic acid (PA) had a significant effect after PDT and was the most critical lipid in the response to PDT. The transcriptomics results showed that multiple transcripts in the glycerolipid and glycerophospholipid metabolism pathways were differentially expressed, and these included five PLDα1 transcripts that catalyze the conversion of phosphatidylcholine (PC) to PA. Furthermore, the enzyme activity of this phospholipase D (PLD) was significantly enhanced in response to PDT, and PDT also significantly increased the protein level of PLDα1 (MA_10436582g0020). In addition, PA is a key factor in gibberellin, abscisic acid and ethylene signal transduction. One GDI1, one DELLA, three ABI1s, two SnRK2s, one CTR and 12 ERFs showed significantly differential expression between SEs before and after PDT in this study. Our data suggest that the observed increases in the PA contents might result from the activation of PLDα by PDT. PA not only affects the physical and chemical properties of the cell membrane but also participates in plant hormone signal transduction. Our work provides novel insight into the molecular mechanism through which PDT promotes the germination of SEs of coniferous tree species and fills the gap in the understanding of the mechanism of somatic embryo lipid remodeling in response to PDT.

Understanding genotype, environment, and genotype-by-environment (G × E) interactions is vital for effective forest breeding. The Catalpa bungei, valued for its rapid growth and high-quality wood, exhibits uncertain genetic variation in growth across diverse ecological conditions. To clarify this, we measured the growth traits of clones over several years at multiple sites to evaluate the effects of genetics and environment on growth. The results indicate that growth traits exhibit significant genetic differences and high repeatability, and the significant G × E interaction highlights the importance of site-specific tree selection. Correlation and regression analysis indicated that MCMT was positively correlated with DBH, whereas DD < 18 was negatively correlated with DBH. TD and CMD showed positive correlations with height and volume. Multivariate regression trees (MRT) analysis showed that clones thrived under specific conditions: TD > 26.65 °C with MCMT > 0.1 °C and CMD > 520.5. Mantel analysis results indicated that TD is the main factor driving the G × E of DBH. To identify clones well-suited for targeted cultivation and stability in various regions, we estimated BLUP values for clone growth and applied BLUP-GGE to assess the yield and stability of 5-year height, 9-year DBH, and 5-year volume. Clone 1-1 was selected for its high and stable DBH, with a 6.22% genetic gain. Clone 22-03 was selected for its high and stable volume, with a 12.11% gain. These elite clones are anticipated to boost C. bungei plantation productivity and are likely to be cultivated and promoted across multiple regions.

Picea belongs to the Pinaceae family and is a famous commercial tree species because of its straight trunk and excellent timber traits. Recently, omics have been widely used for fundamental and mechanism studies on Picea plants. To improve the accessibility to omics and phenotypic data and facilitate further studies, we compiled the sequences of 2 chloroplast genomes (Picea crassifolia and Picea asperata) and 32 complete omics data sets, including 20 transcriptomes, 4 proteomes, 2 degradomes and 6 microRNAs from P. crassifolia, P. asperata, Picea balfouriana and Picea abies tissues under different treatments, in PICEAdatabase. In addition, phenotypic data on plant growth and wood property traits were collected from two field trials of P. crassifolia. PICEAdatabase also includes useful analysis tools, such as BLAST, DESeq2 and JBrowse, to assist with analyses.

Apricot (Prunus armeniaca L.) exhibits a gametophytic self-incompatibility (GSI) system. To identify the S-genotypes of the main apricot cultivars, including 133 native Chinese cultivars and 35 foreign accessions, PCR was performed using a combination of five primers based on the conserved regions of Prunus S-RNase genes. After cloning and sequencing the PCR products, the S-genotypes of all 168 apricot cultivars were determined. A total of 46 different S-RNase alleles, with 15 new alleles, were identified. For all 168 accessions, the top five most frequent S-alleles were S₈, S₁₁, S₉, S₁₆, and S₅₃. S₁₁, S₈, and S₁₆ were the most frequent in Chinese cultivars, and S₉, S₈, and S₂ were mostly found in European accessions. For Chinese apricot cultivars, the distribution of S-alleles among five geographic regions was also investigated. In Northwest China, S₁₆ was the most frequent S-allele. In the Xinjiang region, S₆₆, S₄₉, and S₁₄ were the top three most frequent S-alleles. In North China, S₈, S₁₁, and S₅₃ were the top three most frequent S-alleles. In addition, the self-compatible type, S_C, was not detected in these 133 Chinese accessions. Finally, the phylogenetic tree of apricot S-alleles indicated that there are four groups of S-RNase genes (S₉₇/S₁₀₆, S₁₄/S_14a/S₆₆, S₉/S₁₇/S₄₄, and S₂₃/S₅₃) presenting a very close relation. These results provide more data on the S-genotypes of apricot accessions, which can support future breeding programs by aiding in the selection of the appropriate parents and contributing to efficient orchard design by combining cultivars with suitable pollinizers.