The sucrose nonfermenting 1-related protein kinase (SnRK) plays an important role in responding to abiotic stresses by phosphorylating the target protein to regulate various signaling pathways. However, little is known about the characteristics, evolutionary history, and expression patterns of the SnRK family in black raspberry (Rubus occidentalis L.) or other Rosaceae family species. In this study, a total of 209 SnRK genes were identified in 7 Rosaceae species and divided into 3 subfamilies (SnRK1, SnRK2, and SnRK3) based on phylogenetic analysis and specific motifs. Whole-genome duplication (WGD) and dispersed duplication (DSD) were considered to be major contributions to the SnRK family expansion. Purifying selection was the primary driving force in the SnRK family evolution. The spatial expression indicated that the RoSnRK genes may play important roles in different tissues. In addition, the expression models of 5 RoSnRK2 genes in response to abiotic stresses were detected by qRT-PCR. The proteins encoded by RoSnRK2 genes localize to the cytoplasm and nucleus in order to perform their respective functions. Taken together, this study provided an analysis of the SnRK gene family expansion and evolution, and contributed to the current knowledge of the function of 5 RoSnRK2 genes, which in turn expanded understanding of the molecular mechanisms of black raspberry responses to abiotic stress.

Calcium-dependent protein kinases (CDPKs) are crucial for plant development and stress responses. In this study, we performed a comprehensive genomic analysis of the CDPK gene family in pecan (Carya illinoinensis) and evaluated their potential roles in salt stress responses. A total of 31 CiCDPK genes were identified and classified into four subgroups through phylogenetic analysis. Structural and promoter analyses revealed conserved motifs and regulatory elements linked to stress responses. Gene duplication analysis showed that WGD and DSD events were primary drivers of CiCDPK expansion, shaped by purifying selection. GO and KEGG annotations highlighted roles in kinase activity, calcium binding, and signal transduction, while interaction networks suggested involvement in ROS regulation and ATP-dependent phosphorylation. Tissue-specific expression patterns indicated distinct roles of CiCDPKs, with CiCDPK20 and CiCDPK31 predominantly expressed in male flowers and seeds, respectively. Transcriptome data showed that CiCDPKs exhibited distinct responses to abiotic and biotic stress, highlighting their functional specialization under various conditions. qRT-PCR analysis further confirmed the involvement of 16 CiCDPKs in salt stress adaptation, supporting their critical roles in signal transduction pathways during salinity stress. This study provides insights into CiCDPK functions, offering potential applications in breeding pecan varieties with enhanced salt tolerance.

Pear fruit typically contains abundant highly lignified cells, known as stone cells, which have a negative impact on the fruit's edibility and processing quality. Despite extensive physiological and molecular research, there remains a limited understanding of the precise spatiotemporal aspects of lignification in flesh cells during pear development, particularly regarding the initiation of lignification and expansion of stone cell clusters. Here, an emerging bioorthogonal chemistry-based imaging technique was employed to in vivo visualize cell lignification dynamics in developing pear fruit. Specific identification of active sites undergoing lignification revealed that initial lignification of flesh cells occurred at 10 days after full bloom (DAFB), resulting in the formation of primordial stone cells (PSCs). These PSCs exhibited a random distribution and showed significantly larger diameter and area compared to normal parenchyma cells. Subsequently, PSCs developed pit canals and initiated lignification process in their neighboring cells at 15 DAFB. A cascading effect in the formation of stone cell aggregations was visualized by tracing of the lignification trajectory. This expansion process exhibited a domino effect, whereby lignification progressively spread from one cell to the next, creating a cascading pattern of stone cell formation. Finally, a cellular developmental model was proposed for stone cell formation. This study presented a procedure for applying the cutting-edge technology, click chemistry imaging, to get insights into practical scientific questions. The findings elucidated the spatiotemporal dynamics of active lignification sites in pear fruit at the cellular level, thereby enhancing our understanding of the initiation and aggregation processes in stone cell formation.

Expansins (EXPs) are important components of the plant cell wall. They are involved in plant growth and development and diverse environmental stress respon