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Cinnamomum camphora is one of the most dominant broad-leaved evergreen trees in tropical and subtropical regions. Understanding its response to cold stress is crucial for enhancing its resilience to climate changes and expanding the cultivation range. Cold stress response is a vital strategy for plants to withstand cold stress, typically involving transcriptional changes across various pathways. In this study, RNA-Sequencing (RNA-Seq) was conducted on the leaves of C. camphora subjected to different cold stress treatments (0 h, 2 h, and 12 h). Transcriptome analyses revealed that short-term cold stress treatment rapidly induced the upregulation of genes associated with calcium and ethylene signaling pathways, including GLR2.7, CaM, CPK7, and ERF1/3/4/5/7. Subsequently, 12 h cold response treatment further activated genes related to the cold response, jasmonic acid signaling pathways, and the negative regulation of cellular biosynthetic processes, such as CBF2 and CBF4. Notably, ERFs emerged as the most differentially expressed transcription factors in this study. A total of 133 ERF family members from C. camphora were identified through phylogenetic analysis, and these ERFs were classified into 12 clusters. Many of these ERFs are likely to play pivotal roles in the cold response of C. camphora, especially ERF1/3/4/5/7. These findings offer novel insights into the mechanisms underlying the cold response and present valuable candidates for further research, advancing our understanding of plant responses to cold stress. [ABSTRACT FROM AUTHOR]

The herbaceous peony (Paeonia lactiflora Pall.) plant is world-renowned for its ornamental, medicinal, edible, and oil values. As global warming intensifies, its growth and development are often affected by high-temperature stress, especially in low-latitude regions. Superoxide dismutase (SOD) is an important enzyme in the plant antioxidant systems and plays vital roles in stress response by maintaining the dynamic balance of reactive oxygen species (ROS) concentrations. To reveal the members of then SOD gene family and their potential roles under high-temperature stress, we performed a comprehensive identification of the SOD gene family in the low-latitude cultivar 'Hang Baishao' and analyzed the expression patterns of SOD family genes (PlSODs) in response to high-temperature stress and exogenous hormones. The present study identified ten potential PlSOD genes, encoding 145–261 amino acids, and their molecular weights varied from 15.319 to 29.973 kDa. Phylogenetic analysis indicated that PlSOD genes were categorized into three sub-families, and members within each sub-family exhibited similar conserved motifs. Gene expression analysis suggested that SOD genes were highly expressed in leaves, stems, and dormancy buds. Moreover, RNA-seq data revealed that PlCSD1-1, PlCSD3, and PlFSD1 may be related to high-temperature stress response. Finally, based on the Quantitative Real-time PCR (qRT-PCR) results, seven SOD genes were significantly upregulated in response to high-temperature stress, and exogenous EBR and ABA treatments can enhance high-temperature tolerance in P. lactiflora. Overall, these discoveries lay the foundation for elucidating the function of PlSOD genes for the thermotolerance of herbaceous peony and facilitating the genetic breeding of herbaceous peony cultivars with strong high-temperature resistance. [ABSTRACT FROM AUTHOR]

Winter dormancy (WD) is a crucial strategy for plants coping with potentially deadly environments. In recent decades, this process has been extensively studied in economically important perennial eudicots due to changing climate. However, in evergreen monocots with no chilling requirements, dormancy processes are so far a mystery. In this study, we compared the WD process in closely related evergreen (Iris japonica) and deciduous (I. tectorum) iris species across crucial developmental time points. Both iris species exhibit a 'temporary' WD process with distinct durations, and could easily resume growth under warm conditions. To decipher transcriptional changes, full-length sequencing for evergreen iris and short read RNA sequencing for deciduous iris were applied to generate respective reference transcriptomes. Combining results from a multipronged approach, SHORT VEGETATIVE PHASE and FRUITFULL (FUL) from MADS-box was associated with a dormancy- and a growth-related module, respectively. They were co-expressed with genes involved in phytohormone signaling, carbohydrate metabolism, and environmental adaptation. Also, gene expression patterns and physiological changes in the above pathways highlighted potential abscisic acid and jasmonic acid antagonism in coordinating growth and stress responses, whereas differences in carbohydrate metabolism and reactive oxygen species scavenging might lead to species-specific WD durations. Moreover, a detailed analysis of MIKCC MADS-box in irises revealed common features described in eudicots as well as possible new roles for monocots during temporary WD, such as FLOWERING LOCUS C and FUL. In essence, our results not only provide a portrait of temporary WD in perennial monocots but also offer new insights into the regulatory mechanism underlying WD in plants. [ABSTRACT FROM AUTHOR]