Husk and pellicle as the agri-food waste in the walnut-product industry are in soaring demand because of their rich polyphenol content. This study investigated the differential compounds related to walnut polyphenol between husk and pellicle during fruit development stage. By using ultra-high performance liquid chromatography-quadrupole-orbitrap (UHPLC-Q-Orbitrap), a total of 110 bioactive components, including hydrolysable tannins, flavonoids, phenolic acids and quinones, were tentatively identified, 33 of which were different between husk and pellicle. The trend of dynamic content of 16 polyphenols was clarified during walnut development stage by high-performance liquid chromatography (HPLC). This is the first time to comprehensive identification of phenolic compounds in walnut husk and pellicle, and our results indicated that the pellicle is a rich resource of polyphenols. The dynamic trend of some polyphenols was consistent with total phenols. The comprehensive characterization of walnut polyphenol and quantification of main phenolic compounds will be beneficial for understanding the potential application value of walnut and for exploiting its metabolism pathway.

Global warming poses a significant threat to plant ecosystems and agricultural productivity, primarily through heat stress (HS), which disrupts photosynthesis, respiration, and overall plant metabolism. Epigenetic modifications, including DNA methylation, histone modifications, and RNA modifications, enable plants to dynamically and heritably adjust gene expression in response to environmental stressors. These mechanisms not only help plants survive immediate stress but also confer stress memory, enhancing their resilience to future HS events. This review explores the mechanisms underlying plant thermotolerance, emphasizing the critical role of epigenetic regulation in adapting to HS. It also highlights how DNA methylation modulates stress-responsive genes, histone modifications facilitate transcriptional memory, and RNA modifications influence mRNA stability and translation. Recent advancements in genome editing technologies, such as CRISPR-Cas9, have enabled precise modifications of epigenetic traits, offering new avenues for breeding climate-resilient crops. The integration of these modern tools with traditional breeding methods holds significant promise for developing crops with enhanced thermotolerance. Despite the potential, challenges such as the stability and heritability of epigenetic marks and the complex interplay between different epigenetic modifications need to be addressed. Future research should focus on elucidating these interactions and identifying reliable epigenetic markers for selection. By leveraging the insights gained from epigenetic studies, we can develop innovative breeding strategies to improve crop resilience and ensure sustainable agricultural productivity in the face of global warming. This review underscores the importance of epigenetic regulation in plant adaptation to heat stress and its potential to revolutionize crop breeding, offering a pathway to secure food production and sustainability under changing climatic conditions.

Mulberry fruits are rich in anthocyanins, which are important secondary metabolites that give mulberries their bright color, favorable taste and high nutritional quality, making them a popular fruit. However, few studies have focused on the molecular mechanism underlying anthocyanin accumulation in mulberries and the gene regulatory networks of anthocyanin biosynthetic pathways remain largely unknown. In this study, we performed RNA sequencing to identify differentially expressed genes (DEGs) associated with anthocyanin accumulation between two mulberry genotypes (‘Zi Jing’, ZJ and ‘Zhen Zhu Bai’, ZZB, with purple and white fruit flesh, respectively) at 5, 18, 27 and 31 days after flower. Using transcriptome analysis, we explored several key DEGs involved in the anthocyanin biosynthetic pathway, including the structural genes: CHS, CHI, F3H, DFR1, DFR2 and ANS, known as MBW complex genes: MYB (M.alba_G0017209), MYB (M.alba_G0017689), bHLH (M.alba_G0012659), bHLH (M.alba_G0009347) and bHLH3 (M.alba_G0016257) and the ethylene response factor: ERF (M.alba_G0016603). Of these, changing trends related to expression pattern and anthocyanin content showed their most positive correlation at the post-flowering stage in both genotypes. Our results indicated that ethylene enhances anthocyanin accumulation in mulberry fruits. Furthermore, qRT-PCR was performed to confirm the above-mentioned genes’ expression (except for MYB (M.alba_G0017689) and bHLH (M.alba_G0009347) was significantly up-regulated under ethylene treatment at 300 mg/L. These findings help uncover the gene regulatory networks of the anthocyanin biosynthetic pathway and will contribute to engineering purposes in future mulberry breeding programs.

Mulberry (Morus L.; Moraceae; Rosales) is an economically important tree with a long history in China and valued for its rich nutrient, flavor content, medicinal value and useful ecological functions. Morus species are widely distributed in Asia, Europe, North and South America and Africa and exhibit obvious differences in morphological characteristics and phenological stages due to being distributed in diverse climate zones. The morphological description of the phenological stages of black mulberry (Morus nigra L.) has been established in Mediterranean climates and this study extended the BBCH scale for application in different Morus species, especially for mulberry trees grown in subtropical monsoon climates. In this study, we used the BBCH (Biologische Bundesanstalt, Bundessortenamt and CHemische Industrie) scale to describe in detail the phenological growth stages for Morus species in Wuhan, China (a subtropical monsoon climate). Based on this general scale, eight principal stages, i.e., bud, leaf and shoot development stage, inflorescence emergence stage, flowering stage, fruit development stage, fruit maturation stage, senescence and beginning of dormancy stage, were described. We provide photographic images of some primary and secondary developmental stages to better define and standardize morphological characteristics and phenological descriptions of these mulberries (Morus spp.). In addition, because the color of mulberry fruit varies from white, purple, black, or pink to red at maturity, with mostly monosexual flowers, we have also presented detailed descriptions of morphological traits of flower sexuality and fruit color among these four species. In addition, two late phenological germplasms (late bud sprouting associated with late blooming and late fruit ripening) were screened out according to the BBCH scale. Overall, this study will contribute to advance the field of mulberry breeding and implementation of agronomic practices and facilitate convenient communication between mulberry cultivators and researchers in different areas.

The protective effects of remifentanil preconditioning on serum superoxide dismutase (SOD) and malondialdehyde (MDA) during pump-assisted coronary artery bypass graft (CABG) were investigated. Forty pump-assisted CABG patients were randomly divided into a remifentanil preconditioning group (R group) and a control group (C group, N = 10; normal saline). The R group was further divided into 3 sub-groups (R1, R2, and R3; N = 10 per group) according to the remifentanil dose (0.6, 1.2, and 1.8 μg·kg(-1)·min(-1), respectively). A venous blood sample was taken at anesthesia induction (T0), before cardiopulmonary bypass (CPB) (T1), CPB 30 min (T2), and after CPB (T3), and protein concentrations were measured. Patients were tested 24 h before and after the operation with the Mini-Mental State Examination (MMSE), and the difference was calculated. The MMSE score difference in the R3 group was lower than those of the other 3 groups (P < 0.05). At T2 and T3, the R3 group showed a significant decrease in S-100β protein and MDA and an increase in SOD (P < 0.05) compared with the other groups, and S-100β was negatively correlated with SOD activity (T2: r = -0.76, -0.80, P < 0.01; T3: r = -0.795, P < 0.01), and was positively correlated with MDA density (T2: r = 0.71, P < 0.01; T3: r = 0.71, P < 0.01). In conclusion, high-dosage remifentanil preconditioning played a protective role on brain damage, possibly through inhibition of the oxidative stress response.

Grafting is an ancient agricultural technique that is frequently used to enhance the performance of horticultural plants, including vegetables and woody fruit trees. For successful grafting, genotypes of the compatible scion (the upper part) and the rootstock (the lower part) must interact. Molecular signals, including nutritional and hormonal signals, proteins, and messenger RNAs (mRNAs), are known to be transferred from the rootstock to the scion and vice versa. Nonetheless, there are still numerous mysteries regarding artificial grafts, including the occurrence of genetic/epigenetic alterations due to exchanges between the graft partners, and the long-term ramifications of these alterations on the phenotype are unknown. Recent studies on the interactions between rootstocks and scions suggest that grafting responses have an epigenetic component. In this review, we focus on the current knowledge of epigenetic consequences following grafting. Epigenetic regulations are known to regulate chromatin architecture, alter gene expression, and affect cellular function in plants. Mobile small RNAs, for example, have been shown to modify the DNA methylation pattern of the recipient partner across the graft union. More recently, mRNA 5-methylcytosine (m⁵C) modification has been shown to elucidate the long-distance transport mechanism of grafting in Arabidopsis thaliana. We also discuss how grafts can cause heritable epigenetic alterations that result in novel plant phenotypes, and how this might help increase horticultural crop quality, yield, and stress resistance in the context of climate change.