Backgrounds: As a conserved signaling pathway, mitogen-activated protein kinase (MAPK) cascade regulates cellular signaling in response to abiotic stress. High temperature may contribute to a significant decrease in economic yield. However, research into the expression patterns of StMAPKK family genes under high temperature is limited and lacks experimental validation regarding their role in supporting potato plant growth.Methods: To trigger heat stress responses, potato plants were grown at 35°C. qRT-PCR was conducted to analyze the expression pattern of StMAPKK family genes in potato plants. Plant with StMAPKK5 loss-of-function and gain-of-function were developed. Potato growth and morphological features were assessed through measures of plant height, dry weight, and fresh weight. The antioxidant ability of StMAPKK5 was indicated by antioxidant enzyme activity and H₂O₂ content. Cell membrane integrity and permeability were suggested by relative electrical conductivity (REC), and contents of MDA and proline. Photosynthetic capacity was next determined. Further, mRNA expression of heat stress-responsive genes and antioxidant enzyme genes was examined.Results: In reaction to heat stress, the expression profiles of StMAPKK family genes were changed. The StMAPKK5 protein is located to the nucleus, cytoplasm and cytomembrane, playing a role in controlling the height and weight of potato plants under heat stress conditions. StMAPKK5 over-expression promoted photosynthesis and maintained cell membrane integrity, while inhibited transpiration and stomatal conductance under heat stress. Overexpression of StMAPKK5 triggered biochemical defenses in potato plant against heat stress, modulating the levels of H₂O₂, MDA and proline, as well as the antioxidant activities of CAT, SOD and POD. Overexpression of StMAPKK5 elicited genetic responses in potato plants to heat stress, affecting heat stress-responsive genes and genes encoding antioxidant enzymes.Conclusion: StMAPKK5 can improve the resilience of potato plants to heat stress-induced damage, offering a promising approach for engineering potatoes with enhanced adaptability to challenging heat stress conditions.

The roles of short/small open reading frames (sORFs) have been increasingly recognized in recent years due to the rapidly growing number of sORFs identified in various organisms due to the development and application of the Ribo-Seq technique, which sequences the ribosome-protected footprints (RPFs) of the translating mRNAs. However, special attention should be paid to RPFs used to identify sORFs in plants due to their small size (~30 nt) and the high complexity and repetitiveness of the plant genome, particularly for polyploidy species. In this work, we compare different approaches to the identification of plant sORFs, discuss the advantages and disadvantages of each method, and provide a guide for choosing different methods in plant sORF studies.

The rapid accumulation of genome-scale data has transformed plant biology from descriptive genetics to predictive and increasingly mechanistic genomics. Longan (Dimocarpus longan Lour.) is an economically important subtropical fruit tree in China and Southeast Asia, but compared with model plants and major temperate fruit crops, its genomic resources and functional studies have developed relatively late. Here, we review recent progress in longan genomics with emphasis on three interrelated areas: genome assembly and annotation, transcriptomic resources, and representative gene family studies associated with flowering, somatic embryogenesis, and transporter-mediated stress tolerance. The progression from the first draft genome of ‘Honghezi’ to the chromosome-scale assemblies of ‘Jidanben’ and ‘Shixia’ has substantially improved contiguity and gene annotation, thereby enabling population-genomic analysis, genome-wide gene family identification, and candidate-gene discovery. Available transcriptomic datasets further support studies of reproductive development, stress responses, and embryogenic competence, although cross-study integration remains limited. We also summarize how gene family analyses have advanced the current understanding of floral induction, continuous flowering, somatic embryogenesis, mineral transport, and sugar transport in longan. Importantly, the field is still dominated by cataloguing and expression-based inference, whereas causal validation, pan-genomic analysis, and multi-omics integration remain insufficient. We therefore argue that future progress in longan molecular breeding will depend on integrating high-quality genomic resources with functional validation, standardized comparative annotation, and improved transformation or regeneration systems.

Graft incompatibility remains a significant challenge to the sustainable development of the longan (Dimocarpus longan Lour.) industry, yet the physiological mechanisms associated with scion genotype divergence are not fully understood. This study examined the effects of scion genotype on rootstock–scion interactions using the main cultivar ‘Shixia’ as rootstock. Two scion genotypes from an F1 population of ‘Dawuyuan’ × ‘Shuguan’ were selected: one compatible (DS237) and one incompatible (DS297). Leaf anatomy, photosynthetic physiology, and mineral element composition were analyzed to assess differences in leaf functionality between these two genotypes. The incompatible scion genotype (DS297) showed a trend toward lower potassium and higher magnesium concentrations; however, individual ion comparisons did not remain significant after FDR correction, whereas the K/Mg ratio was significantly altered in both scion and rootstock, being lower in the incompatible scion but higher in the incompatible rootstock. Anatomical analysis revealed reductions in cambium thickness, phloem thickness, vessel diameter, and vessel density in incompatible grafts, as well as thinner upper epidermis and palisade tissue. These structural differences may be associated with altered bidirectional transport. The observed changes may contribute to decreased photoassimilate export and qualitatively assessed starch accumulation in mesophyll cells, and may further contribute to the decline in leaf photosynthetic performance. These findings raise the possibility that mineral-associated developmental defects may be associated with scion genetic composition in this specific longan scion–rootstock combination. However, these findings are based on one compatible and one incompatible genotype on a single rootstock without self-grafted controls or histological evidence from the graft union itself, and should therefore be considered preliminary pending confirmation in additional genotype pairs and direct functional measurements.