PYR/PYL (pyrroloquinoline quinone resistance/PYR1-like) are receptors for abscisic acid (ABA) in plants and play a crucial role in responses to abiotic stress. In this study, we identified 63 members of the StPYL gene family at the tetraploid whole-genome level in potatoes. We analyzed the physicochemical properties of these 63 StPYLs and constructed a phylogenetic tree using Arabidopsis thaliana and potato (Solanum tuberosum L.) cultivar ‘DM’ as the reference. By examining gene structure, conserved protein motifs, and collinearity, we found that StPYLs are highly conserved throughout evolution. The gene expression heat map under salt stress revealed that 57 StPYL genes are involved in the salt stress response. Among them, the expression level of StPYL9a-like changed significantly under salt stress. Through genetic transformation, we observed that overexpression of StPYL9a-like enhanced the growth and survival of potato plants under salt stress compared to the wild type. The contents of proline (Pro), superoxide dismutase (SOD), and chlorophyll in the leaves of overexpressing plants increased, while malondialdehyde (MDA) levels decreased. This suggests that StPYL9a-like positively regulates salt tolerance by affecting antioxidant enzyme activity and osmotic adjustment substances in potatoes. Subcellular localization demonstrated that StPYL9a-like is localized in the nucleus. This study provides a reference for the functional research of PYLs in potatoes, offers a basis for screening potato genes related to salt stress, and lays a foundation for developing salt-tolerant potato varieties.

The AGC kinase family is crucial for regulating plant disease resistance, integrating hormone signals, managing reactive oxygen species (ROS) metabolism, and maintaining redox balance. However, research on AGC kinases in Solanaceae plants is limited, and the functions of most AGC kinases remain unidentified. Using the tetraploid potato (Solanum tuberosum L.) cultivar ‘Tingsha No. 9’, we conducted a genome-wide identification of the AGC gene family and profiled transcript responses to late-blight (Phytophthora infestans) stress. Additionally, we examined the subcellular localization and characterized the phenotypic responses of overexpression lines of the late-blight–responsive kinase StD6PK under late-blight stress. A total of 141 AGC family members were identified in ‘Qingshu No. 9’, categorized into eight subfamilies. This classification includes one cultivar-specific subfamily that was previously unrecognized, as well as 50 AGC family members within subfamily 1. AGC family members had significant differences in physicochemical characteristics and most of which were located in the nucleus. AGC family members are distributed on 46 chromosomes, with the largest number of chromosome 11 and the least number of chromosome 7. Gene duplication is dominated by whole-genome duplication (WGD) and segmental duplication. Ka/Ks values of all collinear pairs are less than 1. Purification selection drives family evolution in a long evolutionary process. Its promoter is rich in light-responsive, hormone-responsive, and stress-responsive elements, and its expression varies significantly in tissues; and some genes are highly expressed in specific organs. RNA-seq analysis revealed that 78.1% of the members responded to late-blight stress, and the expression levels of the selected eight subfamily members all showed significant increases or decreases after inoculation with late blight. StD6PK (Soltu.Q9.Chr04_A40011450.g) was strongly induced at 48~72 h, and its expression level at 72 h was 5.7 times higher than that at 0 h. Stable transformation of potato demonstrated that overexpression of StD6PK could enhance the resistance of potato to late blight, with subcellular localization revealing its nuclear localization characteristic. This study was the first time to complete the identification of AGC family genome of tetraploid potato ‘Qingshu No. 9’, reveal its evolution and expression characteristics, clarify the response characteristics of StD6PK to late blight, and provide insights into the evolutionary and functional basis of the AGC kinase gene family in potato late blight resistance mechanisms, while supplying genetic resources to accelerate the development of late blight-resistant germplasm.

The potato tuber is a metamorphic organ formed by the expansion of the underground stolon tip. It is an economically important organ and an excellent material for studying the occurrence and development of modified plant organs. However, genetic studies have lagged due to the potato’s complex genetic background. In this study, we used stolons and tubers of the potato ‘Qingshu 9’ at different stages of the tuberization process as samples for transcriptome sequencing and systematically analyzed the transcriptome characteristics of tuberization. Through RT-qPCR analysis, 16 candidate genes related to tuberization were identified. Overexpression verification was performed on one candidate gene, StLSH10, and the results indicated that it might be involved in regulating tuberization. This research provides a theoretical basis for elucidating the molecular mechanism of tuberization and offers a new target to improve potato yield and quality through molecular breeding strategies.