Jerusalem artichoke (Helianthus tuberosus L.) is a characteristic crop in the Qinghai-Tibet Plateau which has rapidly developed and gained socioeconomic importance in recent years. Fructans are abundant in tubers and represent the foundation for their formation, processing and utilization of yield; and are also widely used in new sugar-based materials, bioenergy processing, ecological management, and functional feed. To identify key genes in the metabolic pathway of fructans in Jerusalem artichoke, high-throughput sequencing was performed using Illumina Hi Seq™ 2500 equipment to construct a transcriptome library. Qinghai-Tibet Plateau Jerusalem artichoke “Qingyu No.1” was used as the material; roots, stems, leaves, flowers and tubers of Jerusalem artichoke in its flowering stage were mixed into a mosaic of the Jerusalem artichoke transcriptome library, obtaining 63,089 unigenes with an average length of 713.6 bp. Gene annotation through the Nr, Swiss Prot, GO, KOG and KEGG databases revealed 34.95 and 46.91% of these unigenes had similar sequences in the Nr and Swiss Prot databases. The GO classification showed the Jerusalem artichoke unigenes were divided into three ontologies, with a total of 49 functional groups encompassing biological processes, cellular components, and molecular functions. Among them, there were more unigenes involved in the functional groups for cellular processes, metabolic processes, and single-organism processes. 38,999 unigenes were annotated by KOG and divided into 25 categories according to their functions; the most common annotation being general function prediction. A total of 13,878 unigenes (22%) were annotated in the KEGG database, with the largest proportion corresponding to pathways related to carbohydrate metabolism. A total of 12 unigenes were involved in the synthesis and degradation of fructan. Cluster analysis revealed the candidate 12 unigene proteins were dispersed in the 5 major families of proteins involved in fructan synthesis and degradation. The synergistic effect of INV gene is necessary during fructose synthesis and degradation in Jerusalem artichoke tuber development. The sequencing data from the transcriptome of this species can provide a reliable data basis for the identification and assessment of the expression of the members of the INV gene family.A simple sequence repeat (SSR) loci search was performed on the transcriptome data of Jerusalem artichoke, identifying 6635 eligible SSR loci with a large proportion of dinucleotide and trinucleotide repeats, and the most different motifs were repeated 5 times and 6 times. Dinucleotide and trinucleotide repeat motifs were the most frequent, with AG/CT and ACC/GGT repeat motifs accounting for the highest proportion. In this study, a database search of the transcriptome of the Jerusalem artichoke from the Qinghai Tibet Plateau was conducted by high throughput sequencing technology to obtain important transcriptional and SSR loci information. This allowed characterization of the overall expression features of the Jerusalem artichoke transcriptome, identifying the key genes involved in metabolism in this species. In turn, this offers a foundation for further research on the regulatory mechanisms of fructan metabolism in Jerusalem artichoke.

Background: Clematis tangutica (Maxim.) Korsh. is a Tibetan medicinal plant, but its chloroplast genome and plastid gene evolution remain unexplored. Here, we assembled the complete chloroplast genome of C. tangutica and investigated the adaptive evolution of the ycf2 gene. Methods: Chloroplast DNA was extracted from fresh leaves and sequenced on the Illumina HiSeq PE150 platform. We then performed comprehensive genomic analyses, including genome structure characterization, repeat and SSR identification, comparative genomics, and positive selection analysis of the ycf2 gene. Results: The genome is 159,584 bp with a typical quadripartite structure, containing 134 genes and 23 SSRs. Comparative analyses revealed that ycf2 is the most variable gene among the 13 divergent loci identified. Positive selection analysis detected 12 significant sites in ycf2, all clustered in the middle region of the protein. Conclusions: This study provides the first complete chloroplast genome resource for C. tangutica, offers new insights into the adaptive evolution of ycf2 in Ranunculaceae, and yields molecular markers applicable to population genetics, phylogenetic studies, and conservation planning for this species of medicinal importance.

This study investigates the effects of temperature on the growth, development, and bolting characteristics of Lactuca sativa, utilizing the late-maturing variety WS1 and the early-maturing variety WS3 as experimental materials. Three temperature gradients were established: 18 °C/4 °C (low temperature), 25 °C/18 °C (control), and 35 °C/18 °C (high temperature), with treatment durations of 2 d, 6 d, and 10 d, respectively. Each treatment included three biological replicates, allowing for a systematic analysis of changes in agronomic traits, physiological and biochemical indicators, and bolting characteristics of the seedlings. The results indicated that temperature stress significantly influenced seedling growth, although responses varied between the two varieties. Regarding agronomic traits, the plant height and leaf length of WS1 were significantly reduced compared to the control at both 6 d and 10 d of treatment. In contrast, WS3 exhibited significant changes in leaf length, petiole thickness, and fresh weight of the aboveground portion after just 2 d of high-temperature treatment, indicating an early sensitivity to temperature stress. At the physiological level, the activities of catalase (CAT), superoxide dismutase (SOD), and the content of malondialdehyde (MDA) in WS1 significantly increased after 6 d and 10 d of high-temperature treatment. In contrast, the CAT activity in WS3 exhibited a significant increase only during the early stages, while the MDA content was notably higher than that of the control at 2 d and 10 d of treatment. A comparison of the bolting rates among the different varieties indicated that WS1 had a lower bolting rate than WS3, with both varieties showing increased bolting rates over time. Furthermore, the bolting speed of WS3 demonstrated greater sensitivity to temperature fluctuations. In summary, the bolting rates of both varieties increased to varying degrees following stress, with a more pronounced rise observed at elevated temperatures. This finding suggests that high temperatures are more effective than low temperatures in inducing bolting, indicating enhanced adaptability to temperature stress under the experimental conditions. This study elucidates the response characteristics of the late-maturing variety WS1 and the early-maturing variety WS3 to temperature stress, highlighting the differences in tolerance among the varieties.