Anthocyanins are the most valuable pigments in Lycium ruthenicum Murray (L. ruthenicum). Although ultraviolet-B (UV-B) irradiation is a key environmental factor influencing anthocyanin biosynthesis in L. ruthenicum, the deep molecular mechanism remains unclear. Herein, we examined the changes in the total anthocyanin content and transcriptomic characteristics of L. ruthenicum leaves following UV-B irradiation treatment. The results showed a twofold increase in anthocyanin content in the leaves of L. ruthenicum after the treatment. The transcriptome analysis showed that the expression of 24 structural genes identified in the anthocyanin synthesis pathway was up-regulated. In particular, F3’H (Unigene0009145) and C4H (Unigene0046607) exhibit notable up-regulation, suggesting their potential roles in anthocyanin synthesis. Protein interaction network results revealed that MYB1 (Unigene0047706) had the highest connectivity, followed by bHLH (Unigene0014085). Additionally, UVR8 (Unigene0067978) and COP1 (Unigene0008780) were found to be highly involved in UV-B signal transduction. These findings provide new insights into the genetic and biochemical mechanisms that regulate anthocyanin production, and could guide agricultural practices to reduce environmental impacts and improve crop yield and quality.

Rhizobium-driven symbiotic nitrogen-fixation in legumes not only benefits the growth but also enhances the stress tolerance of plants. Isolating and characterizing efficient, drought-tolerant rhizobia is a central goal for improving crop yields in arid regions. Here, we phylogenetically and biochemically characterized a novel strain of Rhizobium (‘QHCD11’) sampled from the root nodules of faba beans growing in an arid agricultural area in Qinghai-Tibet. We further tested the drought tolerance of the strain as well as of ‘Qingcan 14’ faba bean seedlings inoculated with it. Biochemical characterization involved bromothymol blue (BTB) tests, carbon metabolic profiling (Biolog GENIII), DNA–DNA hybridization (dDDH) assays, average nucleotide identity (ANI) analyses, and 16S rRNA sequencing. The result indicated that strain ‘QHCD11’ likely belongs to the Rhizobium indicum species. Drought stress tolerance was assessed by exposure to polyethylene glycol (PEG-6000) at concentrations of 0, 10, 15, and 20%. Increasing concentrations of PEG-6000 tended to result in decreased growth of ‘QHCD11’, although the strain performed better at 20% PEG 6000 than at 15%. Inoculation of drought-stressed faba bean seedlings with strain ‘QHCD11’ improved root vitality, chlorophyll content, antioxidant enzyme activities, and plant height. We suggest that inoculation of faba beans with ‘QHCD11’ is an environmentally sound strategy for mitigating crop drought stress in arid and semi-arid regions. In addition, the results presents here will benefit future studies into faba bean-rhizobia symbioses under drought stress.

The chloroplast genome and evolutionary relationship analysis of Tulipa patens could provide fundamental genetic reference for its molecular breeding and biological research. The complete chloroplast genome of T. patens was sequenced and reported here. The genome was 152,050 bp in length, containing a pair of inverted repeated regions (26,330 bp) which were separated by a large single copy region of 82,184 bp, and a small single copy region of 17,206 bp. A total of 133 functional genes were annotated, including 87 protein-coding genes, 38 tRNA genes, and eight rRNA genes. The phylogenetic relationships of 10 species indicated that T. patens was closely related to Tulipa sylvestris.

The rate of chemical fertilizers’ utilization by crops does not exceed 40%. Environmental pollution and resource waste caused by the excessive application of chemical fertilizers have led to increased interested in using organic fertilizers as replacements for chemical ones. The present study investigated the impact of the combined application of chemical and organic fertilizers on the growth and nutrient utilization efficiency of highland barley (Hordeum vulgare L.). Compared to the application of 100% chemical fertilizers (OFR0), the substitution of chemical fertilizer with 40% organic fertilizer (OFR40) resulted in a significant increase in root length by 4% and improved the nutrient absorption capacity. The crop yields at harvest were not diminished in the combined fertilizer group compared to the OFR0 treatment group, while simultaneously achieving a 60% reduction in chemical fertilizer application. However, a complete substitution with 100% organic fertilizer (OFR100) resulted in a lower yield. This suggests that appropriate proportions of organic fertilizer replacement can maintain yield by increasing root length and enhancing the crop’s nutrient absorption capacity. In order to elucidate the mechanisms by which organic fertilizer modulates crop growth and nutrient utilization efficiency, combined transcriptomic and metabolomic analysis revealed that as the concentration of organic fertilizer increased, the differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) shifted from secondary metabolite synthesis toward nitrogen metabolism. In addition, the gene expression and enzymatic activity of NR (nitrate reductase), GS (glutamine synthetase), and GOGAT (glutamine oxoglutarate aminotransferase) (key genes in the nitrogen metabolism pathways) were significantly enhanced in the OFR40 group. This study’s omics-based approach demonstrates that the combined use of chemical and organic fertilizers enhances nitrogen absorption and utilization through an increased expression of key genes and enzymatic activities within the nitrogen metabolic pathways. This synergistic effect not only maintains crop yields but also reduces the reliance on chemical fertilizers, offering a sustainable strategy for agricultural production.

Light plays a crucial role in anthocyanin biosynthesis and color development in plants. Anthocyanins found in Lycium ruthenicum Murray are crucial for the plant’s defense against UV light and environmental stress, as well as for their economic value in functional foods and nutraceuticals due to their high antioxidant content. Despite this, the molecular mechanisms underlying this process remain incompletely understood. This study explores the molecular mechanisms that drive light-regulated anthocyanin accumulation in L. ruthenicum berries by conducting shading treatments and analyzing the transcriptomic data. Results indicated that shading from 5 to 25 days post-flowering greatly impedes the synthesis of anthocyanin, even if light exposure is increased afterward. This suggests that the early stages of fruit development are crucial for anthocyanin accumulation. In regular lighting conditions, a total of 22 anthocyanin types were detected, with Delphinidin-3-O-(p-coumaroyl)-glucoside (611) and Petunidin-3-O-rutinoside (933) being the most prevalent. When berries were exposed to early light, there was a greater presence of Petunidin-3-O-rutinoside (933), resulting in a black appearance, whereas those not exposed had a lighter color with higher levels of Delphinidin-3-O-(p-coumaroyl)-glucoside (611). RNA-Seq analysis showed a notable decrease in the expression of genes involved in the anthocyanin biosynthesis pathway (such as CHS, CHI, F3H, F3′H, F3′5′H, DFR, and ANS) following shading. Key regulatory genes like GRAS, HD-ZIP, MADS, and mTERF were involved in anthocyanin accumulation in response to light. A proposed model has been developed to elucidate the mechanism by which light controls the biosynthesis of anthocyanin, providing insights into light signal regulation. Our findings provide data to improve the understanding of light-induced anthocyanin accumulation in L. ruthenicum berries.

Anthocyanins, ubiquitous in the Compositae family, are regulated by MYB (v-myb avian myeloblastosis viral oncogene homolog), playing an important role in anthocyanin synthesis. In this study, we analyzed the regulation pathway in which the MYB protein of subgroup 6 promotes dihydroflavonol reductase (DFR) expression in Compositae, and validated this law in Saussurea medusa through yeast one-hybrid experiments. Our results showed that MYB and DFR underwent purification selection, DFR promoter analysis revealed the presence of MYB binding site (GAGTTGAATGG) and bHLH binding site (CANNTG) at the sense strand of 84–116 nucleotide residues from the start codon. These two motifs were separated by 9–10 nucleotide residues, as existed in the DFR promoters of many Compositae plants. Furthermore, the yeast one-hybrid experiment demonstrated that SmMYB1 can activate the promoter of SmDFR. Our results provide a reference for further functional study of DFR in Compositae.