Analysis of controlling genes for tiller growth of Psathyrostachys juncea based on transcriptome sequencing technology

Salvia miltiorrhiza Bunge extract and Przewalskin ameliorate Bleomycin-induced pulmonary fibrosis by inhibition of apoptosis, oxidative stress and collagen deposition via the TGF-β1 pathway

BACKGROUND

Salvia miltiorrhiza Bunge (Labiatae) (DS) is a key part of the traditional Chinese medicine, whose roots are used to remove blood stasis, relieve pain, eliminate carbuncle and calm the nerves. Our research team found that the DS extract could significantly reverse LPS-induced lung injury, and five new diterpenoid quinones in DS extract with excellent lung protective activity for the first time. However, the material basis and mechanism of DS on pulmonary fibrosis (PF) needs to be explored in depth.

OBJECTIVE

Bleomycin (BLM) was employed to establish the PF model, and Transcriptome and Surface plasmon resonance (SPR) ligand fishing technology were used to explore the material basis and mechanism of DS on PF, and provided theoretical research for clinical treatment of PF.

METHODS

DS extract (24.58 or 49.16 mg/kg, i.g.) was administered daily from Day 8 to Day 28, followed by intratracheal BLM drip (5 mg/kg) to induce PF. Data about the influences of DS on PF were collected by transcriptome sequencing technology. Pulmonary ultrasound, airway responsiveness, lung damage, collagen deposition, and the levels of TNF-α, IL-1β, apoptosis, oxidative stress (OS), immune cells, TGF-β1, α-SMA, E-Cadherin and Collage Ⅰ were examined. The affinity component (Przewalskin) in DS extract targeted by TGF-β1 was fished by SPR ligand fishing technology. Furthermore, an in vivo PF mouse model and an in vitro TGF-β1 induced BEAS-2B cell model were established, to explore the mechanism of Przewalskin on PF from the apoptosis, OS and epithelial mesenchymal transformation pathway.

RESULTS

DS extract improved pulmonary ultrasound, reduced lung damage and collagen deposition, downregulated TNF-α, IL-1β, apoptosis, OS, TGF-β1, α-SMA, E-Cadherin and Collage Ⅰ, transformed immune cells following Bleomycin challenge. Furthermore, affinity component (Przewalskin) also improved pulmonary ultrasound and airway responsiveness, reduced lung damage and collagen deposition, downregulated TNF-α, IL-1β, apoptosis, OS in vivo and in vitro.

CONCLUSION

Analysis using a mouse model revealed that DS extract and Przewalskin can relieve clinical symptoms of PF, reduce lung injury and improve lung function. Meanwhile, DS extract and Przewalskin can improve BLM-induced PF by inhibition of, OS, apoptosis and collagen deposition might via the TGF-β1 pathway. This study provides references to identification of novel therapeutic targets, thereby facilitating drug development for PF.

Comparative transcriptome analysis and genetic dissection of vegetative branching traits in foxtail millet (Setaria italica)

KEY MESSAGE

Two major genetic loci, qTN5.1 and qAB9.1, were identified and finely mapped to the 255 Kb region with one potential candidate gene for tiller number and the 521 Kb region with eight candidate genes for axillary branch number, respectively. Vegetative branching including tillering and axillary branching are vital traits affecting both the plant architecture and the biomass in cereal crops. However, the mechanism underlying the formation of vegetative branching in foxtail millet is largely unknown. Here, a foxtail millet cultivar and its bushy wild relative Setaria viridis accession were used to construct segregating populations to identify candidate genes regulating tiller number and axillary branch number. Transcriptome analysis using vegetative branching bud samples of parental accessions was performed, and key differentially expressed genes and pathways regulating vegetative branching were pointed out. Bulk segregant analysis on their F2:3 segregating population was carried out, and a major QTL for tiller number (qTN5.1) and two major QTLs for axillary branch number (qAB2.1 and qAB9.1) were detected. Fine-mapping strategy was further performed on F2:4 segregate population, and Seita.5G356600 encoding β-glucosidase 11 was identified as the promising candidate gene for qTN5.1, and eight genes, especially Seita.9G125300 and Seita.9G125400 annotated as B-S glucosidase 44, were finally identified as candidate genes for regulating axillary branching. Findings in this study will help to elucidate the genetic basis of the vegetative branching formation of foxtail millet and lay a foundation for breeding foxtail millet varieties with ideal vegetative branching numbers.

Interaction of Phytohormones and External Environmental Factors in the Regulation of the Bud Dormancy in Woody Plants

Bud dormancy and release are essential phenomena that greatly assist in adapting to adverse growing conditions and promoting the holistic growth and development of perennial plants. The dormancy and release process of buds in temperate perennial trees involves complex interactions between physiological and biochemical processes influenced by various environmental factors, representing a meticulously orchestrated life cycle. In this review, we summarize the role of phytohormones and their crosstalk in the establishment and release of bud dormancy. External environmental factors, such as light and temperature, play a crucial role in regulating bud germination. We also highlight the mechanisms of how light and temperature are involved in the regulation of bud dormancy by modulating phytohormones. Moreover, the role of nutrient factors, including sugar, in regulating bud dormancy is also discussed. This review provides a foundation for enhancing our understanding of plant growth and development patterns, fostering agricultural production, and exploring plant adaptive responses to adversity.

Association Analysis of Tiller-Related Traits with EST-SSR Markers in Psathyrostachys juncea

Psathyrostachys juncea is a long-lived perennial Gramineae grass with dense basal tillers and soft leaves. It is used widely in cold and dry areas of Eurasia and North America to establish grazing pasture and is even used as an ideal plant for revegetation and ecological restoration. Plant architecture, especially tillering traits, is critical for bunch grasses in breeding programs, and these traits in plants are mostly quantitative traits. In this study, the genetic diversity, population structure, and linkage disequilibrium of 480 individual lines were analyzed using 127 pairs of the EST-SSR marker, and a significant association between ten plant-architecture-related traits of P. juncea and molecular markers was found. The results of the genetic diversity analysis showed that the number of observed alleles was 1.957, the number of effective alleles was 1.682, Shannon's information index was 0.554, observed heterozygosity was 0.353, expected heterozygosity was 0.379, and the polymorphism information content was 0.300. A total of 480 individual lines were clustered into five groups based on population genetic structure, principal coordinate analysis, and unweighted pair group method with arithmetic mean analysis (UPGMA). The linkage disequilibrium coefficient (r2) was between 0.00 and 0.68, with an average of 0.04, which indicated a relatively low level of linkage disequilibrium among loci. The results of the association analysis revealed 55 significant marker-trait associations (MTA). Moreover, nine SSR markers were associated with multiple traits. This study provides tools with promising applications in the molecular selection and breeding of P. juncea germplasm.