Development of Genome-Wide Intron Length Polymorphism (ILP) Markers in Tea Plant (Camellia sinensis) and Related Applications for Genetics Research.

The market value of tea is largely dependent on the tea species and cultivar. Therefore, it is important to develop efficient molecular markers covering the entire tea genome that can be used for the identification of tea varieties, marker-assisted breeding, and mapping important quantitative trait loci for beneficial traits. In this study, genome-wide molecular markers based on intron length polymorphism (ILP) were developed for tea trees. A total of 479, 1393, and 1342 tea ILP markers were identified using the PCR method in silico from the 'Shuchazao' scaffold genome, the chromosome-level genome of 'Longjing 43', and the ancient tea DASZ chromosome-level genome, respectively. A total of 230 tea ILP markers were used to amplify six tea tree species. Among these, 213 pairs of primers successfully characterize products in all six species, with 112 primer pairs exhibiting polymorphism. The polymorphism rate of primer pairs increased with the improvement in reference genome assembly quality level. The cross-species transferability analysis of 35 primer pairs of tea ILP markers showed an average amplification rate of 85.17% through 11 species in 6 families, with high transferability in Camellia reticulata and tobacco. We also used 40 pairs of tea ILP primers to evaluate the genetic diversity and population structure of C. tetracocca with 176 plants from Puan County, Guizhou Province, China. These genome-wide markers will be a valuable resource for genetic diversity analysis, marker-assisted breeding, and variety identification in tea, providing important information for the tea industry.

Salidroside protects pulmonary artery endothelial cells against hypoxia-induced apoptosis via the AhR/NF-κB and Nrf2/HO-1 pathways.

BACKGROUND: The apoptosis of pulmonary artery endothelial cells (PAECs) is an important factor contributing to the development of pulmonary hypertension (PH), a serious cardio-pulmonary vascular disorder. Salidroside (SAL) is a bioactive compound derived from an herb Rhodiola, but the potential protective effects of SAL on PAECs and the underlying mechanisms remain elusive. PURPOSE: The objective of this study was to determine the role of SAL in the hypoxia-induced apoptosis of PAECs and to dissect the underlying mechanisms. STUDY DESIGN: Male Sprague-Dawley (SD) rats were subjected to hypoxia (10% O2) for 4 weeks to establish a model of PH. Rats were intraperitoneally injected daily with SAL (2, 8, and 32 mg/kg/d) or vehicle. To define the molecular mechanisms of SAL in PAECs, an in vitro model of hypoxic cell injury was also generated by exposed PAECs to 1% O2 for 48 h. METHODS: Various techniques including hematoxylin and eosin (HE) staining, immunofluorescence, flow cytometry, CCK-8, Western blot, qPCR, molecular docking, and surface plasmon resonance (SPR) were used to determine the role of SAL in rats and in PAECs in vitro. RESULTS: Hypoxia stimulation increases AhR nuclear translocation and activates the NF-κB signaling pathway, as evidenced by upregulated expression of CYP1A1, CYP1B1, IL-1ß, and IL-6, resulting in oxidative stress and inflammatory response and ultimately apoptosis of PAECs. SAL inhibited the activation of AhR and NF-κB, while promoted the nuclear translocation of Nrf2 and increased the expression of its downstream antioxidant proteins HO-1 and NQO1 in PAECs, ameliorating the hypoxia-induced oxidative stress in PAECs. Furthermore, SAL lowered right ventricular systolic pressure, and decreased pulmonary vascular remodeling and right ventricular hypertrophy in hypoxia-exposed rats. CONCLUSIONS: SAL may attenuate the apoptosis of PAECs by suppressing NF-κB and activating Nrf2/HO-1 pathways, thereby delaying the progressive pathology of PH.

Comparative Transcriptome Analysis of Developing Seeds and Silique Wall Reveals Dynamic Transcription Networks for Effective Oil Production in Brassica napus L.

Vegetable oil is an essential constituent of the human diet and renewable raw material for industrial applications. Enhancing oil production by increasing seed oil content in oil crops is the most viable, environmentally friendly, and sustainable approach to meet the continuous demand for the supply of vegetable oil globally. An in-depth understanding of the gene networks involved in oil biosynthesis during seed development is a prerequisite for breeding high-oil-content varieties. Rapeseed (Brassica napus) is one of the most important oil crops cultivated on multiple continents, contributing more than 15% of the world's edible oil supply. To understand the phasic nature of oil biosynthesis and the dynamic regulation of key pathways for effective oil accumulation in B. napus, comparative transcriptomic profiling was performed with developing seeds and silique wall (SW) tissues of two contrasting inbred lines with ~13% difference in seed oil content. Differentially expressed genes (DEGs) between high- and low-oil content lines were identified across six key developmental stages, and gene enrichment analysis revealed that genes related to photosynthesis, metabolism, carbohydrates, lipids, phytohormones, transporters, and triacylglycerol and fatty acid synthesis tended to be upregulated in the high-oil-content line. Differentially regulated DEG patterns were revealed for the control of metabolite and photosynthate production in SW and oil biosynthesis and accumulation in seeds. Quantitative assays of carbohydrates and hormones during seed development together with gene expression profiling of relevant pathways revealed their fundamental effects on effective oil accumulation. Our results thus provide insights into the molecular basis of high seed oil content (SOC) and a new direction for developing high-SOC rapeseed and other oil crops.