Preliminary Trial to Establish Artificial Grassland in Tibet, China

Tibet Autonomous Region with an average altitude of more than 4,000 m above sea level, altogether cover an area of 1.22 million km2, equivalent to one-eight of the total area of China. High mountains along with forests and rivers in Tibet consist of an important ecological barrier for protecting parts of inland ecosystems. Tibet is also one of the five major pastoral areas in China. The grassland in Tibet covers 0.83 million km2, but the grass is sparse and low, and with low yield in this area. There are nearly 2.8 million people in this region, while the area of arable land is less than 2.533 thousand km2. Nearly 40.5 million tons of hay are needed for about 45 million sheep units in Tibet (Yu et al., 2010), while the actual amount is less than 20 million tons (including 15 million tons per year from natural grassland, and 2～3 million tons per year from the straw of naked barley). It exacerbating the degradation of natural grassland for the contradiction between livestock and grass. Research shows that the most effective measure to maintain local economic growth, coordinated development of ecological security and curb the further degradation of the grassland in Tibet is by planting high yielding and high quality forage crops, changing the traditional way of free grazing and implementing captive feeding gradually

Table1_Immune-related gene signature to predict TACE refractoriness in patients with hepatocellular carcinoma based on artificial neural network.XLSX

Background: Transarterial chemoembolization (TACE) is the standard treatment option for intermediate-stage hepatocellular carcinoma (HCC), while response varies among patients. This study aimed to identify novel immune-related genes (IRGs) and establish a prediction model for TACE refractoriness in HCC patients based on machine learning methods.Methods: Gene expression data were downloaded from GSE104580 dataset of Gene Expression Omnibus (GEO) database, differential analysis was first performed to screen differentially expressed genes (DEGs). The least absolute shrinkage and selection operator (LASSO) regression analysis was performed to further select significant DEGs. Weighted gene co-expression network analysis (WGCNA) was utilized to build a gene co-expression network and filter the hub genes. Final signature genes were determined by the intersection of LASSO analysis results, WGCNA results and IRGs list. Based on the above results, the artificial neural network (ANN) model was constructed in the training cohort and verified in the validation cohort. Receiver operating characteristics (ROC) analysis was used to assess the prediction accuracy. Correlation of signature genes with tumor microenvironment scores, immune cells and immune checkpoint molecules were further analyzed. The tumor immune dysfunction and exclusion (TIDE) score was used to evaluate the response to immunotherapy.Results: One hundred and forty-seven samples were included in this study, which was randomly divided into the training cohort (n = 103) and validation cohort (n = 44). In total, 224 genes were identified as DEGs. Further LASSO regression analysis screened out 25 genes from all DEGs. Through the intersection of LASSO results, WGCNA results and IRGs list, S100A9, TREM1, COLEC12, and IFIT1 were integrated to construct the ANN model. The areas under the curves (AUCs) of the model were .887 in training cohort and .765 in validation cohort. The four IRGs also correlated with tumor microenvironment scores, infiltrated immune cells and immune checkpoint genes in various degrees. Patients with TACE-Response, lower expression of COLEC12, S100A9, TREM1 and higher expression of IFIT1 had better response to immunotherapy.Conclusion: This study constructed and validated an IRG signature to predict the refractoriness to TACE in patients with HCC, which may have the potential to provide insights into the TACE refractoriness in HCC and become the immunotherapeutic targets for HCC patients with TACE refractoriness.</p

Validation of Appropriate Reference Genes for qRT&ndash;PCR Normalization in Oat (Avena sativa L.) under UV-B and High-Light Stresses

Oat is a food and forage crop species widely cultivated worldwide, and it is also an important forage grass in plateau regions of China, where there is a high level of ultraviolet radiation and sunlight. Screening suitable reference genes for oat under UV-B and high-light stresses is a prerequisite for ensuring the accuracy of real-time quantitative PCR (qRT&ndash;PCR) data used in plant adaptation research. In this study, eight candidate reference genes (sulfite oxidase, SUOX; victorin binding protein, VBP; actin-encoding, Actin1; protein PSK SIMULATOR 1-like, PSKS1; TATA-binding protein 2-like, TBP2; ubiquitin-conjugating enzyme E2, UBC2; elongation factor 1-alpha, EF1-&alpha;; glyceraldehyde-3-phosphate dehydrogenase 1, GAPDH1;) were selected based on previous studies and our oat transcriptome data. The expression stability of these reference genes in oat roots, stems, and leaves under UV-B and high-light stresses was first calculated using three frequently used statistical software (geNorm, NormFinder, and BestKeeper), and then the comprehensive stability of these genes was evaluated using RefFinder. The results showed that the most stably expressed reference genes in the roots, stems, and leaves of oat under UV-B stress were EF1-&alpha;, TBP2, and PSKS1, respectively; the most stably expressed reference genes in the roots, stems, and leaves under high-light stress were PSKS1, UBC2, and PSKS1, respectively. PSKS1 was the most stably expressed reference gene in all the samples. The reliability of the selected reference genes was further validated by analysis of the expression of the phenylalanine ammonia-lyase (PAL) gene. This study highlights reference genes for accurate quantitative analysis of gene expression in different tissues of oat under UV-B and high-light stresses

The Caucasian Clover Gene <i>TaMYC2</i> Responds to Abiotic Stress and Improves Tolerance by Increasing the Activity of Antioxidant Enzymes

Abiotic stress affects metabolic processes in plants and restricts plant growth and development. In this experiment, Caucasian clover (Trifolium ambiguum M. Bieb.) was used as a material, and the CDS of TaMYC2, which is involved in regulating the response to abiotic stress, was cloned. The CDS of TaMYC2 was 726 bp in length and encoded 241 amino acids. The protein encoded by TaMYC2 was determined to be unstable, be highly hydrophilic, and contain 23 phosphorylation sites. Subcellular localization results showed that TaMYC2 was localized in the nucleus. TaMYC2 responded to salt, alkali, cold, and drought stress and could be induced by IAA, GA3, and MeJA. By analyzing the gene expression and antioxidant enzyme activity in plants before and after stress, we found that drought and cold stress could induce the expression of TaMYC2 and increase the antioxidant enzyme activity. TaMYC2 could also induce the expression of ROS scavenging-related and stress-responsive genes and increase the activity of antioxidant enzymes, thus improving the ability of plants to resist stress. The results of this experiment provide references for subsequent in-depth exploration of both the function of TaMYC2 in and the molecular mechanism underlying the resistance of Caucasian clover

Genome-wide identification and characterization of NAC transcription factor family members in Trifolium pratense and expression analysis under lead stress

Abstract Background The NAC TF family is widely involved in plant responses to various types of stress. Red clover (Trifolium pratense) is a high-quality legume, and the study of NAC genes in red clover has not been comprehensive. The aim of this study was to analyze the NAC gene family of red clover at the whole-genome level and explore its potential role in the Pb stress response. Results In this study, 72 TpNAC genes were identified from red clover; collinearity analysis showed that there were 5 pairs of large fragment replicators of TpNAC genes, and red clover was found to be closely related to Medicago truncatula. Interestingly, the TpNAC genes have more homologs in Arabidopsis thaliana than in soybean (Glycine max). There are many elements in the TpNAC genes promoters that respond to stress. Gene expression analysis showed that all the TpNAC genes responded to Pb stress. qRT-PCR showed that the expression levels of TpNAC29 and TpNAC42 were significantly decreased after Pb stress. Protein interaction network analysis showed that 21 TpNACs and 23 other genes participated in the interaction. In addition, the TpNAC proteins had three possible 3D structures, and the secondary structure of these proteins were mainly of other types. These results indicated that most TpNAC members were involved in the regulation of Pb stress in red clover. Conclusion These results suggest that most TpNAC members are involved in the regulation of Pb stress in red clover. TpNAC members play an important role in the response of red clover to Pb stress

Physiological analysis of the effect of altitudinal gradients on Leymus secalinus on the Qinghai-Tibetan Plateau.

On the Qinghai-Tibetan Plateau, the high-altitudinal gradients can negatively affect plant distribution and limit plant growth and reproduction. Leymus secalinus (Georgi) Tzvel. is an important forage crop on the Qinghai-Tibetan Plateau and has an excellent ability to fix sand and improve soil. To evaluate the effect of altitude on the physiological characteristics of L. secalinus on the Qinghai-Tibetan Plateau, we measured the lipid peroxidation; chlorophyll a (Chl a), chlorophyll b (Chl b), total carotenoid (Car), soluble protein, proline and soluble sugar contents; and the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in leaves from eight different altitudes in Minhe County and Huangzhong County. The leaves were collected at the initial bloom stage, and the average vertical distance between two adjacent collection sites was approximately 100 meters. The reduction in Chl a and Chl b contents and the increase in Car contents can allow plants to weaken their light absorption and avoid photodamage to the chloroplast. The decrease in malondialdehyde (MDA) content associated with lower lipid peroxidation, and the changes of CAT, SOD and POD activities reflect a higher reactive oxygen species (ROS) scavenging capacity in high-altitude plants. The increase in proline and soluble sugar contents with elevation suggests that proline and soluble sugar may play a key role in the osmotic adjustment of plants in alpine regions. The results suggested that altitudinal gradients negatively affect L. secalinus on the Qinghai-Tibetan Plateau and that the adaptation mechanism and survival strategies of L. secalinus were attributed to the combined effects of multiple protective strategies