Establishment of a risk prediction model for olfactory disorders in patients with transnasal pituitary tumors by machine learning.

To construct a prediction model of olfactory dysfunction after transnasal sellar pituitary tumor resection based on machine learning algorithms. A cross-sectional study was conducted. From January to December 2022, 158 patients underwent transnasal sellar pituitary tumor resection in three tertiary hospitals in Sichuan Province were selected as the research objects. The olfactory status was evaluated one week after surgery. They were randomly divided into a training set and a test set according to the ratio of 8:2. The training set was used to construct the prediction model, and the test set was used to evaluate the effect of the model. Based on different machine learning algorithms, BP neural network, logistic regression, decision tree, support vector machine, random forest, LightGBM, XGBoost, and AdaBoost were established to construct olfactory dysfunction risk prediction models. The accuracy, precision, recall, F1 score, and area under the ROC curve (AUC) were used to evaluate the model's prediction performance, the optimal prediction model algorithm was selected, and the model was verified in the test set of patients. Of the 158 patients, 116 (73.42%) had postoperative olfactory dysfunction. After missing value processing and feature screening, an essential order of influencing factors of olfactory dysfunction was obtained. Among them, the duration of operation, gender, type of pituitary tumor, pituitary tumor apoplexy, nasal adhesion, age, cerebrospinal fluid leakage, blood scar formation, and smoking history became the risk factors of olfactory dysfunction, which were the key indicators of the construction of the model. Among them, the random forest model had the highest AUC of 0.846, and the accuracy, precision, recall, and F1 score were 0.750, 0.870, 0.947, and 0.833, respectively. Compared with the BP neural network, logistic regression, decision tree, support vector machine, LightGBM, XGBoost, and AdaBoost, the random forest model has more advantages in predicting olfactory dysfunction in patients after transnasal sellar pituitary tumor resection, which is helpful for early identification and intervention of high-risk clinical population, and has good clinical application prospects.

A Comparative Analysis between Whole Chinese Yam and Peeled Chinese Yam: Their Hypolipidemic Effects via Modulation of Gut Microbiome in High-Fat Diet-Fed Mice.

Chinese yam is a "medicine food homology" food with medical properties, but little is known about its health benefits on hyperlipidemia. Furthermore, the effect of peeling processing on the efficacy of Chinese yam is still unclear. In this study, the improvement effects of whole Chinese yam (WY) and peeled Chinese yam (PY) on high-fat-diet (HFD)-induced hyperlipidemic mice were explored by evaluating the changes in physiological, biochemical, and histological parameters, and their modulatory effects on gut microbiota were further illustrated. The results show that both WY and PY could significantly attenuate the HFD-induced obesity phenotype, accompanied by the mitigative effect on epididymis adipose damage and hepatic tissue injury. Except for the ameliorative effect on TG, PY retained the beneficial effects of WY on hyperlipemia. Furthermore, 16S rRNA sequencing revealed that WY and PY reshaped the gut microbiota composition, especially the bloom of several beneficial bacterial strains (Akkermansia, Bifidobacterium, and Faecalibaculum) and the reduction in some HFD-dependent taxa (Mucispirillum, Coriobacteriaceae_UCG-002, and Candidatus_Saccharimonas). PICRUSt analysis showed that WY and PY could significantly regulate lipid transport and metabolism-related pathways. These findings suggest that Chinese yam can alleviate hyperlipidemia via the modulation of the gut microbiome, and peeling treatment had less of an effect on the lipid-lowering efficacy of yam.

Enhancing the stability of mung bean-based milk: Insights from protein characteristics and raw material selection.

Plant-based milk (PBM) alternatives are gaining popularity worldwide as the change of consumers' nutritional habits and health attitudes. Mung beans, recognized for their nutritional value, have gained attention as potential ingredients for PBM. Nevertheless, mung bean-based milk (MBM) faces instability issues common to other plant-based milks. This study investigated the factors influencing MBM stability focusing on raw materials. We selected 6 out of 20 varieties based on their MBM centrifugation sedimentation rates, representing both stable and unstable MBM. Stable MBM exhibited distinct advantages, including reduced separation rate, smaller particle size, lower viscosity, fewer protein aggregates, higher soluble protein content, and increased consumer acceptance. Major nutritional components such as protein, starch, and lipids were not significant different between stable and unstable MBM varieties. The pivotal distinction may lay in the protein properties and composition. Stable MBM varieties exhibited significantly improved protein solubility and emulsion stability, along with elevated concentrations of legume-like acidic subunits, basic 7S proteins, and 28 kDa and 26 kDa vicilin-like subunits. The increasement of these proteins likely contributed to the improvement in protein characteristics that affect MBM stability. These findings offer valuable insights for raw material selection and guidance for future mung bean breeding to enhance mung bean milk production.

Enhancing the Thermal Stability of Zein Particle-Stabilized Aeratable Emulsions Through Genipin-Protein Cross-Linking and Its Possible Mechanism of Action.

Protein particle-stabilized emulsions often lack thermal stability, impacting their industrial use. This study investigated the effects of genipin (GP)-zein cross-linked particles with varying GP-to-protein weight ratios (0/0.02/0.1:1) on emulsion thermal stability. Enhanced stability was observed at the GP level of 0.1. Heat treatment increased the covalent cross-linking in raw particles and emulsions. Isolated particles from heated emulsions grew in size (micrometer scale) with higher GP levels, unlike heated raw particles (nanoscale). GP-protein cross-linking reduced the droplet-droplet and particle-emulsifier interactions in the heated emulsion. Spectroscopic analysis and electrophoresis revealed that GP-zein cross-linking increased protein structural stability and inhibited nondisulfide and non-GP cross-linking reactions in heated emulsions. The GP-zein bridges between particles at the oil-water interface create strong connections in the particle layer (shell), referred to as "particle-shell locking", enhancing the thermal stability of emulsion significantly. This insight aids the future design of protein-particle-based emulsions, preserving properties like aeratability during thermal processing.

Non-starch polysaccharides from kidney beans: comprehensive insight into their extraction, structure and physicochemical and nutritional properties.

Kidney beans (Phaseolus vulgaris L.) are an important legume source of carbohydrates, proteins, and bioactive molecules and thus have attracted increasing attention for their high nutritional value and sustainability. Non-starch polysaccharides (NSPs) in kidney beans account for a high proportion and have a significant impact on their biological functions. Herein, we critically update the information on kidney bean varieties and factors that influence the physicochemical properties of carbohydrates, proteins, and phenolic compounds. Furthermore, their extraction methods, structural characteristics, and health regulatory effects, such as the regulation of intestinal health and anti-obesity and anti-diabetic effects, are also summarized. This review will provide suggestions for further investigation of the structure of kidney bean NSPs, their relationships with biological functions, and the development of NSPs as novel plant carbohydrate resources.

Mung bean protein as an emerging source of plant protein: a review on production methods, functional properties, modifications and its potential applications.

Plant protein is rapidly becoming more of a prime interest to consumers for its nutritional and functional properties, as well as the potential to replace animal protein. In the frame of alternative protein new sources, mung bean is becoming another legume crop that could provide high quality plant protein after soybean and pea. In particular, the 8S globulins in mung bean protein have high structural similarity and homology with soybean ß-conglycinin (7S globulin), with 68% sequence identity. Currently, mung bean protein has gained popularity in food industry because of its high nutritional value and peculiar functional properties. In that regard, various modification technologies have been applied to further broaden its application. Here, we provide a review of the composition, nutritional value, production methods, functional properties and modification technologies of mung bean protein. Furthermore, its potential applications in the new plant-based products, meat products, noodles, edible packaging films and bioactive compound carriers are highlighted to facilitate its utilization as an alternative plant protein, thus meeting consumer demands for high quality plant protein resources. © 2023 Society of Chemical Industry.

Physiological and RNA-Seq Analyses on Exogenous Strigolactones Alleviating Drought by Improving Antioxidation and Photosynthesis in Wheat (Triticum aestivum L.).

Drought poses a significant challenge to global wheat production, and the application of exogenous phytohormones offers a convenient approach to enhancing drought tolerance of wheat. However, little is known about the molecular mechanism by which strigolactones (SLs), newly discovered phytohormones, alleviate drought stress in wheat. Therefore, this study is aimed at elucidating the physiological and molecular mechanisms operating in wheat and gaining insights into the specific role of SLs in ameliorating responses to the stress. The results showed that SLs application upregulated the expression of genes associated with the antioxidant defense system (Fe/Mn-SOD, PER1, PER22, SPC4, CAT2, APX1, APX7, GSTU6, GST4, GOR, GRXC1, and GRXC15), chlorophyll biogenesis (CHLH, and CPX), light-harvesting chlorophyll A-B binding proteins (WHAB1.6, and LHC Ib-21), electron transfer (PNSL2), E3 ubiquitin-protein ligase (BB, CHIP, and RHY1A), heat stress transcription factor (HSFA1, HSFA4D, and HSFC2B), heat shock proteins (HSP23.2, HSP16.9A, HSP17.9A, HSP21, HSP70, HSP70-16, HSP70-17, HSP70-8, HSP90-5, and HSP90-6), DnaJ family members (ATJ1, ATJ3, and DJA6), as well as other chaperones (BAG1, CIP73, CIPB1, and CPN60I). but the expression level of genes involved in chlorophyll degradation (SGR, NOL, PPH, PAO, TIC55, and PTC52) as well as photorespiration (AGT2) was found to be downregulated by SLs priming. As a result, the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were enhanced, and chlorophyll content and photosynthetic rate were increased, which indicated the alleviation of drought stress in wheat. These findings demonstrated that SLs alleviate drought stress by promoting photosynthesis through enhancing chlorophyll levels, and by facilitating ROS scavenging through modulation of the antioxidant system. The study advances understandings of the molecular mechanism underlying SLs-mediated drought alleviation and provides valuable insights for implementing sustainable farming practice under water restriction.

Exogenous strigolactones alleviate drought stress in wheat (Triticum aestivum L.) by promoting cell wall biogenesis to optimize root architecture.

Exogenous strigolactones (SLs, GR24) are widely used to alleviate drought stress in wheat. The physiological and biochemical mechanisms via which SLs help overcome drought stress in wheat shoots have been reported; however, the mechanisms in wheat roots are unclear. The present study explored the effects of the exogenous application of SLs on wheat roots' growth and molecular responses under drought stress using physiological analysis and RNA-seq. RNA-seq of roots showed that SLs mainly upregulated signal transduction genes (SIS8, CBL3, GLR2.8, LRK10L-2.4, CRK29, and CRK8) and transcription factors genes (ABR1, BHLH61, and MYB93). Besides, SLs upregulated a few downstream target genes, including antioxidant genes (PER2, GSTF1, and GSTU6), cell wall biogenesis genes (SUS4, ADF3, UGT13248, UGT85A24, UGT709G2, BGLU31, and LAC5), an aquaporin-encoding gene (TIP4-3), and dehydrin-encoding genes (DHN2, DHN3, and DHN4). As a result, SLs reduced oxidative damage, optimized root architecture, improved leaf-water relation, and alleviated drought damage. Thus, the present study provides novel insights into GR24-mediated drought stress management and a scientific basis for proposing GR24 application.

The effect of heat treatment on the lactosylation of milk proteins.

Protein lactosylation is a significant modification that occurs during the heat treatment of dairy products, causing changes in proteins' physical-chemical and nutritional properties. Knowledge of the detailed lactosylation information on milk proteins under various heat treatments is important for selecting appropriate thermo-processing and identifying markers to monitor heat load in dairy products. In the present study, we used proteomics techniques to investigate lactosylated proteins under different heating temperatures. We observed a total of 123 lactosylated lysines in 65 proteins, with lactosylation even occurring in raw milk. The number of lactosylated lysines and proteins increased moderately at 75°C to 130°C, but dramatically at 140°C. We found that 6 out of 10, 9 out of 16, 6 out of 12, and 5 out of 15 lysine residues in κ-casein, ß-lactoglobulin, α-lactalbumin, and αS1-casein, respectively, were lactosylated under the applied heating treatment. Moreover, different lactosylation states of individual lysines and proteins can indicate the intensity of heating processes. Lactosylation of K14 in ß-lactoglobulin could distinguish pasteurized and UHT milk, while lactosylation of lactotransferrin can reflect moderate heat treatment of products.

The impact of insurance status on in-hospital mortality in patients with hyperglycaemic crisis: A propensity score matching analysis.

AIM: This study was designed to determine the associations between insurance status and clinical outcomes among patients with hyperglycaemic crisis. METHODS: Overall, 1668 patients with hyperglycaemic crisis were recruited from the Chongqing Medical University Medical Data Science Academy's big data platform. In-hospital mortality, length of stay and complications (i.e., hypoglycaemia, hypokalemia, pulmonary infection, multiple systemic organ failure, acute kidney injury and deep venous thrombosis) were assessed. Propensity score matching analysis was used to reduce the confounding bias, and univariate and multivariate logistic regression were used to estimate the effect of insurance status on mortality in patients with hyperglycaemic crisis. RESULTS: After matching one uninsured patient to two insured patients with a calliper of 0.02, the uninsured group suffered a higher burden of in-hospital mortality than the insured group (16.9% vs. 9.8%); the insured status (odds ratio = 0.216, 95% confidence interval = 0.079-0.587) was a potential protect factor for in-hospital mortality of patients with hyperglycaemic crisis in the multivariate logistic regression analysis. CONCLUSIONS: Insurance status is associated with the outcomes of hospitalisation for hyperglycaemic crisis; uninsured patients with hyperglycaemic crisis face a higher risk of mortality in China.

Protective Effects of White Kidney Bean (Phaseolus vulgaris L.) against Diet-Induced Hepatic Steatosis in Mice Are Linked to Modification of Gut Microbiota and Its Metabolites.

Disturbances in the gut microbiota and its derived metabolites are closely related to the occurrence and development of hepatic steatosis. The white kidney bean (WKB), as an excellent source of protein, dietary fiber, and phytochemicals, has recently received widespread attention and might exhibit beneficial effects on a high-fat diet (HFD)-induced hepatic steatosis via targeting gut microbiota and its metabolites. The results indicated that HFD, when supplemented with WKB for 12 weeks, could potently reduce obesity symptoms, serum lipid profiles, and glucose, as well as improve the insulin resistance and liver function markers in mice, thereby alleviating hepatic steatosis. An integrated fecal microbiome and metabolomics analysis further demonstrated that WKB was able to normalize HFD-induced gut dysbiosis in mice, thereby mediating the alterations of a wide range of metabolites. Particularly, WKB remarkably increased the relative abundance of probiotics (Akkermansiaceae, Bifidobacteriaceae, and norank_f_Muribaculaceae) and inhibited the growth of hazardous bacteria (Mucispirillum, Enterorhabdus, and Dubosiella) in diet-induced hepatic steatosis mice. Moreover, the significant differential metabolites altered by WKB were annotated in lipid metabolism, which could ameliorate hepatic steatosis via regulating glycerophospholipid metabolism. This study elucidated the role of WKB from the perspective of microbiome and metabolomics in preventing nonalcoholic fatty liver disease, which provides new insights for its application in functional foods.

A comprehensive review on oat milk: from oat nutrients and phytochemicals to its processing technologies, product features, and potential applications.

Plant-based milk alternatives have become increasingly desirable due to their sustainability and the increased consumer awareness of health. Among many varieties of emerging plant-based milk, the smooth texture and flavor of oat milk make it spread rapidly around the world. Furthermore, as a sustainable source of diet, oats can provide rich nutrients and phytochemicals. Issues on the stability, sensory properties, shelf life, and nutritional quality of oat milk have been highlighted in published studies. In this review, the processing techniques, quality improvement, and product features of oat milk are elaborated, and the potential applications of oat milk are summarized. Besides, the challenges and future perspectives of oat milk production in the future are discussed.

Effects of Co-Modification by Extrusion and Enzymatic Hydrolysis on Physicochemical Properties of Black Wheat Bran and Its Prebiotic Potential.

Black wheat bran (BWB) is an important source of dietary fiber (DF) and phenolic compounds and has stronger nutritional advantages than ordinary WB. However, the low content of soluble dietary fiber (SDF) negatively influences its physicochemical properties and nutritive functions. To obtain a higher content of SDF in BWB, we evaluated the impact of co-modification by extrusion and enzymes (cellulase, xylanase, high-temperature α-amylase, and acid protease) on water extractable arabinoxylan (WEAX) in BWB. An optimized co-modification method was obtained through single-factor and orthogonal experiments. The prebiotic potential of co-modified BWB was also evaluated using pooled fecal microbiota from young, healthy volunteers. The commonly investigated inulin served as a positive control. After co-modification, WEAX content was dramatically increased from 0.31 g/100 g to 3.03 g/100 g (p < 0.05). The water holding capacity, oil holding capacity, and cholesterol adsorption capacity (pH = 2.0 and pH = 7.0) of BWB were increased by 100%, 71%, 131%, and 133%, respectively (p < 0.05). Scanning electron microscopy demonstrated a looser and more porous microstructure for co-modified BWB granules. Through in vitro anerobic fermentation, co-modified BWB achieved a higher content of Bifidobacterium and Lactobacillus than inulin fermentation. In addition, co-modified BWB induced the highest butyric acid production, indicating high potential as prebiotics. The results may contribute to improving technologies for developing high-fiber-content cereal products.

Gamma-aminobutyric acid (GABA): a comprehensive review of dietary sources, enrichment technologies, processing effects, health benefits, and its applications.

Gamma-aminobutyric acid (GABA) is a naturally occurring potential bioactive compound present in plants, microorganisms, animals, and humans. Especially, as a main inhibitory neurotransmitter in the central nervous system, GABA possesses a broad spectrum of promising bioactivities. Thus, functional foods enriched with GABA have been widely sought after by consumers. However, the GABA levels in natural foods are usually low, which cannot meet people's demand for health effects. With the increasing public awareness on the food securities and naturally occurring processes, using enrichment technologies to elevate the GABA contents in foods instead of exogenous addition can enhance the acceptability of health-conscious consumers. Herein, this review provides a comprehensive insight on the dietary sources, enrichment technologies, processing effects of GABA, and its applications in food industry. Furthermore, the various health benefits of GABA-enriched foods, mainly including neuroprotection, anti-insomnia, anti-depression, anti-hypertensive, anti-diabetes, and anti-inflammatory are also summarized. The main challenges for future research on GABA are related to exploring high GABA producing strains, enhancing the stability of GABA during storage, and developing emerging enrichment technologies without affecting food quality and other active ingredients. A better understanding of GABA may introduce new windows for its application in developing functional foods.

Physical-Chemical and Sensory Quality of Oat Milk Produced Using Different Cultivars.

Oat milk, as an emerging plant-based milk substitute, has become popular in recent years. However, the stability and flavor of oat milk products are hindering their quality. The examination of the processing capacities of potential oat cultivars could help to improve product quality. In the present study, the properties of oat milk produced from one Australian and three Chinese cultivars were compared. The stability of oat milk produced using our manufacturing process was superior to the commercial product and was highly influenced by cultivars. Positive correlations of the cultivar's protein and plant cell debris content with the final products' separation rate, and the cultivar's lipid content with the final products' creaming, were observed. Among the investigated cultivars, Chinese Bayou 01 (ZBY01) was the most suitable for oat milk processing. Oat milk produced with this cultivar has better stability and sensory acceptability. It can provide around 1% of protein, 9.84 mg/mL of ß-glucan, and 70.96 mg GAE/100 g DW of polyphenols. Our results support one Chinese cultivar for oat milk processing and provide possible criteria for raw material selection.

An update on nutritional profile, phytochemical compounds, health benefits, and potential applications in the food industry of pulses seed coats: A comprehensive review.

Pulses, as a sustainable source of nutrients, are an important choice for human diets, but vast quantities of seed coats generated in pulses processing are usually discarded or used as low-value ruminant feed. It has been demonstrated that pulses seed coats are excellent sources of dietary nutrients and phytochemicals with potential health benefits. With growing interest in the sustainable use of resources and the circular economy, utilization of pulses seed coats to recover these valuable components is a core objective for their valorization and an important step toward agricultural sustainability. This review comprehensively provides a comprehensive insight on the nutritional and phytochemical profiles presented in pulses seed coats and their health benefits obtained from the findings of in vitro and in vivo studies. Furthermore, in the food industry, pulses seed coats can be acted as potential food ingredients with nutritional, antioxidant and antimicrobial characteristics or as the matrix or active components of films for food packaging and edible coatings. A better understanding of pulses seed coats may provide a reference for increasing the overall added value and realizing the pulses' sustainable diets.

Genome-wide association, RNA-seq and iTRAQ analyses identify candidate genes controlling radicle length of wheat.

The radicle, present in the embryo of a seed, is the first root to emerge at germination, and its rapid growth is essential for establishment and survival of the seedling. However, there are few studies on the critical mechanisms underlying radicle and then radicle length in wheat seedlings, despite its importance as a food crop throughout the world. In the present study, 196 wheat accessions from the Huanghuai Wheat Region were screened to measure radicle length under 4 hydroponic culture environments over 3 years. Different expression genes and proteins (DEGs/DEPs) between accessions with extremely long [Yunong 949 (WRL1), Zhongyu 9,302 (WRL2)] and short roots [Yunong 201 (WRS1), Beijing 841 (WRS2)] were identified in 12 sets of root tissue samples by RNA-seq and iTRAQ (Isobaric tags for relative and absolute quantification). Phenotypic results showed that the elongation zone was significantly longer in root accessions with long roots compared to the short-rooted accessions. A genome-wide association study (GWAS) identified four stable chromosomal regions significantly associated with radicle length, among which 1A, 4A, and 7A chromosomes regions explained 7.17% to12.93% of the phenotypic variation. The omics studies identified the expression patterns of 24 DEGs/DEPs changed at both the transcriptional and protein levels. These DEGs/DEPs were mainly involved in carbon fixation in photosynthetic organisms, photosynthesis and phenylpropanoid biosynthesis pathways. TraesCS1A02G104100 and TraesCS2B02G519100 were involved in the biosynthesis of tricin-lignins in cell walls and may affect the extension of cell walls in the radicle elongation zone. A combination of GWAS and RNA-seq analyses revealed 19 DEGs with expression changes in the four accessions, among which, TraesCS1A02G422700 (a cysteine-rich receptor-like protein kinase 6, CRK6) also showed upregulation in the comparison group by RNA-seq, iTRAQ, and qRT-PCR. BSMV-mediated gene silencing also showed that TaCRK6 improves root development in wheat. Our data suggest that TaCRK6 is a candidate gene regulating radicle length in wheat.

Metabolomic Analysis Reveals Changes of Bioactive Compounds in Mung Beans (Vigna radiata) during γ-Aminobutyric Acid Enrichment Treatment.

Soaking together with Heat and Relative Humidity (HRH) treatment has been applied successfully to enrich γ-aminobutyric acid (GABA) in mung beans. However, whether and how the above GABA enrichment processing influences the other bioactive molecules is elusive. In the present study, mung beans were soaked and then treated by HRH for 5 or 7 h. By using metabolomics techniques, the changes of 496 metabolites were determined. The relative content of flavonoids and phenolic acids increased during soaking but slightly decreased during HRH. Intriguingly, soaking and HRH had the opposite effects on the glycosylation of polyphenols. The relative content of glycosylated or un-glycosylated polyphenols increased during soaking or HRH, respectively. The relative content of α-ketoglutaric acid increased more than 20 times after 5 h HRH treatment. Bioactive molecules could be enriched during GABA enrichment processing. Depending on the desired bioactive compounds, soaking and different duration of HRH treatment could be selected.

Effect of an Environment Friendly Heat and Relative Humidity Approach on γ-Aminobutyric Acid Accumulation in Different Highland Barley Cultivars.

In this study, heat and relative humidity (HRH) treatment was applied in highland barley for γ-aminobutyric acid (GABA) accumulation. Tibetan highland barley cultivars (25) were selected for comparison and analysis. HRH treatment could accumulate GABA in several hours with low moisture content and high temperature, and the grains were treated for 2.5 h at 65 °C in this study. The GABA content of processed grains under HRH optimal condition ranged from 26.91 to 76.28 mg·100 g−1, which was significantly higher than the initial content (12.78−43.00 mg·100 g−1). The highest GABA accumulation capacity was observed in two-row yellow cultivars (YT1), increasing from 36.52 to 76.28 mg·100 g−1. Correlation analysis showed that the accumulation of GABA after HRH treatment was positively and significantly (p < 0.05) correlated with the contents of protein (0.52), total free amino acids (0.68), threonine (0.53), serine (0.51), glutamate (0.69), glycine (0.49), alanine (0.46), cysteine (0.57), tyrosine (0.50), lysine (0.53), proline (0.40), and glutamate decarboxylase (GAD) activity (0.62), which were closely related to GABA-shunt pathway. The polyamines contents, diamine oxidase (DAO) and polyamine oxidase (PAO) activities, as the substrates and critical enzymes of polyamine degradation pathway, showed no significant correlation with GABA accumulation. The results suggested that the main pathway of GABA accumulation in highland barley under HRH treatment was GABA-shunt pathway.