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Selection and utilization of salt-tolerant crops are essential strategies for mitigating salinity damage to crop productivity with increasing soil salinization worldwide. This study was conducted to identify salt-tolerant white clover (Trifolium repens) genotypes among 37 materials based on a comprehensive evaluation of five physiological parameters, namely, chlorophyll (Chl) content, photochemical efficiency of PS II (Fv/Fm), performance index on an absorption basis (PIABS), and leaf relative water content (RWC), and to further analyze the potential mechanism of salt tolerance associated with changes in growth, photosynthetic performance, endogenous polyamine metabolism, and Na+/K+ uptake and transport. The results showed that significant variations in salt tolerance were identified among 37 genotypes, as PI237292 and Tr005 were the top two genotypes with the highest salt tolerance, and PI251432 and Korla were the most salt-sensitive genotypes compared to other materials. The salt-tolerant PI237292 and Tr005 not only maintained significantly lower EL but also showed significantly better photosynthetic performance, higher leaf RWC, underground dry weight, and the root to shoot ratio than the salt-sensitive PI251432 and Korla under salt stress. Increases in endogenous PAs, putrescine (Put), and spermidine (Spd) contents could be key adaptive responses to salt stress in the PI237292 and the Tr005 through upregulating genes encoding Put and Spd biosynthesis (NCA, ADC, SAMDC, and SPDS2). For Na+ and K+ accumulation and transport, higher salt tolerance of the PI237292 could be associated with the maintenance of Na+ and Ca+ homeostasis associated with upregulations of NCLX and BTB/POZ. The K+ homeostasis-related genes (KEA2, HAK25, SKOR, POT2/8/11, TPK3/5, and AKT1/5) are differentially expressed among four genotypes under salt stress. However, the K+ level and K+/Na+ ratio were not completely consistent with the salt tolerance of the four genotypes. The regulatory function of these differentially expressed genes (DEGs) on salt tolerance in the white clover and other leguminous plants needs to be investigated further. The current findings also provide basic genotypes for molecular-based breeding for salt tolerance in white clover species.

Abstract Background Chitosan (CTS), a natural polysaccharide, exhibits multiple functions of stress adaptation regulation in plants. However, effects and mechanism of CTS on alleviating salt stress damage are still not fully understood. Objectives of this study were to investigate the function of CTS on improving salt tolerance associated with metabolic balance, polyamine (PAs) accumulation, and Na+ transport in creeping bentgrass (Agrostis stolonifera). Results CTS pretreatment significantly alleviated declines in relative water content, photosynthesis, photochemical efficiency, and water use efficiency in leaves under salt stress. Exogenous CTS increased endogenous PAs accumulation, antioxidant enzyme (SOD, POD, and CAT) activities, and sucrose accumulation and metabolism through the activation of sucrose synthase and pyruvate kinase activities, and inhibition of invertase activity. The CTS also improved total amino acids, glutamic acid, and γ-aminobutyric acid (GABA) accumulation. In addition, CTS-pretreated plants exhibited significantly higher Na+ content in roots and lower Na+ accumulation in leaves then untreated plants in response to salt stress. However, CTS had no significant effects on K+/Na+ ratio. Importantly, CTS enhanced salt overly sensitive (SOS) pathways and also up-regulated the expression of AsHKT1 and genes (AsNHX4, AsNHX5, and AsNHX6) encoding Na+/H+ exchangers under salt stress. Conclusions The application of CTS increased antioxidant enzyme activities, thereby reducing oxidative damage to roots and leaves. CTS-induced increases in sucrose and GABA accumulation and metabolism played important roles in osmotic adjustment and energy metabolism during salt stress. The CTS also enhanced SOS pathway associated with Na+ excretion from cytosol into rhizosphere, increased AsHKT1 expression inhibiting Na+ transport to the photosynthetic tissues, and also up-regulated the expression of AsNHX4, AsNHX5, and AsNHX6 promoting the capacity of Na+ compartmentalization in roots and leaves under salt stress. In addition, CTS-induced PAs accumulation could be an important regulatory mechanism contributing to enhanced salt tolerance. These findings reveal new functions of CTS on regulating Na+ transport, enhancing sugars and amino acids metabolism for osmotic adjustment and energy supply, and increasing PAs accumulation when creeping bentgrass responds to salt stress.

Drought is a serious outcome of climate change reducing the productivity of forage species under arid and semi-arid conditions worldwide. Diethyl aminoethyl hexanoate (DA-6), a novel plant growth regulator, has proven to be involved in the amelioration of critical physiological functions in many agricultural crops under various abiotic stresses, but the role of the DA-6 in improving seed germination has never been investigated under drought stress. The present study was carried out to elucidate the impact of the DA-6 priming on seeds germination of white clover under drought stress. Results showed that seed priming with the DA-6 significantly mitigated the drought-induced reduction in germination percentage, germination vigor, germination index, seed vigor index, root length, shoot length, and fresh weight after 7 days of seed germination. The DA-6 significantly increased the endogenous indole-3-acetic acid, gibberellin, and cytokinin content with marked reduction in abscisic acid content in seedlings under drought stress. In addition, the DA-6 significantly accelerated starch catabolism by enhancing the activities of hydrolases contributing toward enhanced soluble sugars, proline content and ameliorated the antioxidant defense system to enhance the ability of reactive oxygen species scavenging under drought stress. Furthermore, exogenous DA-6 application significantly increased dehydrins accumulation and upregulated transcript levels of genes encoding dehydrins (SK2, Y2SK, or DHNb) during seeds germination under water deficient condition. These findings suggested that the DA-6 mediated seeds germination and drought tolerance associated with changes in endogenous phytohormones resulting in increased starch degradation, osmotic adjustment, antioxidants activity, and dehydrins accumulation during seed germination under water deficient condition.

Physiology characteristics and agronomic trait of peanut during its growing season were studied in both lime concretion black soil and sandy loam soil. Results showed that the chlorophyll content of leaf, SOD, POD and CAT activities, soluble protein content and leaf area index (LAI) in peanut growing season presented single -peak curves. The peak values appeared during 60 to 75 days after seedling emergence. Chlorophyll, soluble protein contents and LAI of peanut in black soil were higher than those in sandy soil. The anti - aging enzymes activities and MDA content of peanut in black soil were lower. The peak value and duration of peak value of LAI and dry matter accumulation rate of peanut in black soil were significantly higher and longer than those in sandy soil. The height of main stem, length of lateral branch, number of pods and other main agronomic characteristics of peanut in black soil were significantly better than that of peanut in sandy soil ( p < 0. 05 ) . Biological yield and pod yield of peanut in black soil were 30% and 42.9% higher compared to that of peanut in sandy soil. [ABSTRACT FROM AUTHOR]

"Ideal Harmoniousness" is one of the principal characteristics of the Chinese culture and the notion of harmony and the explorations of constructing harmonious society are found to be pervasive in the Book of Changes. This paper aims at sorting Out the aims, principles, and particular methodologies of constructing harmonious society laid out in the Book of Changes. It is discerned that these ideas are still of practical significance and important values for our current reference in constructing the Socialist Society. [ABSTRACT FROM AUTHOR]

Background Characteristics of glucose metabolism disorders (GMDs) in different cancers and the contributory role of GMDs in developing cancers are still not so clear. Methods Two thousand four hundred and five patients with malignancy who had been hospitalized in the First Affiliated Hospital of Jinan University were pooled as case group. Two thousand and sixteen non-cancer people who finished health examinations in the Affiliated Yangcheng Hospital of Guangzhou Medical College were enrolled as control group. We compared glucose metabolism among patients with different kinds of malignancy. Based on logistic regression models, we analyzed factors that affect the development of carcinoma. Results (1) Among 2,408 malignancy patients, the total prevalence of diabetes mellitus (DM) and impaired fasting glucose (IFG) reached 28.0%. Pancreatic cancer, lymphoma, liver cancer, leukemia, and colorectal cancer showed most striking hyperglycemia. (2) Leukemia and esophageal cancer accounting for 12.5% and 12.1%, respectively, were the most likely to suffer from hypoglycemia. (3) Older cancer patients seem to be more vulnerable to hyperglycemia, while the younger tend to be more likely to develop hypoglycemia. (4) High level of fasting plasma glucose (FPG) was associated with lung cancer, breast cancer, leukemia, lymphoma, thyroid cancer, bladder cancer, and pancreatic cancer. Patients with DM increased risks for developing colorectal cancer, liver cancer, esophageal cancer, thyroid cancer, cervical cancer, and pancreatic cancer. Conclusions GMDs are frequent events in malignancy patients. Hyperglycemia and hypoglycemia are found in the same kinds or different kinds of cancers, and the incidence of hyperglycemia is higher than that of hypoglycemia. Characteristics of GMDs were dissimilar in different cancers and different ages. Hyperglycemia was a risk factor for many cancers. [ABSTRACT FROM AUTHOR]