TRANSTHYRETIN-LIKE and BYPASS1-LIKE co-regulate growth and cold tolerance in Arabidopsis

BACKGROUND

Cold stress inhibits normal physiological metabolism in plants, thereby seriously affecting plant development. Meanwhile, plants also actively adjust their metabolism and development to adapt to changing environments. Several cold tolerance regulators have been found to participate in the regulation of plant development. Previously, we reported that BYPASS1-LIKE (B1L), a DUF793 family protein, participates in the regulation of cold tolerance, at least partly through stabilizing C-REPEAT BINDING FACTORS (CBFs). In this study, we found that B1L interacts with TRANSTHYRETIN-LIKE (TTL) protein, which is involved in brassinosteroid (BR)-mediated plant growth and catalyses the synthesis of S-allantoin, and both proteins participate in modulating plant growth and cold tolerance.

RESULTS

The results obtained with yeast two hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays showed that B1L directly interacted with TTL. Similar to the ttl-1 and ttl-2 mutants, the b1l mutant displayed a longer hypocotyl and greater fresh weight than wild type, whereas B1L-overexpressing lines exhibited a shorter hypocotyl and reduced fresh weight. Moreover, ttl-1 displayed freezing tolerance to cold treatment compared with WT, whereas the b1l mutant and TTL-overexpressing lines were freezing-sensitive. The b1l ttl double mutant had a developmental phenotype and freezing tolerance that were highly similar to those of ttl-1 compared to b1l, indicating that TTL is important for B1L function. Although low concentrations of brassinolide (0.1 or 1 nM) displayed similarly promoted hypocotyl elongation of WT and b1l under normal temperature, it showed less effect to the hypocotyl elongation of b1l than to that of WT under cold conditions. In addition, the b1l mutant also contained less amount of allantoin than Col-0.

CONCLUSION

Our results indicate that B1L and TTL co-regulate development and cold tolerance in Arabidopsis, and BR and allantoin may participate in these processes through B1L and TTL.

Morphological changes in subregions of hippocampus and amygdala in major depressive disorder patients

Despite many neuroimaging studies in the past years, the neuroanatomical substrates of major depressive disorder (MDD) subcortical structures are still not well understood. Since hippocampus and amygdala are the two vital subcortical structures that most susceptible to MDD, finding the evidence of morphological changes in their subregions may bring some new insights for MDD research. Combining structural magnetic resonance imaging (MRI) with novel morphometry analysis methods, we recruited 25 MDD patients and 28 healthy controls (HC), and investigated their volume and morphological differences in hippocampus and amygdala. Relative to volumetric method, our methods detected more significant global morphological atrophies (p<0.05). More precisely, subiculum and cornu ammonis (CA) 1 subregions of bilateral hippocampus, lateral (LA) and basolateral ventromedial (BLVM) of left amygdala and LA, BLVM, central (CE), amygdalostriatal transition area (ASTR), anterior cortical (ACO) and anterior amygdaloid area (AAA) of right amygdala were demonstrated prone to atrophy. Correlation analyses between each subject's surface eigenvalues and Hamilton Depression Scale (HAMD) were then performed. Correlation results showed that atrophy areas in hippocampus and amygdala have slight tendencies of expanding into other subregions with the development of MDD. Finally, we performed group morphometric analysis and drew the atrophy and expansion areas between MDD-Medicated group (only 19 medicated subjects in MDD group were included) and HC group, found some preliminary evidence about subregional morphological resilience of hippocampus and amygdala. These findings revealed new pathophysiologic patterns in the subregions of hippocampus and amygdala, which can help with subsequent smaller-scale MDD research.

Soybean glycinin decreased growth performance, impaired intestinal health, and amino acid absorption capacity of juvenile grass carp (Ctenopharyngodon idella)

The present study evaluated the influence of dietary soybean glycinin on growth performance, intestinal morphology, free intestinal amino acid (AA) content, and intestinal AA transporter (AAT) mRNA levels in juvenile grass carp (Ctenopharyngodon idella). Results were displayed as follows: (1) 8% dietary glycinin decreased growth performance, inhibited intestinal growth, and caused intestinal histology damage of grass carp; (2) dietary glycinin decreased the content of free neutral AAs including Val, Ser, Tyr, Ala, Pro, and Gln in all intestinal segments, and Thr, Ile, Leu, Phe, and Gly in the MI and DI while downregulated the mRNA levels of corresponding transporters including SLC38A2, SLC6A19b, and SLC6A14 in all intestinal segments, and SLC7A5, SLC7A8, and SLC1A5 in the MI and DI. Dietary glycinin decreased the content of free basic AAs including Arg in the MI and DI and His in all intestinal segments while downregulated cationic AAT SLC7A1 mRNA levels in the MI and DI. Dietary glycinin decreased the content of free acidic AAs including Glu in all intestinal segments and Asp in the MI and DI while decreased mRNA levels of corresponding transporters including SLC1A2a in all intestinal segments and SLC1A3 in the MI and DI; (3) the digestion trial showed that basic subunits of glycinin was hard to digest in the intestine of grass carp; (4) co-administration of glutamine with glycinin partially alleviated the negative effects. Overall, glycinin decreased intestinal AA absorption capacity partly contributed by decreased AATs' mRNA levels and the indigestibility of glycinin.

Evolution and expression analyses of the MADS-box gene family in Brassica napus

MADS-box transcription factors are important for plant growth and development, and hundreds of MADS-box genes have been functionally characterized in plants. However, less is known about the functions of these genes in the economically important allopolyploid oil crop, Brassica napus. We identified 307 potential MADS-box genes (BnMADSs) in the B. napus genome and categorized them into type I (Mα, Mβ, and Mγ) and type II (MADS DNA-binding domain, intervening domain, keratin-like domain, and C-terminal domain [MIKC]c and MIKC*) based on phylogeny, protein motif structure, and exon-intron organization. We identified one conserved intron pattern in the MADS-box domain and seven conserved intron patterns in the K-box domain of the MIKCc genes that were previously ignored and may be associated with function. Chromosome distribution and synteny analysis revealed that hybridization between Brassica rapa and Brassica oleracea, segmental duplication, and homologous exchange (HE) in B. napus were the main BnMADSs expansion mechanisms. Promoter cis-element analyses indicated that BnMADSs may respond to various stressors (drought, heat, hormones) and light. Expression analyses showed that homologous genes in a given subfamily or sister pair are highly conserved, indicating widespread functional conservation and redundancy. Analyses of BnMADSs provide a basis for understanding their functional roles in plant development.

Study on expression of plasma sCD138 in patients with hemorrhagic fever with renal syndrome

BACKGROUND

Until now, there is non-specific treatment, and exploring early and novel biomarkers to determine the disease severity and prognosis of hemorrhagic fever with renal syndrome (HFRS) would be of importance for clinician to take systematic and timely intervention. This study observed the expression of plasma sCD138, a soluble component shedding from the glycocalyx (GCX) to the circulating blood, and evaluated its predictive value on disease severity and prognosis of HFRS.

METHODS

One hundred and seventy-six patients with HFRS who were treated at our center between January 2011 and December 2013 were randomly enrolled in this study. The patients were divided into a mild-type group, a moderate-type group, a severe-type group and a critical-type group according to the HFRS criteria for clinical classification. Thirty-five blood samples from healthy subjects were obtained as the controls. The concentrations of sCD138 were detected using enzyme linked immunosorbent assay (ELISA). The levels of prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib), albumin (ALB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), white blood cells (WBC), platelets (PLT), glucose (GLU), blood urea nitrogen (BUN) and serum creatinine (Scr) in the samples were routinely tested. The levels of sCD138 among the different types were compared; the correlation among sCD138 and the laboratory parameters mentioned above were analyzed. The predictive effectiveness for prognosis of sCD138 was evaluated using the receiver operating characteristic (ROC) curve analysis.

RESULTS

Except for the mild-type, the levels of sCD138 in the moderate-, severe- and critical-type patients during the acute stage were significantly higher than that of the convalescent stage and the control (P<0.05). With the aggravation of the disease, the levels of sCD138 during the acute stage had an increasing tendency, while demonstrated no significant difference among the moderate-, severe- and critical-type patients (P>0.05). sCD138 was negatively correlated with Fib, PLT and ALB, and was positively correlated with WBC and AST (P<0.05). sCD138 demonstrated predictive effectiveness for prognosis with the area under the curve (AUC) of 0.778 (P<0.001).

CONCLUSION

Dynamic detection of plasma sCD138 might be benefit to evaluating the disease severity and prognosis of the patients with HFRS.

Physical and Flavor Characteristics, Fatty Acid Profile, Antioxidant Status and Nrf2-Dependent Antioxidant Enzyme Gene Expression Changes in Young Grass Carp (Ctenopharyngodon idella) Fillets Fed Dietary Valine

This study was conducted to examine the effects of dietary valine on the physical and flavor characteristics, fatty acid (FA) profile, antioxidant status and Nrf2-dependent antioxidant enzyme gene expression in the muscle of young grass carp (Ctenopharyngodon idella) fed increasing levels of valine (4.3, 8.0, 10.6, 13.1, 16.9 and 19.1 g/kg) for 8 weeks. Compared with the control group, the group fed valine showed improved physical characteristics of fish fillets (increased relative shear force, hydroxyproline, protein and lipid levels and decreased cathepsin B and L activities, as well as cooking loss, were observed). Moreover, valine improved the flavor of young grass carp fillets by increasing the amino acid (AA) concentration in fish muscle (increased aspartic acid, threonine, glutamine, cystine, methionine, leucine, tyrosine, phenylalanine, lysine, histidine, arginine and valine concentrations were observed). Additionally, optimal valine supplementation increased the potential health benefits to humans by decreasing the saturated FA (C15:0 and C16:0) concentration and increasing the unsaturated FA (monounsaturated FAs (MUFAs), such as C16:1, C18:1c+t and C20:1, and polyunsaturated FAs (PUFAs), such as C18:3n-3, C20:2 and C22:6) concentration. In addition, the reduced glutathione (GSH) content and the activities of Cu/Zn superoxide dismutase (SOD1), catalase (CAT) and Selenium-dependent glutathione peroxydase (Se-GPx) increased under valine supplementation (P < 0.05). Furthermore, the SOD1, CAT and Se-GPx mRNA levels increased with dietary valine levels, possibly due to the up-regulation of NF-E2-related factor 2 (Nrf2), target of rapamycin (TOR) and ribosomal protein S6 kinase 1 (S6K1) and the down-regulation of Kelch-like-ECH-associated protein 1 (Keap1) in muscle (P < 0.05). In conclusion, valine improved the physical and flavor characteristics, FA profile, and antioxidant status and regulated the expression of the antioxidant enzyme genes Nrf2, Keap1, TOR and S6K1 in fish fillets.