Zinc-finger protein GmZF351 improves both salt and drought stress tolerance in soybean.

Abiotic stress is one of the most important factors reducing soybean yield. It is essential to identify regulatory factors contributing to stress responses. A previous study found that the tandem CCCH zinc-finger protein GmZF351 is an oil level regulator. In this study, we discovered that the GmZF351 gene is induced by stress and that the overexpression of GmZF351 confers stress tolerance to transgenic soybean. GmZF351 directly regulates the expression of GmCIPK9 and GmSnRK, leading to stomata closing, by binding to their promoter regions, which carry two CT(G/C)(T/A)AA elements. Stress induction of GmZF351 is mediated through reduction in the H3K27me3 level at the GmZF351 locus. Two JMJ30-demethylase-like genes, GmJMJ30-1 and GmJMJ30-2, are involved in this demethylation process. Overexpression of GmJMJ30-1/2 in transgenic hairy roots enhances GmZF351 expression mediated by histone demethylation and confers stress tolerance to soybean. Yield-related agronomic traits were evaluated in stable GmZF351-transgenic plants under mild drought stress conditions. Our study reveals a new mode of GmJMJ30-GmZF351 action in stress tolerance, in addition to that of GmZF351 in oil accumulation. Manipulation of the components in this pathway is expected to improve soybean traits and adaptation under unfavorable environments.

Nuclear factor Y subunit GmNFYA competes with GmHDA13 for interaction with GmFVE to positively regulate salt tolerance in soybean.

Soybean is an important crop worldwide, but its production is severely affected by salt stress. Understanding the regulatory mechanism of salt response is crucial for improving the salt tolerance of soybean. Here, we reveal a role for nuclear factor Y subunit GmNFYA in salt tolerance of soybean likely through the regulation of histone acetylation. GmNFYA is induced by salt stress. Overexpression of GmNFYA significantly enhances salt tolerance in stable transgenic soybean plants by inducing salt-responsive genes. Analysis in soybean plants with transgenic hairy roots also supports the conclusion. GmNFYA interacts with GmFVE, which functions with putative histone deacetylase GmHDA13 in a complex for transcriptional repression possibly by reducing H3K9 acetylation at target loci. Under salt stress, GmNFYA likely accumulates and competes with GmHDA13 for interaction with GmFVE, leading to the derepression and maintenance of histone acetylation for activation of salt-responsive genes and finally conferring salt tolerance in soybean plants. In addition, a haplotype I GmNFYA promoter is identified with the highest self-activated promoter activity and may be selected during future breeding for salt-tolerant cultivars. Our study uncovers the epigenetic regulatory mechanism of GmNFYA in salt-stress response, and all the factors/elements identified may be potential targets for genetic manipulation of salt tolerance in soybean and other crops.

A transcriptional regulatory module controls lipid accumulation in soybean.

Soybean (Glycine max) is one of the most important oilseed crops. However, the regulatory mechanism that governs the process of oil accumulation in soybean remains poorly understood. In this study, GmZF392, a tandem CCCH zinc finger (TZF) protein which was identified in our previous RNA-seq analysis of seed-preferred transcription factors, was found to function as a positive regulator of lipid production. GmZF392 promotes seed oil accumulation in both transgenic Arabidopsis and stable transgenic soybean plants by binding to a bipartite cis-element, containing TG- and TA-rich sequences, in promoter regions, activating the expression of genes in the lipid biosynthesis pathway. GmZF392 physically interacts with GmZF351, our previously identified transcriptional regulator of lipid biosynthesis, to synergistically promote downstream gene expression. Both GmZF392 and GmZF351 are further upregulated by GmNFYA, another transcription factor involved in lipid biosynthesis, directly (in the former case) and indirectly (in the latter case). Promoter sequence diversity analysis showed that the GmZF392 promoter may have been selected at the origin of the Glycine genus and further mildly selected during domestication from wild soybeans to cultivated soybeans. Our study reveals a regulatory module containing three transcription factors in the lipid biosynthesis pathway, and manipulation of the module may improve oil production in soybean and other oilseed crops.

GmWRKY54 improves drought tolerance through activating genes in abscisic acid and Ca2+ signaling pathways in transgenic soybean.

WRKY transcription factors play important roles in response to various abiotic stresses. Previous study have proved that soybean GmWRKY54 can improve stress tolerance in transgenic Arabidopsis. Here, we generated soybean transgenic plants and further investigated roles and biological mechanisms of GmWRKY54 in response to drought stress. We demonstrated that expression of GmWRKY54, driven by either a constitutive promoter (pCm) or a drought-induced promoter (RD29a), confers drought tolerance. GmWRKY54 is a transcriptional activator and affects a large number of stress-related genes as revealed by RNA sequencing. Gene ontology (GO) enrichment and co-expression network analysis, together with measurement of physiological parameters, supported the idea that GmWRKY54 enhances stomatal closure to reduce water loss, and therefore confers drought tolerance in soybean. GmWRKY54 directly binds to the promoter regions of genes including PYL8, SRK2A, CIPK11 and CPK3 and activates them. Therefore GmWRKY54 achieves its function through abscisic acid (ABA) and Ca2+ signaling pathways. It is valuable that GmWRKY54 activates an ABA receptor and an SnRK2 kinase in the upstream position, unlike other WRKY proteins that regulate downstream genes in the ABA pathway. Our study revealed the role of GmWRKY54 in drought tolerance and further manipulation of this gene should improve growth and production in soybean and other legumes/crops under unfavorable conditions.

A class B heat shock factor selected for during soybean domestication contributes to salt tolerance by promoting flavonoid biosynthesis.

Soybean (Glycine max) production is severely affected in unfavorable environments. Identification of the regulatory factors conferring stress tolerance would facilitate soybean breeding. In this study, through coexpression network analysis of salt-tolerant wild soybeans, together with molecular and genetic approaches, we revealed a previously unidentified function of a class B heat shock factor, HSFB2b, in soybean salt stress response. We showed that HSFB2b improves salt tolerance through the promotion of flavonoid accumulation by activating one subset of flavonoid biosynthesis-related genes and by inhibiting the repressor gene GmNAC2 to release another subset of genes in the flavonoid biosynthesis pathway. Moreover, four promoter haplotypes of HSFB2b were identified from wild and cultivated soybeans. Promoter haplotype II from salt-tolerant wild soybean Y20, with high promoter activity under salt stress, is probably selected for during domestication. Another promoter haplotype, III, from salt-tolerant wild soybean Y55, had the highest promoter activity under salt stress, had a low distribution frequency and may be subjected to the next wave of selection. Together, our results revealed the mechanism of HSFB2b in soybean salt stress tolerance. Its promoter variations were identified, and the haplotype with high activity may be adopted for breeding better soybean cultivars that are adapted to stress conditions.

Selection for a Zinc-Finger Protein Contributes to Seed Oil Increase during Soybean Domestication.

Seed oil is a momentous agronomical trait of soybean (Glycine max) targeted by domestication in breeding. Although multiple oil-related genes have been uncovered, knowledge of the regulatory mechanism of seed oil biosynthesis is currently limited. We demonstrate that the seed-preferred gene GmZF351, encoding a tandem CCCH zinc finger protein, is selected during domestication. Further analysis shows that GmZF351 facilitates oil accumulation by directly activating WRINKLED1, BIOTIN CARBOXYL CARRIER PROTEIN2, 3-KETOACYL-ACYL CARRIER PROTEIN SYNTHASE III, DIACYLGLYCEROL O-ACYLTRANSFERASE1, and OLEOSIN2 in transgenic Arabidopsis (Arabidopsis thaliana) seeds. Overexpression of GmZF351 in transgenic soybean also activates lipid biosynthesis genes, thereby accelerating seed oil accumulation. The ZF351 haplotype from the cultivated soybean group and the wild soybean (Glycine soja) subgroup III correlates well with high gene expression level, seed oil contents and promoter activity, suggesting that selection of GmZF351 expression leads to increased seed oil content in cultivated soybean. Our study provides novel insights into the regulatory mechanism for seed oil accumulation, and the manipulation of GmZF351 may have great potential in the improvement of oil production in soybean and other related crops.

[Effects of fluid resuscitation on myocardial injury in patients with severe sepsis and septic shock].

OBJECTIVE: To observe the influence of fluid resuscitation on patients suffered from myocardial injury with severe sepsis and septic shock, and to evaluate the markers of myocardial injury during fluid resuscitation. METHODS: Acute physiology and chronic health evaluation II (APACHE II) score of 78 patients with severe sepsis and septic shock induced by combined injuries was 18-35. Serum cardiac troponin I (cTnI), N-terminal-ventricular natriuretic peptide precursor (NT-proBNP) and the hemodynamic parameters were recorded before, 3 days, and 5 days after treatment, and correlative analysis was conducted. RESULTS: Serum cTnI was increased in 62.8% (49/78) patients with severe sepsis and septic shock, and in 73.5% of patients (36/49) the increase was greater than 2-fold of the borderline value, and in 30.6% of patients (15/49) was greater than 4-fold of the borderline value. The patients with elevated serum NT-proBNP at admission accounted for 46.2% (36/78), and after fluid resuscitation treatment, patients with continuously rising value accounted for 74.4% (58/78). The serum cTnI, NT-proBNP, pulmonary arterial wedge pressure (PAWP) and cardiac index (CI) after treatment in survival group (55 cases) were obviously improved, and changes in them in non-survival group (23 cases) was not obvious. The serum cTnI (µg/L) and NT-proBNP (ng/L) levels in the non-survival group were distinctly higher than those of the survival group (cTnI 3 days: 2.09 ± 1.00 vs. 1.57 ± 0.93, 5 days: 1.78 ± 0.67 vs. 0.72 ± 0.51; NT-proBNP 3 days: 3.52 ± 0.73 vs. 3.16 ± 0.65, 5 days: 3.21 ± 0.66 vs. 2.66 ± 0.58), and CI [ml·s(-1)·m(-2)] was obviously lower than that of the survival group (3 days: 57.6 ± 6.2 vs. 68.3 ± 5.6, 5 days: 40.5 ± 4.7 vs. 80.7 ± 6.8, all P < 0.05). The cTnI level (µg/L) of 46 patients whose fluid resuscitation achieved the target was lower than that of the 32 cases without achieving the target (1.16 ± 0.62 vs. 1.97 ± 0.76, P < 0.05), and the CI [ml·s(-1)·m(-2)] was obviously increased (61.2 ± 6.4 vs. 49.3 ± 6.1, P < 0.05). The results suggested that whether the fluid resuscitation achieved the target or not was not related to changes in serum NT-proBNP and PAWP. A positive correlation was found between serum cTnI and NT-proBNP (r = 0.865, Y = 2.069 + 0.695X, P < 0.01), also between NT-proBNP and PAWP (r = 0.762, Y = 1.125 + 4.929X, P < 0.01), and a negative correlation was found between cTnI and CI (r = -0.891, Y = 50.623 - 6.114X, P < 0.01). CONCLUSIONS: There is an obvious myocardial injury in the patient with severe sepsis and septic shock, and fluid resuscitation can improve the myocardial injury; the serum levels of cTnI and NT-proBNP are related to the prognosis of patients, but the significance of NT-proBNP guiding the fluid resuscitation can not be ascertained.

Childhood maltreatment on young adult depression: A moderated mediation model of negative automatic thoughts and self-compassion.

This study examines the mediating role of negative automatic thoughts on the link between childhood maltreatment and young adult depression, and the moderating role of self-compassion in this indirect link. College students (N = 578) completed self-report questionnaires assessing the mentioned study variables. The results showed that childhood maltreatment was positively associated with young adult depression via negative automatic thoughts. Moreover, self-compassion moderated this indirect link such that participants with low self-compassion demonstrated a stronger indirect link than those with high self-compassion. These findings highlight the important role of self-compassion in countering the adverse outcomes of childhood maltreatment.

Three SAUR proteins SAUR76, SAUR77 and SAUR78 promote plant growth in Arabidopsis.

Ethylene perceived by a family of five receptors regulates many developmental processes in Arabidopsis. Here we conducted the yeast two-hybrid assay to screen for additional unidentified proteins that interact with subfamily II ethylene receptor ETR2. Three SAUR proteins, named SAUR76, 77 and 78, were identified to associate with both ETR2 and EIN4 in different assays. Interaction of SAUR76 and SAUR78 with ETR2 was further verified by co-immunoprecipitation and bimolecular fluorescence complementation (BiFC) assays. Expressions of SAUR76-78 are induced by auxin and ethylene treatments. Compared with wild type, SAUR-overexpressing plants exhibit reduced ethylene sensitivity, while SAUR-RNAi lines exhibit enhanced ethylene sensitivity. Overexpressing the three SAURs partially complements the phenotype of subfamily II ethylene receptor loss-of-function double mutant etr2-3ein4-4, which has increased ethylene response and small cotyledon and rosette. saur76 mutation partially suppresses the reduced ethylene sensitivity of etr2-2. SAUR76/78 proteins are regulated by 26S proteasome system and larger tag increases their protein stability. These findings suggest that SAUR76-78 may affect ethylene receptor signaling and promote plant growth in Arabidopsis.

Cardioprotective effect of erythropoietin on sepsis-induced myocardial injury in rats.

BACKGROUND: Sepsis-induced myocardial injury is one of the major predictors of morbidity and mortality of sepsis. The cytoprotective function of erythropoietin (EPO) has been discovered and extensively studied. However, the cardioprotective effects of EPO on sepsis-induced myocardial injury in the rat sepsis model has not been reported. METHODS: The rat models of sepsis were produced by cecal ligation and perforation (CLP) surgery. Rats were randomly (random number) assigned to one of three groups (n=8 for each group): sham group, CLP group and EPO group (1000 IU/kg erythropoietin). Arterial blood was withdrawn at 3, 6, 12, and 24 hours after CLP. cTnI, BNP, CK-MB, LDH, AST, TNF-α, IL-6, IL-10, and CRP were tested by the ELISA assay. Changes of hemodynamic parameters were recorded at 3, 6, 12, 24 hours after the surgery. Histological diagnosis was made by hematoxylin and eosin. Flow cytometry was performed to examine cell apoptosis, myocardium mitochondrial inner membrane potential, and NF-κB (p65). Survival rate at 7 days after CLP was recorded. RESULTS: In the CLP group, myocardial enzyme index and inflammatory index increased at 3, 6, 12 and 24 hours after CLP compared with the sham group, and EPO significantly blocked the increase. Compared with the CLP group, EPO significantly improved LVSP, LV +dp/dt max, LV -dp/dt min, and decreased LVEDP at different time. EPO blocked the reduction of mitochondrial transmembrane potential, suppressed the cardiomyocyte apoptosis, inhibited the activation of NF-κB, and reduced the production of proinflmmatory cytokines. No difference in the survival rate at 7 days was observed between the CLP group and the EPO group. CONCLUSION: Exogenous EPO has cardioprotective effects on sepsis-induced myocardial injury.