Heat-response patterns of the heat shock transcription factor family in advanced development stages of wheat (Triticum aestivum L.) and thermotolerance-regulation by TaHsfA2-10.

BACKGROUND: Heat shock transcription factors (Hsfs) are present in majority of plants and play central roles in thermotolerance, transgenerational thermomemory, and many other stress responses. Our previous paper identified at least 82 Hsf members in a genome-wide study on wheat (Triticum aestivum L.). In this study, we analyzed the Hsf expression profiles in the advanced development stages of wheat, isolated the markedly heat-responsive gene TaHsfA2-10 (GenBank accession number MK922287), and characterized this gene and its role in thermotolerance regulation in seedlings of Arabidopsis thaliana (L. Heynh.). RESULTS: In the advanced development stages, wheat Hsf family transcription profiles exhibit different expression patterns and varying heat-responses in leaves and roots, and Hsfs are constitutively expressed to different degrees under the normal growth conditions. Overall, the majority of group A and B Hsfs are expressed in leaves while group C Hsfs are expressed at higher levels in roots. The expression of a few Hsf genes could not be detected. Heat shock (HS) caused upregulation about a quarter of genes in leaves and roots, while a number of genes were downregulated in response to HS. The highly heat-responsive gene TaHsfA2-10 was isolated through homeologous cloning. qRT-PCR revealed that TaHsfA2-10 is expressed in a wide range of tissues and organs of different development stages of wheat under the normal growth conditions. Compared to non-stress treatment, TaHsfA2-10 was highly upregulated in response to HS, H2O2, and salicylic acid (SA), and was downregulated by abscisic acid (ABA) treatment in two-leaf-old seedlings. Transient transfection of tobacco epidermal cells revealed subcellular localization of TaHsfA2-10 in the nucleus under the normal growth conditions. Phenotypic observation indicated that TaHsfA2-10 could improve both basal thermotolerance and acquired thermotolerance of transgenic Arabidopsis thaliana seedlings and rescue the thermotolerance defect of the T-DNA insertion mutant athsfa2 during HS. Compared to wild type (WT) seedlings, the TaHsfA2-10-overexpressing lines displayed both higher chlorophyll contents and higher survival rates. Yeast one-hybrid assay results revealed that TaHsfA2-10 had transactivation activity. The expression levels of thermotolerance-related AtHsps in the TaHsfA2-10 transgeinc Arabidopsis thaliana were higher than those in WT after HS. CONCLUSIONS: Wheat Hsf family members exhibit diversification and specificity of transcription expression patterns in advanced development stages under the normal conditions and after HS. As a markedly responsive transcriptional factor to HS, SA and H2O2, TaHsfA2-10 involves in thermotolerance regulation of plants through binding to the HS responsive element in promoter domain of relative Hsps and upregulating the expression of Hsp genes.

ZmHsf05, a new heat shock transcription factor from Zea mays L. improves thermotolerance in Arabidopsis thaliana and rescues thermotolerance defects of the athsfa2 mutant.

High temperature directly affects the yield and quality of crops. Plant Hsfs play vital roles in plant response to heat shock. In the present study, ZmHsf05 was isolated from maize (Zea mays L.) using homologous cloning methods. The sequencing analysis demonstrated that CDS of ZmHsf05 was 1080 bp length and encoded a protein containing 359 amino acids. The putative amino acid sequence of ZmHsf05 contained typical Hsf domains, such as DBD, OD, NLS and AHA motif. Subcellular localization assays displayed that the ZmHsf05 is localized to the nucleus. ZmHsf05 was expressed in many maize tissues and its expression level was increased by heat stress treatment. ZmHsf05 rescued the reduced thermotolerance of the athsfa2 mutant in Arabidopsis seedlings. Arabidopsis seedlings of ZmHsf05-overexpressing increased both the basal and acquired thermotolerances. After heat stress, the ZmHsf05-overexpressing lines showed enhanced survival rate and chlorophyll content compared with WT seedlings. The expression of Hsps was up-regulated in the ZmHsf05-overexpressing Arabidopsis lines after heat stress treatment. These results suggested that ZmHsf05 plays an important role in both basal and acquired thermotolerance in plants.

[Nitrogen flow characteristic and use efficiency in mixed crop-livestock system in North China Plain: Hebei Jinlong Circular Agriculture Farm as an example]. / åŽåŒ—å¹³åŽŸç§å »ä¸€ä½“è§„æ¨¡åŒ–å†œåœºæ°®ç´ æµåŠ¨ç‰¹å¾åŠåˆ©ç”¨æ•ˆçŽ‡­­ä»¥æ²³åŒ—津龙循环农业园区为例.

Scale and intensive development of mixed crop-livestock agriculture is inevitable in North China Plain (NCP), and nitrogen (N) is one of the key elements that linked the crop and livestock production. Here, we used Hebei Jinlong Circular Agriculture Farm as an example, to analyze the N flow and use efficiency, by using data from literature, on-farm survey and modeling. Further, several on-farm N management improvement practices were proposed and evaluated through scenario analysis, to supply technical support and scientific basis not only for achieving higher N use efficiency and productivity at the farm level, but also providing a new model of circular agriculture in NCP. Our results indicated that manure and purchased fertilizer were the main N input in crop production, which amounted to 674.6 kg N·hm-2·a-1 and accounted for 88.3% of the total N input. Of all the N input in crop production system, only 41.5% ended up in the crop products and around 190.7 kg N·hm-2·a-1 surplus. The excess input of synthetic fertilizer was the main reason for low N use efficiency and high N surplus for crop system. Purchased feed was the main N input pathway in livestock production system, and accounted for 83.2% of the total N input. The annual N excretion rate was 776.6 t N, and around 36.3% of the excreted N was recycled to the crop system. The N use efficiency was 19.7% for livestock production system. The N use efficiency was 40.7% at the whole farm level. The scenarios analysis showed that reducing purchased fertilizer N input by 50% (scenario 1) and increasing the total maize production via adjustment of cropping structure (scenario 2) would increase the N use efficiency in cropping system by 18.7% and 9.8%, respectively. The whole farm use efficiency could be increased by 19.1% through optimizing the feed compositions and regimes (scenario 3). Therefore, reducing purchased fertilizer N input, adjustment of cropping structure and optimizing the feed compositions could increase the N production capacity and achieve an environmental friendly mixed crop-livestock production system simultaneously in NCP.

Clustering of inflammatory biomarkers and risk of hypertension in a Mongolian population in China.

OBJECTIVE: There is little knowledge on whether there is clustering of inflammatory biomarkers, such as C-reactive protein (CRP), soluble intracellular adhesion molecule1-1 (sICAM-1), and angiotensin II (Ang II), in individuals with hypertension in the Mongolian population. In the present study, we investigated this relationship in a Mongolian population in China. METHODS: A total of 2589 adult Mongolians, aged 20 years and older, were recruited as study participants. Data on demographics, lifestyle, family history of hypertension, blood pressure, and blood chemistry were collected, and inflammatory biomarkers were measured in all participants. RESULTS: The proportion of subjects with increased levels of two or three biomarkers was significantly higher in those with hypertension (21.0% and 6.0%, respectively) than in those with prehypertension (12.7% and 0.5%, respectively) or normotension (8.1% and 0.2%, respectively). The multivariate adjusted odds ratios (95% confidence interval) of hypertension associated with increased levels of one, two or three biomarkers were 0.94 (0.72-1.22), 1.42 (0.93-2.16), and 11.08 (1.45-84.80), respectively, compared with subjects with no increase in any biomarker. CONCLUSION: Hypertension was associated with a cluster of inflammatory biomarkers in the Mongolian population.

[Bioaccumulation of sediment heavy metals in Bellamya aeruginosa and its relations with the metals geochemical fractions].

A 28-day sediment bioaccumulation test was conducted to study the bioaccumulation of river sediment heavy metals in Bellamya aeruginosa, and its relations with the geochemical fractions of the metals. A higher bioaccumulation of Cd, Pb, Cu, Cr, Zn, and Mn was found in the hepatopancreas of B. aeruginosa, with the greatest accumulation of Zn (84.32% +/- 4.36%), followed by Cu (7.67% +/- 2.84%), Pb (3.62% +/- 1.84%), Cr (2.22% +/- 1.03%), Mn (1.33% +/- 0.15%), and Cd (0.83% +/- 0.53%). No significant correlations were observed between the heavy metals accumulations in B. aeruginosa hepatopancreas, but the significant positive correlation between the metals pollution index of hepatopancreas and the Nemerow pollution index of sediments suggested that B. aeruginosa could be used as a potential bioindicator for sediment heavy metals pollution. The biota-sediment accumulation factors (BSAFs) for Cd, Cr, Zn, and Mn from different sediments showed a higher variability, while the BSAFs for Cu and Pb were relatively constant. The bioaccumulation of Cd had significant correlations with exchangeable Cd, weak acid soluble Cd, and oxidizable Cd; Pb bioaccumulation had significant correlation with reducible Pb; Cu bioaccumulation had significant correlation with oxidizable Cu; while Cr and Mn bioaccumulation had no correlations with the total concentrations and geochemical fractions of the two metals. Therefore, it would be inappropriate to use the BSAF as the indicator for the bioaccumulation of heavy metals in B. aeruginosa.

[Single and joint toxicity of perchloroethylene and cadmium on Ctenopharyngodon idellus].

In this paper, the single and joint toxicity of perchloroethylene (PCE) and cadmium (Cd) on grass carp (Ctenopharyngodon idellus) was observed by static test method, and the joint toxicity was evaluated by additive index method. The results showed that the LCs0 of PCE and Cd in 24, 48, 72 and 96 h was 49.12, 41.68, 36.37 and 34.30 mg x L(-1), and 45.58, 34.81, 28.63 and 24.05 mg x L(-1), respectively. Both the two test chemicals had high toxicity on C. idellus, and Cd had higher single toxicity than PCE. When the toxicity ratio was 1:1 and exposure time was 24, 48, 72 and 96 h, the LC50 of PCE and Cd was 24.63, 12.54, 9.88 and 7.08 mg x L(-1), and 17.11, 8.71, 6.87, 4.92 mg x L(-1), and the additive index (AI) was 0.14, 0.81, 0.95 and 1.43, respectively, indicating that the joint toxicity of PCE and Cd was synergistic, and increased with time. At the concentration ratio of 1:1, the LC50 of PCE and Cd in 24, 48, 72 and 96 h was 17.00, 11.81, 10.61 and 9.19 mg x L(-1), and 17.00, 11.81, 10.61 and 9.19 mg x L(-1), and the AI was 0.39, 0.70, 0.51 and 0.54, respectively, and the joint toxicity was also synergistic.