Kruppel样因子15对脂肪沉积和肌纤维类型的影响及其可能机制

Kruppel样因子15(KLF15)是一种新发现的Kruppel样因子家族(KLFs)成员,为一种真核锌指蛋白转录因子。KLF15在动物体内呈现多组织表达特性,该基因过表达能促进动物脂肪沉积,且能影响肉质性状候选基因和Ⅰ型肌纤维基因的表达。因此,深入研究KLF15对脂肪沉积和肌纤维类型的影响及其可能机制,将为改善动物肉品质提供新的思路。本文综述了KLF15的发现、结构特征、表达规律及其与脂肪沉积和Ⅰ型肌纤维之间的关系。     

Excessive nitrogen application decreases grain yield and increases nitrogen loss in a wheat–soil system

Abstract

Excessive use of nitrogen (N) fertilizers in wheat fields has led to elevated NO₃-N concentrations in groundwater and reduced N use efficiency. Three-year field and ¹⁵N tracing experiments were conducted to investigate the effects of N application rates on N uptake from basal and topdressing ¹⁵N, N use efficiency, and grain yield in winter wheat plants; and determine the dynamics of N derived from both basal and topdressing ¹⁵N in soil in high-yielding fields. The results showed that 69.5–84.5% of N accumulated in wheat plants derived from soil, while 6.0–12.5%and 9.2–18.1% derived from basal ¹⁵N and top ¹⁵N fertilizer, respectively. The basal N fertilizer recovery averaged 33.9% in plants, residual averaged 59.2% in 0–200 cm depth soil; the topdressing N fertilizer recovery averaged 50.5% in plants, residual averaged 48.2% in 0–200 cm soil. More top ¹⁵N was accumulated in plants and more remained in 0–100 cm soil rather than in 100–200 cm soil at maturity, compared with the basal ¹⁵N. However, during the period from pre-sowing to pre-wintering, the soil nitrate moved down to deeper layers, and most accumulated in the layers below 140 cm. With an increase of N fertilizer rate, the proportion of the N derived from soil in plants decreased, but that derived from basal and topdressing fertilizer increased; the proportion of basal and top ¹⁵N recovery in plants decreased, and that of residual in soil increased. A moderate application rate of 96–168 kg N ha^?1 led to increases in nitrate content in 0–60 cm soil layer, N uptake amount, grain yield and apparent recovery fraction of applied fertilizer N in wheat. Applying above 240 kg N ha^?1 promoted the downward movement of basal and top ¹⁵N and soil nitrate, but had no significant effect on N uptake amount; the excessive N application also obviously decreased the grain yield, N uptake efficiency, apparent recovery fraction of applied fertilizer N, physiological efficiency and internal N use efficiency. It is suggested that the appropriate application rate of nitrogen on a high-yielding wheat field was 96–168 kg N ha^?1.     

Mineral Composition and Soil-Plant Relationships for Common Guava (Psidium guajava L.) and Yellow Strawberry Guava (Psidium cattleianum var. lucidum) Tree Parts and Fruits

The mineral compositions of the fruit and tree parts of common guava, Psidium guajava L., and strawberry guava, Psidium cattleianum var. lucidum, were determined. The study occurred during three seasons at six locations in Hawaii to assess guava as feed for livestock. Guava bark contained the greatest concentrations of calcium (Ca) and ash; leaves the greatest concentrations of magnesium (Mg), sulfur (S), sodium (Na), boron (B), and manganese (Mn); and the shoots had the greatest concentrations of nitrogen (N), phosphorus (P), and potassium (K). The leaves and the shoots had the greatest concentrations of copper (Cu) and iron (Fe). Between guava and waiwi, guava had greater concentrations of most minerals except for Na in all plant parts, and Mg and ash in the leaves. Guava leaves and shoots meet the macromineral requirements for various phases of sheep, goat, and beef cattle life cycles with the exception of P and Na. Guava shoots do not meet Mn requirements for lactating cows.     

茄子新品种驻茄15号的选育

驻茄15 号是以自交系P04-11 为母本，以高代自交系驻Q-25 为父本配制而成的中早熟绿茄一代杂种。植株生长势强，果实卵圆形，纵径15.0 cm 左右，横径10.6 cm 左右，平均单果质量0.52 kg，果皮绿色、光亮，肉质硬度中等，商品性好，一般每667 m² 前期产量1 100 kg 左右，总产量5 300 kg 左右，田间对青枯病、绵疫病、黄萎病的抗性强于对照郑研早青茄，适宜河南省及周边省份春、秋设施及露地栽培。     

Pea extracellular Cu/Zn-superoxide dismutase responsive to signal molecules from a fungal pathogen

We previously reported that the release of O₂ ⁻ from isolated pea cell walls was enhanced by a 70-kDa glycoprotein elicitor but was suppressed by mucin-type glycopeptide suppressors (supprescins A and B) prepared from pycnospore germination fluid of Mycosphaerella pinodes, causal agent of Mycosphaerella blight of pea. Here, we show that superoxide dismutase (SOD) in the apoplast fluid/cell wall of pea seedlings responds to the fungal elicitor and suppressor molecules. In a pharmacological study and with internal amino acid sequencing, the apoplastic SOD in a pea cultivar Midoriusui was found to be a Cu/Zn type SOD. We cloned a full-length cDNA of the Cu/Zn-SOD and designated it as PsCu/Zn-SOD1. An increase in PsCu/Zn-SOD1 mRNA and the PsCu/Zn-SOD1 protein was induced by treatment with the elicitor more intensively than by wounding. Such induction by the elicitor or wounding, however, was inhibited by the concomitant presence of supprescins. The SOD activity of recombinant PsCu/Zn-SOD1 was regulated directly by these signal molecules in a manner similar to their effect on the SOD activity in the apoplastic fluid and in the cell wall-bound proteins. Based on these findings, we discuss a role for PsCu/Zn-SOD1 in the pea defense response. The nucleotide sequence data of PsCu/Zn-SOD1 reported are available in the DDBJ/EMBL/GenBank databases under accession number AB189165.     

牛GDF9和BMP15基因遗传变异与双胎性状的关系研究

以生长分化因子9(Growth differentiation factor 9,GDF9)基因和骨形态发生蛋白15(Bone morphogenet-ic protein 15,BMP15)基因作为牛双胎性状的候选基因,研究了它们在鲁西牛、秦川牛、南阳牛和中国荷斯坦牛4个品种中的遗传变异,并在鲁西牛群体中研究了其多态位点与双胎性状的关系。结果表明:在鲁西牛中GDF9基因的3′UTR发现缺失突变,而其它3个品种中没有发现该突变。对鲁西牛群体中该多态位点与单、双胎性状之间进行卡方显著性检验表明,单胎牛群体与双胎牛群体基因型分布有极显著的差异(P=0.006),双胎牛群体的B等位基因频率明显大于单胎牛群体。通过生物信息学分析表明,突变体mRNA的二级结构与野生型相比总自由能值差异不大,但突变体mRNA翻译起始位点的二级结构稳定性明显大于野生型。在鲁西牛、南阳牛和秦川牛的BMP15基因中发现编码区第759~762位有GAAA 4个碱基存在缺失突变,但没有检测到突变纯合个体,中国荷斯坦牛中没有检测到该突变。卡方显著性检验表明单胎牛群体和双胎牛群体在该位点基因型组成差异不显著(P=0.947)。     

Can hydrochar and pyrochar affect nitrogen uptake and biomass allocation in poplars?

Positive effects of pyrochar on soil nutrient availability and plant growth are widely reported in literature. However, few studies have reported effects of hydrochars on plant nutrition. A pot trial was conducted over a period of 2 years to investigate the effect of a pyrochar (AGT) and a hydrochar (HTC) on poplar (Populus × generosa , clone AF8) growth, biomass allocation and nitrogen (N) uptake with special emphasis on the quantification (using an isotopic mass balance approach) of char‐derived nitrogen (CDN) absorbed by plants. We found that both pyrochar and hydrochar positively affected above‐ground biomass productivity in the first year, and biomass and nitrogen (N) allocation over the 2 years by reducing the allocation of resources to fine roots. By the end of the experiment, even though the total N uptake was not affected by char, the CDN was more than 24% of the total N absorbed by HTC‐treated plants compared to a negligible amount absorbed by AGT‐treated ones. Finally, char did not affect nitrogen use efficiency (NUE) in the first year of growth, but by the end of the experiment, NUE was higher in the above‐ground biomass of HTC‐treated than in AGT‐ and control poplars.     

培养液中铜水平对PK15细胞内铜离子浓度与CuZn-SOD活性的影响

在 PK15细胞无血清液体培养基中添加 0、7.8、15 .6、31.2、6 2 .5 μmol/L Cu,观察了培养液中不同铜水平对PK15细胞内铜离子浓度和 Cu Zn- SOD活性的影响及二者的相关性。结果表明 ,PK15细胞内铜离子浓度及 Cu Zn-SOD活性均随培养液中添加铜离子浓度升高和培养时间的延长而有不同程度的升高 ,其中以添加 Cu31.2 μmol/L组最高 (P<0 .0 5 )。PK15细胞内 Cu Zn- SOD活性与细胞内铜离子浓度和培养时间呈强正相关 (培养时间 :r=0 .873～0 .980 ,P<0 .0 5 ;铜离子浓度 :r=0 .90 0～ 0 .972 ,P<0 .0 5 )     

Response of Cotton to Irrigation Methods and Nitrogen Fertilization: Yield Components,Water‐Use Efficiency,Nitrogen Uptake,and Recovery

Efficient crop use of nitrogen (N) fertilizer is critical from economic and environmental viewpoints, especially under irrigated conditions. Cotton yield parameters, fiber quality, water‐ and N‐use efficiency responses to N, and irrigation methods in northern Syria were evaluated. Field trials were conducted for two growing seasons on a Chromoxerertic Rhodoxeralf. Treatments consisted of drip fertigation, furrow irrigation, and five different rates of N fertilizer (50, 100, 150, 200, and 250 kg N /ha). Cotton was irrigated when soil moisture in the specified active root depth was 80% of the field capacity as indicated by the neutron probe.

Seed cotton yield was higher than the national average (3,928 kg/ha) by at least 12% as compared to all treatments. Lint properties were not negatively affected by the irrigation method or N rates. Water savings under drip fertigation ranged between 25 and 50% of irrigation water relative to furrow irrigation. Crop water‐use efficiencies of the drip‐fertigated treatments were in most cases 100% higher than those of the corresponding furrow‐irrigated treatments. The highest water demand was during the fruit‐setting growth stage. It was also concluded that under drip fertigation, 100–150 N kg/ha was adequate and comparable with the highest N rates tested under furrow irrigation regarding lint yield, N uptake, and recovery. Based on cotton seed yield and weight of stems, the overall amount of N removed from the field for the drip‐fertigated treatments ranged between 101 and 118kg and 116 and 188 N/ha for 2001 and 2002, respectively. The N removal ranged between 94 and 113 and 111 and 144 kg N/ha for the furrow‐irrigated treatments for 2001 and 2002, respectively.     

Effects of STK15 overexpression on growth of human esophageal carcinoma cell line KYSE150

AIM:To investigate the effects of serine/threonine kinase 15 (STK15) overexpression on the growth of human esophageal squamous-cell carcinoma (ESCC) cell line KYSE150. METHODS:Recombinant pEGFP-C1-STK15 expression vector was transfected into KYSE150 cells using LipofectamineTM 2000 and the expression of STK15 was detected by fluorescence microscopy and Western blotting. The proliferation of the cells in vitro was measured by MTT assay. The cell cycle distribution and apoptosis were detected by flow cytometry. The proliferation of the cells in vivo was measured by tumorigenicity experiment in nude mice. RESULTS:After recombinant pEGFP-C1-STK15 expression vector was stably transfected into KYSE150 cells, GFP-STK15 fusion protein localized to centrosome and spindle. The STK15-overexpressing colonies were further confirmed by Western blotting. MTT assay showed that the proliferation of the cells in STK15 overexpression group was increased compared with control group (P<0.01). Flow cytometry analysis showed that the percentage of the cells in G0/G1 phase and the cell apoptosis in STK15 overexpression group were decreased compared with control group (P<0.01). The tumorigenicity experiment in nude mice showed that the proliferation of the cells in STK15 overexpression group was increased compared with control group (P<0.01). CONCLUSION: Overexpression of STK15 in human ESCC KYSE150 cells promotes the cell growth in vitro and in vivo, indicating that STK15 may serve as a novel therapeutic target for esophageal carcinoma.