Expression of the ipomoelin gene from sweet potato is regulated by dephosphorylated proteins, calcium ion and ethylene

A wound‐inducible cDNA, ipomoelin (IPO) was isolated from the subtraction library of sweet potato (Ipomoea batatas cv. Tainung 57) and used as a molecular probe to investigate the transduction pathway of wounding signal within plant cells. Following mechanical wounding of the leaves of sweet potato, IPO mRNA accumulation peaked at 6 h and then continuously declined. However, IPO gene expression in the apical unwounded leaves began at 6 h after wounding and continued for a further 10 h. Besides mechanical wounding, methyl jasmonate (MeJA) was identified as a signal transducer leading to the accumulation of IPO mRNA. Treatment with salicylic acid reduced the production of IPO mRNA, further supporting the involvement of the octadecanoid pathway in the signal transduction of wounding in sweet potato. In addition, ethylene was involved in the signal pathway and induced the expression of the IPO gene. Furthermore, the application of okadaic acid, a protein phosphatase inhibitor, blocked the accumulation of IPO mRNA induced by MeJA or ethylene, indicating that activation of the IPO gene by both MeJA and ethylene was via dephosphorylated proteins. The presence of a calcium ion chelator or channel blockers also inhibited the expression of the IPO gene after wounding. However, investigation by confocal scanning microscopy further pointed out that mechanical wounding rather than the application of MeJA induced the accumulation of the calcium ion. These results may indicate that the calcium ion is also involved in the activation of IPO mRNA. In addition, wounding signals the accumulation of calcium ion first and then stimulates the biosynthesis of MeJA in sweet potato. Hence, the reaction sequence of signal transducers, including the calcium ion, MeJA and protein kinase/phosphatase, in the wounding signalling pathway of sweet potato is suggested in this report.     

固囊酵母的一个新种

从中国保定槐茂甜面酱中分离到一株酵母。经鉴定,这株酵母菌属于固囊酵母属(Citeromyces),并为该属中的一个新种,命名为保定团囊酵母(Citeromyces baodingensis zhangsp.Nov.)。保定团囊酵母与固囊酵母生理生化特性有显著区别,保定固囊酵母(Citeromycesbaodingensis)不发酵蔗糖、棉子糖,同化半乳糖和纤维二糖,不同化海藻糖和棉子糖,G+C含量为48.5mol％。     

灌溉施肥部位对玉米同化物分配和水分利用的影响

用土柱管栽试验方法研究了不同灌溉施肥深度对夏玉米生长发育、地上地下部分同化物分配、产量和水分利用效率的影响。试验结果表明：土表下灌施抑制了玉米生育早期的地上部分生长,使根系向土壤中下层的分布加强,从而保证了作物中后期对水分养分的吸收利用,提高了水分利用效率。在本试验条件下,玉米生长的最佳灌施深度为30cm。     

Ancestral feeding and survival of offspring in European corn borer

Experiments were conducted to evaluate the influence of ancestral adult feeding by European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), on larval survival in the field and neonate movement behavior in laboratory. Larval survival was higher when either the grandparental or parental generation had fed, but the feeding sites of the surviving larvae were not affected by ancestral feeding condition. This is the first evidence that grandparental feeding could influence larval survival in the field. Larval movement was observed in the laboratory. Silking speed of neonates was faster when either grandparents or parents had fed, while walking speed was faster only when parents had fed. No broad-sense genetic correlation was found between silking speed and walking speed. Broad-sense heritability among feeding histories were not significant for silking speed, but was significantly greater than zero for walking speed when grandparents fed and parents did not. These intergenerational effects could induce complex population dynamics in this species.     

Improvement of glycerol production by Candida krusei in batch and continuous cultures using corn steep liquor

No fermentation parameter was affected at phosphate concentration above 0.4 g l^–1 when KH₂PO₄ was used as phosphate source and the glucose consumption rate was difficult to control when corn steep liquor (CSL) was adopted as the phosphate source. However, if CSL was supplemented as a source of growth factors instead of as the phosphate source, not only glucose uptake and glycerol was improved, but also fermentation became easy to control and a steady state of continuous culture was easily obtained.     

Platelets do not express the oxidized or reduced forms of tissue factor

Background

Expression of tissue factor (TF) antigen and activity in platelets is controversial and dependent upon the laboratory and reagents used. Two forms of TF were described: an oxidized functional form and a reduced nonfunctional form that is converted to the active form through the formation of an allosteric disulfide. This study tests the hypothesis that the discrepancies regarding platelet TF expression are due to differential expression of the two forms.

Methods

Specific reagents that recognize both oxidized and reduced TF were used in flow cytometry of unactivated and activated platelets and western blotting of whole platelet lysates. TF-dependent activity measurements were used to confirm the results.

Results

Western blotting analyses of placental TF demonstrated that, in contrast to anti-TF#5, which is directed against the oxidized form of TF, a sheep anti-human TF polyclonal antibody recognizes both the reduced and oxidized forms. Flow cytometric analyses demonstrated that the sheep antibody did not react with the surface of unactivated platelets or platelets activated with thrombin receptor agonist peptide, PAR-1. This observation was confirmed using biotinylated active site-blocked factor (F)VIIa: no binding was observed. Likewise, neither form of TF was detected by western blotting of whole platelet lysates with sheep anti-hTF. Consistent with these observations, no FXa or FIXa generation by FVIIa was detected at the surface of these platelets. Similarly, no TF-related activity was observed in whole blood using thromboelastography.

Conclusion and significance

Platelets from healthy donors do not express either oxidized (functional) or reduced (nonfunctional) forms of TF.     

甘蔗、玉米气味对亚洲玉米螟成虫产卵和幼虫取食的影响

【目的】农作物间套作对害虫的影响很大程度上取决于害虫的行为反应,通过研究玉米/甘蔗套作系统中植物气味对亚洲玉米螟Ostrinia furnacalis(Guenee)行为的影响,将为利用化学生态手段防治套作田中的害虫提供依据。【方法】通过昆虫触角电位实验、成虫产卵和幼虫取食实验,测定了甘蔗、玉米植株及二氯甲烷漂洗物对亚洲玉米螟成虫产卵、幼虫取食的影响。【结果】亚洲玉米螟成虫在甘蔗植株上的落卵量(卵粒数、卵块数)与玉米植株差异不显著,取食甘蔗植株的幼虫数量显著低于玉米植株。亚洲玉米螟对甘蔗、玉米叶片漂洗物均可产生EAG反应,且在同一浓度下的反应值之间无显著差异。成虫产卵量(卵粒数、卵块数)在0.1 gE/mL浓度的甘蔗和玉米漂洗物间差异不显著;幼虫对经甘蔗叶片漂洗物处理过的饲料的相对取食率均低于65.00%,显著低于玉米漂洗物处理的饲料。【结论】甘蔗和玉米气味对亚洲玉米螟产卵的影响没有差异,但甘蔗气味会导致初孵幼虫表现出很强的逃逸行为。     

二代玉米螟为害玉米产量损失研究

【目的】研究二代亚洲玉米螟Ostrinia furnacalis(Guenee)为害对玉米产量的影响。【方法】以"先玉335"为供试玉米品种,通过人工接虫模拟二代玉米螟不同发生量为害玉米对产量损失的影响。【结果】随着接卵量增加,虫孔数和蛀孔隧道长度增加,玉米单穗粒重降低。单株虫孔数每增加1个,玉米产量损失率增加4.52%;隧道长度每增加10 cm,产量损失率增加8.34%。接卵量与玉米产量损失率的关系符合方程z=-10.0297+4.034 ln(x)。【结论】根据害虫经济阈值的定义,推算出二代玉米螟的防治指标为百株累积卵量12.8块,对二代玉米螟的防治决策具有重要指导作用。     

Application of Bacillus subtilis in the biological control of the phytopathogenic fungus Sporisorium reilianum

Sporisorium reilianum is the causal agent of head smut in corn, a worldwide disease that causes significant economic losses in the principal areas where maize is cultivated. To attack this problem, resistant commercial hybrids and synthetic fungicide seed treatment have been used, but with low effectiveness. In this study, a native strain of Bacillus subtilis isolated from the soil of corn crops in Mixquiahuala, Hidalgo, in central Mexico, was applied as a seed treatment in the field to test for the biological control of head smut. It significantly decreased the Smut Incidence Percentage (SIP) while increasing maize productivity. This work represents the first report in which B. subtilis has been used to control S. reilianum in the field.     

秸秆汽爆炼制木质素制备酚醛泡沫材料

以木质纤维素为原料的生物炼制不仅需要考虑到纤维素和半纤维素,同时也需要考虑到木质素的利用,以提高木质纤维素炼制的整体经济效益。利用汽爆处理的玉米秸秆为原料,通过优化碱提取的温度以及碱浓度,获得木质素得率较高,糖含量较少的提取液,同时该提取液经过浓缩后直接部分替代苯酚与甲醛反应制备酚醛泡沫。结果表明:当提取温度120℃,碱浓度1%,固液比1∶10,提取时间2 h,木质素的提取率达到79.67%。由该提取液替代苯酚制备的酚醛泡沫随着替代率的增加,其泡沫的密度逐渐增加,其压缩强度相对于纯酚醛泡沫也得到了提高。而木质素的加入并没有显著影响其热导率以及阻燃性能,同时由于其利用较为低廉的可再生资源木质素替代不可再生的苯酚原料,成本低,环保性好,具有更好的市场应用前景。采用木质素提液直接制备酚醛泡沫材料,工艺流程简单;增加了副产物木质素的经济价值,提高了整个木质纤维素炼制的经济性。