冬小麦植物铁载体分泌的杂种效应

缺铁是石灰性土壤常见的植物营养问题之一.禾本科植物种或基因型的植物铁载体分泌能力与耐缺铁有关,提高植物铁载体分泌能力是改良缺铁的土壤上植物铁aestivum L.) 3个杂交种及其4个亲本在缺铁营养液中植物铁载体的分泌及杂种的效应.植物铁载体的分泌率通过根分泌物对新形成的Fe(OH)3的活化能力进行测定, 在缺铁症出现时每隔2、3天测定1次.在缺铁条件下,所有基因型都分泌较多的植物铁载体,并且随缺铁症状的发展分泌量增加.杂交种具有对缺铁更敏感的反馈系统,在缺铁条件下,杂交种比亲本分泌铁载体的速度更快、量更高.通过分析杂交种和亲本的关系,认为可以通过对亲本分泌植物铁载体能力和配合力的选择,利用杂种优势来提高小麦铁的利用效率.     

冬小麦植物铁载体分泌的杂种效应

缺铁是石灰性土壤常见的植物营养问题之一。禾本科植物种或基因型的植物铁载体分泌能力与耐缺铁有关 ,提高植物铁载体分泌能力是改良缺铁的土壤上植物铁营养的关键措施之一。在水培条件下分析了冬小麦(TriticumaestivumL .) 3个杂交种及其 4个亲本在缺铁营养液中植物铁载体的分泌及杂种的效应。植物铁载体的分泌率通过根分泌物对新形成的Fe(OH) 3 的活化能力进行测定 ,在缺铁症出现时每隔 2、3天测定 1次。在缺铁条件下 ,所有基因型都分泌较多的植物铁载体 ,并且随缺铁症状的发展分泌量增加。杂交种具有对缺铁更敏感的反馈系统 ,在缺铁条件下 ,杂交种比亲本分泌铁载体的速度更快、量更高。通过分析杂交种和亲本的关系 ,认为可以通过对亲本分泌植物铁载体能力和配合力的选择 ,利用杂种优势来提高小麦铁的利用效率。     

根分泌物对根际难溶性镉的活化作用及对水稻吸收、运输镉的影响

采用人工控制光温条件的蛭石－营养液相结合的培养方法,对根分泌物活化难溶性硫化镉以及对水稻吸收、运输镉的影响进行了研究。结果表明,缺铁水稻根分泌物和缺铁小麦根分泌匀能活化水稻根际的难溶性镉（ＣｄＳ）,促进了水稻对这部分镉的吸收和运输;但二者的活化强度不同,缺铁小麦根分泌物对镉的活化作用较缺铁水稻根分泌物强。     

用Langdon二体代换系统建立小麦染色体RAPD标记

以一套Ｌａｎｇｄｏｎ硬粒小麦二体代换系及其亲本Ｌａｎｇｄｏｎ、中国春和中国春双端体为材料,研究适于硬粒小麦和普通小麦的理想ＲＡＰＤ分析条件,进行小麦Ａ、Ｂ和Ｄ染色体组各个染色体的ＲＡＰＤ分析。结果表明,ＡｍｐｌｉＴａｑＳｔｏｆｆｅｌｆｒａｇｍｅｎｔ比ＴａｑＤＮＡＰｏｌｙｍｅｒａｓｅ优越。所用１２个随机引物中,７个引物扩增出的１３个特异产物,可确定在硬粒小麦ＬａｎｇｄｏｎＡ、Ｂ染色体组和中国春Ｄ染色体组中的１０个个别染色体上。４个标记进一步定位在相应的４个染色体臂上。结果还表明,用Ｌａｎｇｄｏｎ二体代换系统、中国春双端体为材料,容易得到重复性高、特异性强的ＲＡＰＤ标记。     

大麦6H染色体特异性标记的筛选和鉴定

从大麦、小麦和小麦－大麦６Ｈ染色体附加系ＲＡＰＤ分析筛选出对６Ｈ染色体特异的２个ＲＡＰＤ标记,转换为特异性ＰＣＲ标记,利用标记对不同植物材料进行ＰＣＲ扩增鉴定。表明凡含有大麦６Ｈ染色体的材料（Ｂｅｔｚｅｓ、Ｉｇｒｉ、ＣＳ６Ｈ附加系）均能扩增出特异带;而不含６Ｈ染色体的材料,包括小科、黑麦、长穗偃麦草、中间偃麦草、簇毛麦以及含有其他大麦染色体的小麦附加系均不主增出特异带。可见,２对ＰＣＲ引物具有大麦     

E和St基因组特异RAPD片段在部分小麦族植物中的分布

两个Ｅ基因组（包括Ｅｅ和Ｅｂ）特异ＲＡＰＤ片段和两个Ｓｔ基因组特异ＲＡＰＤ片段的序列分析表明,４个片段均为新的ＤＮＡ克隆片段。染色体原位杂交显示ＯＰＤ１２４４４为区域化连续高度重复序列,而ＯＰＦ０３１２９６（Ｅｂ特异）、ＯＰＢ０８５２５（Ｓｔ特异）、ＯＰＮ０１８１７（Ｓｔ特异）为弥散性高度重复序列。研究还显示：大部分ＤＮＡ高度重复序列在亲缘关系较近的小麦族植物基因组间是共享的,差异可能主要是在重复次数及片段长度上,而能否用ＲＡＰＤ技术扩增主要决定于某一基因组的这些重复序列中有无与特定引物相匹配的区域。文中就这些重复序列在小麦远缘杂交后代外源遗传物质检测、多倍体物种染色体组组成研究中的潜在价值进行了讨论。     

铁对小麦吸收不同形态镉的影响

采用营养液培养方法,研究了在供铁与铁与缺铁条件下小麦对不同镉化合物和镉污染土壤中镉的吸收和转移,同时不他陪伴阴离子对小麦吸收镉的影响。结果表明：缺铁培养小麦植株地上部及根中的含镉量均显著高于下沉供铁培养的小麦,小麦对小同化合物的吸收量不同,其吸收的多寡顺序依次为：Ｃｄ（ＮＯ３）２〉ＣｄＳＯ４〉ＣｄＯ。     

植物抗寒冻的分子遗传与基因工程

植物抗寒冻的分子遗传与基因工程费云标,黄涛,舒念红,赵淑慧（中国科学院发育生物学研究所）植物抗寒冻的遗传学研究表明,小麦的２１对染色体中至少有１０对染色体关系到寒冻抗性,在染色体５Ａ和Ｄ,携带着影响小麦抗性的许多基因（Ｇｕｙ１９９０）。寒冻抗性的７０％的诱生能力涉及到染色体５Ａ（Ｓｉｎｇｈ等１９８８）。     

小麦和黑麦染色体在小黑麦×小麦杂种的不同世代群体中的传递

使用单株植物C-带核型鉴定技术,研究了小麦和黑麦染色体在八倍体小黑麦×普通小麦的F_1,BC_1,F_2和F_3代中的遗传行为。黑麦染色体通过花粉和卵细胞的传递率显著不同,通过卵细胞丢失的染色体较多。黑麦染色体在F_2和F_3的传递率为36.0—38.8%,显著低于通过配子的平均传递率。不同的黑麦染色体通过配子的传递是随机的,而在F_2和F_3中却存在着显著的差异,1R的传递率最高,6R、7R最低。发生上述差异的原因可能是黑麦染色体的丢失不仅发生在配子形成和受精阶段,还受具有不同核型的受精卵在发育过程中夭亡的影响。受黑麦染色体的影响,小麦染色体也有不同程度的丢失。在不同的世代群体中,约有7.3—28.1%的植株丢失了小麦染色体。6R、5R和7R对小麦染色体丢失的作用较大。根据本研究的结果,在使用八倍体小黑麦×小麦的杂交方式利用黑麦遗传物质于小麦育种的工作中,F_2和F_3是有效选择的关键世代。本文建议的单株植物C-带核型鉴定技术是实现这一选择目标的有效方法。     

应用荧光原位杂交和RFLP标记检测多小穗小麦新种质10-A中的黑麦染色质

利用ＡＰＡＧＥ、荧光原位杂交技术和ＲＦＬＰ标记,对导入黑麦（ＳｅｃａｌｅｃｅｒｅａｌｅＬ．）多小穗等性状创制的小麦新种质１０＿Ａ进行了分子标记检测。ＡＰＡＧＥ分析发现,１０＿Ａ与其他１ＲＳ／１ＢＬ易位系一样,含有１ＲＳ的醇溶蛋白标记位点Ｇｌｄ１Ｂ３。以黑麦基因组总ＤＮＡ作探针,用中国春（Ｔｒｉｔｉｃｕｍａｅｓｔｉｖｕｍｃｖ．ＣｈｉｎｅｓｅＳｐｒｉｎｇ）基因组ＤＮＡ作封阻,与１０＿Ａ根尖细胞有丝分裂染色体进行荧光原位杂交。结果表明,黑麦的１ＲＳ易位到１０＿Ａ中。用２５个ＲＦＬＰ探针进行Ｓｏｕｔｈｅｒｎ分析,进一步发现１０＿Ａ的１ＢＳ特异限制性片段发生丢失,代之以黑麦１ＲＳ的特异限制性片段,而位于其他染色体上的特异限制性片段未发生缺失。据此认为,多小穗小麦新种质１０＿Ａ属于１ＲＳ／１ＢＬ易位系。同时还讨论了１０＿Ａ在小麦遗传改良中的利用情况。     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.