Genomic constitution and taxonomy of the Chinese hexaploids Elymus cylindricus and E. breviaristatus (Poaceae: Triticeae)

Elymus cylindricus (2n = 6x = 42) and E. breviaristatus (2n = 6x = 42) are distributed in grasslands and deserts of northern and north‐western China. Their genomic constitution and taxonomic status are unclear. Elymus cylindricus was crossed with E. wawawaiensis J.R.Carlson & Barkworth ( StH ), Roegneria grandis Keng ( StY ) and Campeiostachys dahurica (Turcz. ex Griseb.) B.R.Baum, J.L. Y ang & C. Y en var. dahurica ( StYH ). Meiotic pairing in the hybrids E. cylindricus × E. wawawaiensis ( StH ), E. cylindricus × R. grandis ( StY ) and E. cylindricus × C. dahurica var. dahurica ( StYH ) showed on average 10.00, 11.30 and 20.92 bivalents per cell, respectively. Elymus breviaristatus was crossed with C. dahurica var. dahurica ( StYH ) and E. cylindricus. Chromosome pairing in the hybrids of E. breviaristatus × C. dahurica var. dahurica and E. breviaristatus × E. cylindricus showed on average 19.60 and 19.27 bivalents, respectively. Genomic in situ hybridization (GI SH ) revealed the presence of St , Y and H genomes in E. cylindricus and E. breviaristatus. An intergenomic rearrangement was observed in E. cylindricus using GI SH . Meiotic pairing data and GI SH indicated that both E. cylindricus and E. breviaristatus are allohexaploids containing the StYH genomes. Elymus cylindricus and E. breviaristatus should be treated as Campeiostachys dahurica var. cylindrica and Campeiostachys breviaristata, respectively.     

Glucose‐ and mannose‐induced stomatal closure is mediated by ROS production,Ca2+ and water channel in Vicia faba

Sugars act as vital signaling molecules that regulate plant growth, development and stress responses. However, the effects of sugars on stomatal movement have been unclear. In our study, we explored the effects of monosaccharides such as glucose and mannose on stomatal aperture. Here, we demonstrate that glucose and mannose trigger stomatal closure in a dose‐ and time‐dependent manner in epidermal peels of broad bean (Vicia faba). Pharmacological studies revealed that glucose‐ and mannose‐induced stomatal closure was almost completely inhibited by two reactive oxygen species (ROS) scavengers, catalase (CAT) and reduced glutathione (GSH), was significantly abolished by an NADPH oxidase inhibitor, diphenylene iodonium chloride (DPI), whereas they were hardly affected by a peroxidase inhibitor, salicylhydroxamic acid (SHAM). Furthermore, glucose‐ and mannose‐induced stomatal closure was strongly inhibited by a Ca²⁺ channel blocker, LaCl₃, a Ca²⁺ chelator, ethyleneglycol‐bis(beta‐aminoethylether)‐N,N'‐tetraacetic acid (EGTA) and two water channel blockers, HgCl₂ and dimethyl sulfoxide (DMSO); whereas the inhibitory effects of the water channel blockers were essentially abolished by the reversing agent β‐mercaptoethanol (β‐ME). These results suggest that ROS production mainly via NADPH oxidases, Ca²⁺ and water channels are involved in glucose‐ and mannose‐induced stomatal closure.     

Molecular cytogenetic characterization of a new wheat-rye 1BL•1RS translocation line expressing superior stripe rust resistance and enhanced grain yield

Main conclusion

A new wheat-rye 1BL?1RS translocation line, with the characteristics of superior stripe rust resistance and high thousand-kernel weight and grain number per spike, was developed and identified from progenies of wheat-rye- Psathyrostachys huashanica trigeneric hybrids.

Abstract

The wheat-rye 1BL?1RS translocation line from Petkus rye has contributed substantially to the world wheat production. However, due to extensive growing of cultivars with disease resistance genes from short arm of rye chromosome 1R and coevolution of pathogen virulence and host resistance, these cultivars successively lost resistance to pathogens. In this study, a new wheat-rye line K13-868, derived from the progenies of wheat-rye-Psathyrostachys huashanica trigeneric hybrids, was identified and analyzed using fluorescence in situ hybridization (FISH), genomic in situ hybridization (GISH), acid polyacrylamide gel electrophoresis (A-PAGE), and molecular markers. Cytological studies indicated that the mean chromosome configuration of K13-868 at meiosis was 2n = 42 = 0.14 I + 18.78 II (ring) + 2.15 II (rod). Sequential FISH and GISH results demonstrated that K13-868 was a compensating wheat-rye 1BL?1RS Robertsonian translocation line. Acid PAGE analysis revealed that clear specific bands of rye 1RS were expressed in K13-868. Simple sequence repeat (SSR) and rye 1RS-specific markers ω-sec-p1/ω-sec-p2 and O-SEC5′-A/O-SEC3′-R suggested that the 1BS arm of wheat had been substituted by the 1RS arm of rye. At the seedling and adult growth stage, compared with its recurrent wheat parent SM51 and six other wheat cultivars containing the 1RS arm in southwestern China, K13-868 showed high levels of resistance to stripe rust (Puccinia striiformis f. sp. tritici, Pst) pathogens prevalent in China, which are virulent to Yr10 and Yr24/Yr26. In addition, K13-868 expresses higher thousand-kernel weight and more grain number per spike than these controls in two growing seasons, suggesting that this line may carry yield-related genes of rye. This translocation line, with significant characteristics of resistance to stripe rust and high thousand-kernel weight and grain number per spike, could be utilized as a valuable germplasm for wheat improvement.

     

Length–weight relationships for three fish species from the Yalong River,southwestern China

Length–weight relationships were determined for three fish species: Gymnodiptychus pachycheilus (Herzenstein, 1892), Discogobio yunnanensis (Regan, 1907), and Triplophysa pseudostenura (He, Zhang & Song, 2012). Samples were collected from the Yalong River, southwestern China using fishing gear (gillnets, 30 × 15 m, mesh‐size 5 mm) and electroshock fishing (CWB‐2000 P, 12 V, 250 HZ) in June 2007. Prior to this study, length–weight relationships for these three species were unknown. For two of the species [Discogobio yunnanensis (Regan, 1907) and Triplophysa pseudostenura (He, Zhang & Song, 2012)], new maximum standard lengths not yet reported in the scientific literature were noted.     

孢子丝菌复合体分子分型研究进展

孢子丝菌复合体属于双相真菌,全球分布,可引起人类及动物的慢性深部感染。不同地域的菌株在致病力、传播途径及药物敏感性等方面均存在差异。孢子丝菌病作为一种人兽共患病,其发病率逐年上升,出现多次暴发流行。分子分型不仅是明确感染源和传播途径、预防和控制疾病流行的有力手段,同时有助于了解孢子丝菌基因型与表型的相关性,在研究其致病机制以及临床诊治过程中都具有十分重要的意义。本文对孢子丝菌的分子分型方法的研究进行综述。     

偶联羟化反应和辅酶再生体系产9α-羟基雄甾-4-烯-3,17-二酮

9α-羟基雄甾-4-烯-3,17-二酮(9-OH-AD)是一种重要的甾体药物中间体,可以用来制备β-甾酮,地塞米松和其他类固醇化合物。3-甾酮9α-羟基化酶(KSH)是由两个亚基即末端氧化亚基(KshA)和铁氧还蛋白还原亚基(KshB)构成的。在本研究中,人工合成了来源于分枝杆菌Mycobacterium sp.Strain VKM Ac-1817D的kshA和kshB基因,通过优化表达载体促进了KshA和KshB在E.coli BL21(DE3)中的可溶性表达,并探究了催化体系中KSH还原亚基和氧化亚基的最适添加比例。此外,KSH转化雄甾-4-烯-3,17-二酮(AD)为9-OH-AD的过程中需要辅酶NADH。本研究构建了羟基化反应与利用葡萄糖脱氢酶(GDH)的NADH辅酶再生反应的偶联体系。为了进一步提高转化效率,本研究进行了转化条件的优化,并采取了分批补料的策略,最终9-OH-AD产量为4.78 g/L,转化率为96.7%。此种酶介导的转化生产9-OH-AD的方法为甾体药物生产提供了一种环境友好和经济实用型的新策略。     

The Protein Phosphorylation Landscape of Mouse Spermatids during Spermiogenesis

The characteristic tadpole shape of sperm is formed from round spermatids via spermiogenesis, a process which results in dramatic morphological changes in the final stage of spermatogenesis in the testis. Protein phosphorylation, as one of the most important post‐translational modifications, can regulate spermiogenesis; however, the phosphorylation events taking place during this process have not been systematically analyzed. In order to better understand the role of phosphorylation in spermiogenesis, large‐scale phosphoproteome profiling is performed using IMAC and TiO₂ enrichment. In total, 13 835 phosphorylation sites, in 4196 phosphoproteins, are identified in purified mouse spermatids undergoing spermiogenesis in two biological replicates. Overall, 735 testis‐specific proteins are identified to be phosphorylated, and are expressed at high levels during spermiogenesis. Gene ontology analysis shows enrichment of the identified phosphoproteins in terms of histone modification, cilium organization, centrosome and the adherens junction. Further characterization of the kinase‐substrate phosphorylation network demonstrates enrichment of phosphorylation substrates related to the regulation of spermiogenesis. This global protein phosphorylation landscape of spermiogenesis shows wide phosphoregulation across a diverse range of processes during spermiogenesis and can help to further characterize the process of sperm generation. All MS data are available via ProteomeXchange with the identifier PXD011890.