田间转Bt基因水稻上稻飞虱卵量、孵化率及天敌作用

为了评估转基因水稻释放后对非靶标害虫及其天敌的影响, 本研究在浙江大学实验农场和中国水稻研究所实验农场2008和2009年连续两年监测了转Bt基因水稻对田间稻飞虱着卵量、卵孵化率、卵被捕食率、卵被寄生率和卵死亡率的影响。结果表明: 两年2个调查地点3个水稻品系（克螟稻1、克螟稻2和秀水11）上的稻飞虱平均每分蘖着卵量、卵孵化率、卵被捕食率和卵被寄生率的趋势基本一致, 而且田间3个水稻品系上稻飞虱卵量的高峰期均持续2周左右; 但是两年2个调查地点3个水稻品系上稻飞虱卵死亡率则没有一致的趋势。此外, 总体上3个水稻品系上稻飞虱平均每分蘖着卵量、卵孵化率、卵被捕食率、卵被寄生率和卵死亡率差异均不显著（P>0.05）。因此, 稻田中转Bt基因水稻对稻飞虱卵没有显著的影响。     

气候变化背景下中国农业气候资源变化Ⅷ.江西省双季稻各生育期热量条件变化特征

基于江西省地面气象资料和农业气象试验站数据,分析了江西省双季稻生育期的变化趋势,并利用生长度日（GDD）、低温度日（CDD）和高温度日（HDD）对1981-2007年江西省水稻各生育期热量资源的变化趋势进行分析.结果表明：气候变暖背景下,江西省水稻生长季平均气温、平均最低气温和平均最高气温均呈升高趋势,引起双季稻生长季缩短,其中,营养生长期日数减少最明显,而生殖生长期延长;生长度日和高温度日均增加,低温度日减少.研究期间,江西省双季稻有效热量资源增加,低温风险减少,但高温风险增多;江西省水稻有效热量资源的空间变化特征表现为东北部的增幅大于西南部,南部的低温风险大于北部,中部的高温风险最大.     

Primary identifications and palynological observations of Perilla in China

Unresolved controversies concerning classification of the monotypic genus Perilla L. have hindered the complete understanding and subsequent sustainable use of these vital food, oil and medicinal plants to their full potential. We attempted to use scanning electron microscopy to obtain palynological evidence from Perilla plants of 21 samples from seven provinces in China as a potential extra attribute in classification. The findings showed that pollen grains from plants of 11 samples were oblate, while those of the other 10 were suboblate in shape, and there were no any type of prolate pollen grains being observed. Pollen grains of all the samples had diverse exine ornamentations. Based on whether having continuous tecta on the ornamentations, all of the pollen grains derived from the 21 samples were classified into two categories, fourteen of them with irregular reticulates, seven with continuous tecta with no perforations. None of the samples were bireticulates. The ornamentation pattern and size of pollen grains jointly provided evidence that it is appropriate to classify the genus Perilla into five varieties of one species. Furthermore, by comparison, it is concluded that shapes and exine ornamentations of Perilla are unique among those of the seven genera already investigated in the subfamily Lamioideae. Using these pollen features, Perilla could be easily distinguished from two other subtribes (Menthinae Briq. and Thyminae Briq.) in the same tribe, supporting the view that Perilla and other four related genera were divided into one subtribe (Perillinae).     

Mnl2, a novel component of the ER associated protein degradation pathway

In eukaryotes, membrane and soluble proteins of the secretory pathway enter the endoplasmic reticulum (ER) after synthesis in an unfolded state. Directly after entry, most proteins are modified with glycans at suitable glycosylation sites and start to fold. A protein that cannot fold properly will be degraded in a process called ER associated degradation (ERAD). Failures in ERAD, either by loss of function or by premature degradation of proteins, are a cause of severe diseases. Therefore, the search for novel ERAD components to gain better insight in this process is of high importance. Carbohydrate trimming is a relevant process in ER quality control. In this work a novel putative yeast mannosidase encoded by the open reading frame YLR057W was identified and named Mnl2. Deletion of MNL2 diminished the degradation efficiency of misfolded CPY^* in the absence of the cognate mannosidase Mnl1, indicating a specific role in ERAD.     

A double-flowered variety of lesser periwinkle (Vinca minor fl. pl.) that has persisted in the wild for more than 160 years

Background and Aims

Homeotic transitions are usually dismissed by population geneticists as credible modes of evolution due to their assumed negative impact on fitness. However, several lines of evidence suggest that such changes in organ identity have played an important role during the origin and subsequent evolution of the angiosperm flower. Better understanding of the performance of wild populations of floral homeotic varieties should help to clarify the evolutionary potential of homeotic mutants. Wild populations of plants with changes in floral symmetry, or with reproductive organs replacing perianth organs or sepals replacing petals have already been documented. However, although double-flowered varieties are quite popular as ornamental and garden plants, they are rarely found in the wild and, if they are, usually occur only as rare mutant individuals, probably because of their low fitness relative to the wild-type. We therefore investigated a double-flowered variety of lesser periwinkle, Vinca minor flore pleno (fl. pl.), that is reported to have existed in the wild for at least 160 years. To assess the merits of this plant as a new model system for investigations on the evolutionary potential of double-flowered varieties we explored the morphological details and distribution of the mutant phenotype.

Methods

The floral morphology of the double-flowered variety and of a nearby population of wild-type plants was investigated by means of visual inspection and light microscopy of flowers, the latter involving dissected or sectioned floral organs.

Key Results

The double-flowered variety was found in several patches covering dozens of square metres in a forest within the city limits of Jena (Germany). It appears to produce fewer flowers than the wild-type, and its flowers are purple rather than blue. Most sepals in the first floral whorl resemble those in the wild-type, although occasionally one sepal is broadened and twisted. The structure of second-whorl petals is very similar to that of the wild-type, but their number per flower is more variable. The double-flowered character is due to partial or complete transformation of stamens in the third whorl into petaloid organs. Occasionally, ‘flowers within flowers’ also develop on elongated pedicels in the double-flowered variety.

Conclusions

The flowers of V. minor fl. pl. show meristic as well as homeotic changes, and occasionally other developmental abnormalities such as mis-shaped sepals or loss of floral determinacy. V. minor fl. pl. thus adds to a growing list of natural floral homeotic varieties that have established persistent populations in the wild. Our case study documents that even mutant varieties that have reproductive organs partially transformed into perianth organs can persist in the wild for centuries. This finding makes it at least conceivable that even double-flowered varieties have the potential to establish new evolutionary lineages, and hence may contribute to macroevolutionary transitions and cladogenesis.     

Enhanced error-prone RCA mutagenesis by concatemer resolution

Error-prone rolling circle amplification (RCA) is a promising alternative to error-prone PCR for random mutagenesis. The main disadvantage of error-prone RCA is the low transformation efficiency of the DNA concatemer produced in the amplification reaction. We improved the method by introducing loxP recombination site of bacteriophage P1 Cre recombinase into the target plasmid and reducing the concatemer by Cre recombinase to plasmid-sized units, increasing the number of transformants 50-fold in non-error-prone and 13-fold in error-prone conditions. The efficiency improvement was verified by obtaining 115 ± 57 ceftazidime resistant colonies per recombined RCA reaction from randomly mutated TEM-1 β-lactamase gene library whereas only 9 ± 11 colonies were gained without recombination. Supplementation of the error-prone RCA with Cre/loxP recombination is a simple and useful tool to increase the transformable library size.     

Caveolae-mediated endocytosis of the glucosaminoglycan-interacting adipokine tartrate resistant acid phosphatase 5a in adipocyte progenitor lineage cells

Adipogenesis depends on growth factors controlling proliferation/differentiation of mesenchymal stem cells (MSCs). Membrane binding and endocytosis of growth factors are often coupled to receptor activation and downstream signaling leading to specific cellular responses. The novel adipokine tartrate-resistant acid phosphatase (TRAP) 5a exhibits a growth factor-like effect on MSCs and pre-adipocytes and induces hyperplastic obesity in vivo. However its molecular interaction with pre-adipocytes remains unknown. Therefore, this study aimed to investigate membrane interaction of TRAP and its endocytosis routes in pre-adipocytes. Confocal and/or electron microscopy were used to detect TRAP in untreated or TRAP 5a/b treated pre-adipocytes under conditions that allow or inhibit endocytosis in combination with co-staining of endocytotic vesicles. TRAP interaction with heparin/heparan sulfate was verified by gel filtration. It could be shown that TRAP 5a, but not 5b, binds to the membrane of pre-adipocytes where it co-localizes with heparin-sulfate proteoglycan glypican-4. Also in vitro, TRAP 5a exhibited affinity for both heparin and heparan sulfate with heparin inhibiting its enzyme activity. Upon caveolae-mediated endocytosis of saturating levels of TRAP 5a, TRAP 5a co-localized intracellularly with glypican-4 and late endosomal marker Rab-7 positive vesicles. The protein was also located in multivesicular bodies (MVBs) but did not co-localize with lysosomal marker LAMP-1. TRAP 5a endocytosis was also detectable in pre-osteoblasts, but not fibroblasts, embryonic MSCs or mature adipocytes. These results indicate that TRAP 5a exhibits binding to cell surface, endocytosis and affinity to glucosaminoglycans (GAGs) in pre-adipocyte and pre-osteoblast lineage cells in a manner similar to other heparin-binding growth factors.     

ANALYSIS OF THE Vitellogenin GENE OF RICE MOTH,Corcyra cephalonica STAINTON

Vitellogenin (Vg) is a precursor of the major yolk protein, an essential nutrient for the embryonic development of oviparous animals including insects. Here, the gene(CceVg [Corcyra cephalonica Vg] ) encoding the Vg (CceVg of moth, C. cephalonica, was cloned and sequenced. The gene sequence was 6,721‐bp long and contained 5five introns and six exons that together formed a 5,382‐bp open reading frame. The deduced protein (CceVg) consisted of 1,793 amino acid residues, including a 16‐amino‐acid signal peptide. The putative molecular weight of the primary Vg protein was 202.46 kDa. The CceVg contained all conserved domains and motifs that were commonly found in most insect Vgs except the presence of a polyserine tract at the C‐terminal region, which had not been reported in other lepidopteran Vgs. The expression pattern showed thatCceVg was first transcribed at a very low level in the early larval stage but disappeared in later stage larva. In female, theCceVg mRNA was detected in early pupal stage and throughout adult stage. Interestingly, theCceVg mRNA was detected only in mated males at low levels, not in the virgin ones. Injection ofCceVg double‐stranded RNA into early‐emergent females caused severely abnormal ovaries.     

Molecular Characterization of Southern Rice Blacked‐Streaked Dwarf Virus (SRBSDV) from Vietnam

Southern rice black‐streaked dwarf virus (SRBSDV) is a novel putative member of the genus Fijivirus, family Reoviridae. We report here the genomic sequences of a Vietnamese isolate (SRBSDV‐V). The total genome of SRBSDV‐V has 29 115 nucleotides (nt), nine nt shorter than SRBSDV‐GD or ‐HN, but similar in organization to these two Chinese isolates. Nucleotide diversities among SRBSDV isolates were much lower than those among the corresponding ORFs of the available RBSDV isolates and there was a lower purifying selection pressure on SRBSDV than RBSDV, providing first molecular evidence for the view that SRBSDV is of recent origin. In studies of all available SRBSDV sequences, there was no obvious correlation between geographic distances and phylogenetic distribution. A high frequency of genetic recombination was found among both Chinese and Vietnam SRBSDV isolates, suggesting that recombination may play an important role in the molecular variation and evolution of SRBSDV.