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The ability to regulate spatial and temporal expression of genes is a useful tool in biotechnology as well as studies of functional genomics. Such regulation can provide information concerning the function of a gene in a developmental context while avoiding potential harmful effects due to constitutive overexpression of the gene. A GUS gene construct that uses the ecdysone receptor-based chemically inducible system and several different tissue-specific promoters was introduced into the model plant Arabidopsis thaliana and into the crop plant Brassica juncea. Here we describe the results of studies showing that this system provides both temporal and spatial control of transgene expression, and confirm that this system is useful for tissue-specific and temporal induction of gene expression in A. thaliana and B. juncea. 相似文献
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Zheng Lu Jin Joon Ki Hong Dae-Jin Yun Sang Yeoi Lee Young Ju Choi Jeong Dong Bahk Roger N. Beachy Moo Je Cho Chae Oh Lim 《Journal of Plant Biology》2002,45(2):77-82
Nicotiana benthamiana plants were transformed with the movement protein (MP) gene of tobacco mosaic virus (TMV), usingAgrobacterium-mediated transformation. Plants regenerated from the transformed cells accumulated 30-kDa MP and complemented the activity of TMV
MP when infected with chimeric TMVs containing defective MR These transgenic plants displayed stunting, pale-green leaves,
and starch accumulations, indicating that TMV MP altered the carbon partitioning for leaves involved in TMV cell-to-cell movement. 相似文献
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Felicity L. Newell James Sheehan Petra Bohall Wood Amanda D. Rodewald David A. Buehler Patrick D. Keyser Jeffrey L. Larkin Tiffany A. Beachy Marja H. Bakermans Than J. Boves Andrea Evans Gregory A. George Molly E. McDermott Kelly A. Perkins Matthew B. White T. Bently Wigley 《Journal of Field Ornithology》2013,84(3):270-286
Point counts are commonly used to assess changes in bird abundance, including analytical approaches such as distance sampling that estimate density. Point‐count methods have come under increasing scrutiny because effects of detection probability and field error are difficult to quantify. For seven forest songbirds, we compared fixed‐radii counts (50 m and 100 m) and density estimates obtained from distance sampling to known numbers of birds determined by territory mapping. We applied point‐count analytic approaches to a typical forest management question and compared results to those obtained by territory mapping. We used a before–after control impact (BACI) analysis with a data set collected across seven study areas in the central Appalachians from 2006 to 2010. Using a 50‐m fixed radius, variance in error was at least 1.5 times that of the other methods, whereas a 100‐m fixed radius underestimated actual density by >3 territories per 10 ha for the most abundant species. Distance sampling improved accuracy and precision compared to fixed‐radius counts, although estimates were affected by birds counted outside 10‐ha units. In the BACI analysis, territory mapping detected an overall treatment effect for five of the seven species, and effects were generally consistent each year. In contrast, all point‐count methods failed to detect two treatment effects due to variance and error in annual estimates. Overall, our results highlight the need for adequate sample sizes to reduce variance, and skilled observers to reduce the level of error in point‐count data. Ultimately, the advantages and disadvantages of different survey methods should be considered in the context of overall study design and objectives, allowing for trade‐offs among effort, accuracy, and power to detect treatment effects. 相似文献
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Phosphorylation and/or Presence of Serine 37 in the Movement Protein of Tomato Mosaic Tobamovirus Is Essential for Intracellular Localization and Stability In Vivo 下载免费PDF全文
Shigeki Kawakami Hal S. Padgett Daijiro Hosokawa Yoshimi Okada Roger N. Beachy Yuichiro Watanabe 《Journal of virology》1999,73(8):6831-6840
The P30 movement protein (MP) of tomato mosaic tobamovirus (ToMV) is synthesized in the early stages of infection and is phosphorylated in vivo. Here, we determined that serine 37 and serine 238 in the ToMV MP are sites of phosphorylation. MP mutants in which serine was replaced by alanine at positions 37 and 238 (LQ37A238A) or at position 37 only (LQ37A) were not phosphorylated, and mutant viruses did not infect tobacco or tomato plants. By contrast, mutation of serine 238 to alanine did not affect the infectivity of the virus (LQ238A). To investigate the subcellular localization of mutant MPs, we constructed viruses that expressed each mutant MP fused with the green fluorescent protein (GFP) of Aequorea victoria. Wild-type and mutant LQ238A MP fusion proteins showed distinct temporally regulated patterns of MP-GFP localization in protoplasts and formation of fluorescent ring-shaped infection sites on Nicotiana benthamiana. However mutant virus LQ37A MP-GFP did not show a distinct pattern of localization or formation of fluorescent rings. Pulse-chase experiments revealed that MP produced by mutant virus LQ37A was less stable than wild-type and LQ238A MPs. MP which contained threonine at position 37 was phosphorylated, but the stability of the MP in vivo was very low. These studies suggest that the presence of serine at position 37 or phosphorylation of serine 37 is essential for intracellular localization and stability of the MP, which is necessary for the protein to function. 相似文献
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This study focuses on the role of protein turnover in the accumulation of the storage protein β-conglycinin (7S protein) during soybean embryogenesis. The results of pulse:chase experiments using 3H-leucine indicate that the turnover of the subunits of β-conglycinin by proteolysis is more rapid in early stages of cotyledon maturation than in later stages. 相似文献