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Effects of pre-harvest chemical application on rice desiccation and seed quality
Yong-qi He, Jin-ping Cheng, Liang-feng Liu, Xiao-dan Li, Bin Yang, Hong-sheng Zhang, Zhou-fei Wang
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2015, 16(10): 813-823.
https://doi.org/10.1631/jzus.B1500032
Pre-harvest desiccation may increase the efficiency of seed production. Field studies were conducted to determine the effects of diquat, paraquat, and ethephon applications on grain moisture, grain weight, and seed germination of hybrid rice Yanliangyou 88 (Oryza sativa ssp. indica) and conventional rice Wuyunjing 7 (Oryza sativa ssp. japonica). In 2013, we tested 12 treatments applied at four weeks (Yanliangyou 88) and six weeks (Wuyunjing 7) after heading. Results showed that reductions in moisture content were significant two and four days after chemical application. Chemical applications had no adverse effects on 1000-grain weight, germination percentage, or germination index, but there were negative effects on the percentage of normal seedlings. Desiccation effects increased with increase in the period after application, while the effect of ethephon combined with diquat or paraquat on desiccation was limited compared with that of diquat or paraquat alone in a short period after application. In 2013, chemical applications reduced the moisture content by from 0.5% to 6.4%, the germination percentage by from 0% to 3.3%, and the percentage of normal seedlings by from 13.3% to 100.0%. Among the treatments, diquat applied at 120 g/ha resulted in effective desiccation with fewer negative effects on grain weight and seed germination in 2013 and 2014. Therefore, diquat may have potential as a pre-harvest chemical desiccation treatment for rice. These results may provide a basis for developing and implementing protocols for large scale field trials.
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Generation of insect-resistant and glyphosate-tolerant rice by introduction of a T-DNA containing two Bt insecticidal genes and an EPSPS gene
Qi-chao Zhao, Ming-hong Liu, Xian-wen Zhang, Chao-yang Lin, Qing Zhang, Zhi-cheng Shen
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2015, 16(10): 824-831.
https://doi.org/10.1631/jzus.B1500056
Insect resistance and glyphosate tolerance have been two of the most important traits in the genetic improvement of various crops. In this study, two Bacillus thuringiensis (Bt) insecticidal genes, Cry1Ac and Cry1Ig, and a modified glyphosate-tolerant 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene (G10) were combined into a single transferred DNA (T-DNA) fragment and introduced into rice by Agrobacterium-mediated transformation. A transgenic line with single-copy T-DNA insertion named GAI-14 was found to be highly resistant to striped stem borer and rice leaf roller, and tolerant to glyphosate. Analysis of T-DNA border sequence suggested that the transgenes were inserted at the chromosome 3 and appeared to have not interrupted any known or putative genes. A field trial observed no significant difference in the basic agronomic traits between GAI-14 and the recipient rice.
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Estimation of rice phenology date using integrated HJ-1 CCD and Landsat-8 OLI vegetation indices time-series images
Jing Wang, Jing-feng Huang, Xiu-zhen Wang, Meng-ting Jin, Zhen Zhou, Qiao-ying Guo, Zhe-wen Zhao, Wei-jiao Huang, Yao Zhang, Xiao-dong Song
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2015, 16(10): 832-844.
https://doi.org/10.1631/jzus.B1500087
Accurate estimation of rice phenology is of critical importance for agricultural practices and studies. However, the accuracy of phenological parameters extracted by remote sensing data cannot be guaranteed because of the influence of climate, e.g. the monsoon season, and limited available remote sensing data. In this study, we integrate the data of HJ-1 CCD and Landsat-8 operational land imager (OLI) by using the ordinary least-squares (OLS), and construct higher temporal resolution vegetation indices (VIs) time-series data to extract the phenological parameters of single-cropped rice. Two widely used VIs, namely the normalized difference vegetation index (NDVI) and 2-band enhanced vegetation index (EVI2), were adopted to minimize the influence of environmental factors and the intrinsic difference between the two sensors. Savitzky-Golay (S-G) filters were applied to construct continuous VI profiles per pixel. The results showed that, compared with NDVI, EVI2 was more stable and comparable between the two sensors. Compared with the observed phenological data of the single-cropped rice, the integrated VI time-series had a relatively low root mean square error (RMSE), and EVI2 showed higher accuracy compared with NDVI. We also demonstrate the application of phenology extraction of the single-cropped rice in a spatial scale in the study area. While the work is of general value, it can also be extrapolated to other regions where qualified remote sensing data are the bottleneck but where complementary data are occasionally available.
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Functional characterization of an invertase inhibitor gene involved in sucrose metabolism in tomato fruit
Ning Zhang, Jing Jiang, Yan-li Yang, Zhi-he Wang
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2015, 16(10): 845-856.
https://doi.org/10.1631/jzus.B1400319
In this study, we produced tomato plants overexpressing an invertase inhibitor gene (Sly-INH) from tomato, using a simple and efficient transient transformation system. Compared with control plants, the expression of Sly-INH was highly upregulated in Sly-INH overexpressing plants, as indicated by real-time polymerase chain reaction (PCR). Physiological analysis revealed that Sly-INH inhibited the activity of cell wall invertase (CWIN), which increased sugar accumulation in tomato fruit. Furthermore, Sly-INH mediated sucrose metabolism by regulating CWIN activity. Our results suggest that invertase activity is potentially regulated by the Sly-INH inhibitor at the post-translational level, and they demonstrate that the transient transformation system is an effective method for determining the functions of genes in tomato.
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Isolation and characterization of a crude oil degrading bacteria from formation water: comparative genomic analysis of environmental Ochrobactrum intermedium isolate versus clinical strains
Lu-jun Chai, Xia-wei Jiang, Fan Zhang, Bei-wen Zheng, Fu-chang Shu, Zheng-liang Wang, Qing-feng Cui, Han-ping Dong, Zhong-zhi Zhang, Du-jie Hou, Yue-hui She
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2015, 16(10): 865-874.
https://doi.org/10.1631/jzus.B1500029
In this study, we isolated an environmental clone of Ochrobactrum intermedium, strain 2745-2, from the formation water of Changqing oilfield in Shanxi, China, which can degrade crude oil. Strain 2745-2 is aerobic and rod-shaped with optimum growth at 42 °C and pH 5.5. We sequenced the genome and found a single chromosome of 4 800 175 bp, with a G+C content of 57.63%. Sixty RNAs and 4737 protein-coding genes were identified: many of the genes are responsible for the degradation, emulsification, and metabolizing of crude oil. A comparative genomic analysis with related clinical strains (M86, 229E, and LMG3301T) showed that genes involved in virulence, disease, defense, phages, prophages, transposable elements, plasmids, and antibiotic resistance are also present in strain 2745-2.
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Midgut immune responses induced by bacterial infection in the silkworm, Bombyx mori
Lei Zhang, Yan-wen Wang, Zhi-qiang Lu
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2015, 16(10): 875-882.
https://doi.org/10.1631/jzus.B1500060
Insect gut epithelial cells produce reactive oxygen species (ROS) and antimicrobial peptides (AMPs) to protect hosts from pathogenic microorganisms. In this study, we evaluate the pathogenicity of Pseudomonas aeruginosa and Bacillus bombysepticus in the silkworm, Bombyx mori. Survival curves show that B. bombysepticus is deadly when larval silkworms are infected orally. Bacterial infection caused intestinal hydrogen peroxide (H2O2) and nitric oxide (NO) levels to increase significantly by 8 and 16 h post-infection (hpi), respectively. Real-time quantitative polymerase chain reaction (qPCR) analysis shows that the transcription levels of dual oxidase (Duox) and catalase (CAT) are highly up-regulated by P. aeruginosa infection at 8 hpi. P. aeruginosa infection induced nitric oxide synthase 2 (NOS2) expression at 16 hpi, which contributes to the generation of NO. mRNA levels of AMP genes, specifically Glovorin 2 and Glovorin 3, which obviously increase during the early infection stage. These results indicate that invading bacteria elevate intestinal ROS and NO levels and induce AMP gene transcription, which contributes to intestinal immune defense.
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8 articles
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