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61.
62.
Cryptic relatedness was suggested to be an important source of confounding in population-based association studies (PBAS). The impact of cryptic relatedness on the performance of haplotype phase inference and haplotype-based association tests is not clear. In this study, we used the Hapmap genetic data to simulate a set of related samples. We evaluated the accuracy of haplotype phase inferred by PHASE 2.1 and calculated the power, type I error rates, accuracy and positive prediction value (PPV) of haplotype frequency-based association tests (HFAT) and haplotype similarity-based association tests (HSAT) under various scenarios, considering relatedness levels, disease models and sample sizes. Cryptic relatedness appeared to slightly increase the accuracy of haplotype phase inference. We observed significant negative effect of cryptic relatedness on the performance of HFAT and HSAT. Ignoring cryptic relatedness may increase spurious association results in haplotype-based PBAS. 相似文献
63.
为了探讨CO2浓度升高下不同水稻品种荣优398 (RY)和粤杂889(YZ)吸收重金属Cd差异性的原因,利用水培试验研究了不同浓度Cd处理下两种水稻吸收Cd的差异及根形态的变化特征.结果表明:低Cd处理(5、10、20 μmol·L-1)显著增加水稻生物量;当Cd浓度高于50 μmol·L-1时,Cd胁迫效果开始显现,水稻生物量减少.CO2浓度升高显著增加了水稻的生物量,增加了YZ茎Cd含量而降低了RY茎Cd含量.在5~200 μmol·L-1的Cd浓度下,CO2浓度升高增加了YZ活性根在总根长中的比例,降低了RY活性根的比例.CO2浓度升高下不同水稻品种根形态的变化是导致其对Cd吸收差异性的原因之一. 相似文献
64.
Pingyong Sun Wuhan Zhang Yihua Wang Qiang He Fu Shu Hai Liu Jie Wang Jianmin Wang Longping Yuan Huafeng Deng 《植物学报(英文版)》2016,58(10):836-847
Traits such as grain shape, panicle length and seed shattering, play important roles in grain yield and harvest. In this study, the cloning and functional analysis of PANICLE TRAITS 2 (PT2), a novel gene from the Indica rice Chuandali (CDL), is reported. PT2 is synonymous with Growth‐Regulating Factor 4 (OsGRF4), which encodes a growth‐regulating factor that positively regulates grain shape and panicle length and negatively regulates seed shattering. Higher expression of OsGRF4 is correlated with larger grain, longer panicle and lower seed shattering. A unique OsGRF4 mutation, which occurs at the OsmiRNA396 target site of OsGRF4, seems to be associated with high levels of OsGRF4 expression, and results in phenotypic difference. Further research showed that OsGRF4 regulated two cytokinin dehydrogenase precursor genes (CKX5 and CKX1) resulting in increased cytokinin levels, which might affect the panicle traits. High storage capacity and moderate seed shattering of OsGRF4 may be useful in high‐yield breeding and mechanized harvesting of rice. Our findings provide additional insight into the molecular basis of panicle growth. 相似文献
65.
Xiaowei Ding Kaihui Liu Baiwan Deng Wenqiang Chen Wenjun Li Feihu Liu 《World journal of microbiology & biotechnology》2013,29(10):1831-1838
In this study, a total of 161 endophytic fungal isolates from Camptotheca acuminata were obtained and classified to 16 taxa according to morphological and molecular analysis. These taxa were composed of 2 frequent genera (Botryosphaeria and Fusarium) and 14 infrequent groups such as Xylaria, Diaporthe, Rhizopus, Epicoccum, and Preussia, demonstrating that fungal endophytes in C. acuminata were highly abundant and diverse. Antimicrobial activity screening using filter-paper diffusion method showed that 47.6 % of the tested isolates had antimicrobial activity against at least one of the test microorganisms. Screening of fungal endophyte-derived camptothecin analogues by TLC and LC–MS/MS3 demonstrated that a strain Botryosphaeria dothidea, X-4 could produce 9-methoxycamptothecin (9-MCPT) when cultured in Sabouraud’s dextrose broth for 12 days under shake flask and bench-scale fermention conditions. This work showed that the fungal endophytes from C. acuminata could be an alternative source for the production of 9-MCPT and other natural antimicrobial compounds. 相似文献
66.
Li Han Xuan Zhou Yiting Zhao Shusheng Zhu Lixia Wu Yunlu He Xiangrui Ping Xinqi Lu Wuying Huang Jie Qian Lina Zhang Xi Jiang Dan Zhu Chongyu Luo Saijie Li Qian Dong Qijing Fu Kaiyuan Deng Xin Wang Lei Wang Sheng Peng Jinsong Wu Weimin Li Jií Friml Youyong Zhu Xiahong He Yunlong Du 《植物学报(英文版)》2020,62(9):1433-1451
Endophytic fungi can be beneficial to plant growth. However, the molecular mechanisms underlying colonization of Acremonium spp. remain unclear.In this study, a novel endophytic Acremonium strain was isolated from the buds of Panax notoginseng and named Acremonium sp. D212. The Acremonium sp. D212 could colonize the roots of P. notoginseng,enhance the resistance of P. notoginseng to root rot disease, and promote root growth and saponin biosynthesis in P. notoginseng. Acremonium sp. D212 could secrete indole-3-acetic acid(IAA) and jasmonic acid(JA), and inoculation with the fungus increased the endogenous levels of IAA and JA in P. notoginseng. Colonization of the Acremonium sp. D212 in the roots of the rice line Nipponbare was dependent on the concentration of methyl jasmonate(Me JA)(2–15 μmol/L) and 1-naphthalenacetic acid(NAA)(10–20 μmol/L). Moreover, the roots of the JA signaling-defective coi1-18 mutant were colonized by Acremonium sp. D212 to a lesser degree than those of the wild-type Nipponbare and mi R393 boverexpressing lines, and the colonization was rescued by Me JA but not by NAA. It suggests that the cross-talk between JA signaling and the auxin biosynthetic pathway plays a crucial role in the colonization of Acremonium sp. D212 in host plants. 相似文献
67.
68.
Genome-wide regulation of 5hmC, 5mC, and gene expression by Tet1 hydroxylase in mouse embryonic stem cells 总被引:2,自引:0,他引:2
Xu Y Wu F Tan L Kong L Xiong L Deng J Barbera AJ Zheng L Zhang H Huang S Min J Nicholson T Chen T Xu G Shi Y Zhang K Shi YG 《Molecular cell》2011,42(4):451-464
DNA methylation at the 5 position of cytosine (5mC) in the mammalian genome is a key epigenetic event critical for various cellular processes. The ten-eleven translocation (Tet) family of 5mC-hydroxylases, which convert 5mC to 5-hydroxymethylcytosine (5hmC), offers a way for dynamic regulation of DNA methylation. Here we report that Tet1 binds to unmodified C or 5mC- or 5hmC-modified CpG-rich DNA through its CXXC domain. Genome-wide mapping of Tet1 and 5hmC reveals mechanisms by which Tet1 controls 5hmC and 5mC levels in mouse embryonic stem cells (mESCs). We also uncover a comprehensive gene network influenced by Tet1. Collectively, our data suggest that Tet1 controls DNA methylation both by binding to CpG-rich regions to prevent unwanted DNA methyltransferase activity, and by converting 5mC to 5hmC through hydroxylase activity. This Tet1-mediated antagonism of CpG methylation imparts differential maintenance of DNA methylation status at Tet1 targets, ultimately contributing to mESC differentiation and the onset of embryonic development. 相似文献
69.
红松单木高生长模型的研究 总被引:11,自引:0,他引:11
1引言生长模型是定量研究树木生长过程的有效手段。它既可对林木生长作出现实的评价,也可用来预估将来各测树因子的变化;既是编制修订各种数表的基础,也是森林经营中各种措施实施的依据。在林学上,生长模型主要包括单木生长模型和林分生长模型,其中单木生长模型是林... 相似文献