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61.
Mengjiao Zhu Lijie Han Ya Lv Yishan Liu Pan Li Haichun Jing Hongwei Cai 《植物学报(英文版)》2018,60(10):938-955
Tillering contributes to grain yield and plant architecture and therefore is an agronomically important trait in sorghum (Sorghum bicolor). Here, we identified and functionally characterized a mutant of the Non‐dormant Axillary Bud 1 (NAB1) gene from an ethyl methanesulfonate‐mutagenized sorghum population. The nab1 mutants have increased tillering and reduced plant height. Map‐based cloning revealed that NAB1 encodes a carotenoid‐cleavage dioxygenase 7 (CCD7) orthologous to rice (Oryza sativa) HIGH‐TILLERING DWARF1/DWARF17 and Arabidopsis thaliana MORE AXILLARY BRANCHING 3. NAB1 is primarily expressed in axillary nodes and tiller bases and NAB1 localizes to chloroplasts. The nab1 mutation causes outgrowth of basal axillary buds; removing these non‐dormant basal axillary buds restored the wild‐type phenotype. The tillering of nab1 plants was completely suppressed by exogenous application of the synthetic strigolactone analog GR24. Moreover, the nab1 plants had no detectable strigolactones and displayed stronger polar auxin transport than wild‐type plants. Finally, RNA‐seq showed that the expression of genes involved in multiple processes, including auxin‐related genes, was significantly altered in nab1. These results suggest that NAB1 functions in strigolactone biosynthesis and the regulation of shoot branching via an interaction with auxin transport. 相似文献
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本文提出Logistic方程参数优化估计的人工神经网络方法,并选取一组标样进行具体尝试。结果表明,用这种方法估计Logistic方程参数效果极好。 相似文献
64.
太湖大型底栖动物群落结构及多样性 总被引:33,自引:0,他引:33
为揭示现阶段太湖大型底栖动物群落现状及其对生态环境变化的响应, 于2007年2月至2008年11月对太湖大型底栖动物进行为期两周年的季度调查。30个采样点共记录底栖动物3门7纲19科40种, 底栖动物平均密度和生物量空间差异较大, 平均密度高值出现在梅梁湾、竺山湾及河口, 主要为寡毛纲颤蚓类; 平均生物量高值出现在贡湖湾、西湖区、东太湖和东部湖湾, 主要为软体动物。霍甫水丝蚓(Limnodrilus hoffmeisteri)、中华河蚓(Rhyacodrilus sinicus)、河蚬(Corbicula fluminea)、铜锈环棱螺(Bellamya aeruginosa)、中国长足摇蚊(Tanypus chinensis)和钩虾属一种(Gammarus sp.)是现阶段太湖大型底栖动物的优势种。聚类分析将30个采样点分成3组, 相似性分析检验表明各聚类组大型底栖动物群落具有显著差异(P<0.05)。多样性分析结果表明, 东太湖和东部湖湾物种多样性、丰富度和均匀度最高, 优势种为腹足纲螺类; 梅梁湾、竺山湾及河口多样性最低、密度最高, 霍甫水丝蚓和中华河蚓在该区占据绝对优势; 贡湖湾、湖心和西湖区多样性处于中等水平, 其优势种为河蚬。研究结果表明营养水平、底质类型以及水生植被的分布是决定太湖大型底栖动物群落结构及多样性的关键因子。 相似文献
65.
Lei Wang Kunzheng Cai Yuting Chen Guoping Wang 《Biological trace element research》2013,152(2):275-283
Bacterial wilt caused by Ralstonia solanacearum is a serious soil-borne disease of Solanaceae crops. In this study, the soil microbial effects of silicon-induced tomato resistance against R. solanacearum were investigated through pot experiment. The results showed that exogenous 2.0 mM Si treatment reduced the disease index of bacterial wilt by 19.18 % to 52.7 % compared with non-Si-treated plants. The uptake of Si was significantly increased in the Si-treated tomato plants, where the Si content was higher in the roots than that in the shoots. R. solanacearum inoculation resulted in a significant increase of soil urease activity and reduction of soil sucrase activity, but had no effects on soil acid phosphatase activity. Si supply significantly increased soil urease and soil acid phosphatase activity under pathogen-inoculated conditions. Compared with the non-inoculated treatment, R. solanacearum infection significantly reduced the amount of soil bacteria and actinomycetes by 52.5 % and 16.5 %, respectively, but increased the ratio of soil fungi/soil bacteria by 93.6 %. After R. solanacearum inoculation, Si amendments significantly increased the amount of soil bacteria and actinomycetes and reduced soil fungi/soil bacteria ratio by 53.6 %. The results suggested that Si amendment is an effective approach to control R. solanacearum. Moreover, Si-mediated resistance in tomato against R. solanacearum is associated with the changes of soil microorganism amount and soil enzyme activity. 相似文献
66.
采用碱裂解法、化学改良方法、CTAB法、酚氯法等4种方法提取从泉州红树林沉积物中筛选出多环芳烃降解菌群YL的质粒,并分别转化至大肠杆菌感受态细胞,然后采用富集筛选的手段,最终确立最佳方案得到一组质粒转化菌群.该转化菌群可以利用芘作为其生长的惟一碳源和能源,并能在21 d内将50 mg·L-1的芘降解85.69%.而受体菌E.coli DH5α的芘降解率仅为2.006%.由此可以证明,降解质粒已成功转化进宿主细胞,并发挥降解作用.YL的质粒含有降解芘的基因. 相似文献
67.
Jiayuan Sheng Lei Huang Xiangcheng Zhu Jin Cai Zhinan Xu 《Applied microbiology and biotechnology》2014,98(4):1785-1794
Bacterial peptidoglycan is the cell wall component responsible for various biological activities. Its cytoplasmic precursor UDP-N-acetylmuramyl pentapeptide is biosynthesized by the first six enzymes of peptidoglycan synthetic pathways (Mur enzymes), which are all proved to be important targets for antibiotic screening. In our present work, the genes encoding Mur enzymes from Escherichia coli were co-expressed in the cell-free protein synthesis (CFPS) system, and the activities of Mur enzymes derived from CFPS system were validated by the synthesis of the final product UDP-N-acetylmuramyl pentapeptide. Then this in vitro reconstituted Mur biosynthetic pathway was used to screen a panel of specific antisense oligonucleotides for MurA and MurB. The selected oligonucleotides were proved to eliminate the expression of Mur enzymes, and thus inhibit the Mur biosynthetic pathway. The present work not only developed a rapid method to reconstruct and regulate a biosynthetic pathway in vitro, but also may provide insight into the development of novel antibiotics targeting on peptidoglycan biosynthetic pathway. 相似文献
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