高粱SBP-box基因家族全基因组鉴定及表达分析

SQUAMOSA PROMOTER BINDING PROTEIN box (SBP-box)基因家族编码一类绿色植物特有的转录因子,其功能涉及作物遗传改良的许多方面,如产量、株型、抗逆性等,具有重要的实际应用价值。本研究通过生物信息学方法从高粱(Sorghum bicolor L.)全基因组中鉴定出18个SBP-box基因,分布于9条染色体上,其中8个基因位于基因组重复区域。系统发育分析表明高粱SBP-box基因家族可分为6个亚家族,其中SbSBP12、SbSBP3和SbSBP15分别与玉米ZmLG1、ZmTGA1和ZmUB2/3直系同源。基于RNA-seq数据的表达分析发现高粱SBP-box基因在花序原基中表达量最高,SbSBP9和SbSBP17为花序原基特异表达基因,SbSBP5、SbSBP8和SbSBP18等基因受外源ABA和PEG胁迫上调表达,表明SBP-box基因可能参与高粱对非生物逆境的响应。本研究为高粱SBP-box家族重要基因的克隆提供了参考,相关基因可作为高粱遗传改良的候选基因。     

Occurrence of exotic eels in natural waters of South Korea

We surveyed the proportion of anguillid eel species inhabiting South Korea natural waters. From September 2014 to August 2015, 429 eels were collected in various habitats for identification using morphological features and DNA-based molecular methods. We found 424 Japanese eels (Anguilla japonica, 98.8%), two European eels (A. anguilla, 0.5%), one American eel (A. rostrata, 0.23%), one tropical eel (A. marmorata, 0.23%), and one short-finned eel (A. bicolor pacifica, 0.23%). Three (A. anguilla, A. rostrata, and A. bicolor pacifica) are exotic species to the natural waters of South Korea; this study is the first record of their distribution in this region. Specifically, A. anguilla was found in the Lake Soyang and Cheongpyeong, while A. rostrata was found only in the Lake Cheongpyeong, and A. bicolor pacifica was found in the Geum River estuary.     

黑盾胡蜂单母建群习性的观察

通过引蜂筑巢研究黑盾胡蜂VespabicolorFabricius单母建群的生物学习性。结果表明 :母蜂在最初 3只子代工蜂羽化之前兼负蜂王和工蜂的职能 ,建成外包巢壁内具有 3 4个巢房的小巢 ,饲育的幼虫数不超过 1 7只 ,各虫态历期分别为卵期 5 5d ,幼虫期 1 2d,蛹期 1 2 5d ;母蜂日外勤飞翔次数与天气相关 ,晴天可达 42次 ,其中近 80 %为捕食。作者认为 ,黑盾胡蜂单母建群时期可能是其生活史中既脆弱又关键的阶段。     

不同坡位胡枝子光合特性及其影响因子研究

采用Li-6400光合分析仪,在自然条件下对不同坡位胡枝子叶片净光合速率(Pn)、蒸腾速率(Tr)及其相关环境因子的日进程进行了观测。结果表明:在5月份晴天条件下,不同坡位胡枝子叶片Pn、Tr日变化均呈单峰曲线,而水分利用效率(WUE)表现出早晚高、中午低的变化趋势。它们的叶片Pn峰值不同坡位均出现在11:00,而且上坡位峰值和日平均值略高于下坡位和平地(P>0.05);Tr峰值上坡位出现在11:00,下坡位和平地均出现在13:00,且上坡位峰值和日平均值显著低于下坡位和平地(P<0.01);上坡和平地WUE均在15:00达到最大值,但下坡位推迟到17:00,而且上坡位峰值和日平均值略高于下坡和平地(P>0.05)。胡枝子叶片Pn与PAR、Ca、RH等生态因子间的拟合方程分别为:Y上pn=-26.148 0.002 3xPAR 0.11xCa-0.84xRH,Y平pn=-19.148 0.001 9xPAR 0.106xCa 0.86xRH,Y下pn=-27.148 0.002xPAR-1.16xRH,其主要生态影响因子及其大小顺序为XPAR>XRH>XCa。研究发现,不同坡位胡枝子叶片主要光合指标日变化趋势相似,但其峰值出现时间和高低有别,其主要生态影响因子为光合有效辐射、大气相对湿度和大气二氧化碳浓度。     

Cooperatively breeding Arabian babblers call differently when mobbing in different predator-induced situations

Cooperatively breeding Arabian babblers (Turdoides squamiceps) havea repertoire of different calls that they use in predator-induced contexts.We investigated their vocal mobbing behavior in two different predator-inducedsituations. We presented territorial groups of babblers a perched,stuffed owl representing an avian predator and a cat representinga ground predator. Babblers approached in both situations andmobbed the predators with the same two call types. In both predator-inducedsituations their first call was a short, metallic-sounding "tzwick."In response to the cat, babblers continued to primarily usetzwicks. However, in continued response to the owl, the babblersprimarily used long trills. The experiments indicate that differencesin use of two common call types during mobbing provide informationon differences in predator-induced situations, although no calltype per se identified a specific situation. The experiments suggestthat the short tzwicks indicate a higher risk or urgency thantrills and that combinations of both call types may providegraded information about differences in predator-induced situations.The relatively stable groups of these cooperative breeders mighthave favored evolution for using different calls in differentmobbing situations.     

Pseudogamous Apomixis in Maize and Sorghum in Diploid-Tetraploid Crosses

Apomictic seed development is a complex process including formation of unreduced embryo sac, parthenogenetic embryo development from the egg cell, and endosperm formation either autonomously, or due to fertilization of polar nuclei by the sperm (under pseudogamous form of apomixis). In the latter case, an obstacle to the normal endosperm development is disturbance of maternal (m) -to-paternal (p) genomic ratio 2m: 1p that occurs in the cases of pollination of unreduced embryo sac with haploid sperms. Usage of tetraploid pollinators can overcome this problem because in such crosses maternal-to-paternal genomic ratio is 4m: 2p that provides formation of kernels with plump endosperm. Using tetraploid lines as pollen parents we observed formation of plump kernels on the ears and panicles of diploid maize and sorghum accessions. These kernels had hybrid endosperm and diploid maternaltype embryo or hybrid embryo with different ploidy level (2n, 3n, 4n). The frequencies of plump kernels on the ear ranged from 0.2-0.3% to 5.7-6.2% counting from the number of ovaries. Maternal-type plants were found in two maize lines, their frequency varying from 10.7 to 37.5% of the progeny plants. In CMS-lines of sorghum pollinated with tetraploid sorghum accessions, the frequency of plump kernels ranged from 0.6 to 14.0% counting from the number of ovaries; the frequency of maternal-type plants varied from 33.0 up to 96.1%. The hybrid nature of endosperm of the kernels that gave rise to maternal-type plants has been proved by marker gene expression and by SDS-electrophoresis of endosperm proteins. These data testify to variable modes of seed formation under diploid × tetraploid crosses in maize and sorghum both by amphi- and by apomixis. Therefore, usage of tetraploid pollinators might be a promising approach for isolation of apomixis in maize and sorghum accessions.     

Sorghum roots are inefficient in uptake of EDTA-chelated lead

BACKGROUND AND AIMS: Ethylene diamine tetraacetic acid (EDTA)-assisted phytoremediation has been developed to clean up lead (Pb)-contaminated soil; however, the mechanism responsible for the uptake of EDTA-Pb complex is not well understood. In this study, the accumulation process of Pb from EDTA-Pb is characterized in comparison to ionic Pb [Pb(NO(3))(2)] in sorghum (Sorghum bicolor). METHODS: Sorghum seedlings were exposed to a 0.5 mM CaCl(2) (pH 5.0) solution containing 0, 1 mM Pb(NO(3))(2) or EDTA-Pb complexes at a molar ratio of 1:0.5, 1:1, 1:2 and 1:4 (Pb:EDTA). The root elongation of sorghum at different ratios of Pb:EDTA was measured. Xylem sap was collected after the stem was severed at different times. The concentration of Pb in the shoots and roots were determined by an atomic absorption spectrometer. In addition, the roots were stained with Fluostain I for observation of the root structure. KEY RESULTS: Lead accumulation in the shoots of the plants exposed to EDTA-Pb at 1:1 ratio was only one-fifth of that exposed to ionic Pb at the same concentration. Lead accumulation decreased when transpiration was suppressed. The concentration of Pb in the xylem sap from the EDTA-Pb-treated plants was about 1/25,000 of that in the external solution. Root elongation was severely inhibited by ionic Pb, but not by EDTA-Pb at a 1:1 ratio. Root staining showed that a physiological barrier was damaged in the roots exposed to ionic Pb, but not in the roots exposed to EDTA-Pb. CONCLUSIONS: All these results suggest that sorghum roots are inefficient in uptake of EDTA-chelated Pb and that enhanced Pb accumulation from ionic Pb was attributed to the damaged structure of the roots.     

Cadmium Accumulation by Jack-Bean and Sorghum in Hydroponic Culture

Among the technologies used to recuperate cadmium (Cd) contaminated soils, phytoextraction are particularly important, where the selection of suitable plants is critical to the success of the soil remediation. Thus, the objectives of this study were to evaluate the responses of jack-bean and sorghum to Cd supply and to quantify Cd accumulation by these species grown in hydroponic culture. The plants were subjected to 0, 15, 30, or 60 μmol Cd L^?1 in the nutrient solution, and gas exchange, plant growth and Cd accumulation were measured at 25 days after starting Cd treatments. The Cd supply severely reduced growth of shoots and roots in both species. In jack-bean, Cd decreased photosynthesis by 56–86%, stomatal conductance by 59–85% and transpiration by 48–80%. The concentrations and amounts of Cd accumulated in the plant tissues were proportional to the metal supply in the nutrient solution. Sorghum was more tolerant than jack-bean to Cd toxicity, but the latter showed a greater metal concentration and accumulation in the shoot. Therefore, jack-bean would be more suitable than sorghum for use in Cd phytoremediation programs based on phytoextraction.