共查询到20条相似文献，搜索用时 46 毫秒
1.
A gravity-insensitive mutant was isolated from rice (Oryza sativa L. Cv. Zhonghua 11) transformed by Agrobacterium tumefaciens. The mutant's shoot growth (prostrate growth) was insensitive to gravity; whereas root growth displayed a normal positive gravitropism.Histological observation of root caps and leaf sheaths indicated that there was no significant difference in the number and size of amyloplasts in cells of the mutant and cells of the wild type 相似文献
2.
INTRODUCTION The most obvious manifestation of gravitys effect on plants is the downward bending of roots and the upward growth of shoots. Gravity is an important factor in plant development (Barlow, 1995). The starch-statolith hypothesis proposed by Haberlandt and Nmec (Audus, 1962) is the most widely accepted view of how plants perceive gravity. Physiological data suggested that the amyloplast containing starch granules act as the statolith in higher plants. Sedimented amyloplasts ar… 相似文献
3.
维生素C又称坏血酸是人类营养中所需要的最重要的维生素之一,缺乏维生素C会产生坏血病。本文利用“2,4-二硝基苯肼法”测定抗坏血酸在马齿苋、面条菜、蓬蓬菜、山芹菜、猫耳菜中的含量。结果表明在五种野菜中猫耳菜和面条菜中含抗坏血酸最多,其次是蓬蓬菜和山芹菜,马齿苋中抗坏血酸含量最少。 相似文献
4.
Hong-bo Zhang Hai-feng Zhang Qi-he Chen Hui Ruan Ming-liang Fu Guo-qing He 《Journal of Zhejiang University. Science. B》2009,10(10):769-776
Proteinase A (PrA), encoded by PEP4 gene, is a key enzyme in the vacuoles of Saccharomyces cerevisiae. We characterized the effects of PrA on cell growth and glucose metabolism in the industrial S. cerevisiae WZ65. It was observed that the lag phase of cell growth of partial PEP4 gene deletion mutant (36 h) and PrA-negative mutant (48 h) was significantly ex-tended, compared with the wild type strain (24 h) (P<0.05), but PrA had no effect on glucose metabolism either under shaking or steady state cultivations. The logistic model was chosen to evaluate the effect of PrA on S. cerevisiae cell growth, and PrA was found to promote cell growth against insufficient oxygen condition in steady state cultivation, but had no effect in shaking culti-vation. The effects of glucose starvation on cell growth of partial PEP4 gene deletion strain and PrA-negative mutant were also evaluated. The results show that PrA partial deficiency increased the adaption ofS. cerevisiae to unfavorable nutrient environment, but had no effect on glucose metabolism under the stress of low glucose. During heat shock test, at 60 ℃ the reduced cell viability rate (RCVR) was 10% for the wild type S. cerevisiae and 90% for both mutant strains (P<0.01), suggesting that PrA was a negative factor for S. cerevisiae cells to survive under heat shock. As temperatures rose from 60 ℃ to 70 ℃, the wild type S. cerevisiae had significantly lower relative glucose consumption rate (RGCR) (61.0% and 80.0%) than the partial mutant (78.0% and 98.5%) and the complete mutant (80.0% and 98.0%) (P<0.05), suggesting that, in coping with heat shock, cells of the PrA mutants increased their glucose consumption to survive. The present study may provide meaningful information for brewing industry; however, the role of PrA in industrial S. cerevisiae physiology is complex and needs to be further investigated. 相似文献
5.
植物生长调节物质对玉米根尖愈伤组织培养的影响 总被引：6，自引：0，他引：6
以玉米根尖为实验材料，研究不同种类的生长素和细胞分裂素在不同浓度及不同配比下，对愈伤组织培养的影响．通过本研究得出，植物生长调节物质是影响玉米离体根尖愈伤组织培养的重要因素，不同激素种类及不同浓度配比的效果是不一样的．对玉米晴3幼根根尖愈伤组织的培养，2.4-D 2mg／L与BA 1mg／L搭配，效果最好；对玉米大黄幼根根尖愈伤组织的培养，2，4-D 2 mg／L与KT 0．5 mg／L搭配，效果最好． 相似文献
6.
To understand the feasibility of its application to the in situ remediation of contaminated groundwater, the dechlori-nation of 2,4-dichlorophenol (2,4-DCP) by Ni/Fe nanoparticles in the presence of humic acid (HA) was investigated. We found that, as high performance liquid chromatography (HPLC) was used, the 2,4-DCP was first quickly reduced to o-chlorophenol (o-CP) andp-chlorophenol (p-CP), and then reduced to phenol as the final product. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Ni/Fe nanoparticles, as the HA concentration increased, the removal rate decreased evidently. It also demonstrated that 2,4-DCP was reduced more easily to o-CP than to p-CP, and that the sequence of the tendency in dechlorination of intermediates was p-CP>o-CP. Transmission electron microscope (TEM) showed that HA could act as an adsorbate to compete reactive sites on the surface of Ni/Fe nanoparticles to decrease the dechlorination rate. Also we con-cluded that the dechlorination reaction of 2,4-DCP over Ni/Fe nanoparticles progressed through catalytic reductive dechlorination. 相似文献
7.
植物体内活性氧代谢及功能研究进展 总被引：1，自引：0，他引：1
徐新娟 《河南科技学院学报》2007,35(2):10-12
最近生物化学和遗传学研究证明活性氧不仅仅是需氧生物细胞的代谢副产物,而且还是细胞内重要的信号分子,其中过氧化氢在介导植物体对生物和非生物胁迫响应中起一种信号分子作用。作为信号分子的活性氧有其特定的合成途径、专一性的代谢响应机制、专一性的作用靶标和信号调节完成之后的代谢消除途径。过氧化氢介导的信号调节作用包括ABA控制的气孔关闭、生长激素控制的根的向地性生长中、氧剥夺抗性的产生等。过氧化氢的合成和作用与一氧化氮有关系。过氧化氢调节的下游信号事件包括细胞内钙流动、蛋白质磷酸化和基因表达。钙和小G蛋白信号通路对于细胞内部过氧化氢的稳定状态维持具有重要作用。 相似文献
8.
INTRODUCTION Lipase (EC 3.1.1.3) is an important hydrolysis enzyme (Jaeger et al., 1994) excreted to the envi-ronment by plant roots and microorganisms. Many pollutants such as organophosphorus pesticides and synthetic polyesters and polyamides can be degraded by lipase (Monroy-Noyola et al., 1999; Marten et al., 2003). In soil, enzymatic reactions occur in a het-erogeneous rather than homogeneous environment (Huang et al., 1998). Catalytic function of lipase, an extracelluar enzyme, … 相似文献
9.
采用不同浓度的两种酚酸类物质及其混合物对大巢菜种子及幼苗进行处理,测定其对大巢菜发芽率、营养生长及其某些生理指标的影响。结果表明,酚酸类物质及其混合物可以显著延缓大巢菜种子发芽所需要的时间,降低最终的萌发率;对大巢菜幼苗的根长度、苗高度及干物质积累有一定的抑制作用;同时,根系活力与叶绿素含量也有不同程度的下降。 相似文献
10.
野生红景天原变种Rhodiala rosea L.var rosea。种子自然萌发率很低,故采用人工种子繁殖和根茎繁殖,通过二年的实验,两种繁殖方法获得的新株,生长发育与野生株相似,均能开花结果,其种子及根茎均能延续繁殖后代。 相似文献
11.
To understand the feasibility of its application to the in situ remediation of contaminated groundwater, the dechlorination of 2,4-dichlorophenol （2,4-DCP） by Ni/Fe nanoparticles in the presence of humic acid （HA） was investigated. We found that, as high performance liquid chromatography （HPLC） was used, the 2,4-DCP was first quickly reduced to o-chlorophenol （o-CP） andp-chlorophenol （p-CP）, and then reduced to phenol as the final product. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Ni/Fe nanoparticles, as the HA concentration increased, the removal rate decreased evidently. It also demonstrated that 2,4-DCP was reduced more easily to o-CP than to p-CP, and that the sequence of the tendency in dechlorination of intermediates was p-CP〉o-CP. Transmission electron microscope （TEM） showed that HA could act as an adsorbate to compete reactive sites on the surface of Ni/Fe nanoparticles to decrease the dechlorination rate. Also we concluded that the dechlorination reaction of 2,4-DCP over Ni/Fe nanoparticles progressed through catalytic reductive dechlorination. 相似文献
12.
The remediation of groundwater which contains chlorinated organic compounds （COCs） by nanoscale bimetallic catalysts has received increasing interest in recent years. This report presents the dechlorination of 2,4-dichlorophenol （2,4-DCP） by Pd-Fe bimetallic nanoparticles in the presence of humic acid （HA） to investigate the feasibility of using Pd-Fe for the in situ remediation of contaminated groundwater. Our experimental results indicated that HA had an adverse effect on the dechlorination of 2,4-DCP by Pd-Fe nanoparticles. The rate constant k values of 2,4-DCP dechlorination were 0.017, 0.013, 0.009, 0.006 and 0.004 min^-1 for HA concentrations of 0, 5, 10, 15 and 20 mg/L, respectively. The relationship between HA dosage and k values can be described as a linear model. 相似文献
13.
以乙酰丙酮、2,6-二异丙基苯胺(或2,6-二甲基苯胺)和对甲苯磺酸为原料通过两步反应高产率的合成了N,N'-二(2,6-二异丙基苯基)-2,4-戊二亚胺(1)和N,N'-二(2,6-二甲基苯基)-2,4-戊二亚胺(2),产率分别为78%和72%,并用元素分析和1HNMR对产物进行了结构表征. 相似文献
14.
建立了柑橘中农药2,4-二氯苯氧乙酸（2,4-D）残留量的高效液相色谱（HPLC）测定方法．样品用乙酸乙酯超声波提取,硅藻土固相萃取预处理并富集浓缩10倍后HPLC分离测定．结果表明,测定2,4-D的线性范围是1．00~20．00mg·kg,市售六种柑橘类水果中2,4-D含量在O．28～O．90mg·kg,结果的相对标准偏差为0．6％～2．6％,2,4-D回收率为86％～92％． 相似文献
15.
2，4-D在明胶／壳聚糖微球中的包埋与释放 总被引：3，自引：0，他引：3
以明胶／壳聚糖复合物为水相,液体石蜡为连续油相,农药2,4-二氯苯氧乙酸（2,4-D）为芯材,Span80为乳化剂,通过醛交联,采用反相乳液法制备了2,4-D-明胶／壳聚糖微球．考察了制备条件对微球形貌及包封率的影响,并研究了2,4-D在微球中的释放性能．结果表明：当Span80为1mL,油水比为4：1,用一定量甲醛与戊二醛的混合物为交联剂,芯壁材比大于1：14时,制备的微球形态圆整,表面光滑,分散性较好．该复合微球中2,4-D的包封率为70．8％,具有良好的缓释性能,作为一种新型农药剂型可望在农业领域得到应用． 相似文献
16.
Qin LU Jian-ping LU Xiao-dong LI Xiao-hong LIU Hang MIN Fu-cheng LIN 《Journal of Zhejiang University. Science. B》2008,9(7)
In this study the MTP1 gene, encoding a type Ⅲ integral transmembrane protein, was isolated fi'om the rice blast fungus Magnaporthe oryzae. The Mtpl protein is 520 amino acids long and is comparable to the Ytpl protein of Saccharomyces cerevisiae with 46% sequence similarity. Prediction programs and MTP1-GFP (green fluorescent protein) fusion expression results indicate that Mtpl is a protein located at several membranes in the cytoplasm. The functions of the MTP1 gene in the growth and development of the fungus were studied using an MTP1 gene knockout mutant. The MTP1 gene was primarily ex-pressed at the hyphal and conidial stages and is necessary for conidiation and conidial germination, but is not required for patho-genicity. The △mtpl mutant grew more efficiently than the wild type strain on non-fermentable carbon sources, implying that the MTP1 gene has a unique role in respiratory growth and carbon source use. 相似文献
17.
高产柠檬酸突变菌株以玉米粉为原料的生物反应器扩大生产研究 总被引：2，自引：0，他引：2
Wei HU Jing LIU Ji-hong CHEN Shu-yang WANG Dong LU Qing-hua WU Wen-jian LI 《Journal of Zhejiang University. Science. B》2014,15(11):1006-1010
研究目的：研究高产黑曲霉突变菌株以玉米粉为原料的生物反应器扩大发酵,以期获得适合于工业化生产柠檬酸的发酵工艺。
创新要点：以玉米粉为原料,系统地研究了筛选得到的高产菌株在50L生物反应器中不同糖浓度发酵生产柠檬酸的特性,最终优化出适合于工业化生产柠檬酸的发酵工艺。
研究方法：（1）利用淀粉酶对粉碎后的玉米进行液化,然后过滤,最终得上清液;（2）以50L生物反应器作为发酵设备,对筛选得到的高产柠檬酸菌株进行扩大培养;（3）通过测定不同培养时期中积累的柠檬酸含量和剩余的残总糖,最终优化出高效率生产柠檬酸的发酵工艺。
重要结论：以不同糖浓度的液化玉米粉上清液作为碳源,突变菌株H4002能积累177．7--196．0g,L的柠檬酸,效率能达到2．96～3．27g/（L·h）,尤其当糖浓度为210g／L,H4002菌株表现出最佳的柠檬酸生产水平,如柠檬酸积累187．5g/L,生产效率达3．13g／（L·h）。上述结果说明了突变菌株H4002拥有快速生产柠檬酸的能力。 相似文献
18.
Rao AQ Hussain SS Shahzad MS Bokhari SY Raza MH Rakha A Majeed A Shahid AA Saleem Z Husnain T Riazuddin S 《Journal of Zhejiang University. Science. B》2006,7(4):291-298
Wild cotton species can contribute a valuable gene pool for agronomically desirable cultivated tetraploid cultivars. In order to exploit diploid cotton a regeneration system is required to achieve transformation based goals. The present studies aimed at optimizing the conditions for regeneration of local varieties as well as wild species of cotton. Different callus induction media were tested with varying concentrations of hormones in which sucrose was used as nutritional source. Different explants （hypocotyls, cotyledon, root） were used to check the regeneration of both local cotton plants and wild relatives using T ＆ G medium, BAP medium, CIM medium, EMMS medium, and cell suspension medium. Different stages of embryogenicity such as early torpedo stage, late torpedo stage, heart stage, globular stage and cotyledonary stage were observed in wild relatives of cotton. The results of this study pave the way for establishing future transformation methods. 相似文献
19.
In this study the MTP1 gene, encoding a type III integral transmembrane protein, was isolated from the rice blast fungus Magnaporthe oryzae. The Mtp1 protein is 520 amino acids long and is comparable to the Ytp1 protein of Saccharomyces cerevisiae with 46% sequence similarity. Prediction programs and MTP1-GFP (green fluorescent protein) fusion expression results indicate that Mtp1 is a protein located at several membranes in the cytoplasm. The functions of the MTP1 gene in the growth and development of the fungus were studied using an MTP1 gene knockout mutant. The MTP1 gene was primarily expressed at the hyphal and conidial stages and is necessary for conidiation and conidial germination, but is not required for pathogenicity. The Deltamtp1 mutant grew more efficiently than the wild type strain on non-fermentable carbon sources, implying that the MTP1 gene has a unique role in respiratory growth and carbon source use. 相似文献
20.
野生药食两用植物青葙的溶液培养试验 总被引：1，自引：0，他引：1
以野生药食两用植物青葙(Celosia argentea)为材料,选用A、B、C三种营养液配方对其进行水培生产试验,研究了上述三种营养液处理对青葙幼苗生长和可溶性蛋白含量的影响.结果表明:A配方培养的青葙幼苗虽然叶片数、茎长、最长根长、鲜重、干物重比B、C两种配方处理的略高,且根系体积和根系活力明显高于后两者.但在青葙主要用来食用的地上部分之间,C处理的鲜重、干物重和含水量均高于B处理而与A处理极其相近,而C处理的可溶性蛋白质含量高于A、B两种处理.三种处理的青葙幼苗以C处理的根冠比最大.三种营养液配方中C配方最适合用于青葙的水培生产. 相似文献