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1.
Ramesh Maheshwari 《Resonance》2008,13(6):541-547
Most plants are attached via their roots to specialized fungi. The filamentous hyphae of these fungi extend beyond the nutrient-depleted
zone in the soil, absorbing and supplying nutrients to the plants in exchange for photosynthetically-made carbon compounds
manufactured by the plant. The hyphae also attach to litter and decompose the organic matter, releasing the mineral ions sequestered
in the structural polymers. The mineral ions are absorbed and translocated to the roots. Most plants are so dependent on their
fungal partners for supplying nutrients that they languish or die without them. Our understanding of this fascinating interaction,
to a large extent, has come from the pioneering work of Sir David J Read, FRS, Emeritus Professor of Plant Sciences at the
University of Sheffield, UK.
Ramesh Maheshwari is a former Professor and Chairman of the Department of Biochemistry, Indian Institute of Science, Banglaore.
This is his sixth article for Resonance. 相似文献
2.
丛枝菌根真菌可以与绝大多数陆生植物共生,它可以吸收铵态氮、硝态氮、一些氨基酸和一些复杂的有机氮素,吸收的氮素在根外菌丝中转化成精氨酸,并以这种形式运输到根内菌丝,在根内菌丝和根细胞界面,精氨酸再进一步转化为NH4^＋后转移到宿主植物体,参与植物氮素代谢,而转移的氮量及对宿主植物氮营养的贡献与宿主植物、真菌以及基质养分和水分条件有关． 相似文献
3.
内生真菌与牧草寄主形成互利的共生体,一方面植物为内生真菌提供光合产物和矿物质;另一方面内生真菌促进植物生长发育,增加了其抗逆性等．但是内生真菌可产生多种麦角生物碱,家畜采食这种牧草后,会产生中毒综合征,所以在未来的研究中应以创造有益的牧草一内生真菌共生体作为目标,从而提高牧草的应用价值． 相似文献
4.
Si-sheng Sun Xiao-mei Chen Shun-xing Guo 《Journal of Zhejiang University. Science. B》2014,15(2):109-115
Santalum album Linn. is an evergreen and hemi-parasitic tree, the heartwood-sandalwood of which was used during a long history in traditional Chinese medicine. Kuhnia rosmarinifolia Vent. is a good host for 1- or 2-year-old growing S. album. The interaction between S. album and K. rosmarinifolia is still little known. Many studies have been carried out on a number of plants for identification and diversity of endophytes. In this study, in total 25 taxa of endophytic fungi were isolated from the roots of S. album and the roots of K. rosmarinifolia. The most frequently isolated genera were Penicillium sp. 1 and Fusarium sp. 1 in the roots of S. album and K. rosmarinifolia, respectively. S. album is a root parasite of K. rosmarinifolia. The interesting result is that they apparently do not share the same endophytic fungi isolates. This study for the first time explored the content of endophytic fungi from S. album and K. rosmarinifolia, which provides important information for further studies. 相似文献
5.
INTRODUCTION Biosphere pollution by heavy metals and nu-cleotides was accelerated dramatically during the last few decades due to mining, smelting, manufacturing, treatment of agricultural soils with agro-chemicals and soil sludge, etc. Problems associated with the contamination of soil and water such as animal wel-fare, health, fatalities and disruptions of natural eco-systems are well documented (He et al., 2005). Heavy metals such as Pb, Cr, As, Cu, Cd, and Hg, being added to our so… 相似文献
6.
Mycorrhizoremediation an enhanced form of phytoremediation 总被引：2，自引：0，他引：2
Khan AG 《Journal of Zhejiang University. Science. B》2006,7(7):503-514
Study of plant roots and the diversity of soil micro biota, such as bacteria, fungi and microfauna associated with them, is important for understanding the ecological complexities between diverse plants, microbes, soil and climates and their role in phytoremediation of contaminated soils. The arbuscular mycorrhizal fungi （AMF） are universal and ubiquitous rhizosphere mi- croflora forming symbiosis with plant roots and acting as biofertilizers, bioprotactants, and biodegraders. In addition to AMF, soils also contain various antagonistic and beneficial bacteria such as root pathogens, plant growth promoting rhizobacteria including free-living and symbiotic N-fixers, and mycorrhiza helping bacteria. Their potential role in phytoremediation of heavy metal （HM） contaminated soils and water is becoming evident although there is need to completely understand the ecological complexities of the plant-microbe-soil interactions and their better exploitation as consortia in remediation strategies employed for contaminated soils. These multitrophic root microbial associations deserve multi-disciplinary investigations using molecular, biochemical, and physiological techniques. Ecosystem restoration of heavy metal contaminated soils practices need to incorporate microbial biotechnology research and development. This review highlights the ecological complexity and diversity of plant-microbe-soil combinations, particularly AM and provides an overview on the recent developments in this area. It also discusses the role AMF play in phytorestoration of HM contaminated soils, i.e. mycorrhizoremediation. 相似文献
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INTRODUCTION Plants have defense mechanisms against patho-gen infection by inducing systemic resistance in re-sponse to localized pretreatment with biological cotrol agents, thus making them resistant to subsequpathogen infection (Caruso et al., 1999; Hammschmidt, 1999; Mohammadi and Kazemi, 2002; yada et al., 1995; Pozo et al., 2002; Ray et al., 199Biological control of plant pathogens has receivmuch more attention. It is well known that plants amicroorganisms symbiosis is a defense m… 相似文献
9.
It is important to research the rules about accumulation and distribution of arsenic and cadmium by tea plants, which will give us some scientific ideas about how to control the contents of arsenic and cadmium in tea. In this study, by field inves- tigation and pot trial, we found that mobility of arsenic and cadmium in tea plants was low. Most arsenic and cadmium absorbed were fixed in feeding roots and only small amount was transported to the above-ground parts. Distribution of arsenic and cadmium, based on their concentrations of unit dry matter, in tea plants grown on un-contaminated soil was in the order: feeding roots>stems≈main roots>old leaves>young leaves. When tea plants were grown on polluted soils simulated by adding salts of these two metals, feeding roots possibly acted as a buffer and defense, and arsenic and cadmium were transported less to the above- ground parts. The concentration of cadmium in soil significantly and negatively correlated with chlorophyll content, photosyn- thetic rate, transpiration rate and biomass production of tea plants. 相似文献
10.
Zheng Hu-zhe Cui Chun-lan Zhang Yu-ting Wang Dan Jing Yu Kim Kil Yong 《Journal of Zhejiang University. Science. B》2005,6(8):778-786
The activities of enzymes responsible for lignification in pepper, pre-inoculation with arbuscular mycorrhizal (AM) fungus
ofGlomus intraradices and/or infection with pathogenic strain ofPhytophthora capsici, and the biological control effect ofG. intraradices on Phytophthora blight in pepper were investigated. The experiment was carried out with four treatments: (1) plants pre-inoculated
withG. intraradices (Gi), (2) plants pre-inoculated withG. intraradices and then infected withP. capsici (Gi+Pc). (3) plants infected withP. capsici (Pc), and (4) plants without any of the two microorganisms (C). Mycorrhizal colonization rate was reduced by about 10% in
pathogen challenged plants. Root mortality caused by infection ofP. capsici was completely eliminated by pre-inoculation with antagonisticG. intraradices. On the ninth day after pathogen infection, Peroxidase (POD) activity increased by 116.9% in Pc-treated roots but by only
21.2% in Gi+Pc-treated roots, compared with the control, respectively. Polyphenol oxidase (PPO) and Phenylalanine ammonia-lyase
(PAL) activities gradually increased during the first 3 d and dramatically decreased in Pc-treated roots but slightly decreased
in Gi+Pc-treated roots, respectively. On the ninth day after pathogen infection, PPO and PAL decreased by 62.8% and 73.9%
in Pc-treated roots but by only 19.8% and 19.5% in Gi+Pc-treated roots, compared with the control, respectively. Three major
POD isozymes (45000, 53000 and 114000) were present in Pc-treated roots, while two major bands (53000 and 114000) and one
minor band (45000) were present in spectra of Gi+Pc-treated roots, the 45000 POD isozyme was significantly suppressed byG. intraradices, suggesting that the 45000 POD isozyme was induced by the pathogen infection but not induced by the antagonisticG. intraradices. A 60000 PPO isozyme was induced in Pc-treated roots but not induced in Gi+Pc-treated roots. All these results showed the
inoculation of antagonisticG. intraradices alleviates root mortality, activates changes of lignification-related enzymes and induces some of the isozymes in pepper
plants infected byP. capsici. The results suggested thatG. intraradices is a potentially effective protection agent againstP. capsici.
Project supported by Korea Science and Engineering Foundation (KOSEF) through the Agricultural Plants Stress Research Center
(APSRC) at Chonnam National University, Korea 相似文献
11.
返魂草黑斑病发病规律及防治药剂筛选初报 总被引：1，自引：0，他引：1
致病菌为半知菌亚门、丛梗孢目、暗梗孢科、链格孢属真菌.病菌首先从植株底部老熟叶片开始侵染发病.一般发病株率为60~100%.病情指数40、60以上.室内和田间药剂筛选试验表明,用世高、加瑞农等药剂适时防治,同时加强科学管理措施,可保障植株正常开花结实,最大限度减少经济损失. 相似文献
12.
王淑芳 《遵义师范学院学报》2012,14(3):76-78
文章阐述了发根农杆菌诱导毛状根的技术特点,分析了影响利用毛状根进行药物生产时的主要因素,探讨了目前毛状根培养存在的问题,同时为通过毛状根培养技术生产有用药物提供了建议。 相似文献
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现有抗癌药物大部分是人工合成与半合成 ,或者是从天然植物中直接提取。细胞培养技术虽然已取得一定成功 ,但尚未能实现工业化生产。①② 而从内生真菌次生代谢产物中寻找抗癌药物的工作国内外均才开始 ,并成为一个新的热点。本文就近年来国内外对内生真菌产癌活性成分的研究进展作一综述 相似文献
15.
苦参不同器官中的生物碱含量分析 总被引：2，自引：0，他引：2
[目的]探讨苦参不同器官中的生物碱含量,为该资源植物的合理应用提供依据.[方法]用薄层色谱法(TLC)分析测定了辽宁产苦参不同器官中苦参碱及氧化苦参碱含量.[结果]各类器官,除叶片外,氧化苦参碱含量均显著超过苦参碱含量;苦参碱含量以种子中的为最高,占干重的0.065%,其次为茎(0.034%)、根(0.016%)、叶(0.013%);氧化苦参碱含量以根最高,占干重的3.847%,其次为种子(1.982%)、茎(0.140%),叶中未检测到;粗老根(直径大于1 cm)与细嫩根(直径在0.5~1.0 cm)中的两种生物碱含量差别不大.[结论]达到一定生长年限后,生物碱积累不再有明显增加而趋于饱和;大部分器官中,氧化苦参碱含量高于苦参碱含量;种子及茎更适合作为苦参碱的提取器官. 相似文献
16.
稀土对菊花试管苗生长有明显影响。添加稀土后试管苗生长速度快,,根粗苗壮,根冠比大,但根数少。20ppm浓度稀土明显抑制菊花试管苗的株高,对根无抑制作用。50ppm浓度稀土对试管苗的茎、叶、根生长都有促进作用。 相似文献
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18.
采用营养液培养方式,探讨和比较硝态氮(NO3--N)和铵态氮(NH4+-N)两种不同供氮形态及其供应水平(0、3、7.5、15、22.5、30、37.5 mmol/L)下,供试玉米利民15和皖玉9号的生物学性状对以磷酸钙模拟的低生物有效磷胁迫的适应性差异。结果表明:当供氮水平低于22.5 mmol/L时,对玉米供应NH4+-N或NO3--N均可产生提高其对低生物有效磷胁迫适应性的效应。随供氮水平的升高,在两种供氮形态营养条件下,玉米幼苗植株生物量、地上部和根系干重、株高、叶面积和根体积的变化趋势均基本呈现报酬递减规律,而当供氮水平在0～7.5 mmol/L变化时,玉米的生物量干重均出现最高值。不同品种玉米对NH4+-N和NO3--N营养的响应既存在共性:NO3--N营养玉米植株株高和根体积始终高于NH4+-N营养植株,但也存在基因型差异。从植株含磷量分析,当氮水平高于3 mmol/L时,NH4+-N营养利民15的磷含量始终高于NO3--N营养玉米;而皖玉9号则在供NH4+-N水平高于22.5 mmol/L时,出现磷含量低于等氮水平下的NO3--N营养玉米的现象;其中利民15的植株磷含量与其生物量干重之间呈极显著的负相关关系(r=-0.77**,n=11),而皖玉9号的植株磷含量则与其生物量干重之间呈极显著的正相关关系(r=0.96**,n=11)。此外,在等氮水平下,两种供氮形态营养玉米的叶面积、单位叶面积光合速率、单株水平的根系活力之间没有明显的差异,因此,在低生物有效磷胁迫条件下,玉米在不同供氮形态营养条件下的适应性机制不同,其适应性强弱主要取决于是否为适宜的供氮水平。 相似文献
19.
The effect of Al and Cd on the growth, photosynthesis, and accumulation of Al, Cd and plant nutrients in two soybean genotypes were determined using hydroponic culture. There were six treatments: pH 6.5; pH 4.0; pH 6.5 1.0 μmol/L Cd; pH 4.0 1.0 μmol/L Cd; pH 4.0 150 μmol/L Al; pH 4.0 1.0 μmol/L Cd 150 μmol/L Al. The low pH (4.0) and Al treatments caused marked reduction in root length, shoot height, dry weight, chlorophyll content (SPAD value) and photosynthetic rate. Al-sensitive cv. Zhechun 2 accumulated comparatively more Al and Cd in plants than Al-tolerant cv. Liao 1. Compared with pH 6.5, pH 4.0 resulted in significant increase in Cd and Al concentration in plants. Combined application of Cd and Al enhanced their accu-mulation in roots, but caused a reduction in shoots. The concentrations of all 10 nutrients (P, K, Ca, Mg, Fe, Mn, Cu, Zn and B), except Mo were also increased when plants were exposed to pH lower than pH 6.5. Al addition caused a reduction in the con-centration of most nutrients in plant roots and shoots; but K, Mn and Zn in roots were increased. Treatments with Cd alone or together with Al reduced the concentrations of all the plant nutrients in plants. Al-sensitive genotype Zhechun 2 has lower nutrient concentration than Al-tolerant genotype Liao 1. The current findings imply that Al and Cd are synergistic in their effect on plant growth, physiological traits and nutrient uptake. 相似文献
20.
植物生长调节剂对植物的生长发育有重要影响。本实验以模式植物拟南芥菜为材料,调查了外加生长素类和细胞分裂素类生长调节剂对拟南芥菜子叶、下胚轴和根生长的影响,使人们对植物生长调节剂在植物发育调控中的作用,以及在器官发育中的功能和作用的分子机理有更进一步的认识。 相似文献