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1.
Plant growth promotion by rhizobacteria is a widely spread phenomenon. However only a few rhizobacteria have been studied thoroughly. Rhizobium is the best-studied rhizobacterium. It forms a symbiosis with a restricted host range. Azospirillum is another plant-growth-promoting rhizobacterium which forms rhizocoenoses with a wide range of plants. In both bacteria, the interaction with the plant involves the attraction toward the host plant and the attachment to the surface of the root. Both bacteria are attracted to plant roots, but differ in specificity. Attachment to plant roots occurs in two steps for both bacteria: a quick, reversible adsorption, and a slow, irreversible anchoring to the plant root surface. However, for the two systems under study, the bacterial surface molecules involved in plant root attachment are not necessarily the same.
Correspondence to: J. Vanderleyden. 相似文献
2.
Valentina Cova Roberta Paris Stella Passerotti Elena Zini Cesare Gessler Ilaria Pertot Nazia Loi Rita Musetti Matteo Komjanc 《Tree Genetics & Genomes》2010,6(3):389-403
The Malus–Venturia inaequalis interaction is the most studied plant–pathogen interaction involving a woody species. Besides the cloning of an apple scab
resistance gene HcrVf2, several sequences have been recently identified that are modulated after pathogen recognition in Vf-resistant genotypes. Among these, there is a putative leucine-rich repeat receptor-like protein kinase from the apple scab-resistant
cv. Florina, named LRPKm1 that is induced after V. inaequalis inoculation and salicylic acid treatment. In this work, the isolation, characterization, and mapping of four new genes belonging
to the LRPKm multigene family are reported. According to their cumulative expression profiles in HcrVf2-transgenic and wild-type apple plants treated with V. inaequalis, LRPKm genes have been divided in two groups. LRPKm1 and LRPKm3, giving a response related to the presence of HcrVf2, are probably involved in the recognition of pathogen-derived signals. LRPKm2 and LRPKm4, with an expression profile unrelated to the HcrVf2 gene, are putatively involved in the plant basal defense. Furthermore, we have localized LRPKm proteins at the cytological
level in the plasma membrane of epidermal cells in resistant genotypes following pathogen challenge, thus confirming software
predictions and molecular results. The possible involvement of LRPKm proteins in apple scab resistance and in the plant basal
defense makes them attractive for a better comprehension of the molecular mechanisms of the signal transduction pathways after
pathogen recognition. 相似文献
3.
Role of glucosinolates in plant invasiveness 总被引:1,自引:0,他引:1
Caroline Müller 《Phytochemistry Reviews》2009,8(1):227-242
Many plants have been intentionally or accidentally introduced to new habitats where some of them now cause major ecological
and economic threats to natural and agricultural ecosystems. The potential to become invasive might depend on plant characteristics,
as well as on specific interactions with other organisms acting as symbionts or antagonists, including other plants, microbes,
herbivores, or pollinators. The invasion potential furthermore depends on abiotic conditions in the habitat. Several species
of the Brassicaceae, well known for their glucosinolate–myrosinase defence system, are invasive species. Various factors are
reviewed here that might explain why these species were so successful in colonising new areas. Specific emphasis is laid on
the role of glucosinolates and their hydrolysis products in the invasion potential. This particular defence system is involved
specifically in plant–plant, plant–microbe and plant–insect interactions. Most research has been done on the mechanisms underlying
invasion success of Alliaria petiolata and Brassica spp., followed by Bunias orientalis and Lepidium draba. Some examples are also given for plants that are not necessarily considered as invasives, but which were well investigated
with respect to their interference potential with their biotic environment. For each species, most likely a combination of
different plant characteristics enhanced the competitive abilities and led to diverse invasive phenotypes. 相似文献
4.
5.
N. L. Radyukina S. Mapelli Yu. V. Ivanov A. V. Kartashov I. Brambilla Vl. V. Kuznetsov 《Russian Journal of Plant Physiology》2009,56(3):323-331
Functioning of the antioxidant system in roots and leaves of Plantago major L. in water culture at the stage of 5–6 genuine leaves of the plants subjected to NaCl (100 mM) action for 96 h was investigated.
This plant exhibited a pronounced organ specificity of antioxidant defense system functioning. The roots were characterized
by high constitutive activities of superoxide dismutase and three forms of peroxidase, and a lower catalase activity. Constitutive
level of polyamines in roots was higher than in leaves. In both leaves and roots during first 24 h, the polyamine content
declined but spermidine remained to be a predominant polyamine. The analysis of differential expression of the genes encoding
enzymes of polyamine biosynthesis demonstrated certain differences in these plant organs. The changes in expression of genes
MET1, SPMS1, and SPMS2 were observed in roots, whereas in leaves expression of MET1, SAMDC1, SPDS1, and SPMS1 was altered. These changes are possibly one of the mechanisms responsible for the regulation of polyamine endogenous level
under salinity. In contrast to leaves, in roots, the oxidative degradation of spermidine by polyamine oxidase can take part
in the regulation of endogenous spermidine level. Taken together, these findings allowed us to conclude that, unlike leaves,
the roots of P. major under salinity conditions possessed a higher activity of the antioxidant system protecting plants from injurious action of
oxidative stress, thereby providing survival of this plant species under stress conditions.
Published in Russian in Fiziologiya Rastenii, 2009, Vol. 56, No. 3, pp. 359–368.
This text was submitted by the authors in English. 相似文献
6.
Indira Devi S Talukdar NC Chandradev Sharma K Jeyaram K Rohinikumar M 《Indian journal of microbiology》2011,51(1):14-21
Development of microbial inoculants from rhizobacterial isolates with potential for plant growth promotion and root disease
suppression require rigorous screening. Fifty-four (54) fluorescent pseudomonads, out of a large collection of rhizobacteria
from broad bean fields of 20 different locations within Imphal valley of Manipur, were initially screened for antifungal activity
against Macrophomina phaseolina and Rhizoctonia solani, of diseased roots of broad bean and also three other reference fungal pathogens of plant roots. Fifteen fluorescent pseudomonas
isolates produced inhibition zone (8–29 mm) of the fungal growth in dual plate assay and IAA like substances (24.1–66.7 μg/ml)
and soluble P (12.7–56.80 μg/ml) in broth culture. Among the isolates, RFP 36 caused a marked increase in seed germination,
seedling biomass and control of the root borne pathogens of broad bean. PCR–RAPD analysis of these isolates along with five
MTCC reference fluorescent pseudomonas strains indicated that the RFP-36 belonged to a distinct cluster and the PCR of its
genomic DNA with antibiotic specific primers Phenazine-1-carboxylic acid and 2, 4-diacetyl phloroglucinol suggested possible
occurrence of gene for the potent antibiotics. Overall, the result of the study indicated the potential of the isolate RFP
36 as a microbial inoculant with multiple functions for broad bean. 相似文献
7.
Zn uptake by maize plants may be affected by the presence of arbuscular mycorrhizal fungi (AMF). Collembola often play an important controlling role in the inter-relationship between AMF and host plants. The objective of this experiment was to examine whether the presence of Collembola at different densities (0.4 and 1 individuals g−1 dry soil) and their activity have any effect on Zn uptake by maize through the plant–AMF system. The presence of the AMF (Glomus intraradices) and of the Collembola species Folsomia candida was studied in a laboratory microcosm experiment, applying a Zn exposure level of 250 mg kg−1 dry soil. Biomass and water content of the plants were no different when only AMF or when both AMF and Collembola were present. In the presence of AMF the Zn content of the plant shoots and roots was significantly higher than without AMF. This effect was reduced by Collembola at both low and high density. High densities of Collembola reduced the extent of AMF colonization of the plant roots and hyphal length in the soil, but low densities had no effect on either. The results of this experiment reveal that the F. candida–G. intraradices interaction affects Zn uptake by maize, but the mechanisms are still unknown. 相似文献
8.
Fungal gene expression in early symbiotic interactions between Laccaria bicolor and red pine 总被引:1,自引:1,他引:0
Podila G.K. Zheng J. Balasubramanian S. Sundaram S. Hiremath S. Brand J.H. Hymes M.J. 《Plant and Soil》2002,244(1-2):117-128
Ectomycorrhizas are mutualistic symbiotic organs formed by interaction between plant roots and fungi. Mycorrhizal initiation, development and functional maintenance involve morphological changes that are mediated by activation and suppression of several fungal and plant genes. During the pre-infection stage, a harmonized cross-talk takes place between the symbionts, to determine their compatibility. Upon mutual recognition, the symbionts initiate further physiological and morphological changes essential for the formation of the symbiotic organ. In order to understand the molecular mechanisms underlying these events, we developed an interaction-specific cDNA library from Laccaria bicolor that represents fungal genes regulated by its interaction with Pinus resinosa roots. Membrane array analyses of these cDNAs suggested that a wide variety of genes are involved in the pre-infection stage processes. 相似文献
9.
10.
Several chemical changes in soil are associated with plant growth-promoting rhizobacteria. An endosporeforming bacterium,
strain XTBG34, was isolated from a Xishuangbanna Tropical Botanical Garden soil sample and identified as Bacillus megaterium. The strain’s volatiles had remarkable plant growth promotion activity in Arabidopsis thaliana plants; after 15 days treatment, the fresh weight of plants inoculated with XTBG34 was almost 2-fold compared with those
inoculated with DH5α. Head space volatile compounds produced by XTBG34, trapped with headspace solid phase microextraction
and identified by gas chromatography-mass spectrometry, included aldehydes, alkanes, ketones and aroma components. Of the
11 compounds assayed for plant growth promotion activity in divided Petri plates, only 2-pentylfuran increased plant growth.
We have therefore identified a new plant growth promotion volatile of B. megaterium XTBG34, which deserves further study in the mechanisms of interaction between plant growth-promoting rhizobacteria and plants. 相似文献
11.
Shouhei Ueda Tadahiro Okubo Takao Itioka Usun Shimizu-kaya Masaya Yago Yoko Inui Takao Itino 《Ecological Research》2012,27(2):437-443
In the Southeast Asian tropics, Arhopala lycaenid butterflies feed on Macaranga ant-plants inhabited by Crematogaster (subgenus Decacrema) ants tending Coccus-scale insects. A recent phylogenetic study showed that (1) the plants and ants have been codiversifying for the past 20–16
million years (Myr), and that (2) the tripartite symbiosis was formed 9–7 Myr ago, when the scale insects became involved
in the plant–ant mutualism. To determine when the lycaenids first parasitized the Macaranga tripartite symbiosis, we constructed a molecular phylogeny of the lycaenids that feed on Macaranga by using mitochondrial and nuclear DNA sequence data and estimated their divergence times based on the cytochrome oxidase I molecular clock. The minimum age of the lycaenids was estimated by the time-calibrated phylogeny to be 2.05 Myr, about one-tenth
the age of the plant–ant association, suggesting that the lycaenids are latecomers that associated themselves with the pre-existing
symbiosis of plant, ant, and scale insects. 相似文献
12.
Chandra S 《Biotechnology letters》2012,34(3):407-415
Agrobacterium
rhizogenes is a natural plant genetic engineer. It is a gram-negative soil bacterium that induces hairy root formation. Success has
been obtained in exploring the molecular mechanisms of transferred DNA (T-DNA) transfer, interaction with host plant proteins,
plant defense signaling and integration to plant genome for successful plant genetic transformation. T-DNA and corresponding
expression of rol genes alter morphology and plant host secondary metabolism. During transformation, there is a differential loss of a few
T-DNA genes. Loss of a few ORFs drastically affect the growth and morphological patterns of hairy roots, expression pattern
of biosynthetic pathway genes and accumulation of specific secondary metabolites. 相似文献
13.
Few studies of plant–pollinator interactions in fragmented landscapes evaluate the consequences of floral visitor variation
on multiple stages of plant reproduction. Given that fragmentation potentially has positive or negative effects on different
organisms, and that self-incompatible plant species depend on pollinators for sexual reproduction, differences in floral visitor
assemblages may affect certain plant reproductive stages. We evaluated how pollinator assemblage, availability of floral resources,
pollination, reproductive output, and seed and seedling performance of Psychotria suterella Muell. Arg. varied among three fragmentation categories: non-fragmented habitats, fragments connected by corridors, and isolated
fragments. Richness and frequency of floral visitors were greater in fragments than in non-fragmented sites, resulting mainly
from the addition of species typically found in disturbed areas. Although 24 species visited Psychotria suterella flowers, bumblebees were considered the most important pollinators, because they showed the highest frequency of visits and
were present in eight out of ten sites. Additionally, the number of pollen tubes per flower per visit was lower in areas without
bumblebees. The increased visitation in fragments seemed to enhance pollination slightly. However, fruit and seed output,
germination, and seed and seedling mass were similar in non-fragmented sites, connected sites, and isolated fragments. Our
results suggested that, even for a self-incompatible species, responses to habitat fragmentation at different stages of plant
reproduction might be decoupled from the responses observed in floral visitors, if fruit set is not pollen limited. If all
reproductive stages were considered, variation on the small scale was more important than the variation explained by fragmentation
category. In spite of its self-incompatible breeding system, this plant–pollinator system showed resilience to habitat fragmentation,
mainly as a result of high availability of potential mates to P. suterella individuals, absence of pollen limitation, and the presence of bumblebees (Bombus spp.) throughout this highly connected landscape. 相似文献
14.
15.
Roberta Paris Valentina Cova Giulia Pagliarani Stefano Tartarini Matteo Komjanc Silviero Sansavini 《Tree Genetics & Genomes》2009,5(1):81-91
Apple scab resistance is one of the most well-characterized plant–pathogen interactions in a woody plant species. While the
HcrVf2 gene from the wild apple Malus floribunda 821 has proved capable of conferring scab resistance to the susceptible cv. Gala after genetic transformation, its identification
represents only the first step in understanding the molecular mechanisms and, hence, the network of genes underlying the defence
response. We used a PCR-based suppression subtractive hybridization to identify apple genes that are differentially expressed
after Venturia inaequalis inoculation. Subtractive hybridization was performed between cDNA from challenged leaves of HcrVf2-resistant transgenic Gala and susceptible cv. Gala plants. A library of 523 unigenes was constructed and characterized by
assigning a putative function via comparison with public databases. This set of pathogen-modulated apple genes includes many
defence-related genes and is therefore an important source of information for understanding the molecular basis of the Malus–V. inaequalis interaction.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
16.
C. K. Deepa Syed G. Dastager Ashok Pandey 《World journal of microbiology & biotechnology》2010,26(12):2277-2283
A Gram-positive rod-shaped bacterium isolated on nutrient agar plates incubated at 28 ± 2°C. The identity of the bacterium
was confirmed by sequencing of the 16S rRNA gene and it reveals that it shares highest similarity with Bacillus thioparus CECT 7196T (99.08%). It was capable of growing at temperatures ranging from 4 to 40°C, but optimum growth was observed at 28 ± 2°C.
Strain NII-0902 is endowed with multiple plant growth promotion attributes such as phosphate solubilization, Indole acetic
acid (IAA), siderophore and HCN production, which were expressed differentially at sub-optimal temperatures (5–40°C). It was
able to solubilize phosphate (17.7 μg ml−1), and produce IAA (139.7 μg ml−1) at 28 ± 2°C. Qualitative detection of siderophore production and HCN were also observed. At 5°C it was found to express
all the plant growth promotion attributes except HCN production. The ability to colonize roots is a sine qua non condition
for a rhizobacteria to be considered a true plant growth-promoting rhizobacteria (PGPR). Bacillus sp. NII-0902 has a potential ability to colonize roots visualized by transparency, bacterial growth (turbid, milky and narrow
zone) along and around roots and truly supported by scanning electron micrograph. Hence, it is proposed that, Bacillus thioparus sp. NII-0902 could be deployed as an inoculant to attain the desired results of bacterization. 相似文献
17.
Buchnera aphidicola is a prokaryotic endosymbiont of the aphid Schizaphis graminum. From past and present nucleotide sequence analyses of the B. aphidicola genome, we have assembled a 34.7-kilobase (kb) DNA segment. This segment contains genes coding for 32 open reading frames
(ORFs), which corresponded to 89.9% of the DNA. All of these ORFs could be identified with homologous regions of the Escherichia coli genome. The order of the genes with established functions was groELS–trmE–rnpA–rpmH–dnaA–dnaN–gyrB–atpCDGAHFEB–gidA–fdx–hscA– hscB–nifS–ilvDC–rep–trxA–rho. The order of genes in small DNA fragments was conserved in both B. aphidicola and E. coli. Most of these fragments were in approximately the same region of the E. coli genome. The latter organism, however, contained many additional inserted genes within and between the fragments. The results
of the B. aphidicola genome analyses indicate that the endosymbiont has many properties of free-living bacteria.
Received: 15 August 1997 / Accepted: 29 August 1997 相似文献
18.
Jian-Chun Guo Rui-Jun Duan Xin-Wen Hu Kai-Mian Li Shao-Ping Fu 《Transgenic research》2010,19(2):197-209
19.
Veena Veena Christopher G. Taylor 《In vitro cellular & developmental biology. Plant》2007,43(5):383-403
Agrobacterium rhizogenes is the etiological agent for hairy-root disease (also known as root-mat disease). This bacterium induces the neoplastic growth
of plant cells that differentiate to form “hairy roots.” Morphologically, A. rhizogenes-induced hairy roots are very similar in structure to wild-type roots with a few notable exceptions: Root hairs are longer,
more numerous, and root systems are more branched and exhibit an agravitropic phenotype. Hairy roots are induced by the incorporation
of a bacterial-derived segment of DNA transferred (T-DNA) into the chromosome of the plant cell. The expression of genes encoded
within the T-DNA promotes the development and production of roots at the site of infection on most dicotyledonous plants.
A key characteristic of hairy roots is their ability to grow quickly in the absence of exogenous plant growth regulators.
As a result, hairy roots are widely used as a transgenic tool for the production of metabolites and for the study of gene
function in plants. Researchers have utilized this tool to study root development and root–biotic interactions, to overexpress
proteins and secondary metabolites, to detoxify environmental pollutants, and to increase drought tolerance. In this review,
we provide an up-to-date overview of the current knowledge of how A. rhizogenes induces root formation, on the new uses for A. rhizogenes in tissue culture and composite plant production (wild-type shoots with transgenic roots), and the recent development of
a disarmed version of A. rhizogenes for stable transgenic plant production. 相似文献
20.
ANA PINEDA ROXINA SOLER BERHANE T. WELDEGERGIS MPOKI M. SHIMWELA JOOP J. A. VAN LOON MARCEL DICKE 《Plant, cell & environment》2013,36(2):393-404
Beneficial soil‐borne microbes, such as mycorrhizal fungi or rhizobacteria, can affect the interactions of plants with aboveground insects at several trophic levels. While the mechanisms of interactions with herbivorous insects, that is, the second trophic level, are starting to be understood, it remains unknown how plants mediate the interactions between soil microbes and carnivorous insects, that is, the third trophic level. Using Arabidopsis thaliana Col‐0 and the aphid Myzus persicae, we evaluate here the underlying mechanisms involved in the plant‐mediated interaction between the non‐pathogenic rhizobacterium Pseudomonas fluorescens and the parasitoid Diaeretiella rapae, by combining ecological, chemical and molecular approaches. Rhizobacterial colonization modifies the composition of the blend of herbivore‐induced plant volatiles. The volatile blend from rhizobacteria‐treated aphid‐infested plants is less attractive to an aphid parasitoid, in terms of both olfactory preference behaviour and oviposition, than the volatile blend from aphid‐infested plants without rhizobacteria. Importantly, the effect of rhizobacteria on both the emission of herbivore‐induced volatiles and parasitoid response to aphid‐infested plants is lost in an Arabidopsis mutant (aos/dde2‐2) that is impaired in jasmonic acid production. By modifying the blend of herbivore‐induced plant volatiles that depend on the jasmonic acid‐signalling pathway, root‐colonizing microbes interfere with the attraction of parasitoids of leaf herbivores. 相似文献