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1.
L. Guerra-Guimarães M. C. Silva C. Struck A. Loureiro M. Nicole C. J. RodriguesJr. C. P. P. Ricardo 《Biologia Plantarum》2009,53(4):702-706
Two Coffea arabica — Hemileia vastatrix incompatible interactions (I1: coffee cv. Caturra — rust race VI and I2: coffee cv S4 Agaro — rust race II) and a compatible interaction (coffee cv. Caturra — rust race II) were compared in relation
to the infection process and chitinase activity. In the two incompatible interactions the fungus ceased growth in the early
infection stages, while in the compatible interaction no fungus growth inhibition was observed. A high constitutive level
of chitinase activity was detected in the intercellular fluid of healthy leaves. Upon infection, chitinase isoforms were more
abundant in incompatible interactions than in the compatible interaction. Immunodetection showed that class I chitinases are
particularly relevant in the incompatible interactions and might participate in the defence response of the coffee plants. 相似文献
2.
Rice (Oryza sativa) cv. Nipponbare expresses non-host resistance (NHR) to the wheat leaf rust fungus, Puccinia triticina f. sp. tritici (Ptt). When the leaves of cv. Nipponbare were inoculated with Ptt, approx 93% of the urediniospores germinated on the leaf surface, but only 10% of the germinated spores formed appressoria
over the stomata at one day post inoculation (1 dpi). Hydrogen peroxide (H2O2) accumulated in host cells around the appressoria at 3 dpi. Approx. 3% of the appressoria produced short hyphae inside the
leaf, and fluorescence was observed in tissue invaded by the hyphae by 7 dpi. At 22 dpi, 0.2% of the sites with appressoria
formed branching infection hypha in mesophyll cells, but no substomatal vesicles, haustorial mother cells or haustoria were
observed. Proteins were extracted from leaves 3 dpi and analyzed by two-dimensional gel electrophoresis (2-DE). A total 33
spots were reproducibly up-regulated and 9 were down-regulated by infection compared to the water inoculated control. Of these,
30 were identified by MALDI-TOF Mass Spectrometry. The identified proteins participate in defense/stress responses, energy/carbohydrate
metabolism, oxidation–reduction processes, protein folding/turnover/cleavage/degradation, signal transduction and cell death
regulation. The results indicates that NHR of rice to Ptt is consistent with a shift in protein and energy metabolism, increased antimicrobial activities, possibly including phytoalexin
accumulation and cell wall reinforcement, increased cell repair, antioxidive and detoxification reactions, and enhanced prevention
of plant cell death. Nearly half of the up-regulated identified proteins were associated with chloroplast and mitochondrial
physiology suggesting important roles for these organelles during NHR. 相似文献
3.
4.
On the family Brassicaceae, the causal agent responsible for downy mildew disease was originally regarded as a single species,
Peronospora parasitica (now under Hyaloperonospora), but it was recently reconsidered to consist of many distinct species. In this study, 11 specimens of Peronospora
drabae and P. norvegica parasitic on the genus Draba were investigated morphologically and molecularly. Pronounced differences in conidial sizes (P. drabae: 14–20 × 12.5–15.5 μm; P. norvegica: 20–29 × 15.5–22 μm) and 7.8% sequence distance between their ITS1-5.8S-ITS2 rDNA sequences confirmed their status as distinct
species. Based on ITS phylogeny and morphology (monopodially branching conidiophores, flexuous to sigmoid ultimate branchlets,
hyaline conidia and lobate haustoria), the two species unequivocally belong to the genus Hyaloperonospora and not to Peronospora to which they were previously assigned. Therefore, two new combinations, Hyaloperonospora drabae and H. norvegica, are proposed. The two taxa are illustrated and compared using the type specimen for H. norvegica and authentic specimens for H. drabae, which is lectotypified. 相似文献
5.
A genetic transformation system has been developed for callus cells of Crataegus
aronia using Agrobacterium
tumefaciens. Callus culture was established from internodal stem segments incubated on Murashige and Skoog (MS) medium supplemented with
5 mg l−1 Indole-3-butyric acid (IBA) and 0.5 mg l−1 6-benzyladenine (BA). In order to optimize the callus culture system with respect to callus growth and coloration, different
types and concentrations of plant growth regulators were tested. Results indicated that the best average fresh weight of red
colored callus was obtained on MS medium supplemented with 2 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1.5 mg l−1 kinetin (Kin) (callus maintenance medium). Callus cells were co-cultivated with Agrobacterium harboring the binary plasmid pCAMBIA1302 carrying the mgfp5 and hygromycin phosphotransferase (hptII) genes conferring green fluorescent protein (GFP) activity and hygromycin resistance, respectively. Putative transgenic calli
were obtained 4 weeks after incubation of the co-cultivated explants onto maintenance medium supplemented with 50 mg l−1 hygromycin. Molecular analysis confirmed the integration of the transgenes in transformed callus. To our knowledge, this
is the first time to report an Agrobacterium-mediated transformation system in Crataegus
aronia. 相似文献
6.
Quan-le Xu Zhe Hu Chun-yuan Li Xin-yu Wang Chong-ying Wang 《In vitro cellular & developmental biology. Plant》2009,45(5):583-590
Two protocols were developed for the efficient regeneration of Sinningia speciosa from leaf explants via two developmental pathways. The first method involved formation of callus and buds, followed by subsequent
root growth, in Murashige and Skoog medium (MS) containing 2.0 mg l−1 6-benzylaminopurine (BA) and 0.2 mg l−1 α-naphthalene acetic acid (NAA), with a regeneration efficiency of 99.0%. The second method involved producing callus and
roots, followed by subsequent formation of buds, in MS medium supplemented with 1.0–5.0 mg l−1 NAA, and resulted in a regeneration efficiency of 90.4%. Our experiments indicate that the root-first pathway resulted in
a lower plant regeneration efficiency. Through five continual generations using the buds-first method, a total of 215 regenerated
plants were obtained in the last generation, and eight exhibited a phenotype we named tricussate whorled phyllotaxis (twp). Six of the regenerated twp variant plants maintained their tricussate whorled phyllotaxis phenotype, showing no other abnormalities, while one reverted
to a wild type before flowering and another formed two rounds of sepals. Physiological analysis revealed that the twp plants responded differently than wild type to exogenous NAA and 2,3,5-triiodobenzoic acid (TIBA), while high-performance
liquid chromatography (HPLC) analysis showed that the levels of endogenous indole-3-acetic acid (IAA) and gibberellin (GA)
were lower in twp than wild-type plants. These results suggest that the formation of the twp mutant may be related to phytohormones and that the twp variant could be an important material for investigating the molecular mechanism of plant phyllotaxis patterning. 相似文献
7.
Two experiments were performed to determine how application of the cytokinin benzyladenine (BA) influenced flowering in Doritaenopsis and Phalaenopsis orchid clones. In the first experiment, two vegetative orchid clones growing in 15-cm pots were transferred from a 28°C greenhouse
that inhibited flowering to a 23°C greenhouse for flower induction (day 0). A foliar spray (0.2 L m−2) containing BA at 100, 200, or 400 mg L−1 or 25, 50, or 100 mg L−1 each of BA and gibberellins A4 + A7 (BA+GA) was applied on days 0, 7, and 14. Plants treated with BA alone at 200 or 400 mg L−1 had a visible inflorescence 3–9 days earlier and had a mean of 0.7–3.5 more inflorescences and 3–8 more flowers per plant
than nontreated plants. The application of BA+GA had no effect on inflorescence number and total flower number at the rates
tested. In the second experiment, three orchid clones received a single foliar spray of BA at 200 mg L−1 at six time points relative to time of transfer from 29°C to 23°C (−1, 0, +1, +2, +4, or +6 weeks). A separate group of plants
received a BA application at week 0 but was maintained at 29°C. Inflorescence number was greatest in all three orchid clones
when plants were treated with BA 1 week after the temperature transfer. Plants that were sprayed with BA and maintained at
29°C did not initiate inflorescences. The promotion of flowering by the application of BA suggests that cytokinins at least
partially regulate inflorescence initiation of Doritaenopsis and Phalaenopsis, but its promotion is conditional and BA application cannot completely substitute for an inductive low temperature. 相似文献
8.
A protocol for in vitro induction of crape myrtle tetraploids using nodes from in vitro-grown shoots (2n = 48) was established. Nodal buds were excised from in vitro-grown shoots, maintained on proliferation medium containing
Murashige and Skoog medium supplemented with 4.44 μM 6-benzyladenine , 0.54 μM α-naphthaleneacetic acid, and treated with
a range of concentrations of colchicine under three different conditions. Nodal bud explants treated in liquid proliferation
medium supplemented with either 15 or 20 mM colchicine for 24 h turned necrotic and died; whereas, those cultured on solid
proliferation medium supplemented with either 125 or 250 μM colchicine for 30 days survived, but no tetraploid plants were
obtained. However, when explants were cultured in liquid proliferation medium containing 250, 500 or 750 μM colchicine for
10 days, tetraploid plants (2n = 96) were obtained. Incubation of explants in medium containing 750 μM colchicine promoted the highest frequency of survival
(40%) of explants and of recovered tetraploids (60%). Morphological and anatomical characteristics of leaves, including leaf
index, stomata size and number, stomata index (length/width), and number of chloroplasts in guard cells correlated with ploidy
of crape myrtle plants. The number of chloroplasts in guard cells of stomata was a stable and reliable marker in discriminating
plants of different ploidy levels. Chromosome counts and flow cytometry confirmed these findings. 相似文献
9.
Besma Sghaier-Hammami Inmaculada Redondo-López Ana M. Maldonado-Alconada Sira Echevarría-Zomeño Jesús V. Jorrín-Novo 《Acta Physiologiae Plantarum》2012,34(3):905-922
The present work is directed at studying changes at the proteome level in Arabidopsis thaliana leaves in response to Pseudomonas syringae virulent (Pst) and avirulent (Pst avrRpt2) strains. Arabidopsis leaves were sampled from challenged plants at 4, 8 and 24 h post inoculation. Proteins were TCA–acetone–phenol
extracted and subjected to 2-DE (5–8 pH range) and MS/MS (MALDI–TOF–TOF) analysis. Out of 800 matched spots on each of the
36 gels analysed, 147 spots were either absent in at least one of the conditions studied (time or treatments; qualitative
variable spots) or differentially accumulated between time and treatments (quantitative variable spots). Out of the 24 proteins
successfully identified over TAIR10 database, 23 have not been reported previously in similar proteomics studies of the Arabidopsis thaliana–Pseudomonas syringae interaction. The exhaustive statistical analysis performed, including principal component and heat map, showed that 24 h
post inoculation can clearly discriminate the challenged plants from the control. The protein change occurred early (4 h post
inoculation) following the virulent pathogen infection, whereas the change occurred later (24 h post inoculation) following
the avirulent pathogen inoculation. Concerning the variable proteins, three behavioural groups can be observed: group 1 (common
protein changes in response to virulent and avirulent pathogen infection), group 2 (protein changes in response to virulent
pathogen infection) and group 3 (protein changes in response to avirulent pathogen infection). Differential identified proteins
following the pathogen infection belonged to different groups including those of oxidative stress defence, enzymes of metabolic
pathways and molecular chaperones. 相似文献
10.
Salicylic acid-induced changes to growth and phenolic metabolism in <Emphasis Type="Italic">Matricaria chamomilla</Emphasis> plants 总被引:1,自引:0,他引:1
The influence of salicylic acid (SA) doses of 50 and 250 μM, for a period of up to 7 days, on selected physiological aspects
and the phenolic metabolism of Matricaria chamomilla plants was studied. SA exhibited both growth-promoting (50 μM) and growth-inhibiting (250 μM) properties, the latter being
correlated with decrease of chlorophylls, water content and soluble proteins. In terms of phenolic metabolism, it seems that
the higher SA dose has a toxic effect, based on the sharp increase in phenylalanine ammonia-lyase (PAL) activity (24 h after
application), which is followed by an increase in total soluble phenolics, lignin accumulation and the majority of the 11
detected phenolic acids. Guaiacol-peroxidase activity was elevated throughout the experiment in 250 μM SA-treated plants.
In turn, some responses can be explained by mechanisms associated with oxidative stress tolerance; these mitigate acute SA
stress (which is indicated by an increase in malondialdehyde content). However, PAL activity decreased with prolonged exposure
to SA, indicating its inhibition. Accumulation of coumarin-related compounds (umbelliferone and herniarin) was not affected
by SA treatments, while (Z)- and (E)-2-β-d-glucopyranosyloxy-4-methoxycinnamic acids increased in the 250 μM SA-treated rosettes. Free SA content in the rosettes increased
significantly only in the 250 μM SA treatment, with levels tending to decrease towards the end of the experiment and the opposite
trend was observed in the roots. 相似文献
11.
12.
Xin Li Hui-Ying Yu Yi-Feng Lin Hong-Mei Teng Lei Du Guo-Gang Ma 《Biotechnology letters》2010,32(10):1487-1495
The morphological effects of CF66I, an antifungal compound produced by Burkholderia cepacia, on growing hyphae of Fusarium oxysporum were studied by fluorescence microscopy (FM) and transmission electron microscopy (TEM). At 20 μg/ml, CF66I strongly inhibited
growth and induced significant changes of the hyphal morphology. These changes included swelling of hyphae with considerable
thickening cell wall and abnormal chitin deposition, which was indicative of the alterations in cell wall structure. Furthermore,
fluorescein diacetate (FDA) staining indicated the loss of intracellular esterase activity. CF66I probably inhibits fungal
growth by interfering with the cell metabolic pathways. At 120 μg/ml, CF66I killed F. oxysporum (accompanied by propidium iodide permeation, intracellular cytoplasm leakage and crushing of hyphal tips), probably by direct
damage to the cell membrane. Thus, there are two different antifungal mechanisms of CF66I, depending on its concentration,
and further studies on this compound might be useful for us to develop a new class of antifungal agents. 相似文献
13.
C. Douglas Boyette Mark A. Weaver Robert E. Hoagland Kenneth C. Stetina 《World journal of microbiology & biotechnology》2008,24(11):2721-2726
A mycelial formulation of the fungus Myrothecium verrucaria (IMI 361690) containing 0.20% Silwet L-77 surfactant was found to be highly efficacious in controlling the exotic invasive
weed kudzu. The mycelium can be rapidly (48–72 h) produced in several media, including an inexpensive soy flour–corn meal
medium. Mycelial yields were 2, 10, and 25 g dry weight l−1 in Czapek-Dox, Richard’s V-8, and soy flour–corn meal media, respectively. Scale-up production in soy flour–corn meal medium
using laboratory fermenters (10–25 l), resulted in a mycelial formulation that caused 90% mortality of naturally-occurring
mature (0.9–1.0 m in height) kudzu within 48 h after application in field experiments. HPLC analyses revealed that the mycelium
produced in this liquid culture contained no detectable amounts of the trichothecene mycotoxins roridin A and verrucarin A
(limit of detection 2 μg ml−1). This has resulted in a safer, yet effective bioherbicidal product. We anticipate that these findings should improve the
probability of EPA registration and subsequent commercial development of this bioherbicide. 相似文献
14.
K. Samuel D. Debashish B. Madhumita G. Padmaja Siva Ram Prasad V. Bhaskara Ramana Murthy P. S. Rao 《In vitro cellular & developmental biology. Plant》2009,45(4):466-473
The propagation of Givotia rottleriformis Griff. is difficult as a result of long seed dormancy associated with poor seed germination. The present study was undertaken
to develop a protocol to overcome seed dormancy by culture of zygotic embryo axes and then develop an efficient method for
micropropagation of Givotia. Best germination frequency (78.3%) was achieved from mature zygotic embryo axes isolated from acid-scarified fresh seeds
when cultured on Murashige and Skoog (MS) medium (half-strength major salts) with 28.9 μM gibberellic acid (GA3). Efficient plant conversion was achieved by transfer of 10-d-old germinated embryos to MS medium (half-strength major salts)
supplemented with 1.2 μM kinetin (KN) and 0.5 μM indole-3-butyric acid (IBA). However, acid scarification of 1-yr-old seeds
decreased the germination frequency of zygotic embryo axes in comparison to those obtained from non-acid-scarified seeds which
germinated (96.2%) and converted into plants (80.3%) on MS basal (half-strength major salts) medium. Multiple shoot bud induction
was achieved by culture of shoot tips derived from in vitro germinated seedlings on MS medium with 0.5 μM thidiazuron for 4 wk, and the shoots elongated after transfer to a secondary
medium with 1.2 μM KN. A maximum number of 7.8 shoots per explant with an average shoot length of 3.2 cm was achieved after
two subcultures on this medium. The in vitro regenerated shoots rooted (41.5%) on half-strength MS medium with 0.5 μM IBA. The in vitro generated seedlings and micropropagated plants were established in soil with a survival frequency of 70% and 60%, respectively. 相似文献
15.
Some strains of white rot fungi, non-lignolytic fungi and litter-decomposing basidiomycetes have been recognized as PAH degraders.
The purpose of our research was to enlarge the scope of PAH-degrading fungi and explore the huge endophytic microorganism
resource for bioremediation of PAHs. In this study, phenanthrene was used as a model PAHs compound. Nine strains of endophytic
fungi isolated from four kinds of plant from Eupharbiaceae were screened for degradation of phenanthrene. The endophytic fungus Ceratobasidum stevensii (strain B6) isolated from Bischofia polycarpam showed high degradation efficiency and was selected for further studies. Into the fungal culture, 100 mg l−1 phenanthrene was added, and after 10 days of incubation, about 89.51% of the phenanthrene was removed by strain B6. Extracellular
ligninolytic enzyme activities of strain B6 were tested. The results showed that manganese peroxidase [MnP] was the predominant
ligninolytic enzyme and that its production was greatly induced by the presence of phenanthrene. To confirm the involvement
of MnP in phenanthrene degradation, promotion and inhibition studies on MnP in different concentration level of Mn2+ and NaN3 were performed. Additionally, fungal mycelium-free and resuspended experiments were carried out. The results showed no apparent
correlation between MnP activity and phenanthrene degradation. The mycelium and fresh medium were the crucial factors affecting
the degradation of phenanthrene. To date, this is the first report on PAH degradation by Ceratobasidum stevensii. This study suggests that endophytic fungi might be a novel and important resource for microorganisms that have PAH-degrading
capabilities. 相似文献
16.
Alexandre Alonso Alves Lúcio Mauro da Silva Guimarães Agnaldo Rodrigues de Melo Chaves Fábio Murilo DaMatta Acelino Couto Alfenas 《Acta Physiologiae Plantarum》2011,33(5):1831-1839
One of the most important diseases of eucalyptus plantations is caused by the rust fungus Puccinia psidii. While the genetic basis of rust resistance has been addressed recently, little is known about the physiological aspects
of Eucalyptus–P. psidii interaction. In order to fill this gap, we undertook a study investigating the effects of P. psidii infection on photosynthetic processes of two E. urophylla clones with contrasting resistance to the pathogen. Our results show that gas exchange and chlorophyll a fluorescence parameters were virtually unaffected in the resistant clone. In the susceptible clone, photosynthetic rates
were chiefly constrained by biochemical limitations to carbon fixation. Photosynthesis was impaired only in symptomatic tissues
since the reductions in photosynthetic rates were proportional to the diseased leaf area. Rust infection provoked chronic
photoinhibition to photosynthesis in the susceptible clone. Overall, differences in the ability for light capture, use and
dissipation may play a significant role in explaining the clonal differences in Eucalyptus in response to P. psidii infection. To our knowledge, this is the first report of the effect of rust infection on gas exchange and chlorophyll a fluorescence parameters in Eucalyptus. 相似文献
17.
A. Roldán Serrano J. Luna del Castillo J. Jorrín Novo A. Fernández Ocaña M. V. Gómez Rodríguez 《Biologia Plantarum》2007,51(1):149-152
Systemic acquired resistance (SAR) can be induced in plants by incompatible pathogens, pathogen derived extracts, or certain
chemicals as benzothiadiazole (BTH). The aim of this work was to compare changes in peroxidase and chitinase activities, enzymes
considered as PR-proteins, caused by BTH and the pathogen Plasmopara halstedii. Hypocotyls from susceptible and resistant BTH-treated sunflower seedlings showed increased peroxidase and chitinase activities.
Inoculation with P. halstedii increased chitinase and peroxidase activities in inoculated hypocotyls from susceptible but not from resistant sunflower
seedlings. 相似文献
18.
Xiao-Long Huang Bo Yang Chun-Gen Hu Jia-Ling Yao 《Plant Cell, Tissue and Organ Culture》2009,99(2):209-215
Inflorescence induction and morphogenesis of regenerated flowers were investigated in vitro in Dioscorea zingiberensis C. H. Wright. Inflorescence induction was influenced by the type and concentration of phytohormones. When floral bud explants
were incubated on a Murashige and Skoog medium containing a combination of 2.0 mg l−1 6-benzyladenine and 0.5 mg l−1 indole-3-butyric acid, the highest frequency of inflorescence induction was observed. However, in the presence of gibberellic
acid, induction efficiency was reduced although node length of inflorescence was increased. Ontogenetic studies revealed that
the inflorescence primordia originated directly from axillary epidermal cells of the perianth and bract of the explants after
7 days. In vitro, male flowers developed normally and blossomed after 90–100 days. In addition, some bisexual flowers were
observed. These results demonstrated that there were differences in sexual differentiation of floral buds in vitro compared
with that in vivo. 相似文献
19.
Earlier, a pollen-specific Oryza sativa indica pollen allergen gene (OSIPA), coding for expansins/pollen allergens, was isolated from rice, and its promoter—upon expression in tobacco and Arabidopsis—was found active during the late stages of pollen development. In this investigation, to analyze the effects of different
putative regulatory motifs of OSIPA promoter, a series of 5′ deletions were fused to β-glucuronidase gene (GUS) which were stably introduced into rice and Arabidopsis. Histochemical GUS analysis of the transgenic plants revealed that a 1631 bp promoter fragment mediates maximum GUS expression
at different stages of anther/pollen development. Promoter deletions to −1272, −966, −617, and −199 bp did not change the
expression profile of the pollen specificity. However, the activity of promoter was reduced as the length of promoter decreased.
The region between −1567 and −199 bp was found adequate to confer pollen-specific expression in both rice and Arabidopsis systems. An approximate 4-fold increase in the GUS activity was observed in the pollen of rice when compared to that of Arabidopsis. As such, the OSIPA promoter seems promising for generation of stable male-sterile lines required for the production of hybrids in rice and other
crop plants. 相似文献
20.
Wajahatullah Khan Carlos Costa Alfred Souleimanov Balakrishnan Prithiviraj Donald L. Smith 《Plant Growth Regulation》2011,63(3):243-249
Lipo-chitooligosaccharides (LCOs) are bacteria-to-plant signals required for the establishment of rhizobia–legume nitrogen
fixing symbioses. The ability of LCO [Nod Bj V (C18:1, MeFuc)] isolated from B. japonicum (strain 532C), and of oligomers of chitosan (tetramer, pentamer) and chitin (pentamer) to affect the developmental morphology
of roots in Arabidopsis thaliana (L.) Heynh ecotype Columbia (Col-0) was assessed using an interactive scanner-based image analysis system. LCOs have been
shown to play a role in plant organogenesis at nanomolar concentrations. LCO and the chitin pentamer promoted root growth
and development in Arabidopsis at concentrations of 10 nM and 100 μM, respectively. The LCO treated Arabidopsis plants had about 35% longer roots than untreated control plants. Similarly, treatment with 100 μM chitin pentamer (CHIT5)
resulted in 26% longer roots than the untreated plants; however, chitosan oligomer (CH4 or CH5) treated plants did not differ
from the control plants at either concentration (100 or 1 μM). Both LCOs and the chitin pentamer at higher concentrations
increased root surface area, mean root diameter and number of root tips. However, leaf area increase was observed only in
plants treated with LCO at 10 nM. 相似文献