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1.
Gabriela Forchetti Oscar Masciarelli María J. Izaguirre Sergio Alemano Daniel Alvarez Guillermina Abdala 《Current microbiology》2010,61(6):485-493
Endophytic bacterial strains SF2 (99.9% homology with Achromobacter xylosoxidans), and SF3 and SF4 (99.9% homology with Bacillus pumilus) isolated from sunflower grown under irrigation or drought were selected on the basis of plant growth-promoting bacteria (PGPB) characteristics. Aims of the study were to examine effects of inoculation with SF2, SF3, and SF4 on sunflower cultivated under water stress, to evaluate salicylic acid (SA) production by these strains in control medium or at Ψa = ?2.03 MPa, and to analyze effects of exogenously applied SA, jasmonic acid (JA), bacterial pellets, and bacterial supernatants on growth of pathogenic fungi Alternaria sp., Sclerotinia sp., and Verticillum sp. Growth response to bacterial inoculation was studied in two inbred lines (water stress-sensitive B59 and water stress-tolerant B71) and commercial hybrid Paraiso 24. Under both water stress and normal conditions, plant growth following inoculation was more strongly enhanced for Paraiso 24 and B71 than for B59. All three strains produced SA in control medium; levels for SF3 and SF4 were higher than for SF2. SA production was dramatically higher at Ψa = ?2.03 MPa. Exogenously applied SA or JA caused a significant reduction of growth for Sclerotinia and a lesser reduction for Alternaria and Verticillum. Fungal growth was more strongly inhibited by bacterial pellets than by bacterial supernatants. Our findings indicate that these endophytic bacteria enhance growth of sunflower seedlings under water stress, produce SA, and inhibit growth of pathogenic fungi. These characteristics are useful for formulation of inoculants to improve growth and yield of sunflower crops. 相似文献
2.
Juan Pablo Oliver Alexandra Castro Carina Gaggero Tomas Cascón Eric A. Schmelz Carmen Castresana Inés Ponce de León 《Planta》2009,230(3):569-579
The moss Physcomitrella patens (P. patens) is a useful model to study abiotic stress responses since it is highly tolerant to drought, salt and osmotic stress. However,
very little is known about the defense mechanisms activated in this moss after pathogen assault. In this study, we show that
P. patens activated multiple and similar responses against Pythium irregulare and Pythium debaryanum, including the reinforcement of the cell wall, induction of the defense genes CHS, LOX and PAL, and accumulation of the signaling molecules jasmonic acid (JA) and its precursor 12-oxo-phytodienoic acid (OPDA). However,
theses responses were not sufficient and infection could not be prevented leading to hyphae colonization of moss tissues and
plant decay. Pythium infection induced reactive oxygen species production and caused cell death of moss tissues. Taken together, these data indicate
that Pythium infection activates in P. patens common responses to those previously characterized in flowering plants. Microscopic analysis also revealed intracellular
relocation of chloroplasts in Pythium-infected tissues toward the infection site. In addition, OPDA, JA and its methyl ester methyl jasmonate induced the expression
of PAL. Our results show for the first time JA and OPDA accumulation in a moss and suggest that this defense pathway is functional
and has been maintained during the evolution of plants.
Authors Juan Pablo Oliver and Alexandra Castro contributed equally to this work. 相似文献
3.
Ricard Brossa Marta L��pez-Carbonell Tana Jubany-Mar�� Leonor Alegre 《Journal of Plant Growth Regulation》2011,30(3):322-333
The interplay between jasmonic acid (JA) and abscisic acid (ABA) in plant responses to water stress and in water-stress-enhanced
oxidative stress was investigated in Arabidopsis thaliana plants subjected to water stress by water deprivation. For this purpose a drought assay was conducted using Arabidopsis mutants impaired in ABA (aba2), JA (aos), and ascorbate (vtc1) biosynthesis. Our results show an interaction between ABA and JA during their biosynthesis. Moreover, the coordinated action
of ABA and JA protected wild-type, aba2, and aos plants from the effects of stress. However, this effect was not observed in the vtc1 mutant, which showed a distinct decrease in the F
v/F
m ratio, concomitant with a marked fall in relative water content (RWC), despite high endogenous concentrations of JA and ABA.
This finding indicates the relevance of ascorbate metabolism in plant acclimation to stress. Despite the interaction between
the two phytohormones, drought-associated stomatal closure is regulated mainly by ABA and weakly by JA, whereas JA plays a
role in the formation of antioxidants regulating ascorbate and glutathione metabolism. A time course analysis revealed the
relevance of plant age and stress duration in the responses of the mutants compared to wild-type plants. Here we discuss the
relationship between ABA, JA, ascorbate, and glutathione in plants under water stress. 相似文献
4.
This study examined the role of endogenous abscisic acid (ABA) and jasmonic acid (JA) in indirect somatic embryogenesis of
Medicago sativa L. A multiplex GC-MS/MS technique allowed quantitative single-run analyses of ABA, JA, 12-oxophytodienoic acid (OPDA) and
indole-3-acetic acid (IAA). The preparation of initial explants led to a strong accumulation of ABA, JA and OPDA but not of
IAA. Substantially higher levels of ABA, JA and OPDA were detected in developing somatic embryos than in callus or embryogenic
suspension. Fluridone (FLD) decreased ABA, JA and OPDA levels. Indoprofen (INP) appeared to be a specific inhibitor of octadecanoid
biosynthesis. Somatic embryo production and development were negatively affected by FLD or INP. Only INP (0.5 μM) applied
during proliferation phase increased the number of cotyledonary embryos. The results strongly indicate the involvement of
ABA and JA in somatic embryogenesis of M. sativa. Surprisingly, low IAA contents in comparison to stress-related compounds (ABA, JA and OPDA) were detected in explants, embryogenic
tissues and somatic embryos. 相似文献
5.
Patricia Piccoli Claudia Travaglia Ana Cohen Laura Sosa Paula Cornejo Ricardo Masuelli Rubén Bottini 《Plant Growth Regulation》2011,64(2):207-210
This paper informs the characterization by 16SrDNA partial sequence analysis of an endophytic diazotrophic bacterium isolated
from roots of the halophyte shrub Prosopis strombulifera. The bacterium produced ABA, IAA, GA1, GA3 and jasmonic acid in chemically-defined culture medium as assessed by GC-EIMS. The results emphasize the role of phytohormones
produced by endophytic bacteria in the association host-beneficial microorganisms, especially under conditions of adverse
environments. 相似文献
6.
Biotic signaling molecules including abscisic acid (ABA) are involved in signal transduction pathways that mediate the defense
response of plants to environmental stresses. The antimicrobial protein gene CaAMP1, previously isolated from pepper (Capsicum annuum), was strongly induced in pepper leaves exposed to ABA, NaCl, drought, or low temperature. Because transformation is very
difficult in pepper, we overexpressed CaAMP1 in Arabidopsis. CaAMP1-overexpressing (OX) transgenic plants exhibited reduced sensitivity to ABA during the seed germination and seedling stages.
Overexpression of CaAMP1 conferred enhanced tolerance to high salinity and drought, accompanied by altered expression of the AtRD29A gene, which is correlated with ABA levels and environmental stresses. The transgenic plants were also highly tolerant to
osmotic stress caused by high concentrations of mannitol. Together, these results suggest that overexpression of the CaAMP1 transgene modulates salt and drought tolerance in Arabidopsis through ABA-mediated cell signaling.
The nucleotide sequence data reported here have been deposited in the GenBank database under the accession number AY548741. 相似文献
7.
Plant aquaporins are believed to facilitate water transport across cell membranes. However, the relationship between aquaporins
and drought resistance in plants remains unclear. VfPIP1, a putative aquaporin gene, was isolated from Vicia faba leaf epidermis, and its expression was induced by abscisic acid (ABA). Our results indicated that the VfPIP1 protein was
localized in the plasma membrane, and its expression in V. faba was induced by 20% polyethylene glycol 6000. To further understand the function of VfPIP1, we obtained VfPIP1-expressing transgenic Arabidopsis thaliana plants under the control of the CaMV35S promoter. As compared to the wild-type control plants, the transgenic plants exhibited
a faster growth rate, a lower transpiration rate, and greater drought tolerance. In addition, the stomata of the transgenic
plants closed significantly faster than those of the control plants under ABA or dark treatment. These results suggest that
VfPIP1 expression may improve drought resistance of the transgenic plants by promoting stomatal closure under drought stress. 相似文献
8.
Hilda Pedranzani Rosario Sierra-de-Grado Ana Vigliocco Otto Miersch Guillermina Abdala 《Plant Growth Regulation》2007,52(2):111-116
There is considerable evidence suggesting that jasmonates (JAs) play a role in plant resistance against abiotic stress. It
is well known that in Angiosperms JAs are involved in the defense response, however there is little information about their
role in Gymnosperms. Our proposal was to study the involvement of JAs in Pinus pinaster Ait. reaction to cold and water stress, and to compare the response of two populations of different provenances (Gredos and
Bajo Tiétar) to these stresses. We detected 12-oxo-phytodienoic acid (OPDA), jasmonic acid (JA), and the hydroxylates 11-hydroxyjasmonate
and 12-hydroxyjasmonate in foliage and shoots of P. pinaster plants. The response of the Gredos population to cold stress differed from that of Bajo Tiétar. Gredos plants showed a lower
JA-basal level than Bajo Tiétar; under cold stress JA increased twofold at 72 h, while it decreased in Bajo Tiétar plants.
The hydroxylates slightly increased in both populations due to cold stress treatment. Under water stress, plants from Gredos
showed a remarkable JA-increase; thus the JA-response was much more prominent under water stress than under cold stress. In
contrast, no change was found in JA-level in Bajo Tiétar plants under water stress. The level of JA-precursor, OPDA, was very
low in control plants from Gredos and Bajo Tiétar. Under water stress OPDA increased only in plants from Bajo Tiétar. Therefore,
we inform here of a different JAs-accumulation pattern after the stress treatment in P. pinaster from two provenances, and suggest a possible correlation with adaptations to diverse ecological conditions. 相似文献
9.
10.
M. A. Khan S. Asaf A. L. Khan A. Adhikari R. Jan S. Ali M. Imran K.‐M. Kim I.‐J. Lee 《Plant biology (Stuttgart, Germany)》2020,22(5):850-862
- Salt stress negatively affects growth and development of plants. However, it is hypothesized that plant growth‐promoting endophytic bacteria can greatly alleviate the adverse effects of salinity and can promote growth and development of plants. In the present research, we aimed to isolate endophytic bacteria from halotolerant plants and evaluate their capacity for promoting crop plant growth.
- The bacterial endophytes were isolated from selected plants inhabiting sand dunes at Pohang beach, screened for plant growth‐promoting traits and applied to rice seedlings under salt stress (NaCl; 150 mm ).
- Out of 59 endophytic bacterial isolates, only six isolates, i.e. Curtobacterium oceanosedimentum SAK1, Curtobacterium luteum SAK2, Enterobacter ludwigii SAK5, Bacillus cereus SA1, Micrococcus yunnanensis SA2, Enterobacter tabaci SA3, resulted in a significant increase in the growth of Waito‐C rice. The cultural filtrates of bacterial endophytes were tested for phytohormones, including indole‐3‐acetic acid, gibberellins and organic acids. Inoculation of the selected strains considerably reduced the amount of endogenous ABA in rice plants under NaCl stress, however, they increased GSH and sugar content. Similarly, these strains augmented the expression of flavin monooxygenase (OsYUCCA1) and auxin efflux carrier (OsPIN1) genes under salt stress.
- In conclusion, the pragmatic application of the above selected bacterial strains alleviated the adverse effects of NaCl stress and enhanced rice growth attributes by producing various phytohormones.
11.
HrpN, a protein produced by the plant pathogenic bacterium Erwinia amylovora, has been shown to stimulate plant growth and resistance to pathogens and insects. Here we report that HrpN activates abscisic acid (ABA) signalling to induce drought tolerance (DT) in Arabidopsis thaliana L. plants grown with water stress. Spraying wild-type plants with HrpN-promoted stomatal closure decreased leaf transpiration rate, increased moisture and proline levels in leaves, and alleviated extents of damage to cell membranes and plant drought symptoms caused by water deficiency. In plants treated with HrpN, ABA levels increased; expression of several ABA-signalling regulatory genes and the important effector gene rd29B was induced or enhanced. Induced expression of rd29B, promotion of stomatal closure, and reduction in drought severity were observed in the abi1-1 mutant, which has a defect in the phosphatase ABI1, after HrpN was applied. In contrast, HrpN failed to induce these responses in the abi2-1 mutant, which is impaired in the phosphatase ABI2. Inhibiting wild-type plants to synthesize ABA eliminated the role of HrpN in promoting stomatal closure and reducing drought severity. Moreover, resistance to Pseudomonas syringae developed in abi2-1 as in wild-type plants following treatment with HrpN. Thus, an ABI2-dependent ABA signalling pathway is responsible for the induction of DT but does not affect pathogen defence under the circumstances of this study.Hong-Ping Dong and Haiqin Yu contributed equally to this study and are regarded as joint first authors. 相似文献
12.
Jalel Mahouachi Rosa Argamasilla Aurelio Gómez-Cadenas 《Journal of Plant Growth Regulation》2012,31(1):1-10
The effects of exogenous foliar glycine betaine (GB) and abscisic acid (ABA) on papaya responses to water stress were investigated
under distinct water regimes. Papaya seedlings (Carica papaya L. cultivar “BH-65”) were pretreated with GB or ABA and subsequently subjected to consecutive periods of drought, rehydration,
and a second period of drought conditions. Results indicated that water stress induced ABA, jasmonic acid (JA), and proline
accumulation but did not modify malondialdehyde (MDA) concentration. In addition, water deprivation reduced photosynthetic
rate, stomatal conductance, relative water content (RWC), leaf fresh weight, and increased leaf abscission. GB applied prior
to drought imposition decreased the impact of water stress on ABA, JA, proline accumulation, leaf water status, growth, and
photosynthetic performance. However, ABA-pretreated plants did not show alteration of most of these parameters under water
stress conditions when compared with non-pretreated plants except a clear induction of JA accumulation. Taken together, the
data suggest that GB may modulate ABA, JA, and proline accumulation through the control of stomatal movement and the high
availability of compatible solutes, leading to improvement of leaf water status, growth, and photosynthetic machinery function.
In contrast, exogenous ABA did not stimulate papaya physiological responses under drought, but interestingly ABA in combination
with drought could induce progressive JA synthesis, unlike drought alone, which induces a transitory JA increase and may trigger
endogenous ABA accumulation. The data also suggest that irrespective of the pretreatments, papaya did not suffer oxidative
damage. 相似文献
13.
The aims of the present study are to find out whether the effects of arbuscular mycorrhizal (AM) symbiosis on plant resistance
to water deficit are mediated by the endogenous abscisic acid (ABA) content of the host plant and whether the exogenous ABA
application modifies such effects. The ABA-deficient tomato mutant sitiens and its near-isogenic wild-type parental line were used. Plant development, physiology, and expression of plant genes expected
to be modulated by AM symbiosis, drought, and ABA were studied. Results showed that only wild-type tomato plants responded
positively to mycorrhizal inoculation, while AM symbiosis was not observed to have any effect on plant development in sitiens plants grown under well-watered conditions. The application of ABA to sitiens plants enhanced plant growth both under well-watered and drought stress conditions. In respect to sitiens plants subjected to drought stress, the addition of ABA had a cumulative effect in relation to that of inoculation with G. intraradices. Most of the genes analyzed in this study showed different regulation patterns in wild-type and sitiens plants, suggesting that their gene expression is modulated by the plant ABA phenotype. In the same way, the colonization
of roots with the AM fungus G. intraradices differently regulated the expression of these genes in wild-type and in sitiens plants, which could explain the distinctive effect of the symbiosis on each plant ABA phenotype. This also suggests that
the effects of the AM symbiosis on plant responses and resistance to water deficit are mediated by the plant ABA phenotype. 相似文献
14.
Jasmonoyl isoleucine accumulation is needed for abscisic acid build‐up in roots of Arabidopsis under water stress conditions 下载免费PDF全文
Carlos de Ollas Vicent Arbona Aurelio GóMez‐Cadenas 《Plant, cell & environment》2015,38(10):2157-2170
Phytohormones are central players in sensing and signalling numerous environmental conditions like drought. In this work, hormone profiling together with gene expression of key enzymes involved in abscisic acid (ABA) and jasmonate biosynthesis were studied in desiccating Arabidopsis roots. Jasmonic acid (JA) content transiently increased after stress imposition whereas progressive and concomitant ABA and Jasmonoyl Isoleucine (JA‐Ile) accumulations were detected. Molecular data suggest that, at least, part of the hormonal regulation takes place at the biosynthetic level. These observations also point to a possible involvement of jasmonates on ABA biosynthesis under stress. To test this hypothesis, mutants impaired in jasmonate biosynthesis (opr3, lox6 and jar1‐1) and in JA‐dependent signalling (coi1) were employed. Results showed that the early JA accumulation leading to JA‐Ile build up was necessary for an ABA increase in roots under two different water stress conditions. Signal transduction between water stress‐induced JA‐Ile accumulation and COI1 is necessary for a full induction of the ABA biosynthesis pathway and subsequent hormone accumulation in roots of Arabidopsis plants. The present work adds a level of interaction between jasmonates and ABA at the biosynthetic level. 相似文献
15.
Yiming Zhang Jinfen Yang Shaoyun Lu Jiongliang Cai Zhenfei Guo 《Journal of Plant Growth Regulation》2008,27(2):151-158
Abscisic acid (ABA) regulates plant adaptive responses to various environmental stresses. 9-cis-epoxycarotenoid dioxygenase (NCED) is the key enzyme of ABA biosynthesis in higher plants. A NCED gene, SgNCED1, was overexpressed in transgenic tobacco plants which resulted in 51–77% more accumulation of ABA in leaves. Transgenic tobacco
plants decreased stomatal conductance, transpiration rate, and photosynthetic rate but induced activities of superoxide dismutase
(SOD), catalase (CAT), and ascorbate-peroxidase (APX). Hydrogen peroxide (H2O2) and nitric oxide (NO) in leaves were also induced in the transgenic plants. Compared to the wild-type control, the transgenic
plants improved growth under 0.1 M mannitol-induced drought stress and 0.1 M NaCl-induced salinity stress. It is suggested
that the ABA-induced H2O2 and NO generation upregulates the stomatal closure and antioxidant enzymes, and therefore increases drought and salinity
tolerance in the transgenic plants. 相似文献
16.
Jasmonic acid (JA), its methyl ester (MeJA) and the biosynthetic precursor 12-oxophytodienoic acid (OPDA) were detected quantitatively
during somatic embryogenesis of Medicago sativa L. Using GC-MS analysis, these compounds were found in initial explants, in calli and in somatic embryos in the nanogram
range per gram of fresh weight. In distinct stages of somatic embryogenesis, JA and 12-OPDA accumulated preferentially in
cotyledonary embryos. Initial explants exhibited about five-fold higher JA content than OPDA content, whereas in other stages
OPDA accumulated predominantly. These data suggest that also in embryogenic tissues OPDA and JA may have individual signalling
properties. 相似文献
17.
ENDOPHYTIC BACTERIA FROM SEEDS OF NICOTIANA TABACUM CAN REDUCE CADMIUM PHYTOTOXICITY 总被引:1,自引:0,他引:1
Chiara Mastretta Safiyh Taghavi Daniel van der Lelie Alessio Mengoni Francesca Galardi Christina Gonnelli 《International journal of phytoremediation》2009,11(3):251-267
Although endophytic bacteria seem to have a close association with their host plant, little is known about the influence of seed endophytic bacteria on initial plant development and on their interactions with plants under conditions of metal toxicity. In order to further elucidate this close relationship, we isolated endophytic bacteria from surface sterilized Nicotiana tabacum seeds that were collected from plants cultivated on a cadmium-(Cd) and zinc-enriched soil. Many of the isolated strains showed Cd tolerance. Sterilely grown tobacco plants were inoculated with either the endogenous microbial consortium, composed of cultivable and noncultivable strains; single strains; or defined consortia of the most representative cultivable strains. Subsequently, the effects of inoculation of endophytic bacteria on plant development and on metal and nutrient uptake were explored under conditions with and without exposure to Cd. In general, seed endophytes were found to have a positive effect on plant growth, as was illustrated by an increase in biomass production under conditions without Cd. In several cases, inoculation with endophytes resulted in improved biomass production under conditions of Cd stress, as well as in a higher plant Cd concentration and total plant Cd content compared to noninoculated plants. These results demonstrate the beneficial effects of seed endophytes on metal toxicity and accumulation, and suggest practical applications using inoculated seeds as a vector for plant beneficial bacteria. 相似文献
18.
19.
Takahiro Hashimoto Kosaku Takahashi Michio Sato P. K. G. S. S. Bandara Kensuke Nabeta 《Plant Growth Regulation》2011,65(2):239-245
Allene oxide cyclase (AOC) is a key enzyme in the octadecanoid pathway of flowering plants that synthesizes 12-oxo-phytodienoic
acid (OPDA), which is a biosynthetic precursor of the signal molecule jasmonic acid (JA). A database search of the Physcomitrella patens genome revealed the presence of an AOC gene unique from the two previously reported AOC genes, PpAOC1 and PpAOC2. After cloning the identified AOC gene, designated PpAOC3, the obtained cDNA sequence (897 bp) was larger than the predicted AOC gene (765 bp) in the database because a speculated intron was not fully deleted. Although PpAOC3 did not display high similarity
with AOC proteins from other species, recombinant PpAOC3 exhibited AOC activity and translocated to chloroplasts, as is observed
for other AOC proteins. Notably, the expression profile of PpAOC3 differed from the other PpAOCs, as its expression in protonemata was higher than that in gametophores. Although the function of oxylipins such as OPDA
and JA remains elusive in P. patens, further characterization of the enzymes in the octadecanoid pathway and the role of oxylipin will aid in the elucidation
of physiological processes in this model bryophyte. 相似文献
20.
Silencing of OPR3 in tomato reveals the role of OPDA in callose deposition during the activation of defense responses against Botrytis cinerea 下载免费PDF全文
Loredana Scalschi Maite Sanmartín Gemma Camañes Pilar Troncho José J. Sánchez‐Serrano Pilar García‐Agustín Begonya Vicedo 《The Plant journal : for cell and molecular biology》2015,81(2):304-315
Cis‐(+)‐12‐oxo‐phytodienoic acid (OPDA) is likely to play signaling roles in plant defense that do not depend on its further conversion to the phytohormone jasmonic acid. To elucidate the role of OPDA in Solanum lycopersicum (tomato) plant defense, we have silenced the 12‐oxophytodienoate reductase 3 (OPR3) gene. Two independent transgenic tomato lines (SiOPR3‐1 and SiOPR3‐2) showed significantly reduced OPR3 expression upon infection with the necrotrophic pathogen Botrytis cinerea. Moreover, SiOPR3 plants are more susceptible to this pathogen, and this susceptibility is accompanied by a significant decrease in OPDA levels and by the production of JA‐Ile being almost abolished. OPR3 silencing also leads to a major reduction in the expression of other genes of the jasmonic acid (JA) synthesis and signaling pathways after infection. These results confirm that in tomato plants, as in Arabidopsis, OPR3 determines OPDA availability for JA biosynthesis. In addition, we show that an intact JA biosynthetic pathway is required for proper callose deposition, as its pathogen‐induced accumulation is reduced in SiOPR3 plants. Interestingly, OPDA, but not JA, treatment restored basal resistance to B. cinerea and induced callose deposition in SiOPR3‐1 and SiOPR3‐2 transgenic plants. These results provide clear evidence that OPDA by itself plays a major role in the basal defense of tomato plants against this necrotrophic pathogen. 相似文献