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1.
In this study we used the cuttings of Populus przewalskii Maximowicz as experimental material and sodium nitroprusside (SNP) as nitric oxide (NO) donor to determine the physiological
and biochemical responses to drought stress and the effect of NO on drought tolerance in woody plants. The results indicated
that drought stress not only significantly decreased biomass production, but also significantly increased hydrogen peroxide
content and caused oxidative stress to lipids and proteins assessed by the increase in malondialdehyde and total carbonyl
contents, respectively. The cuttings of P. przewalskii accumulated many amino acids for osmotic adjustment to lower water potential, and activated the antioxidant enzymes such
as superoxide dismutase, guaiacol peroxidase and ascorbate peroxidase to maintain the balance of generation and quenching
of reactive oxygen species. Moreover, exogenous SNP application significantly heightened the growth performance of P. przewalskii cuttings under drought treatment by promotion of proline accumulation and activation of antioxidant enzyme activities, while
under well-watered treatment the effect of SNP application was very little. 相似文献
2.
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
3.
Kunjupillai Vijayan Shyama Prasad Chakraborti Sezai Ercisli Partha Deb Ghosh 《Plant Growth Regulation》2008,56(1):61-69
Mulberry is an economically important tree, used for feeding the silkworm Bombyx mori L. Effect of different levels of NaCl on growth and development of mulberry has been studied using five mulberry genotypes
selected on the basis of their performance under in vitro salinity. The study while endorsing the efficacy of in vitro screening
of axillary buds of mulberry for salt tolerance, showed genotypic variability in its response to salinity. Salinity reduced
growth and development of all genotypes. However, the putative tolerant genotypes showed better performance than the putative
susceptible genotypes. Under low salinity (<0.5% NaCl) salt tolerant genotypes showed an increase in chlorophyll and protein
concentrations, while in susceptible genotypes both were reduced by 3–58% at 0.5% NaCl and 50–64% at 1.00% NaCl. Leaf thickness
increased by 16% at 1.00% NaCl in C776 and reduced by 1.0% in Mandalaya. The increase in chlorophyll concentration and leaf
thickness under high salinity can be considered as preliminary selection parameters for salt tolerance in mulberry. The study
confirmed the efficacy of in vitro method for screening of large number of genotypes for salt tolerance in mulberry. 相似文献
4.
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
5.
Maria Dolores Arias Padrò Andrea Frattarelli Alessandra Sgueglia Emiliano Condello Carmine Damiano Emilia Caboni 《Plant Cell, Tissue and Organ Culture》2012,108(1):167-172
Shoot apices of in vitro-grown plantlets of white mulberry, Morus alba L. cv Florio, were cryopreserved using either encapsulation-dehydration or vitrification. For encapsulation-dehydration,
alginate beads containing apices were dehydrated for 1, 3, 5 or 7 days in a liquid medium containing various sucrose concentrations
(0.5, 0.75, 1.0 or 1.25 M). Bead desiccation was performed using silica gel for either 0, 4, 6, 8, 9 or 14 h. For vitrification,
apices were directly immersed for either 5, 15, 30 or 60 min in a vitrification solution (PVS2). Following encapsulation-dehydration,
treatment of alginate beads with 0.75 M sucrose was more effective in promoting re-growth of explants after immersion in liquid
nitrogen than in the presence of 0.5 M sucrose for either 1 or 3 days. Re-growth of explants was also observed following vitrification
and this reached 47% with increasing duration of the PVS2 treatment from 5 to 30 min. Overall, the highest frequency of explant
re-growth was obtained when explants were subjected to encapsulation-dehydration in the presence of 0.75 M along with a 3 day
sucrose dehydration pre-treatment and followed by desiccation for 9 h in silica gel. 相似文献
6.
Seasonal changes of antioxidant activity, total phenolic and anthocyanin constituent of Morus nigra L. and Morus alba L. stems were investigated. Stems tissues of these species exhibited different antioxidant activity. Antioxidant action as
well as anthocyanin constituents of these species reached the highest value in October whereas the lowest in February. Also,
total phenolic constituents showed the similar pattern.
An erratum to this article is available at . 相似文献
7.
Mokhtar Guerfel Alexandros Beis Tasos Zotos Dalenda Boujnah Mokhtar Zarrouk Angelos Patakas 《Acta Physiologiae Plantarum》2009,31(4):825-831
Differences in abscisic acid (ABA) accumulation between two olive cultivars were studied by enzyme-linked immunosorbent assay
in roots and leaves, leaf water potential (Ψl), stomatal conductance (g
s) as well as photosynthetic rate (A) were also determined in well-watered (WW) and water-stressed (WS) plants of two olive
cultivars ‘Chemlali’ and ‘Chetoui’. ‘Chemlali’ was able to maintain higher leaf CO2 assimilation rate and leaf stomatal conductance throughout the drought cycle when compared with ‘Chetoui’. Furthermore, leaf
water potential of ‘Chemlali’ decreased in lower extent than in Chetoui in response to water deficit. Interestingly, significant
differences in water-stress-induced ABA accumulation were observed between the two olive cultivars and reflect the degree
of stress experienced. Chemlali, a drought tolerant cultivar, accumulated lower levels of ABA in their leaves to regulate
stomatal control in response to water stress compared to the drought sensitive olive cultivar ‘Chetoui’ which accumulated
ABA in large amount. 相似文献
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In vitro responses of embryogenic sugarcane (Saccharum officinarum L.; cv. CoC-671) calli stressed with different levels of NaCl (0.0, 42.8, 85.6, 128.3, 171.1, 213.9 or 256.7 mM) were studied.
The results showed that a significant decrease in callus growth and cell viability occurred with ≥85.6 mM NaCl. Higher amounts
of free proline and glycine betaine were accumulated in NaCl-stressed calli. Although the leached and retained Na+ contents increased, the retained K+ content decreased with increasing levels of NaCl. Such a mechanism implies that sugarcane can be considered as a Na+-excluder. The accumulation of salt ions and osmolytes could play an important role in osmotic adjustment in sugarcane cells
under salt stress. 相似文献
11.
Anirban Guha Debashree Sengupta Girish Kumar Rasineni Attipalli Ramachandra Reddy 《Trees - Structure and Function》2012,26(3):903-918
The present study investigated drought-induced responses of non-enzymatic antioxidants in four diverse mulberry genotypes (Morus indica L. S-36, M-5, MR-2 and V-1). Inside the glasshouse, potted plants were subjected to four water regimes for 75 days: (a) control: pots maintained at 100% pot water holding capacity (PC) (b) low water stress: 75% PC (c) medium water stress: 50% PC and (d) high water stress: 25% PC. Photosynthetic leaf gas exchange and non-enzymatic antioxidants including α-tocopherol, ascorbic acid (AA), glutathione, proline and total carotenoids were measured in leaves at regular intervals. Amongst all, V-1 was relatively drought tolerant and showed exceeded accumulation of α-tocopherol and AA-glutathione pool in association with higher carotenoids and proline contents. Susceptible S-36, M-5 and MR-2 could not induce any significant up-regulation in AA-glutathione pool leading to endogenous loss of α-tocopherol and more lipid peroxidation. Reactive oxygen species (ROS) like hydrogen peroxide (H2O2) and superoxide (O2 · ?) showed apparent accumulation in water-stressed leaves and significantly contributed to lipid peroxidation in susceptible genotypes when compared to V-1. Our study demonstrated that proline, AA and glutathione were the major non-enzymatic antioxidants in mulberry with α-tocopherol and carotenoids as good additional indicators for drought stress tolerance. These non-enzymatic antioxidants can cumulatively render effective protection against oxidative damage and can be considered as reliable markers for screening drought-tolerant mulberry genotypes. 相似文献
12.
Phytohormone abscisic acid (ABA) regulates many aspects of plant development and growth. To explore the molecular mechanism
of ABA, we identified the novel ABA-regulated genes in Arabidopsis thaliana by searching for genes possessing two or more ABREs (ABA-responsive elements). One of these genes, two or more ABREs-containing gene 2 (TMAC2) is highly induced by ABA and NaCl. Database searches revealed that TMAC2 encodes a protein with no domains of known function. Expression of TMAC2-GFP fusion protein in Arabidopsis mesophyll protoplasts indicated that TMAC2 is targeted to the nucleus. Although the gene has a basal level of expression
in various Arabidopsis organs/tissues except for adult leaves, a high expression level was detected in roots. Constitutive overexpression of TMAC2 in plants resulted in the insensitivity to ABA and NaCl, suggesting that TMAC2 plays a negative role in ABA and salt stress responses. Furthermore, TMAC2-overexpressing plants exhibited the short roots, late flowering and starch-excess phenotypes. RT-PCR analysis showed that
decreased expression of two floral- and one starch degradation-related genes, SOC1/AGL20 and SEP3/AGL9, and SEX1, respectively, may lead to altered phenotypes of TMAC2-overexpressing plants. Taken together, our data reveal that TMAC2 acts in the nucleus and is an important negative regulator
of ABA and salt stress responses, and could play a critical role in controlling root elongation, floral initiation and starch
degradation.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users. 相似文献
13.
Jianming Gao Qiang Xiao Liping Ding Mingjie Chen Liang Yin Jinzhi Li Shiyi Zhou Guangyuan He 《Plant Growth Regulation》2008,56(1):89-95
To evaluate oxidative stress and the plant antioxidant system of Alternanthera philoxeroides [Mart.] Griseb and Oryza sativa L. in the response to drought, root and leaf tissues of drought-treated A. philoxeroides and O. sativa were collected and relative water content, stomatal conductance, the concentrations of malondialdehyde, proline and the activities
of superoxide dismutase, peroxidases, catalase and total antioxidative activity investigated. The results showed that drought
treatment had almost no effect on relative water content in A. philoxeroides but reduced relative water content in O. sativa.
A. philoxeroides maintained a greater stomatal conductance than O. sativa under drought stress. In A. philoxeroides levels of lipid peroxidation were lower than in O. sativa and did not change during the experiment. After exposure to drought, concentrations of proline and activities of superoxide
dismutase, peroxidases and catalase in A. philoxeroides were between 10% and 30% higher than in O. sativa, whereas total antioxidative activity in A. philoxeroides was several-fold higher than in O. sativa. 相似文献
14.
Vanildo?Silveira Tiago?S.?Balbuena Claudete?Santa-Catarina Eny?I.S.?Floh Miguel?P.?Guerra Walter?Handro
Amino acids, polyamines, 3-indoleacetic acid (IAA), abscisic acid (ABA), buffer-soluble protein and starch contents and dry matter accumulation were analyzed in megagametophytes containing developing embryos during seed development in Pinus taeda. The highest total amino acids and polyamine contents occurred at the cotyledonary stage, followed by a significant decrease in the mature seed. Free polyamines exhibited higher levels than conjugated ones, with putrescine being the predominant type until the cotyledonary stage, and spermidine at the mature seed stage. IAA content increased continually from the globular stage reaching the maximum at the cotyledonary stage, followed by a decrease in the mature seed. The highest ABA level occurred at the globular stage, followed by a continuous reduction until stabilization at the pre-cotyledonary stage. Buffer-soluble protein and starch contents, and dry matter increased progressively during development, reaching their maximum values at the mature stage. 相似文献
15.
Lanthanum ions antagonize calcium and are used as a Ca2+ channel blocker but their direct effects are unknown. We investigated lanthanum effects on endogenous abscisic acid (ABA)
levels in protoplasts and intact primary roots of Zea mays L. Application of 1 mM La3+ reduced primary root elongation, caused swelling of root tips, and essentially doubled the ABA content in intact roots but
decreased ABA in root protoplasts in a concentration-dependent manner. Osmotic stress increased ABA level in protoplasts more
than in intact roots. Temporal ABA changes in response to La3+ treatment indicate that La3+ affects root growth at least partially via ABA pathway. 相似文献
16.
An efficient in vitro screening method has been developed for mulberry (Morus spp. ) to screen salinity-tolerant genotypes from a large population. Axillary buds from field-grown plants were cultured on MS medium containing five different concentrations (0.0%, 0.25%, 0.5%, 0.75% and 1.00%) of sodium chloride (NaCl) in order to study the shoot growth pattern. Rooting was also tested at four different concentrations of NaCl (0.0%, 0.1%, 0.2% and 0.3.%). NaCl has been found to inhibit the growth and development of mulberry shoots and roots in vitro. The survivability of the axillary buds of the genotypes tested was reduced from 83.7% for the controls to 6.1% in 1.0% NaCl. The average number of roots developed by the genotypes ranged from 11.9 (controls) to 0.2 (0.3% NaCl). Out of the 63 genotypes tested, only seven—Rotundiloba, English black, Kolitha-3, Berhampore-A, Kajli, BC259 and C776—developed roots in 0.3% NaCl. Root growth was also reduced drastically from 1.8 cm for the controls to 0.1 cm in 0.3% NaCl. To test the reproducibility of the results in soil, five tolerant and two susceptible genotypes, identified in this in vitro study, were selected and tested under ex vitro conditions. The significant correlation coefficients obtained between the performances of these genotypes under both types of cultural conditions revealed that in vitro screening of mulberry through axillary bud culture is an easy and efficient method to identify salt-adapted genotypes within a limited space and time period.Abbreviations BA 6-Benzylaminopurine - dS m-1 Deci-Siemens per meter - EC Electric conductivity - NAA -Naphthaleneacetic acidCommunicated by G.C. Phillips 相似文献
17.
Bafana A Devi SS Krishnamurthi K Chakrabarti T 《Applied microbiology and biotechnology》2007,76(5):1145-1152
This study was designed to isolate and characterize endophytic bacteria from sunflower (Helianthus annuus) grown under irrigation and water stress (drought) conditions, to analyze growth of isolated bacteria under drought condition,
and to evaluate the ability of bacteria isolated from plants cultivated under drought to produce jasmonates (JAs) and abscisic
acid (ABA). Bacteria were isolated from soil samples collected when sunflower plants were at the end of the vegetative stage.
A total of 29 endophytic strains were isolated from plants grown under irrigation or drought condition. Eight strains (termed
SF1 through SF8) were selected based on nitrogen-fixing ability. All eight strains showed positive catalase and oxidase activities;
five strains (SF2, SF3, SF4, SF5, SF7) solubilized phosphates; none of the strains produced siderophores. Strains SF2, SF3,
SF4, and SF5, the ones with the highest phosphate solubilization ability, strongly inhibited growth of the pathogenic fungi
Verticillum orense and Sclerotinia sclerotiorum but had less inhibitory effect on Alternaria sp. Among the eight strains, SF2 showed 99.9% sequence homology with Achromobacter xiloxidans or Alcaligenes sp., while the other seven showed 99.9% homology with Bacillus pumilus. Strains SF2, SF3, and SF4 grown in control medium produced jasmonic acid (JA), 12-oxo-phytodienoic acid (OPDA), and ABA.
These three strains did not differ in amount of JA or OPDA produced. ABA content was higher than that of JA, and production
of both ABA and JA increased under drought condition. The characteristics of these isolated bacterial strains have technological
implications for inoculant formulation and improved growth of sunflower crops. 相似文献
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We investigated the effects of exogenous glycinebetaine (GB) and drought stress (DS) on grain yield (GY) and production of
dry matter (DM) and osmolytes in two maize (Zea mays L.) cultivars i.e. Shaandan 9 (S9) and Shaandan 911 (S911) during the entire growing period. Drought stress substantially reduced DM and GY but increased free proline, endogenous
GB, soluble sugar and K+ concentrations in leaves of both cultivars. The DM production, GY, drought index (DI) and concentrations of these osmolytes
were greater for S9 than those for S911 under DS. The significant differences in these parameters suggested that S9 was more drought-tolerant as compared to S911. Additionally, foliar application of GB increased the concentrations of all osmolytes measured, DM and GY of both cultivars
under DS. These positive responses of exogenous GB spray were more pronounced in S911 as compared to those in S9. Further correlation analysis involving a number of parameters indicated that maize production was tighterly correlated with
accumulation of the osmolytes measured during DS rather than well-watered controls. Accordingly, this study demonstrated the
notion of an anti-drought role of exogenous GB by osmoregulation under DS, particularly in this drought sensitive cultivar.
Thus, exogenous GB application might be firstly used with drought sensitive species/cultivars when exposed to DS. 相似文献