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ABSTRACT: A sand culture experiment was conducted to investigate the rooting of stem cuttings and growth of Tamarix chinensis irrigated with various dilutions of saline soil solutions extract (0 to 32 g L -1) containing about 31.5% Na + . Rooting of stem cuttings was higher at lower salinity, inhibited greatly when salinity was higher than 12 g L -1 , but still 43% of stem cuttings rooted at 32 g L -1 salinity treatment. Sapling growth was stimulated at 4 to 8 g L -1 salinity level and inhibited significantly by higher than 12 g L -1 salinity treatment although growth continued at 32 g L -1 salinity. Na + content in roots, stems and leaves increased with increase in salinity, while Ca 2+ and K + content in leaves and stems decreased. The contents of Ca 2+ and K + in roots remained unaffected by various treatments. With increase in salinity Mg 2+ content increased in stems and leaves but decreased in roots. Proline contents of leaf, stem and root increased with increase in salinity which became more conspicuous at the salinity level of 12 g L -1 and above. Osmotic regulation was also formed an important mechanism for Tamarix chinensis while growing under salinity.
Pakistan Journal of Botany 01/2010; 42:4133-4142. · 0.84 Impact Factor
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ABSTRACT: Ethylene is invariably produced during seed germination but its role in regulating seed dormancy and germination is poorly understood. Seeds of 22 halophytic species having different life forms - salt secreting dicots, salt secreting monocots, stem succulents and leaf succulents were germinated in Petri dishes kept in a growth chamber set at 20/30 degrees C (night/day) temperature and a 12 hr light period. Sodium chloride and ethephon were added to the medium from the beginning of the experiment. Seed germination was recorded every other day for twenty days. Application of ethylene did not have any significant effect on releasing seeds from innate dormancy. However, it appeared to have a role in alleviation of salinity effects which varied from negative in certain species to almost complete alleviation of high salinity effects in others. Our data indicates that ethylene appears to have little role in breaking innate seed dormancy however, in most halophyte seeds studied, application of ethylene alleviate the salinity effect to various degrees. Halophyte seeds which could germinate under saline conditions approaching twice the salinity of seawater may offer clues to understand management of seed germination under highly saline conditions.
Comptes rendus biologies 09/2009; 332(9):806-15. · 1.71 Impact Factor
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Hideki Goda,
Eriko Sasaki,
Kenji Akiyama,
Akiko Maruyama-Nakashita,
Kazumi Nakabayashi, Weiqiang Li,
Mikihiro Ogawa,
Yukika Yamauchi,
Jeremy Preston,
Ko Aoki, [......],
Shinjiro Yamaguchi,
Eiji Nambara,
Yuji Kamiya,
Hideki Takahashi,
Masami Yokota Hirai,
Tetsuya Sakurai,
Kazuo Shinozaki,
Kazuki Saito,
Shigeo Yoshida,
Yukihisa Shimada
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ABSTRACT: We analyzed global gene expression in Arabidopsis in response to various hormones and in related experiments as part of the AtGenExpress project. The experimental agents included seven basic phytohormones (auxin, cytokinin, gibberellin, brassinosteroid, abscisic acid, jasmonate and ethylene) and their inhibitors. In addition, gene expression was investigated in hormone-related mutants and during seed germination and sulfate starvation. Hormone-inducible genes were identified from the hormone response data. The effects of each hormone and the relevance of the gene lists were verified by comparing expression profiles for the hormone treatments and related experiments using Pearson’s correlation coefficient. This approach was also used to analyze the relationships among expression profiles for hormone responses and those included in the AtGenExpress stress-response data set. The expected correlations were observed, indicating that this approach is useful to monitor the hormonal status in the stress-related samples. Global interactions among hormones-inducible genes were analyzed in a pairwise fashion, and several known and novel hormone interactions were detected. Genome-wide transcriptional gene-to-gene correlations, analyzed by hierarchical cluster analysis (HCA), indicated that our data set is useful for identification of clusters of co-expressed genes, and to predict the functions of unknown genes, even if a gene’s function is not directly related to the experiments included in AtGenExpress. Our data are available online from AtGenExpressJapan; the results of genome-wide HCA are available from PRIMe. The data set presented here will be a versatile resource for future hormone studies, and constitutes a reference for genome-wide gene expression in Arabidopsis.
The Plant Journal 05/2008; 55(3):526 - 542. · 6.16 Impact Factor
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Hideki Goda,
Eriko Sasaki,
Kenji Akiyama,
Akiko Maruyama-Nakashita,
Kazumi Nakabayashi, Weiqiang Li,
Mikihiro Ogawa,
Yukika Yamauchi,
Jeremy Preston,
Ko Aoki, [......],
Shinjiro Yamaguchi,
Eiji Nambara,
Yuji Kamiya,
Hideki Takahashi,
Masami Yokota Hirai,
Tetsuya Sakurai,
Kazuo Shinozaki,
Kazuki Saito,
Shigeo Yoshida,
Yukihisa Shimada
[show abstract]
[hide abstract]
ABSTRACT: We analyzed global gene expression in Arabidopsis in response to various hormones and in related experiments as part of the AtGenExpress project. The experimental agents included seven basic phytohormones (auxin, cytokinin, gibberellin, brassinosteroid, abscisic acid, jasmonate and ethylene) and their inhibitors. In addition, gene expression was investigated in hormone-related mutants and during seed germination and sulfate starvation. Hormone-inducible genes were identified from the hormone response data. The effects of each hormone and the relevance of the gene lists were verified by comparing expression profiles for the hormone treatments and related experiments using Pearson's correlation coefficient. This approach was also used to analyze the relationships among expression profiles for hormone responses and those included in the AtGenExpress stress-response data set. The expected correlations were observed, indicating that this approach is useful to monitor the hormonal status in the stress-related samples. Global interactions among hormones-inducible genes were analyzed in a pairwise fashion, and several known and novel hormone interactions were detected. Genome-wide transcriptional gene-to-gene correlations, analyzed by hierarchical cluster analysis (HCA), indicated that our data set is useful for identification of clusters of co-expressed genes, and to predict the functions of unknown genes, even if a gene's function is not directly related to the experiments included in AtGenExpress. Our data are available online from AtGenExpressJapan; the results of genome-wide HCA are available from PRIMe. The data set presented here will be a versatile resource for future hormone studies, and constitutes a reference for genome-wide gene expression in Arabidopsis.
The Plant Journal 05/2008; 55(3):526-42. · 6.16 Impact Factor
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ABSTRACT: A soil column experiment was conducted to study the water and salt redistribution in a coastal saline soil under infiltration of saline ice meltwater. Four salinity levels (0, 5000, 10,000, and 15,000 mg l-1 diluted seawater) and three volumes (1800, 2700, and 3600 ml) of source water were used. The results indicated that the soil water content increased with the volume of applied ice. In the top soil layers, water content was higher under salt-free ice treatment than under saline ice treatments. In the deeper soil layers, however, the saline ice treatments showed higher water content than the salt-free ice treatment. While infiltration of meltwater reduced the salt content of the surface layer of all the treatments, the desalting depths of the saline ice treatments were greater than the desalting depth of the salt-free ice treatment. The results demonstrated that in the monsoon regions, saline soils could be improved through infiltration with meltwater of saline ice.
Agricultural Water Management 01/2008; 95(4):498-502. · 2.00 Impact Factor
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ABSTRACT: Suaeda salsa (leaf succulence) and Limonium bicolor (secreting) are common halophytic species grown in coastal saline soil area in China. They possess different physiological
adaptations which help them to avoid salt stress. Their mechanism of salt tolerance is varied and not properly understood.
Therefore, the proposed plan to grow them in highly saline conditions could be hampered. The present study was designed to
study the effect of salinity on growth and various solute compositions. Growth of S. salsa showed a 94% and 48% increases in comparison to control in 50 and 100 mM NaCl respectively in both shoot and root while at
high salinity (400 mM NaCl) shoot and root dry weight were not significantly different from control. However, in L. bicolor root showed little promotion of shoot growth at 150 and 100 mM NaCl respectively and growth was substantially inhibited at
400 mM NaCl. Suaeda salsa accumulated more Na+ and Cl− ions in comparison to L. bicolor. These ions accumulated more in shoots of S. salsa whereas distributions of ions were similar in both shoots and roots of
L. bicolor. Shoot soluble sugar decreased and proline increased with increase of external salinities of both species but shoots of L. bicolor contained relatively higher amount of sugar and proline at high salinity levels.
05/2006: pages 135-143;
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ABSTRACT: Seed germination in annual halophytes usually occurs when soil salinity levels are low and soil moisture is relatively high
[1]. Optimum germination of halophyte seeds is often obtained under freshwater and inhibited by increasing salinity concentrations
[2–4], but the ability to germinate at higher salinities is varied with species, for example Salicornia herbacea germinated
at 1,700 mM NaCl [5], Arthrocnemum macrostachyum can germinate at 1,000 mM NaCl solution with 10% germination percentage [6]. Some secreting halophytes could also germinate above seawater salinity [7–11]. Most secreting halophytes show germination
at NaCl concentrations ranging from 0.34–0.52 M NaCl. Few of them have low salt tolerance during germination [12–14].
12/2005: pages 45-53;
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ABSTRACT: The study on the toxicity of heavy metals Hg2+, Cd+, Cu2+ and Pb2+ to Arabidopsis se d germination and seedling growth showed that the test heavy metals had a stronger toxicity on seedling growth than on seed germination. The toxicity on seedlings was in order of Cu2+ > Hg2+ > Cd2+ /Pb2+, while on seeds was Hg2+ > Cd2+ > Pb2+/Cu2+. Seed germination rate was decreased with increasing stress duration, and different heavy metals showed different toxicity at different stress duration. For example, Hg2+ displayed a stronger toxicity at 12 - 24 h stress, while Cd2+ was at 0 - 12 h stress. It seemed that seed coat played an important role in seed tolerance to heavy metals. The interaction between non-toxic ions and heavy metal ions on seed germination showed that Ca2+, Mg2+, K+ and Na+ at 5 mmol x L(-1) could enhance the toxicity of Hg2+, but did not affect Cd2+ toxicity. For seedling growth, Ca2+, Mg2+, K+ and Na+ might enhance the toxicity of Hg2+, Ca2+ might alleviate the toxicity of Cd2+ but enhance the toxicity of Cu2+ , and K+ might alleviate Pb2+ toxicity. The mechanism of heavy metals injury was discussed in the paper.
Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban 11/2005; 16(10):1943-7.
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ABSTRACT: Suaeda salsa, a leaf succulent shrub in the family Chenopodiaceae, is one of the most important halophytes in China. Suaeda salsa produces dimorphic seeds (soft brown seeds and hard black seeds). Seeds of S. salsa were collected from the coastal salt flats near Huanghua City, China. Experiments were conducted to determine the salinity-alleviating effect of plant growth regulators, nitric oxide, nitrate, nitrite and light on the germination of dimorphic seeds of S. salsa. Brown seeds had a higher germination rate than black seeds in all experiments. Black seeds were more sensitive to salt in the absence of light in comparison to brown seeds. Brown seeds absorbed water more quickly in comparison to black seeds and were found to be more tolerant of salt stress. Our results showed that 1-aminocyclopropane-1-carboxylate (ACC, the immediate precursor of ethylene), nitrite, GA(4) and BA improved seed germination in the presence of salt. However, nitrate, GA(1), GA(3) failed to alleviate salt stress. ABA inhibited seed germination and seedling growth. Possible mechanisms involved in the alleviation of salt stress in S. salsa seeds and the ecological adaptation of the seeds to the environment are discussed.
Journal of Plant Research 07/2005; 118(3):207-14. · 1.75 Impact Factor
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ABSTRACT: Seed is a developmental stage that is highly protective against external stresses in the plant life cycle. In this study, we analyzed toxicity of essential (Cu2+ and Zn2+) and non-essential heavy metals (Hg2+, Pb2+ and Cd2+) on seed germination and seedling growth in the model species Arabidopsis. Our results show that seedling growth is more sensitive to heavy metals (Hg2+, Pb2+, Cu2+ and Zn2+) in comparison to seed germination, while Cd2+ is the exception that inhibited both of these processes at similar concentrations. To examine if toxicity of heavy metals is altered developmentally during germination, we incubated seeds with Hg2+ or Cd2+ only for a restricted period during germination. Hg2+ displayed relatively strong toxicity at period II (12–24h after imbibition), while Cd2+ was more effective to inhibit germination at period I (0–12h after imbibition) rather than at period II. The observed differences are likely to be due in part to selective uptake of different ions by the intact seed, because isolated embryos (without seed coat and endosperm) are more sensitive to both Hg2+ and Cd2+ at period I. We assessed interactive toxicity between heavy metals and non-toxic cations, and found that Ca2+ was able to partially restore the inhibition of seedling growth by Pb2+ and Zn2+.
Plant Growth Regulation 04/2005; 46(1):45-50. · 1.60 Impact Factor
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ABSTRACT: Flixweed is one of the most abundant weeds in North America and China, and causes a reduction in crop yields. Dormancy of flixweed seeds is deep at maturity and is maintained in soil for several months. To identify regulators of seed dormancy and germination of flixweed, the effect of environmental and hormonal signals were examined using dormant and non-dormant seeds. The level of dormancy was decreased during after-ripening and stratification, but long imbibition (over 5days) at 4C in the dark resulted in the introduction of secondary dormancy. The strict requirement of duration of cold treatment for the break of dormancy may play a role in the seasonal regulation of germination. The germination of non-dormant flixweed seeds was critically regulated by red (R) and far-red (FR) light in a photoreversible manner. Sodium nitroprusside, a donor of nitric oxide (NO), promoted germination of half-dormant seeds, suggesting that NO reduced the level of seed dormancy. As has been shown in other related species, light elevated sensitivity to GA4 in dark-imbibied flixweed seeds, but cold treatment did not affect GA4-sensitivity unlike in Arabidopsis. Taken together, our results indicate that seed germination in flixweed and its close relative Arabidopsis is controlled by similar as well as distinct mechanisms in response to various endogenous and environmental signals.
Plant Growth Regulation 02/2005; 45(3):199-207. · 1.60 Impact Factor
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Communications in Soil Science and Plant Analysis 01/2004; Nos. 15 & 16(pp. 2111–2123):2111-2123. · 0.51 Impact Factor
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01/2003;
