Effects on physiological characteristics of Honeysuckle (Lonicera japonica Thunb) and the role of exogenous calcium under drought stress
Li Qiang, Cao Jianhua, Yu Longjiang, Li Maoteng, Liao Jinjing, Gan Lu
Lonicera japonica Thunb as the traditional Chinese herb is widely planted in southwestern China to harness rocky desertification due to its adaptability to the rock-desertificated environment. However, how the drought stress limits the Lonicera japonica Thunb’s physiological and photosynthetic characteristics is not clear. Therefore, a series of pot-cultivation experiments were dealt/performed with 30 mmol.L-1 and 15 mmol.L-1 of exogenous CaCl2 to investigate the chlorophyll content, soluble sugar content, proline content and the photosynthetic rate of Lonicera japonica Thunb under drought stress. Moreover, the possible roles of Ca in plant processes, are discussed. Under the drought stress, the content of chlorophyll, soluble sugar, proline, catalase enzyme activity and the photosynthetic characteristics in Lonicera japonica Thunb are changed by 1.5 mg.g-1, 0.11 mg.g-1, 13 mg.g-1, 0.5 u.mg-1 and 4.3 umol.m-2.s-1 respectively. The samples dealt with the additional/higher Ca2+ content during drought stress have a higher catalase enzyme activity and chlorophyll content because it can alleviate the cell membrane leakage and the chlorophyll decomposition. Moreover, proline content and soluble sugar content were found decreased/lower compared with the results without the additional Ca2+ in the soil.
Pages 1-5 | Full Text PDF
Improved shoot organogenesis of gloxinia (Sinningia speciosa) using silver nitrate and putrescine treatment
Eui-Ho Park, Hanhong Bae, Woo Tae Park, Yeon Bok Kim, Soo Cheon Chae and Sang Un Park
An improved method for shoot organogenesis and plant regeneration in Sinningia speciosa was established. Leaf explants were cultured on Murashige and Skoog (MS) medium supplemented with different combinations of benzylaminopurine (BAP) and naphthalene-acetic acid (NAA) for shoot induction. MS media including BAP (2 mg/L) and NAA (0.1 mg/L) resulted in the highest efficiency in shoot regeneration per explant (12.3 ± 0.8) and in the greatest shoot growth (1.2 ± 0.1 cm) after 6 weeks. For improving shoot induction, the ethylene inhibitor silver nitrate and the polyamine putrescine were added to the regeneration medium. The addition of silver nitrate (7 mg/L) increased the shoot number (23.9 ± 1.6) and length (1.7 ± 0.2 cm) after 6 weeks. Similarly, putrescine (50 mg/L) improved the shoot number (19.2 ± 1.6) and growth (1.7 ± 0.2 cm). The rooted plants were hardened and transferred to soil with a 90% survival rate. This method of producing S. speciosa regenerated plants could be used as a possible micropropagation and plant transformation protocol.
Pages 6-9 | Full Text PDF
Effects of organic additives and different carbohydrate sources on proliferation of protocorm-like bodies in Dendrobium Alya Pink
N. Nambiar, C.S. Tee, M. Maziah
The purpose of this study was to investigate the effect of the addition of different organic additives and sugar types as carbon source on the growth and proliferation of protocorm-like bodies (PLBs) of a very new Dendrobium hybrid known as D. Alya Pink (DAP). PLBs were supplemented with of homogenates of banana, tomato, and coconut water at various concentrations. Proliferation rate was recorded on a fresh weight basis. The effect of various types of local banana homogenate was also used to evaluate their efficiency in proliferating the PLBs. Six types of sugar were used to evaluate their effect on the growth of DAP PLBs. Results showed that banana and tomato homogenate was not effective for PLB proliferation DAP as control gave the highest fresh weight of 0.48 ± 0.02g. Coconut water was found to be the best organic additive for the proliferation of PLBs of DAP which showed a four-fold increase of fresh weight (0.59 ± 0.03g) compared to the initial weight of 0.15g in just four weeks. Highest growth was recorded in PLBs supplemented with glucose, fructose and sucrose with 0.94 ± 0.55 g, 9.1 ± 0.82 g and 6.51 ± 0.52 g of PLBs respectively. Galactose, mannitol and sorbitol were not suitable to promote the growth of PLBs. In this study, coconut water was selected to be the best organic additive and glucose as the suitable carbohydrate source for the proliferation of D. Alya Pink PLBs when compared to the other homogenates and sugar types.
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Genetic analysis of salt tolerance in vegetative stage in wheat (Triticum aestivum)
H. Dashti, M. R. Bihamta, H. Shirani and M.M. Majidi
Identification of genetic control of salt tolerance at the growth stage provides useful information for constructing breeding programs for wheat. Inheritance of salinity tolerance was studied in a cross between ‘Tabasi’ (P1) a tolerant and ‘Ghods’ (P2) a susceptible bread wheat (T. aestivum) cultivar, F1, F2 and backcross generations (BC1 and BC2) under saline conditions (EC=14 dS m-1) in a greenhouse. Eight characters were recorded: biological dry weight (DW), heading date (HD), plant height (PH), K+ concentration (K+), Na+ concentration (Na+), K+/Na+ ratios, total number of tillers per plant (NT) and ratio of fertile tillers per total tillers in each plant (RFT). Generation mean analysis of these traits revealed the involvement of additive and non-additive type gene effects in controlling most of the traits. The epistatic effects [i] for DW, Na+, K+/Na+ and PH, [j] for DW and PH, [l] for DW, Na+, K+/Na+, NT, PH and HD were significant. Additive [d] effects were significant for all measured traits and dominance [h] effects were significant for all except K+ and RFT. High narrow sense heritability (0.60) was estimated for K+/Na, indicating this may be used as a useful indicator index for the selection of salt tolerant genotypes at the vegetative growth stage in wheat. In consideration of demonstrable additive and non-additive effects in controlling measured traits, recurrent selection followed by pedigree breeding may prove useful in improving salinity tolerance in vegetative stage wheat.
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Influence of media and auxins on growth and falvone production in hairy root cultures of baikal skullcap, Scutellaria baicalensis
Young Seon Kim, Xiaohua Li, Woo Tae Park, Md Romij Uddin, Nam Il Park, Yeon Bok Kim, Mi Young Lee, Sang Un Park
The hairy root culture of Scutellaria baicalensis was studied using different media, strength of medium and addition of various concentrations of auxins to the culture media to optimize the growth and flavone production. Hairy roots grown in full-strength SH medium showed the highest levels of hairy root growth (0.32 g/30 mL). However, the levels of the flavones baicalin, baicalein, and wogonin were higher in the hairy root cultures using half-strength B5 than those of the other media used in this study. The growth rates of the hairy roots did not vary significantly between auxin treatments. However, the auxins were observed to increase flavone production in S. baicalensis hairy root culture. The auxin indole acetic acid (IAA) at 1 mg/L performed the best for the accumulation of baicalin and baicalein. Meanwhile, the highest levels of wogonin were observed for hair root cultures in the presence of indolebutyric acid at 1 mg/L, followed by IAA at 0.1 mg/L. These findings indicate that hairy root cultures of S. baicalensis using half-strength B5 media supplemented with auxin could be a valuable alternative approach for flavonoid production.
Pages 24-27 | Full Text PDF
Overexpressing Arabidopsis jasmonic acid carboxyl methyltransferase (AtJMT) results in stimulation of root growth and ginsenoside heterogeneity in Panax ginseng
Yun-Soo Kim, Jung-Yeon Han, Soon Lim, Hyun-Jung Kim, Mi-Hyun Lee, Yong-Eui Choi
Methyl jasmonate (MeJA) triggers the production of secondary metabolites in plants and participates in a diverse range of plant developmental processes. MeJA is derived from jasmonic acid (JA) via the octadecanoid pathway and the reaction is catalyzed by jasmonic acid carboxyl methyltransferase (JMT). In this study, transgenic Panax ginseng roots were constructed to express an Arabidopsis jasmonic acid carboxyl methyltransferase (AtJMT). The transgenic lines exhibited high expression of genes (PgSS1, PgSE1, and PgDDS) involved in ginsenoside biosynthetic pathways as well as a MeJA-responsive gene (PgPR10-2). These alterations of the gene expressions led to 3-fold increase in the growth of transgenic roots. Overexpression of AtJMT gene strongly affected the ginsenoside heterogeneity (protopanaxadiol/protopanaxatriol ratio) although total ginsenoside accumulation was slightly increased in transgenic roots. Protopanaxadiol group of ginsenosides (Rb1, Rc, and Rb2) increased about 2-fold in transgenic roots compared to those in wild-type. The results suggest that overexpression of AtJMT stimulate not only the growth of roots but also the production of protopanaxadiol-group in transgenic roots.
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Influence of salicylic acid on morphological and physiological responses of banana (Musa acuminata cv. ‘Berangan’, AAA) shoot tips to in vitro water stress induced by polyethylene glycol
Siamak Shirani Bidabadi, Maziah Mahmood, Bahram Baninasab, Cyrus Ghobadi
Growth and productivity of banana is seriously restricted by water deficit. Salicylic acid (SA) induces biotic and abiotic stress tolerance in crops. To study the ameliorative effects of SA on water stress in banana (Musa acuminata cv. ‘Berangan’, AAA), shoot tip explants with 8 mm in size were treated with varying SA concentrations (0, 1, 2 and 3 mM) and incubated on MS media containing different levels (0, 1, 2 and 3 %) of PEG in vitro. After 2 months, proliferation rate, fresh weight increase, relative water content, chlorophyll level, proline accumulation, malondialdehyde (MDA) and H2O2 contents were measured and analyzed. The results indicated that with increasing levels of PEG, proliferation rate, fresh weight increase, relative water content and chlorophyll concentrations were significantly decreased. The SA concentrations improved shoot tips performance by increasing proliferation rate, fresh weight increase and relative water content. Although non SA - treated shoot tips were not significantly responsive to increasing levels of PEG in terms of elevated proline content, they responded positively to supply of SA by showing significant increase in proline and chlorophyll contents under water stressed conditions. SA treatments also enhanced plant tolerance against oxidative stress. This was observed through significant reduction in H2O2 and MDA contents of SA - treated shoot tips under water stress conditions. The results revealed that exogenous application of SA helped to reduce the harmful effects of water deficit on banana regenerants in vitro.
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Immune regulation of avian influenza vaccine in hens using Hypericum perforatum L. methanol extraction
Wu Jiang, Ying Liu, Hong Zheng, Yueping Zheng, Hanglin Xu, Hongfei Lu*
Hypericum perforatum L. has been widely used for centuries as a medicinal herb. In present study, the effect of Hypericum perforatum extract (HPE) as a dietary supplement on humoral regulation to influenza vaccine in hens was investigated. Chicks were immunized with reassortant avian influenza (AI) virus H5 subtype vaccine, inactivated (H5N1, Re-5+Re-4 strain) administered intramuscularly on day 20 of age (primary vaccination) followed by a boosted 20 days after the first vaccination. Chicks received the basal soybean meal-corn diet supplemented with 0 (control), 250, 500, and 1,000 mg kg-1 HPE for 7 days starting on the day of each vaccination. Antibody concentration against AI was measured by enzyme-linked immunosorbent assay (ELISA) method and antibody titer within a few days of vaccination detected by hemagglutination inhibition (HI) test. Diet supplementation with HPE at 500 mg kg-1 was associated with increased antibody level to H5 subtype AI by 9.82% after the first vaccination and by 30.63% after the boost (P £ 0.05). Furthermore, HPE also increased Re-4 polyclonal H5 subtype AI antibody titer by 11.27% after first immunization and 27.40% after second immunization (P £ 0.05), respectively. While, Re-5 polyclonal H5 subtype AI antibody titer in 500 mg kg-1 HPE addition level of HPE were higher than control group after 1st vaccination and the 2nd vaccination, especially increased by 7.70% and 16.44% in antibody peaks (P £ 0.05), respectively. HPE administered as a dietary supplement in the peri-immunization period augmented the humoral immunity of hens to the influenza vaccine. These findings suggest that HPE may be useful in the poultry industry.
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Advances in metallotionein studies in forest trees
DU Jia, YANG Jing-Li, LI Cheng-Hao
Metallothioneins (MTs), which widely distributed in eukaryotic and prokaryotic organisms, are a class of cysteine-rich heavy metal-binding proteins with low molecular weights. Their biological functions differ among organisms and isoforms. Increasing environmental pollution due to industrialization have led to the accumulation of heavy metals in soils with consequent health risks to human. Forest tree MTs may be involved in plant metal tolerance and accumulation and as metal chelators scavenge reactive oxygen species (ROS). They are playing increasingly important roles in environmental cleanup. This paper review the classification, function, expression, and characteristics of forest tree MTs and the proposed directions for future research. Further studies will clarify the roles of forest tree MT genes in metal homeostasis and scavenging of ROS and assess the applicability of forest tree MTs to phytoremediation of contaminated soils.
Pages 46-51 | Full Text PDF
Salt tolerance enhance in indica rice (Oryza sativa L. spp. indica) seedlings using exogenous sucrose supplementation
Kongake Siringam, Niran Juntawong, Suriyan Cha-um, Thanapol Boriboonkaset, Chalermpol Kirdmanee
Salt-affected soil is an abiotic stress which is an acute problem, interrupting the metabolic processes of plants, resulting in reduced growth and productivity. The objective of this study was to enhance the salt tolerance ability of Pathumthani 1 (PT1) sensitive rice cultivars using exogenous sucrose. Fourteen-day-old seedlings of PT1, along with Homjan (HJ), salt-tolerant (positive control), were cultured in MS liquid medium supplemented with 0.0, 29.2, 58.4 or 116.8 mM sucrose, then exposed to 0.0 or 342.0 mM NaCl. An osmotic potential (Ys) in the leaf tissues of rice seedlings dropped significantly when subjected to 342 mM NaCl. Exogenous sugar application in the culture medium was directly absorbed and enriched in rice seedling, leading to soluble sugar accumulation and played a key role as osmoregulation of salt defense mechanism. The increase in Ys in the leaf tissues of salt stressed seedlings directly caused damage to the ultrastructure of chloroplstic organelles, as well as to photosynthetic pigments i.e. chlorophyll a, chlorophyll b and total chlorophyll. Chlorophyll content and chlorophyll fluorescence parameters were stabilised in salt-stressed rice seedlings pre-treated with 58.4 mM sucrose, resulting in enhanced growth performance. A positive correlation between photosynthetic pigment degradation and chlorophyll fluorescence diminution was demonstrated. Exogenous application of 58.4 mM sucrose to the culture medium may play a role as an alternative way to enhance salt tolerance in rice, especially in PT1, a salt-susceptible cultivar.
Pages 52-59 | Full Text PDF