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Cadmium (Cd) is toxic to the ecosystem even at low concentrations. To mitigate Cd toxicity as well as to enhance plant growth, endophytes extracted from different sources have been effectively used. In the current study, the role of an endophytic bacterial strain Serratia sp. IU01, in alleviating Cd toxicity and promoting growth was evaluated in Brassica juncea in the hydroponic system. Cd stress significantly reduced the growth attributes (root/shoot length and biomass) of the host plant in comparison to control plants. A significant increase was observed in the shoot, root length and biomass of B. juncea plants inoculated with Serratia sp. IU01 (9.8 ± 0.28 cm, 12.16 ± 1.44 cm, 299.5 ± 39.5 mg, respectively) compared to control (8.6 ± 0.28 cm, 7.16 ± 0.76 cm, 125.27 ± 5.40 mg, respectively), sole Cd-treated (5.5± 0.5 cm, 4.33± 1.15 cm, 103.73 ± 7.18 mg, respectively), and inoculated Cd-treated plants (5.67± 0.58 cm, 6± 1.53 cm, 137.33 ± 6.66 mg, respectively). Growth parameters were retrieved in inoculated plants under Cd stress but the differences were non-significant in comparison to the un-inoculated Cd-treated plants. High-performance liquid chromatography (HPLC) analysis revealed significantly elevated steady-state levels of one of the most abundant versatile antioxidant molecules in the cell i.e., glutathione (GSH) in response to Cd stress. However, under Cd stress, inoculation of the plants with Serratia sp. IU01 led to a significant decrease in roots' GSH contents (75 ± 15.56 pmol mg-1 FW) compared with the un-inoculated Cd-treated (141 ± 7.2 pmol mg-1 FW) and control set of plants (123.6 ± 1.2 pmol mg-1 FW) presumably via the release of antioxidants by the endophytes in the roots of internal tissues of the host plant. These results demonstrated the potential of Serratia sp. IU01 in mitigating Cd-induced toxicity and promoting plant growth in Cdpolluted environments. [ABSTRACT FROM AUTHOR]

Among the toxic heavy metal(loid)s, cadmium (Cd) and arsenic (As) have devastating effects on crop productivity and human health. In plants, mechanisms of detoxification of Cd and As proceed via a glutathione (GSH) dependent common pathway, despite their different modes of toxicity. In this context, the present study aimed to investigate how the common detoxification mechanisms for Cd and As influence the physiological and biochemical responses of seedlings of an important plant used for phytoremediation purposes, Brassica juncea, under Cd and As stress.We demonstrated that Cd and As trigger mostly distinct, but partly overlapping, responses in B. juncea. Exposure of B. juncea seedlings to 100 µM Cd stress for 12 days in a hydroponic system led to a significant reduction in the growth of roots and shoots, and in total chlorophyll content. However, As stress caused a decline in root length only. High-performance liquid chromatography analyses revealed a significant increase in cysteine levels in roots and shoots in response to As stress compared with control and Cd-treated plants. Concomitant elevated sulfur content in response to As stress was observed in roots and shoots. In terms of GSH content, Cd and As triggered similar responses, with a significant decrease in GSH in roots, and non-significant changes in shoots, compared with untreated plants. Inductively coupled plasma-atomic emission spectroscopy revealed that under Cd stress, plants preferentially accumulated zinc (Zn) in the roots compared with iron (Fe) and manganese (Mn). Responses in roots under As and Cd stress were similar with respect to Fe accumulation but opposite in terms of Zn and Mn accumulation. Our data provide valuable insights for design of future strategies for sustainable plant growth on As and Cd polluted soils. [ABSTRACT FROM AUTHOR]

Serine acetyltransferase (SAT) (EC 2.3.1.30) is the rate-limiting enzyme of cysteine (Cys) biosynthesis, providing the decisive precursor for the ubiquitous defense thiol glutathione (GSH). Together with O -acetylserine (thiol) lyase (OAS-TL; EC 2.5.1.47) SAT generates Cys in the cytosol, plastids, and mitochondria of vascular plants. The current study aimed to overproduce Cys and GSH for enhanced stress tolerance via overexpression of the feedback-insensitive isoform of serine acetyltransferase from tobacco, i.e., NtSAT4. Constitutive overexpression of NtSAT4 in Brassica napus resulted in the 2.6-fold–4-fold higher SAT activity in different subcellular compartment-specific lines. This higher SAT activity led to a 2.5-fold–3.5-fold higher steady-state level of free Cys and 2.2-fold–5.3-fold elevated level of GSH in leaves compared with nontransformed plants. Among the compartment-specific lines, the mitochondrial targeted NtSAT4 overexpressor line M-182 showed the highest levels of Cys (3.5-fold) and GSH (5.3-fold) compared with wild-type plants. Overexpression of NtSAT4 conferred a physiological advantage in terms of enhanced tolerance against oxidative stress with hydrogen peroxide and the heavy metal cadmium (Cd). The NtSAT4 overexpressor lines showed a significantly higher amount of iron (Fe) translocation from roots to shoots compared with nontransformed plants. Overall, these results suggest that overexpression of NtSAT4 is a promising approach to creating plants with tolerance to heavy metals and oxidative stress and, in addition, may potentially improve plant nutrition in terms of enhanced Fe translocation from roots to shoots. • NtSAT4 overexpression elevates Cys and GSH levels in subcellular compartment-specific manner. • The mitochondrial targeted overexpression of NtSAT4 produces the highest levels of Cys and GSH. • The engineered transgenic lines show enhanced stress tolerance against heavy metals and oxidative stress. • Elevated Cys and GSH in the transgenic lines results in enhanced Fe translocation from roots to shoots. [ABSTRACT FROM AUTHOR]

Present study was conducted in the Institute of Biotechnology and Genetic Engineering (IBGE), Faculty of Crop Production, University of Agriculture, Peshawar, Pakistan during 2013 to find out the response of different mutants (cad 2-1 and sir 1-1) of Arabidopsis thaliana impaired in GSH biosynthesis under arsenic (As) stress. Results showed that reduced Glutathione level in cad2-1 and biosynthetic capacity of the sir1-1 mutants made these plants highly sensitive to As applied in the form of sodium arsenate at 100 μM and 200 μM concentrations. Ten days old seedlings of mutants when exposed to sodium arsenate for 14 days were severely affected compared to wild-type plants. This was shown in their growth phenotype, reduced root length, reduced biomass, reduced chlorophyll contents resulting in pale color of the leaves. The seedlings of cad2-1 mutant were found eventually bleached after 12 days when exposed to 200 μM concentration of sodium arsenate whereas the wild-type seedlings were found viable and greenish under the same conditions. Experiments on direct germination showed that seeds of cad2-1 mutant were unable to germinate in the presence of 100 μM and 200 μM concentrations of sodium arsenate unlike wild-type and sir1-1. These results showed that relative anthocyanin contents were accumulated approximately thirteen-fold in the cad2-1 mutant in 200 μM concentration of sodium arsenate which clearly suggest that optimal availability of GSH is critical for the survival of plants under As stress. [ABSTRACT FROM AUTHOR]

Selenium (Se) hyperaccumulation, the capacity of some species to concentrate Se to levels upwards of 0.1% of dry weight, is an intriguing phenomenon that is only partially understood. Questions that remain to be answered are: do hyperaccumulators have one or more Se-specific transporters? How are these regulated by Se and sulfur (S)? In this study, hyperaccumulator Stanleya pinnata was compared with related non-hyperaccumulator Brassica juncea with respect to S-dependent selenate uptake and translocation, as well as for the expression levels of three sulfate/selenate transporters (Sultr) and three ATP sulphurylases (APS). Selenium accumulation went down ~10-fold with increasing sulfate supply in B. juncea, while S. pinnata only had a 2-3-fold difference in Se uptake between the highest (5mM) and lowest sulfate (0mM) treatments. The Se/S ratio was generally higher in the hyperaccumulator than the non-hyperaccumulator, and while tissue Se/S ratio in B. juncea largely reflected the ratio in the growth medium, S. pinnata enriched itself up to 5-fold with Se relative to S. The transcript levels of Sultr1;2 and 2;1 and APS1, 2, and 4 were generally much higher in S. pinnata than B. juncea, and the species showed differential transcript responses to S and Se supply. These results indicate that S. pinnata has at least one transporter with significant selenate specificity over sulfate. Also, the hyperaccumulator has elevated expression levels of several sulfate/selenate transporters and APS enzymes, which likely contribute to the Se hyperaccumulation and hypertolerance phenotype. [ABSTRACT FROM AUTHOR]

Morphological and anatomical study of eight prevalent weed species belonging to seven different families present in maize fields of Mir Ali, North Waziristan Agency, Pakistan was conducted during August and September of 2009 and 2010. The study comprised of noxious weeds like, Alhagi maurorum, Amaranthus viridis, Conyza bonariensis, Digera arvensis, Lippia nodiflora, Oxalis corniculata, Polygonum barbatum and Portulaca oleracea at full vegetative growth stages. Permanent microscopic preparations were made to measure and analyze elements of the anatomy of stems and root (epidermis, cortex, collenchyma, central cylinder and diameter). It was concluded that, Alhagi maurorum equipped with elaborate vascular bundles both in root and stem clarified its adaptation in the severe rainfed climate of the area. Because of its significant seed dispersal, it is acclimatized throughout the area. Other weeds like Amaranthus viridis, Conyza bonariensis, Digera arvensis, Lippia nodiflora, Oxalis corniculata, Polygonum barbatum and Portula caoleracea having the peculiar characteristics of typical mesophyte are well adopted and can complete their life cycle along with the maize crop. Due to special morphological and anatomical features of majority of the species studied, the capacity of rapid absorption of water along with minerals from the soil are enough to compensate the rapid loss of water, and thus can be easily adopted along with the maize crop. [ABSTRACT FROM AUTHOR]

Growth potential of three indigenous landraces (Kulat brown, Kulat white, Mothi) and two improved varieties (NARC-II and Swat-84) of soybean planted under four dates from April to July during 2004 and 2005 growing season were compared. Relative growth rate (RGR) was determined at 1) early vegetative growth 2) bloom and 3) seed filling stages and seed yield. Differences in RGR due to planting dates, varieties and planting dates x varieties were significant at early vegetative and bloom stages. At seed filling stage, varieties and planting dates x varieties did not show variation in RGR. Maximum RGR at the early vegetative growth, bloom and seed filling stages was recorded for July (89mg g-1 day-1) May (58.8 mg g-1day-1) and April (8 mg g-1day-1) planted crops, respectively. Similarly maximum seed yield (1459 kg ha-1) was observed in April planted crop. The average RGR recorded for early vegetative growth, bloom and seed filling stages was 71.6, 40.1 and 4.8 mg g-1day-1 respectively. At early vegetative growth, maximum RGR (79.6 mg g-1day-1) was observed for Kulat brown. At bloom, maximum RGR (46.3 mg g-1day-1) was recorded for Kulat white. At seed filling no difference was observed in RGR among the varieties. The overall average RGR for the landraces (42.4 mg g-1day-1) was greater than the RGR of improved varieties (34.1 mg g-1day-1). Improved varieties produced maximum seed yield (1306 kg ha-1) as compared to landraces (1245 kg ha-1). [ABSTRACT FROM AUTHOR]

Brassica napus is one of the most important sources of vegetable oil in the world. Efficient and reproducible protocols were developed for Agrobacterium-mediated transformation of B. napus in the current study. Synthetic chitinase (NIC) gene encoding antimicrobial protein in plasmid pEKH was transformed to Abasyn-95 cultivar of B. napus to produce transgenic plants. The role of a number of factors such as different ratios of growth regulators, various concentrations of growth hormones and chemicals, which can directly or indirectly influence the process of transformation, was evaluated. Hypocotyls and cotyledons from in vitro grown seedlings were used as explants for transformation. Culturing of the explants on solidified MS plates supplemented with different hormone ratios and concentrations showed that the media supplemented with 2 mg L-1 2, 4-dichlorophenoxyacetic acid (2, 4-D), 0.5 mg L-1benzylaminopurine (BAP) and 0.1 mg L-1naphthaleneacetic acid (NAA) is the best combination among all tested conditions for callus induction. Maximum shooting was observed on MS medium containing 0.5 mg L-1 BAP and 2 mg L-1 2, 4-D. The transgenic nature of the calli and regenerated shoots was confirmed by PCR analysis viaNIC gene specific primers using their isolated genomic DNA as template. [ABSTRACT FROM AUTHOR]

Selenium (Se)-fortified broccoli ( Brassica oleracea var. italica) has been proposed as a functional food for cancer prevention, based on its high glucosinolate (GSL) content and capacity for Se accumulation. However, as selenate and sulphate share the initial assimilation route, Se fertilization could interfere with sulphur metabolism and plant growth. Consequently, GSL accumulation could be compromised. To evaluate these potentially adverse effects of Se fertilization, we performed a comprehensive study on sand-grown young broccoli plants (weekly selenate applications of 0.8 µmol plant via the root) and field-grown adult broccoli plants during head formation (single foliar selenate application: 25.3 or 253 µmol plant). The results show that under these conditions, Se application does not affect plant growth, contents of cysteine, glutathione, total GSL, glucoraphanin (major aliphatic GSL) or the expression of BoMYB28 (encoding a functionally confirmed master regulator for aliphatic GSL biosynthesis). Conversely, due to the changed expression of sulphate transporters ( BoSULTR1;1, 1;2, 2;1, and 2;2), sulphate and total S contents increased in the shoot of young plants while decreasing in the root. We conclude that broccoli can be fertilized with Se without reduction in GSL content, even with Se accumulation exceeding the level recommended for human consumption. [ABSTRACT FROM AUTHOR]

Phytohormone abscisic acid (ABA) is the canonical trigger for stomatal closure upon abiotic stresses like drought. Soil-drying is known to facilitate root-to-shoot transport of sulfate. Remarkably, sulfate and sulfide—a downstream product of sulfate assimilation—have been independently shown to promote stomatal closure. For induction of stomatal closure, sulfate must be incorporated into cysteine, which triggers ABA biosynthesis by transcriptional activation of NCED3. Here, we apply reverse genetics to unravel if the canonical ABA signal transduction machinery is required for sulfate-induced stomata closure, and if cysteine biosynthesis is also mandatory for the induction of stomatal closure by the gasotransmitter sulfide. We provide genetic evidence for the importance of reactive oxygen species (ROS) production by the plasma membrane-localized NADPH oxidases, RBOHD, and RBOHF, during the sulfate-induced stomatal closure. In agreement with the established role of ROS as the second messenger of ABA-signaling, the SnRK2-type kinase OST1 and the protein phosphatase ABI1 are essential for sulfate-induced stomata closure. Finally, we show that sulfide fails to close stomata in a cysteine-biosynthesis depleted mutant. Our data support the hypothesis that the two mobile signals, sulfate and sulfide, induce stomatal closure by stimulating cysteine synthesis to trigger ABA production. [ABSTRACT FROM AUTHOR]

Genetic variations among eight Pakistani tomato (Solanum lycopersicum L.) accessions were investigated using morphological traits and randomly amplified polymorphic DNA (RAPD) primers. Significant differences among accessions were observed for most of the quantitative and qualitative morphological traits. The RAPD-PCR assay amplified a total of 39 different alleles with 33 polymorphic alleles resulting in an 84.25% rate of polymorphism among eight tomato accessions. The most informative primers were B06 and H05 by revealing the maximum number of bands in the germplasm. The dendrogram for the morphological traits classified the germplasm into a single larger cluster except for genotype 17880. The dendrogram constructed for the molecular data clearly segregated the germplasm into two clusters. The accessions 17862 and 17870 were placed in the small cluster while the rest of the accessions were grouped together in the larger cluster. Genetic similarity ranged from 0.31 to 0.83 with an average of 0.68 for all evaluated accessions. [ABSTRACT FROM AUTHOR]

Caprine mycoplasmosis is an important infectious respiratory complication lead to significant health issue and causes heavy economic losses in small ruminant population throughout the world. The study was designed to identify and characterize the pathogenic member of mycoplasma cluster the Mycoplasma capricolum sub specie capripneumoniae (Mccp) isolated from goat suffering from respiratory syndrome in the natural outbreak. The study was carried out during November, 2013 to April, 2015 in the Khyber Pakhtunkhwa (KPK), Pakistan. A total of 825 samples from nasal discharge, tracheal swab, pleural fluid and lung tissue were collected from goat clinically suspected for Contagious Caprine Pleuro Pneumonia (CCPP). The samples taken in PPLO transport media were cultured on modified Hay Flick media and incubated at 37° C with 5% CO2 for 7-12 days. Out of total 267 (32.36%) were positive for mycoplasma growth showing mass turbidity, whirling movement in culture broth and typical fried egg colonies in agar media. The positive culture was identified through biochemical assay and confirmed as Mccp through PCR by using cluster and specie specific primers. Out of 267 positive samples 55 (20.59%) were confirmed as Mycoplasma mycoides cluster and 23 (8.61%) were identified as Mccp. Sequencing of the 16-S rRNA gene blast search revealed 99% sequence homology with Mccp compared with eight available sequences at NCBI. The presence of Mccp was for the first time reported in small ruminants of Khyber Pakhtunkhwa. [ABSTRACT FROM AUTHOR]