Showing papers by "Sowbiya Muneer published in 2018"

Tracing the role of plant proteins in the response to metal toxicity: a comprehensive review.

Abstract: Plants are sessile in nature, but are capable to evade from high level concentration of heavy metals like Cd, Hg, Cu, through various metabolic pathways Some of the pathways regulate normal metabolism in plants, whereas others are required for for their survival under metal toxicity Different plant proteins act as transporters to transfer metal from one organelle to the other and further eliminate it out from the plants Initially, exposure of heavy metals/metalloids to plants lead to over expression of proteins which in turn stimulate other stress-related genes Further, they activate signalling mechanism like MAPK cascade, Cd-Calmodulin signalling pathway, and oxidation signalling pathway that lead to generation of ROS (reactive oxygen species) Once these ROS (highly unstable) are formed, they generate free radicals which react with macromolecules like proteins and DNA This has negative impact on plant growth and leads to ageing and, eventually, cell death The uncontrolled, destructive processes damage plants physiologically and ultimately lead to oxidative stress Activation of antioxidant enzymes like SOD (superoxide dismutase) and CAT (catalase) allows plants to cope under oxidative stress conditions Among plant proteins, some of the antioxidant enzymes like glutathione, and APX (ascorbate peroxidase) play defensive roles against abiotic stress in plants Chaperones help in protein folding to maintain protein stability under stress conditions With this background, the present review gives a brief account of the functions, localization and expression pattern of plant proteins against metal/metalloid toxicity Moreover, the aim of this review is also to summarize the cutting edge research of plant protein and metal interfaces and their future prospects

Red and Blue Light Emitting Diodes (LEDs) Participate in Mitigation of Hyperhydricity in In Vitro-Grown Carnation Genotypes (Dianthus Caryophyllus)

Abstract: The present study was to determine the factors that can reduce hyperhydricity in in vitro-propagated carnation genotypes. The carnation genotypes (Green Beauty, Purple Beauty, and Inca Magic) were grown in vitro under normal and hyperhydric conditions in white fluorescent light (FL) in which half of the hyperhydric plants were grown in red and blue LEDs (light emitting diodes). It was observed that hyperhydricity leads to oxidative stress in terms of TBARS (thiobarbituric acid reactive substances) content, whereas stress was alleviated by R (red) and B (blue) LEDs. The multiprotein complex proteins such as ATPase (RCI + LHC1) PSII-core dimer, PSII-monomer/ATPs synthase, and PSII-monomer/cyt b6f had decreased levels in hyperhydric conditions grown in white FL; however, the expression level of these photosynthetic proteins was retained in hyperhydric plants grown in R and B LEDs. Moreover, the immunoblots of two photosynthetic proteins (PsaA and PsbA) and stress-responsive proteins such as superoxide dismutase, ascorbate peroxidase, and catalase showed recovery of hyperhydricity in carnation genotypes grown in R and B LEDs. Our present study signifies that red (R) and blue light (B) LEDs reduced the hyperhydricity to control levels by maintaining the composition of thylakoid proteins and antioxidative defense mechanisms in carnation genotypes.

Foliar or subirrigational silicon supply modulates salt stress in strawberry during vegetative propagation

Abstract: Availability of silicon (Si) to the plant as a silicic acid could be a limiting factor for crop productivity. Although the effect of Si has been shown to vary by plant species, Si has been shown to improve photosynthesis, and to remediate nutrient imbalances and abiotic stresses in plants. Plants of two Korean strawberry cultivars ‘Seolhyang’ and ‘Maehyang’ at a propagation stage was grown for 58 days with a complete nutrient solution (EC of 0.8 dS m−1) and also with supplementation of either 0, 35, or 70 mg L−1 Si from either potassium silicate (K2SiO3), sodium silicate (Na2SiO3), or calcium silicate (CaSiO3). The Si in solution was supplied to the roots through subirrigational nutrient solution or to the leaves by daily foliar applications. The growth and development of the plants were assessed after this period. Then the plants were subjected to one of different salt stress conditions (EC of either 0.0, 0.8, 1.6, or 2.4 dS m−1) for 14 days. The high EC (2.4 dS m−1) resulted in oxidative stress in the form of H2O2 and O 2 −1 in the leaves of the Si-non-treated plants as compared to Si-treated plants, and no or less stress was observed in the 0.0, and 0.8 or 1.6 dS m−1, respectively. However, Si, especially supplied from K2SiO3, relieved the stress level. Interestingly, the isozyme activities of three important antioxidant enzymes, superoxide dismutase, catalase and guaiacol peroxidase, were abundantly increased in the Si-treated plants, particularly with K2SiO3, even under the high EC (2.4 dS m−1) treatment and decreased in the Si-non-treated plants. The observed responses to Si supply in high salt-stressed plants indicate that Si, particularly supplied from K2SiO3, has a significant role in limiting the negative effects of salt stress by maintaining antioxidative enzymes during the vegetative propagation.

Proteomic Analysis of Aphid-Resistant and -Sensitive Rose (Rosa Hybrida) Cultivars at Two Developmental Stages.

Abstract: The rose is one the most commercially grown and costly ornamental plants because of its aesthetic beauty and aroma. A large number of pests attack its buds, flowers, leaves, and stem at every growing stage due to its high sugar content. The most common pest on roses are aphids which are considered to be the major cause for product loss. Aphid infestations lead to major changes in rose plants, such as large and irregular holes in petals, intact leaves and devouring tissues. It is hypothesized that different cut rose cultivars would have different levels of sensitivity or resistance to aphids, since different levels of infestation are observed in commercially cut rose production greenhouses. The present work compared four cut rose cultivars which were bred in Korea and were either resistant or sensitive to aphid infestation at different flower developmental stages. An integrative study was conducted using comprehensive proteome analyses. Proteins related to ubiquitin metabolism and the stress response were differentially expressed due to aphid infestation. The regulations and possible functions of identified proteins are presented in detail. The differential expressions of the identified proteins were validated by immunoblotting and blue native page. In addition, total sugar and carbohydrate content were also observed.

Hazardous gases (CO, NO x, CH 4 and C 3 H 8) released from CO 2 fertilizer unit lead to oxidative damage and degrades photosynthesis in strawberry plants

Abstract: CO2 boilers/direct heating systems used in greenhouses often lead to incomplete combustion, which results in the formation of hazardous gases, such as carbon monoxide (CO), nitroxide (NOX) and other hydrocarbons. In this study, strawberry plants that were grown on rockwool cubes were transferred to airtight bottles and treated with CO, NOX, CH4 and C3H8 gases for 1–48 hours. Oxidative damage due to hazardous gases was observed, as indicated by H2O2 and $${{\bf{O}}}_{{\bf{2}}}^{{\boldsymbol{-}}1}$$ determination. Photosynthetic pigments were reduced, and stomatal guard cells were damaged and remained closed compared to the control. The activity of other photosynthetic parameters was negatively related to hazardous gases. Reduction in the expression of multiprotein complexes was highly observed under hazardous gas treatments. This study highlighted that hazardous gases (CO, NOX, CH4 and C3H8) emitted due to incomplete combustion of CO2 fertilization units/or direct heating systems resulted in the formation of ROS in shoots and limited photosynthetic metabolism. We predicted that major steps must be incorporated to improve the efficiency of CO2 boiler/heating systems to decrease the emission of these hazardous gases and other hydrocarbons and to reduce the observed risks that are key to the reduction of crops.

Silicon application during vegetative propagation affects photosynthetic protein expression in strawberry

Abstract: We examined the effect of source, concentration, and application method of silicon (Si) on the growth, development, and photosynthetic capacity of Fragaria × ananassa ‘Maehyang’ and ‘Seolhyang’. We applied 0, 35, or 70 mg L−1 Si in a potassium silicate (K2SiO3), sodium silicate (Na2SiO3), or calcium silicate (CaSiO3) solution to plants via subirrigational supply or foliar application. Plant height of ‘Maehyang’ was highest with the 70 mg L−1 Si Na2SiO3 foliar application, but it was not significantly different among treatments in ‘Seolhyang’. Crown size was not significantly affected by source, concentration, or application method in both cultivars. Elemental concentrations in the shoot and root of ‘Maehyang’ were the highest in the 35 mg L−1 Si Na2SiO3 treatment for both application methods. Elemental concentrations in the shoot and root of ‘Seolhyang’ were the highest in the 70 mg L−1 Si K2SiO3 foliar application. Photosynthetic proteins abundantly increased in both cultivars with the 35 or 70 mg L−1 Si K2SiO3 treatment, for both application methods. Moreover, two important photosynthetic proteins, viz. PsaA and PsbA, were expressed and their expressions were higher with the 35 or 70 mg L−1 Si K2SiO3 treatment, for both application methods. These results suggested that 35 or 70 mg L−1 Si, supplied in the form of K2SiO3, promoted photosynthetic protein expressions the greatest, regardless of the application method, in both ‘Maehyang’ and ‘Seolhyang’.

Application of NIR-Spectroscopy to predict the harvesting maturity, fruit ripening and storage ability of Ca-chitosan treated baby kiwifruit

Abstract: In this study, near infrared (NIR) spectroscopy was performed to establish a non-destructive method to predict the harvesting maturity, fruit ripening and storage ability of Ca-chitosan treated baby kiwifruit. Destructive measurements of firmness, dry matter (DM), soluble solids content (SSC), and acidity was performed. The calibration range investigated for dry matter content (DM) and SSC using NIR reflectance spectrums were observed at 729-975 nm wavelengths. NIR predictions of those quality factors were calculated using the modified partial least square regression method. The predicted R2 value for DM and SSC was 0.73, and the standard error deviation (SED) value was greater than 2. The correlation between the actual value and predicted model of DM were r = 0.74. The correlation between the predicted DM content and the actual SSC, using SSC model was r = 0.65. The correlation between the predicted value of SSC and the actual value of SSC (baby kiwifruits ripen with ethylene) was r = 0.48, which was lower than the actual SSC model. Further, Ca-chitosan pre-harvest treatment on baby kiwifruit showed considerable effects on baby kiwifruit quality. The actual DM content of untreated fruits was 21.4% and it was 22.3% in Ca-chitosan treated fruits. Also, the predicted DM content was significantly high in Ca-chitosan treated fruits (22.7%) compared to untreated fruits. NIR spectroscopy is an effective and efficient method to measure DM and SSC to determine the fruit harvest maturity hence, date of harvest and storability for quality baby kiwifruits from the marketing point of view. Key words: Ca-chitosan, firmness, harvest index, maturation, nondestructive measurement.

Slight vapor deficit accelerates graft union healing of tomato plug seedling

Abstract: The application of grafting in tomato production has substantially improved tomato quality and yields. It has been demonstrated that humidity plays an important role in the graft healing of seedlings. This study focuses on the optimum relative humidity (RH) conditions for scion and rootstock healing of grafted tomato (Solanum lycopersicum L.) seedlings. Two tomato cultivars, ‘Super Sunload’ and ‘Super Dotaerang’, grafted onto ‘B-Blocking’ rootstock were subjected to one of three RH regimens: 70–80, 80–90, or 90–100%. The results showed that the scions of both cultivars showed apparent wilting under the 70–80 and 80–90% RH treatments. On this basis, the 90–100% RH treatment was subdivided into 95–96, 97–98, and 99–100% RH treatments, which were then applied. Among these subdivided RH treatments, the fresh weights of the scions and rootstocks significantly increased in response to the treatments of 97–98 and 99–100% RH, and the graft union connection of both cultivars was also enhanced after two days of healing. Furthermore, lower levels of endogenous H2O2 and less activity of antioxidant enzymes were observed in both cultivars in response to treatment with 95–96 or 97–98% RH, which indicated that less oxidative stress occurred. Overall, it is suggested that 97–98% is the optimal RH level for the graft healing of tomato seedlings.