Drought stress, being the inevitable factor that exists in various environments without recognizing borders and no clear warning thereby hampering plant biomass production, quality, and energy. It is the key important environmental stress that occurs due to temperature dynamics, light intensity, and low rainfall. Despite this, its cumulative, not obvious impact and multidimensional nature severely affects the plant morphological, physiological, biochemical and molecular attributes with adverse impact on photosynthetic capacity. Coping with water scarcity, plants evolve various complex resistance and adaptation mechanisms including physiological and biochemical responses, which differ with species level. The sophisticated adaptation mechanisms and regularity network that improves the water stress tolerance and adaptation in plants are briefly discussed. Growth pattern and structural dynamics, reduction in transpiration loss through altering stomatal conductance and distribution, leaf rolling, root to shoot ratio dynamics, root length increment, accumulation of compatible solutes, enhancement in transpiration efficiency, osmotic and hormonal regulation, and delayed senescence are the strategies that are adopted by plants under water deficit. Approaches for drought stress alleviations are breeding strategies, molecular and genomics perspectives with special emphasis on the omics technology alteration i.e., metabolomics, proteomics, genomics, transcriptomics, glyomics and phenomics that improve the stress tolerance in plants. For drought stress induction, seed priming, growth hormones, osmoprotectants, silicon (Si), selenium (Se) and potassium application are worth using under drought stress conditions in plants. In addition, drought adaptation through microbes, hydrogel, nanoparticles applications and metabolic engineering techniques that regulate the antioxidant enzymes activity for adaptation to drought stress in plants, enhancing plant tolerance through maintenance in cell homeostasis and ameliorates the adverse effects of water stress are of great potential in agriculture.

Drought Stress Impacts on Plants and Different Approaches to Alleviate Its Adverse Effects.

Approximately 1 billion ha of the global land surface is currently salt-affected, representing about 7% of the earth's land surface. Whereas most of it results from natural geochemical processes, an estimated 30% of irrigated lands globally are salt-affected through secondary human-induced salinization. Application of lower quality, alternative irrigation water is further threatening expansion of the areal extent of soil salinity, in addition to climate change causing increases of salt-water intrusion in coastal areas and increasing crop water requirements. The reduced availability of freshwater resources for irrigation, the continued reduction of the world's cultivated agricultural area by land degradation and urbanization, in conjunction with a growing world population further complicates the problem seeking sustainable solutions. This scoping review prioritizes critical knowledge gaps and makes recommendations for 10 priorities in soil salinity research toward a sustainable and productive agricultural system for a food-secure future world. We also include basin-specific case studies that illustrate progress of the world's major irrigated areas in addressing impacts of soil salinization. By identifying research priorities, we seek to accelerate enhanced research funding to bring new knowledge and innovative solutions toward mitigation of soil salinity impacts. We further want to inspire the science community to develop new directions in salinity research.

Critical knowledge gaps and research priorities in global soil salinity

In this paper, a framework for investigation on mobile phone and human head interaction are presented for L- and S-band applications. The proposed compact metamaterial design helps to reduce the Specific Absorption Rate (SAR) value that exposed to the human head. A recent achievement in metamaterial field allows this unusual material widely used in mobile phone applications to enhance the accomplishment and consequently received substantial attention among researchers. Hence, a multi-split square ring metamaterial design developed on a 1.6 mm thick dielectric substrate layer known as Epoxy Resin Fiber (FR-4). Electromagnetic properties of the proposed metamaterial structure were calculated through numerical simulation tool using the Finite Integration Technique (FIT) in Computer Simulation Technology Microwave Studio (CST). A few designs were used to conduct parametric studies with altering the substrate material, design structure, array arrangement and phone distance from the human head. 0.3–4 GHz frequency range was utilized in this simulation, where the proposed design established resonance frequencies precisely at 1.81 (L-band) and 3.79 GHz (S-band). The measured results show the resonance frequencies occurred at 1.82 and 3.72 GHz. Therefore, with a little bit discrepancy between the numerical and measurement results, it made the comparison was largely in agreement. The SAR value shows that a reduction by 36.87% and 45.54% at L- and S-band respectively for averaged over 1 g of tissue volume. While for averaged over 10 g of tissue volume, integrated metamaterial design in mobile phone reduced by 35.29% and 48.36% at L- and S-band respectively.

Specific absorption rate reduction of multi split square ring metamaterial for L- and S-band application

Quinoa (Chenopodium quinoa Willd.) is a halophytic crop that shows resistance to multiple abiotic stresses, including salinity. In this study we investigated the salinity tolerance mechanisms of six contrasting quinoa cultivars belonging to the coastal region of Chile using agro-physiological parameters (plant height (PH), number of branches/plant (BN), number of panicles/plant (PN), panicle length (PL), biochemical traits (leaf C%, leaf N%, grain protein contents); harvest index and yield (seed yield and plant dry biomass (PDM) under three salinity levels (0, 10, and 20 d Sm-1 NaCl). The yield stability was evaluated through comparision of seed yield characteristics [(static environmental variance (S2) and dynamic Wricke's ecovalence (W2)]. Results showed that significant variations existed in agro-morphological and yield attributes. With increasing salinity levels, yield contributing parameters (number of panicles and panicle length) decreased. Salt stress reduced the leaf carbon and nitrogen contents. Genotypes Q21, and AMES13761 showed higher seed yield (2.30 t ha-1), more productivity and stability at various salinities as compared to the other genotypes. Salinity reduced seed yield to 44.48% and 60% at lower (10 dS m-1) and higher salinity (20 dS m-1), respectively. Grain protein content was highest in NSL106398 and lowest in Q29 when treated with saline water. Seed yield was positively correlated with PH, TB, HI, and C%. Significant and negative correlations were observed between N%, protein contents and seed yield. PH showed significant positive correlation with APL, HI, C% and C:N ratio. HI displayed positive correlations with C%, N% and protein content., All measured plant traits, except for C:N ratio, responded to salt in a genotype-specific way. Our results indicate that the genotypes (Q21 and AMES13761) proved their suitability under sandy desert soils of Dubai, UAE as they exhibited higher seed yield while NSL106398 showed an higher seed protein content. The present research highlights the need to preserve quinoa biodiversity for a better seedling establishment, survival and stable yield in the sandy desertic UAE environment.

https://www.mdpi.com/2223-7747/9/12/1763/pdf

Agro-Morphological, Yield and Quality Traits and Interrelationship with Yield Stability in Quinoa (Chenopodium quinoa Willd.) Genotypes under Saline Marginal Environment.

Cultivating new crop cultivars with multiple abiotic stress tolerances is important for crop production. The abscisic acid-stress-ripening (ASR) protein has been shown to confer abiotic stress tolerance in plants. However, the mechanisms of ASR function under stress condition remain largely unclear. In this study, we characterized all ASR family members in common wheat and constitutively overexpressed TaASR1-D in a commercial hexaploid wheat cultivar Zhengmai 9023. The transgenic wheat plants exhibited increased tolerance to multiple abiotic stresses and increased grain yields under salt stress condition. Overexpression of TaASR1-D conferred enhanced antioxidant capacity and ABA sensitivity in transgenic wheat plants. Further, RNA in situ hybridization results showed that TaASR1-D had higher expression levels in the vascular tissues of leaves and the parenchyma cells around the vascular tissues of roots and stems. Yeast one-hybrid and electrophoretic mobility shift assays revealed that TaASR1-D could directly bind the specific cis-elements in the promoters of TaNCED1 and TaGPx1-D. In conclusion, our findings suggest that TaASR1-D can be used to breed new wheat cultivars with increased multiple abiotic stress tolerances, and TaASR1-D enhances abiotic stress tolerances by reinforcing antioxidant capacity and ABA signalling.

TaASR1-D confers abiotic stress resistance by affecting ROS accumulation and ABA signalling in transgenic wheat.

Productivity of food crops like wheat, a staple food of major portion of the world, is hampered due to salinity stress, thereby threatening food security. With the advancements in plant physiology and molecular biology based techniques, a number of structural and regulatory genes (transcription factors, miRNA, siRNA etc.) have been identified that contribute to inducing salinity tolerance responses. Location of these salt tolerant genes or genetic loci on specific chromosomes has also been partially characterized through QTL mapping. This information helps in efficient transfer of these genes into other crop cultivars through molecular breeding tools. Although plant salt tolerance mechanisms include osmotic adjustment, ion exclusion, ion inclusion, efficient antioxidant system, hormonal signaling etc., ion exclusion has long been recognized as central to salinity tolerance in wheat. Ion exclusion involves highly coordinated activity of a variety of channels, pumps and antiporters at parenchyma cells in root, stem and leaves associated with xylem. A number of molecular markers have been identified which are associated with ion exclusion or Na+ exclusion. However, some of them are associated with undesirable traits thereby producing lower crop productivity, e.g. Kna1. Thus, it is imperative to assess novel sources of ion exclusion with subsequent characterization before their introgression into other crop cultivars. In this review, recent advancements in identifying novel sources of ion exclusion in wheat have been discussed at length. In addition, up to what extent marker assisted breeding using these ion exclusion sources will help improve crop salt tolerance in wheat, thereby reducing global food security threat. An effective new paradigm is the targeted identification of specific genetic determinants of stress adaptation that have evolved in nature and their precise introgression into elite varieties.

Genetic basis of ion exclusion in salinity stressed wheat: implications in improving crop yield

This Paper is about the reduction of specific absorption rate (SAR) of wearable rectangular patch antenna for 1.8GHz and 2.45GHz wireless applications. Antenna is designated on a 3mm X 3mm X 3mm resolution truncated Hugo body model in Computer simulation technology software. The ramification reveals the specific absorption rate simulated value that were reduced by 89% compared to previously achieved SAR reduction of 83.5%. A reduction of power absorption was also noticed as the space of patch antenna increased. The SAR of Patch antennas are reduced from 0.0005 to 0.00041 SAR Avg (mW/g) at frequencies of 1.8GHZ & 2.45GHZ respectively resulting in a significant improvement in antenna performance. The improvement in directivity & gain has been observed and bandwidth of about 65% has achieved with Specific absorption rate reduction.

The Reduction of Specific Absorption Rate at Different Frequencies

Performance Analysis of Current Injection Techniques for Shunt Active Power Filter

Due to the intense competition, the study of dissatisfaction among costumers has become the focus point of many firms. Hence this study focuses on consumer complaining intention keeping. Telecommunication firms have been kept in focus and descriptive research was conducted. The results show that attitude towards complaining, perceived possibility of success, subjective norms, all show significant effect on complaining intention and keeping previous experience as a antecedent excluding subjective norms. The research can give a deep insight to telecommunication firms for managing dissatisfaction

/pdf/determinants-of-consumer-complaining-behavior-a-study-based-c0kswthgzy.pdf

Abdur Rehman

Papers

Genetic basis of ion exclusion in salinity stressed wheat: implications in improving crop yield

The Reduction of Specific Absorption Rate at Different Frequencies

Performance Analysis of Current Injection Techniques for Shunt Active Power Filter

Determinants of Consumer Complaining Behavior: A study based on telecommunication firms of Pakistan