Sumira Jan

Current Perspectives on Plant Growth-Promoting Rhizobacteria

The rhizosphere of plant species is an inimitable ecosystem that harbors an extensive range of microbes. Research in the wide areas of rhizosphere biotechnology highlighting new bioinoculants has received ample attention during recent past, and suitable expertises have been developed. However, the global recognition of such technologies by farmers is still overwhelmed with doubts owing to limited shelf-life and efficiency of the products which demonstrate discrepancies. This review illustrates plant growth-promoting rhizobacteria with detailed emphasis on nutrient acquisition and potential roles in conferring tolerance against abiotic stresses. The review demonstrates the recent research in the field of genomic and proteomic analysis, where systematic characterization of potentially effective rhizobacteria is being carried out by screening the extensive bacterial gene pool based on modern molecular tools. The review concludes by emphasizing the efforts made in the proteomics field which could compensate for understanding of prompt evolution in microbe-derived and plant-derived protein and metabolite substitute that activates vulnerability or resistance.

Arbuscular mycorrhizal symbiosis and abiotic stress in plants: A review

Abiotic stresses (such as salinity, drought, cold, heat, mineral deficiency and metals/metalloids) have become major threats to the global agricultural production. These stresses in isolation and/or combination control plant growth, development and productivity by causing physiological disorders, ion toxicity, and hormonal and nutritional imbalances. Some soil microorganisms like arbuscular mycorhizal fungi (AMF) inhabit the rhizosphere and develop a symbiotic relationship with the roots of most plant species. AMF can significantly improve resistance of host plants to varied biotic and abiotic stresses. Taking into account recent literature, this paper: (a) overviews major abiotic stresses and introduces the arbuscular mycorrhizae symbiosis (b) appraises the role and underlying major mechanisms of AMF in plant tolerance to major abiotic stresses including salinity, drought, temperature regimes (cold and heat), nutrient-deficiency, and metal/metalloids; (c) discusses major molecular mechanisms potentially involved in AMF-mediated plant-abiotic stress tolerance; and finally (d) highlights major aspects for future work in the current direction.

Phytoremediation: A Green Technology

Phytoremediation is a lucrative plant-based advancement to remediation that takes lead in its knack to degrade environmental contaminants and to metabolize diverse pollutants. Heavy metals and organic pollutants are the central candidates for phytoremediation. To eliminate contaminants from soil, sediment, and/or water, plants can degrade organic pollutants or restrain and alleviate metal pollutants by substituting as filters or traps. Plants are exclusive organisms fitted with significant metabolic and absorption competence, plus transport systems that translocate nutrients or pollutants exclusively from the growth milieu, soil, or water. An in-depth perceptive of the physiological and molecular process of phytoremediation emerged as an efficient biological and engineering stratagem intended to optimize and enhance the prospective of phytoremediation process. Besides, various field experiments established the viability of using plants for cleaner environment. Metal-contaminated waters and soils are a main ecological crisis, and the majority of conventional remediation methods do not present adequate exposition. Utilization of genetically tailored plants is particularly selected for more efficient phytoremediation. In this chapter, we will illustrate numerous biological processes of heavy metal uptake, translocation, and resistance plus approaches for enhancing phytoremediation potential. Commercialization of bioremediation via genetically engineered microbes is contorted by debate over the expertise; transgenic plants may take center stage for environmental cleanup.

Approaches to Heavy Metal Tolerance in Plants

Phytoremediation is a lucrative plant-based advancement to remediation that takes lead in its knack to degrade environmental contaminants and to metabolize diverse pollutants. Heavy metals and organic pollutants are the central candidates for phytoremediation. To eliminate contaminants from soil, sediment, and/or water, plants can degrade organic pollutants or restrain and alleviate metal pollutants by substituting as fi lters or traps. Plants are exclusive organisms fi tted with signifi cant metabolic and absorption competence, plus transport systems that translocate nutrients or pollutants exclusively from the growth milieu, soil, or water. An in-depth perceptive of the physiological and molecular process of phytoremediation emerged as an effi cient biological and engineering stratagem intended to optimize and enhance the prospective of phytoremediation process. Besides, various fi eld

Differential response of terpenes and anthraquinones derivatives in Rumex dentatus and Lavandula officinalis to harsh winters across north-western Himalaya

Herbs adapted to diverse climates exhibit distinct variability to fluctuating temperatures and demonstrate various metabolic and physiological adaptations to harsh environments. In this research, Rumex dentatus L. and Lavandula officinalis L. were collected before snowfall in September–November to evaluate variability in major phytoconstituents to diverse seasonal regime. LC-MS was used for simultaneous determination of eight anthraquinone derivatives in R. dentatus, i.e. emodin, physcion, chrysophanol, physcion glucoside, endocrocin, emodin glucoside, chrysophanol glucoside and chromone derivatives and monoterpenes in L. officinalis i.e. (Z)-β-ocimene, (E)-β-ocimene, terpene alcohol, terpin-4-ol, acetate ester-linalyl acetate and bicyclic sesquiterpene (E)-caryophyllene. The correlation analysis confirmed significant variation in anthraquinone glucoside and terpene content within Rumex and Lavender, respectively, and altitude was established as the determinant factor in secondary metabolism of both herbs. The study concludes the propagation of herbs in bioclimatic belts which favour accumulation of major constituents and validate their greater pharmacological activity.

Variation in adaptation mechanisms of medicinal herbs to the extreme winter conditions across the North Western Himalaya

The North Western Himalaya region is characterized by extreme seasonal variability and local changes in microclimate. Plants adapted to this region demonstrate marked variability to the extreme winter conditions. This region, designated as a biodiversity hotspot, is rich in medicinal herbs, which exhibit diverse growth and adaptation mechanisms to the harsh environment. In the present study, physiological mechanisms of adaptation to the winter season conditions were compared in five medicinal herbs. Components of the photosynthetic machinery, and osmoregulation which are of importance for secondary metabolism is not well known in these alpine herbs and was studied. The medicinal herbs Rumex dentatus, Atropa accuminata, Lupinus polyphyllus, Hyoscyamus niger, and Lavandula officinalis were collected before snowfall in September–November to evaluate variability in metabolic and physiological responses to the varied seasonal regimes. Plants were followed over a period of 8 weeks (summer to early winter) in th...

Microclimatic variation in UV perception and related disparity in tropane and quinolizidine alkaloid composition of Atropa acuminata, Lupinus polyphyllus and Hyoscyamus niger.

The aim of current research was to evaluate the physiological adjustment in three medicinal herbs viz., Atropa acuminata, Lupinus polyphyllus and Hyoscyamus niger to the winter period characterised by intense UV flux in Kashmir valley across the North Western Himalaya. Quinolizidine (QA) and tropane alkaloid (TA) concentrations were analysed in these herbs thriving at two different altitudes via GC-MS and correlated by PCA analysis. This study investigated the hypothesis that UV reflectance and absorbance at low temperatures are directly related to disparity in alkaloid accumulation. Among QAs in L. polyphyllus, ammodendrine and lupanine accumulated at higher concentration and exhibited significant variation of 186.36% and 95.91% in ammodendrine and lupanine respectively in both sites. Tetrahydrohombifoline displayed non-significant variation of about 9.60% irrespective of sites. Among tropane alkaloid (TA), hyoscyamine was recorded as the most abundant constituent irrespective of the plant and site while apotropine accumulated in lesser quantity in A. acuminata than H. niger. However, apotropine demonstrated significant variation of 175% among both sites. The final concentration of quinolizidine (QA) and tropane alkaloid (TA) reflects the interplay between reflectance and absorbance of UV radiation response field. These findings suggest that spectral response of UV light contributes directly to alkaloid biosynthesis.

Effects of presowing gamma irradiation on the photosynthetic pigments, sugar content and carbon gain of Cullen corylifolium (L.) Medik.

To determine the effects of gamma radiation on the photosynthetic pigments, sugar content and total carbon gain, seeds of Cullen corylifolium (L.) Medik. were irradiated with variable doses (0, 2.5, 5, 10, 15, and 20 kGy) at the rate of 1.65 kGy h-1 from 60Co gamma source. Cullen corylifolium represents an important Chinese medicine with adequate levels of secondary metabolites, thus we hypothesized that gamma irradiation could modulate primary metabolites which could supplement secondary metabolite levels. The seeds were then transferred to field for biochemical analysis at different developmental stages; pre-flowering, flowering and post-flowering. Gamma dosage at 10 kGy resulted in a significant increase in concentration of chlorophyll a (61.17%), chlorophyll b (93.18%) and total chlorophyll (71.66%), suggesting that low doses of radiation could activate photosynthetic pigment system while at 15 and 20 kGy dose resulted in depletion of such parameters. Sugar and total C analysis of plants irradiated at 10 kGy demonstrated significantly maximum (216.01%) sugar content in leaves at all developmental stages and significantly minimum (46.13%) and (57.81%) in plants raised from seeds irradiated at 15 and 20 kGy respectively. Effective stimulatory dose for C. corylifolium ‘11062’ is 10 kGy. In contrast, the carotenoid content of the plants exposed to 15 and 20 kGy was maximum than control. Significance of such stimulation correlated with increasing C mass of the plant concerned is discussed in the light of newer aspects in research.

Feasibility of radiation technology for wastewater treatment

AbstractA wide range of remediation technologies have been employed for degradation of domestic, agricultural, industrial and municipal wastewater. Besides being economically attractive, each remediation technology has to be flexible enough to span a wide range of applications. Ionizing radiation is recognized valuable procedure for this rationale, as the radical initiated degradation can switch various pollutants into comparatively lesser disparaging substances. However, the lack of comparative data in studies using radiation technique is a main concern in further using up of this method for wastewater treatment. The main purpose of this review is to conclude the optimized radiation dose and procedures, in combination with other processes, to treat wastewater contaminated with low and high concentration of organic compounds. This review will highlight on studies carried out by various workers for exploiting ionizing and non-ionizing energies for the comparative competence in wastewater treatment.

Soil amendments of fly ash: effects on function and biochemical activity of Carthamus tinctorius L. plants

Proper disposal and recycling of different industrial waste materials have long been recognized as a prime environmental concern. The present study evaluated the effects of soil amendment of fly ash, a major industrial waste material, on soil properties, plant growth, productivity and metabolites production of safflower (Carthamus tinctorius L.). The soil was amended with varied concentrations of fly ash (0%, 5%, 10%, 25%, 50%, 75% per pot) prior to sowing under field conditions in the herbal garden of Jamia Hamdard. Sampling was conducted at different growth stages, i.e. pre-flowering, flowering and post-flowering. Our results demonstrate that fly ash concentrations up to 25% improved the physicochemical properties of the soil as compared to non-treated control resulting in increased availability to the plant of macro and micronutrients and thereby stimulating plant growth and productivity. Contents of photosynthetic pigments, sugars, protein, and nitrate reductase (NR) activity increased under 25% fly a...