TiO2 nanoparticle biosynthesis and its physiological effect on mung bean (Vigna radiata L.)

AbstractTiO2 nanoparticle (NPs) biosynthesis is a low cost, ecofriendly approach developed using the fungi Aspergillus flavus TFR 7. To determine whether TiO2 NPs is suitable for nutrient, we conducted a two part study; biosynthesis of TiO2 NP and evaluates their influence on mung bean. The characterized TiO2 NPs were foliar sprayed at 10mgL−1 concentration on the leaves of 14 days old mung bean plants. A significant improvement was observed in shoot length (17.02%), root length (49.6%), root area (43%), root nodule (67.5%), chlorophyll content (46.4%) and total soluble leaf protein (94%) as a result of TiO2 NPs application. In the rhizosphere microbial population increased by 21.4–48.1% and activity of acid phosphatase (67.3%), alkaline phosphatase (72%), phytase (64%) and dehydrogenase (108.7%) enzyme was observed over control in six weeks old plants owing to application of TiO2 NPs. A possible mechanism has also been hypothesized for TiO2 NPs biosynthesis

Not Available

Not AvailableA field study was undertaken to identify a potential biological indicator for arid soils. The study area covered five districts (111,681 km2) in which annual rainfall varied from 217 to 427 mm and soil texture ranged from sandy to clay loam. The surface 30 cm of arid soil from agricultural field sites differing in soil properties and cropping pattern were used in the study. Soil physicochemical, microbiological, and biochemical parameters (pH, EC, organic C, total N, available N, total P, mineral P, available P, phosphate solubilizing bacteria, arbuscular mycorrhizal fungi, nitrifying bacteria, microbial biomass, acid and alkaline phosphatase, phytase, dehydrogenase, and fluorescein diacetate (FDA) hydrolysable enzymes) were identified as indicators of soil quality. Ten of the 12 parameters studied exhibited significant correlation between FDA hydrolysable enzyme activity and the other enzyme activities (acid phosphatase, alkaline phosphatase, phytase, dehydrogenase). A strong linear regression (R2 = 0.61; p < 0.01) between the FDA hydrolysable enzyme activity and microbial biomass was observed. The results demonstrated that FDA hydrolysable enzyme activity is a potential biological indicator of arid soils and is a better indicator than dehydrogenase activity, already considered as a biological indicator.Not Availabl

Not Available

Not AvailableChlorophytum borivilianum, due to the presence of high valued industrially important steroidal saponins in its roots, has attracted pharmacological societies worldwide and motivated the farmers of arid and semi-arid zones to cultivate this medicinal herb on commercial scale. However, drought stress is a major abiotic constraint in the successful cultivation of this crop in these areas. One possible way to enhance its production is to improve its drought tolerance through arbuscular mycorrhizal symbiosis. The mechanism by which mycorrhizal symbiosis protects the plants against reactive oxygen species, induced by drought stress, is investigated by evaluating the activity of a set of antioxidant enzymes in relation to different mycorrhizal inocula at various growth stages. The influence of three mycorrhizal inocula viz., Glomus fasciculatum, G. intraradices and G. mosseae on superoxide dismutase, catalase, glutathione reductase, glutathione-s-transferase, polyphenol oxidase and peroxidase enzyme activities were evaluated in well-watered and drought stressed conditions. The result revealed that the entire mycorrhizal plant materials showed higher drought tolerance effect than non-mycorrhizal ones by enhancing antioxidant enzyme activities. Antioxidant activities were more at 180 days of crop harvest. Therefore, it is recommended to harvest C. borivilianum roots at 180 days crop age. Mycorrhizal drought-stressed roots showed significantly higher antioxidant activities than the well-watered conditions. Thus, it can be assumed that higher antioxidant activities in roots of mycorrhizal plants might have contributed to alleviate the oxidative damage to biomolecules. The cultivation of C. borivilianum with arbuscular mycorrhizae in aridzone, therefore, can be a value addition against drought stress.Not Availabl

Not Available

Not AvailableThe efficiency of phosphatases produced by clover, barley, oats and wheat was investigated in soils treated with sodium glycerophosphate, lecithin and phytin. Root exudates of aseptically grown clover were also examined for the breakdown of different organic P compounds in order to test the efficiency of plant-produced phosphatases. In general, the plants were able to use P from all the organic sources used in the study almost as efficiently as inorganic sources. Dry-matter yield, P uptake, acid and alkaline phosphatase activity and microbial population were increased in all the P treatments. Organic P enhanced alkaline phosphatase activity. Lecithin increased fungal, and phytin bacterial growth. There was no alkaline phosphatase activity in the asepticallly grown clover root exudates. Phosphatase released in aseptic culture after 4 weeks of clover growth was able to efficiently hydrolyse sodium glycerophosphate, lecithin and phytin. The amount of organic P hydrolysed in this and in the soil experiment surpassed plant uptake by a factor of 20. This suggests that the limiting factor on plant utilization of organic P is the availability of hydrolysable organic P sources.Not Availabl

Not Available

Not AvailableSeven most efficient phytase and phosphatases producing fungi were isolated from the soils of arid and semi-arid regions of India and tested for their efficiency on hydrolysis of two important organic P compounds: phytin and glycerophosphate. The native soil organic P may be exploited after using these organisms as seed inoculants, to help attain higher P nutrition of plants. The identified organisms belong to the three genera: Aspergillus, Emmericella and Penicillium. Penicillium rubrum released the most acid into the medium during growth. Aspergillus niger isolates were found to accumulate biomass the fastest. A significant negative correlation (r ¼ 20:593; n ¼ 21; p , 0.01) was observed between the development of fungal mat and pH of the media. The extracellular (E) phosphatases released by different fungi were less than their intracellular (I) counterpart, but the trend was reversed in case of phytase production. The E:I ratio of different fungi ranged from 0.39 to 0.86 for acid phosphatase, 0.29 to 0.41 for alkaline phosphatases and 9.4 to 19.9 for phytase. The efficiency of hydrolysis of different organic P compounds of different fungi varied from 2.12–4.85 mg min21 g21 for glycerophosphate to 0.92–2.10 mg min21 g21 for phytin. The trend of efficiency was as follows: Aspergillus sp. . Emmericella sp. . Penicillium sp. The results indicated that the identified fungi have enough potential to exploit native organic phosphorus to benefit plant nutrition

Not Available

Not AvailableThe plant and microbial contribution towards different plant beneficial enzyme activities (dehydrogenase, esterase, acid phosphatase, alkaline phosphatase, and phytase) was partitioned under four arid crops (pearl millet, clusterbean, mung bean, moth bean) at critical growth stage. The experiment was conducted at Aridisol under five different organic matter levels. The results showed phytase mainly contributed by the microorganisms especially under the soil having rich in organic matter. Acid phosphatase was contributed more by plants than microorganisms, while most of the alkaline phosphatase was contributed by microorganisms. The organic matter helped to improve in the root activity which influenced the esterase and dehydrogenase build up in the rhizosphere. Organic matter up to 4% level may influence dehydrogenase activity. It also enhanced esterase activity, which was more under pearl millet. There was little variation in alkaline phosphatase activity among the three legumes tested. In general, more alkaline phosphatase activity was noticed under pearl millet.Not Availabl

Not Available

Not AvailablePhosphorus is one of the major plant growth limiting nutrients although it is abundant in soils in both inorganic and organic forms. In soils the hydrolysis of organic P is predominantly mediated by the activity of phosphatases, such as acid and alkaline phosphatases and phytase released by plant roots and microorganisms. In order to evaluate the effect of Emericella rugulosa on soil enzyme activities and crop yield, an experiment was conducted under green house conditions and field (clusterbean as a test crop). A significantly higher enzyme activities and improvement in plant biomass, root length and P content was observed in sterilized soil mainly due to increased population of Emericella rugulosa. The test plants influenced acid phosphatase and phytase activity but resulted in no significant increase in alkaline phosphatase activity in the inoculated soil. The depletion of organic P was much higher than mineral and phytin P. The microbial contribution was significantly (p=0.05) higher than the plant contribution to the hydrolysis of the different P fractions. A significant (p=0.05) improvement in seed and straw yield and P concentration of seed and straw resulted from inoculation. The results suggested that Emericella rugulosa produces phosphatases and phytase, which mobilize P from native P sources and enhance the production of clusterbean in an arid soil.Not Availabl

Not Available

Book chapter in Microbes for Plant Stress Management, pp 105-118 © 2016, New India Publishing Agency, New Delhi, India (Editors: D.J. Bagyaraj and Jamaluddin)Microbiological synthesis of nanoparticles has emerged as rapidly developing research area in nanotechnology across the globe with various biological entities being employed in production of nanoparticles constantly forming an impute alternative for conventional methods. Simple prokaryotes to complex eukaryotic organisms including higher plants are used for the fabrication of nanoparticles. In the present article, the synthesis of important plant nutrients like Mg, Zn, Ag, Au, Ti, P and Fe nanoparticles from different fungal species, their characterization and application potential of nanonutrients in agriculture is elaborately discussed.Not Availabl