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81.
The present study is the first attempt from any Indian wetland, where palynological data is assessed to understand the flooding histories of the Sakali and Duboi wetlands in the Majuli River Island, a part of the Indo-Burma hotspot. Palynological analyses of surface soil samples from these wetlands were carried out in order to explore the flooding histories of this island. The presence of extra-local taxa such as Rhododendron, Tsuga and Castanopsis, in the Sakali wetland is strongly suggestive of river water transportation and flooding on the Majuli Island in the recent past. In contrast, dominance of local arboreal taxa and low abundance or absence of extra-local pollen taxa in the Duboi wetland does not indicate flooding. Correspondence analysis (CA) was applied on the present dataset to reveal possible correlations between the surface samples of the wetlands and the major group of palynotaxa. The CA successfully discriminated the samples from the two wetlands and also marked strong correlations between flood indicators extra-local taxa with the samples of the Sakali wetland and local arboreal elements with the Duboi samples. The present result will not only provide a baseline for future palaeovegetation and palaeoclimate reconstructions, but will also help in deciphering palaeoflood episodes from these wetlands. 相似文献
82.
Kalpana Nautiyal Md Golam Kibria Yoko Akazawa-Ogawa Yoshihisa Hagihara Yutaka Kuroda 《Biochemical and biophysical research communications》2019,508(4):1043-1049
ScFv is emerging as a therapeutic alternative to the full-length monoclonal antibodies due to its small size and low production cost, but its low solubility remains a limiting factor toward wider use. Here, we increased the solubility of an Anti-epidermal growth factor receptor ScFv (Anti-EGFR ScFv) by attaching, a short 12-residue solubility enhancing peptide (SEP) tag at its C terminus. We first estimated the solubility increase by running 500-ns Brownian dynamics (BD) simulations. We then experimentally evaluated the predictions by producing recombinant Anti-EGFR ScFv with and without a SEP tag (called C9R) in E. coli. At 20?°C, ~85% of Anti-EGFR ScFv-C9R expressed in the soluble fraction, whereas all of the Anti-EGFR ScFv remained in the insoluble fraction. The total yield of Anti-EGFR ScFv-C9R was 17.15?mg which was ~3 times higher than that of Anti-EGFR ScFv refolded from the insoluble fraction. Static and dynamic light scattering demonstrated the higher solubility of the purified Anti-EGFR ScFv-C9R, and Circular Dichroism (CD) indicated its high thermal stability, whereas the untagged protein aggregated at 37?°C and pH 6. Finally, the binding activity of Anti-EGFR ScFv-C9R to EGFR was confirmed by surface plasmon resonance (SPR). Altogether, these results illustrate the improved biophysical and biochemical characteristics of Anti-EGFR ScFv-C9R and emphasize the potentials of SEP-tags for enhancing the solubility of aggregation-prone antibody fragments. 相似文献
83.
Vasvi Chaudhry Puneet S. ChauhanAradhana Mishra Ridhi GoelMehar H. Asif Shrikant S. MantriSumit K. Bag Sunil K. SinghSamir V. Sawant Chandra Shekhar Nautiyal 《Journal of biotechnology》2013
Paenibacillus lentimorbus NRRL B-30488, a plant growth-promoting bacterium was isolated from Sahiwal cow's milk. The strain shows antagonism against phytopathogens, Fusarium oxysporum f. sp. ciceri and Alternaria solani. Its genome contains gene clusters involved in nonribosomal synthesis of secondary metabolites involved in antimicrobial activities. The genome sequence of P. lentimorbus NRRL B-30488 provides the genetic basis for application of this bacterial strain in plant growth promotion, plant protection and degradation of organic pollutants. 相似文献
84.
A plant growth–promoting Paenibacillus lentimorbus NRRL B-30488 (B-30488) was isolated from cows’ milk. Bacterial colonization and growth responses of different plant species
after inoculation with B-30488 were evaluated in a controlled environment and in microplot assays. Survival and colonization
of B-30488 in the phytosphere of plants and soil was monitored using a chromosomally located rifampicin-marked mutant B-30488
(B-30488R). The strain showed variable ability to invade plants. The interaction between B-30488R and Fusarium oxysporum f. sp. ciceri was studied by scanning electron microscopy. Chitinase and β-1,3-glucanase enzymes were produced when B-30488R was grown
in the presence of colloidal chitin as sole carbon source. Deliberate dilution of B-30488R with field soil offers a reliable
process for decreasing the cost of bacterial inoculants in developing countries. Seed treatment of chickpea demonstrated significantly
(P = 0.05) greater seedling mortality in nonbacterized compared with bacterized seedlings. Bacterization significantly (P = 0.05) improved seed germination, plant height, number of pods/plant–1, and seed dry weight. 相似文献
85.
Aradhana Mishra Chandra Shekhar Nautiyal 《World journal of microbiology & biotechnology》2009,25(7):1175-1180
Present study describes chickpea (Cicer arietinum) growth, microbial activity and community composition in a soil samples spiked with 0, 20 (LCD) and 80 g (HCD) diesel/kg
soils, amended with Trichoderma ressei. T. ressei had stimulatory effect on the plant growth parameters as compared with un-inoculated control chickpea plant. Root length,
shoot length, plant dry weight and chlorophyll content enhanced 128, 31, 46, 79%, respectively, as compared over the un-inoculated
control. At LCD in the presence of T. ressei chickpea root length, shoot length, plant dry weight and chlorophyll content was maximum indicating that at this concentration
of diesel chickpea plants could grow very well and T. ressei amendment had synergistic effect. Effect on microbial population was most evident at HCD and resulted in 4.84 log unit reduction
of heterogeneous bacterial population, as compared with LCD which caused reduction of 2.8 log unit, compared with non-diesel
spiked control soil. Impact of diesel on soil was somewhat lessened in the presence of T. ressei. Our results indicated that application of diesel improved the organic matter status of soils which was in turn reflected
in the higher dehydrogenase activity. This could be due to diesel being a good source of hydrocarbon readily available for
microbial activity. The structure of the microbial community in rhizosphere was analyzed through the sole-carbon-source utilization
profiles using ECO Biolog microplates. Significant differences were found among the diversity and evenness indices on effect
of diesel on chickpea rhizosphere microflora in presence and absence of T. ressei, based on Tukey’s test (at P = 0.05). Principal component analysis of substrate source utilization pattern on Biolog Eco plates by chickpea rhizosphere
microflora in presence and absence of T. ressei was determined. Distinct resolution of soil microbial communities in the presence of either diesel or, T. ressei observed thus revealed differences in the microbial metabolic profiles for the different treatments. Our results demonstrated
that characteristics of the dynamics in microbial communities complemented well with organic matter status of soils and dehydrogenase
activity. The technique highlighted the usefulness of this parameter for ecological indication of land use change in diesel
contaminated ecosystems. 相似文献
86.
87.
High temperature is a common constraint during anthesis and grain-filling stages of wheat leading to huge losses in yield.
In order to understand the mechanism of heat tolerance during monocarpic senescence, the present study was carried out under
field conditions by allowing two well characterized Triticum aestivum L. cultivars differing in heat tolerance, Hindi62 (heat-tolerant) and PBW343 (heat-susceptible), to suffer maximum heat stress
under late sown conditions. Senescence was characterized by measuring photosynthesis related processes and endoproteolytic
activity during non-stress environment (NSE) as well as heat-stress environment (HSE). There was a faster rate of senescence
under HSE in both the genotypes. Hindi62, having pale yellow flag leaf with larger area, maintained cooler canopy under high
temperatures than PBW343. The tolerance for high temperature in Hindi62 was clearly evident in terms of slower green-leaf
area degradation, higher stomatal conductance, higher stability in maximum PSII efficiency, Rubisco activity and Rubisco content
than PBW343. Both the genotypes exhibited lower endopeptidase activity under HSE as compared to NSE and this difference was
more apparent in Hindi62. Serine proteases are the predominant proteases responsible for protein degradation under NSE as
well as HSE. Flag leaf of both the genotypes exhibited high-molecular-mass endoproteases (78 kDa and 67 kDa) isoforms up to
full grain maturity which were inhibited by specific serine protease inhibitor in both the environments. In conclusion, the
heat-tolerant Hindi62 exhibited a slower rate of senescence than the heat-susceptible PBW343 during HSE, which may contribute
towards heat stability. 相似文献
88.
Drought is a major environmental factor that limits chickpea production. An improvement in the adaption of crop to the fluctuating environmental conditions is therefore a major aim in chickpea breeding. However, the complexity of the trait has allowed only marginal progress. Our findings provide a solution to the current situation in the form of improved plant‐growth‐promoting effects caused by the biofilm formation of Paenibacillus lentimorbus B‐30488 (B‐30488) under water‐limiting conditions. In vitro assays demonstrating the biofilm‐forming ability of B‐30488 and the factors enhancing it were studied. Greenhouse experiments were conducted for validating the in vitro results and assessing the effect of seed coating supplements in alleviating drought stress effects in chickpea seedlings. The chickpea seed bacterisation with B‐30488 along with sodium alginate (1%) and CaCl2 (1 mM) caused an increase in germination percent and increased colony‐forming units (CFU) of B‐30488 in rhizosphere, resulting in amelioration of drought stress by positively influencing the dehydration‐induced physiological responses. The whole study reflects a prospective role of sodium alginate and CaCl2 in influencing the biofilm formation of B‐30488, and depicts the assistance of seed coating supplements in stress adaptation and protection of plants by alleviation of drought stress effects in chickpea without causing any major changes in the functional diversity of soil micro‐organisms. 相似文献
89.
Chandra Shekhar Nautiyal 《Current microbiology》1997,35(1):52-58
A procedure that consumes less screening time was developed for screening chickpea rhizosphere-competent bacteria for suppression
of the chickpea pathogenic fungi Fusarium oxysporum f. sp. ciceri, Rhizoctonia bataticola and Pythium sp. Of the 478 bacteria obtained by random selection of the predominant, morphologically distinct colonies, 386 strains that
effectively colonize chickpea roots could be divided broadly into three different groups. The first group consisted of 44
good chickpea rhizosphere colonizers with 107 to 108 colony-forming units (CFU)/g root; the second group consisted of 253 medium chickpea rhizosphere colonizers with 104 to 106 CFU/g root; and the third group consisted of 89 poor chickpea rhizosphere colonizers with 100 (nondetectable) to 103 CFU/g root. Forty-four Rifr strains from the first group of good chickpea rhizosphere colonizers were further screened for their in vitro biocontrol
activity against F. oxysporum f. sp. ciceri, R. bataticola, and Pythium sp. One bacterial strain was selected for further work because of its unique ability to inhibit all three fungi and its good
chickpea rhizosphere colonization ability. This is the first report of a single biocontrol bacterium active against three
most devastating pathogenic fungi of chickpea. In a greenhouse test, chickpea seed bacterization with P. fluorescens NBRI1303 increased the germination of seedlings by 25%, reduced the number of diseased plants by 45%, compared with nonbacterized
controls. Increases in seedling dry weight, shoot length, and root length ranged from 16% to 18%. Significant growth increases
in shoot length, dry weight, and grain yield, averaging 11.59%, 17.58%, and 22.61% respectively above untreated controls,
were attained in field trials in Agra and Jhansi. A rifampicin-resistant mutant P. fluorescens NBRI1303R of the P. fluorescens NBRI1303, used to monitor chickpea root colonization, confirmed the rapid and aggressive colonization by the bacterium, making
it a potential biocontrol agent against chickpea phytopathogenic fungi. The results, demonstrating an increase in the efficiency
of screening and detection of plant beneficial strains, should greatly benefit future studies.
Received: 23 December 1996 / Accepted: 28 January 1997 相似文献
90.
S. Nautiyal 《Biologia Plantarum》1984,26(3):230-234
During high altitude acclimatization the highest number of amino acids were found in temperateArtemisia species (A. vestita) and the lowest one in tropical species (A. scoparia). The amount of free amino acids in temperateArtemisia species was higher when this was grown at 3600 m altitude. InA. scoparia, A. vulnaris andA. parviflora, the higher amount of individual amino acids was ascertained in plants grown at lower altitudes.
InA. vestita, the nitrogen contents per unit dry matter was lower in plants grown at high altitude. In the other three species, the contents
were significantly higher in the leaves of plants grown at a higher altitude. The nitrogen contents per unit leaf dry matter
determined during active growth of plants were minimum inA. parviflora and maximum inA. vestita. With progressing plant senescence the concentration of nitrogen decreased in all species studied. 相似文献