EFFECT OF PHOSPHATE-SOLUBILIZING STRAINS OF AZOTOBACTER CHROOCOCCUM ON YIELD TRAITS AND THEIR SURVIVAL IN THE RHIZOSPHERE OF WHEAT GENOTYPES UNDER FIELD CONDITIONS

2001 ◽  
Vol 49 (2) ◽  
pp. 141-149 ◽  
Author(s):  
N. Narula ◽  
V. Kumar ◽  
R. K. Behl

A field experiment was carried out to investigate the establishment of phosphate-dissolving strains of Azotobacter chroococcum, including soil isolates (wild type) and their mutants, in the rhizosphere and their effect on the growth attributes and root biomass of three genetically divergent wheat cultivars (Triticum aestivum L.). Four fertilizer doses were applied: 90 kg N ha—1, 90 kg N + 60 kg P2O5ha—1, 120 kg N ha—1and 120 kg N + 60 kg P2O5ha—1, besides a control plot without fertilizers or bioinoculants. Phosphate-solubilizing and phytohormone-producing parent soil isolates and mutant strains of A. chroococcum were isolated and selected following the enrichment method. On an overall basis the mutant strains performed better than the soil isolates for in vitro phosphate solubilization (11–14%) and growth hormone production (11.35%). Seed inoculation of wheat varieties with phosphate-solubilizing and phytohormone-producing A. chroococcum showed a better response over the control. Mutant strains of A. chroococcum showed a higher increase in grain (15.30%) and straw (15.10%) yield over the control and better survival (12–14%) in the rhizosphere as compared to their parent soil isolate (P4). Mutant strain M15 performed better in all three varieties in terms of increase in grain yield (20.8%) and root biomass (20.6%) over the control.

2021 ◽  
Vol 12 ◽  
Author(s):  
Mahreen Yahya ◽  
Ejaz ul Islam ◽  
Maria Rasul ◽  
Iqra Farooq ◽  
Naima Mahreen ◽  
...  

Phosphorous (P) deficiency is a major challenge faced by global agriculture. Phosphate-solubilizing bacteria (PSB) provide a sustainable approach to supply available phosphates to plants with improved crop productivity through synergistic interaction with plant roots. The present study demonstrates an insight into this synergistic P-solubilizing mechanism of PSB isolated from rhizosphere soils of major wheat-growing agro-ecological zones of Pakistan. Seven isolates were the efficient P solubilizers based on in vitro P-solubilizing activity (233-365 μg ml–1) with a concomitant decrease in pH (up to 3.5) by the production of organic acids, predominantly acetic acid (∼182 μg ml–1) and gluconic acid (∼117 μg ml–1). Amplification and phylogenetic analysis of gcd, pqqE, and phy genes of Enterobacter sp. ZW32, Ochrobactrum sp. SSR, and Pantoea sp. S1 showed the potential of these PSB to release orthophosphate from recalcitrant forms of phosphorus. Principal component analysis indicates the inoculation response of PSB consortia on the differential composition of root exudation (amino acids, sugars, and organic acids) with subsequently modified root architecture of three wheat varieties grown hydroponically. Rhizoscanning showed a significant increase in root parameters, i.e., root tips, diameter, and surface area of PSB-inoculated plants as compared to uninoculated controls. Efficiency of PSB consortia was validated by significant increase in plant P and oxidative stress management under P-deficient conditions. Reactive oxygen species (ROS)-induced oxidative damages mainly indicated by elevated levels of malondialdehyde (MDA) and H2O2 contents were significantly reduced in inoculated plants by the production of antioxidant enzymes, i.e., superoxide dismutase, catalase, and peroxidase. Furthermore, the inoculation response of these PSB on respective wheat varieties grown in native soils under greenhouse conditions was positively correlated with improved plant growth and soil P contents. Additionally, grain yield (8%) and seed P (14%) were significantly increased in inoculated wheat plants with 20% reduced application of diammonium phosphate (DAP) fertilizer under net house conditions. Thus, PSB capable of such synergistic strategies can confer P biofortification in wheat by modulating root morphophysiology and root exudation and can alleviate oxidative stress under P deficit conditions.


2006 ◽  
Vol 33 (7) ◽  
pp. 685 ◽  
Author(s):  
Aravind K. Jukanti ◽  
Phil L. Bruckner ◽  
Andreas M. Fischer

Polyphenol oxidases (PPOs) have been implicated in plant defence reactions. From an applied point of view, high PPO activity is associated with browning / darkening of fresh and processed food. Owing to its complex genome and economic importance, wheat (Triticum aestivum L.) represents an interesting system to advance our understanding of plant PPO function. We have previously shown that wheat PPOs are organised in a multigene family, consisting of two distinct phylogenetic clusters with three members each. In this study, we demonstrate that members of one cluster are not expressed in developing kernels or senescing flag leaves. Transcriptional regulation of one major gene in the other cluster largely controls PPO levels in these tissues, at least in the wheat varieties used for this study. Our data further indicate that the product of this gene is present as a latent enzyme during early kernel development, and that the latent enzyme is activated during later developmental phases. Enzyme activation can be achieved in vitro by limited tryptic digestion, but our data do not indicate activation by a proteolytic mechanism in vivo. Together, results presented in this study provide important insights into the regulation of wheat PPO function.


2011 ◽  
Vol 79 (10) ◽  
pp. 4061-4067 ◽  
Author(s):  
Tanis C. Dingle ◽  
George L. Mulvey ◽  
Glen D. Armstrong

ABSTRACTAlthough toxins A and B are known to be important contributors to the acute phase ofClostridium difficileinfection, the role of colonization and adherence to host tissues in the overall pathogenesis of these organisms remains unclear. Consequently, we used the recently introduced intron-based ClosTron gene interruption system to eliminate the expression of two reportedC. difficilecolonization factors, the major flagellar structural subunit (FliC) and the flagellar cap protein (FliD), to gain greater insight into how flagella and motility contribute toC. difficile's pathogenic strategy. The results demonstrate that interrupting either thefliCor thefliDgene results in a complete loss of flagella, as well as motility, inC. difficile. However, both thefliCandfliDmutant strains adhered better than the wild-type 630Δerm strain to human intestine-derived Caco-2 cells, suggesting that flagella and motility do not contribute to, or may even interfere with,C. difficileadherence to epithelial cell surfacesin vitro. Moreover, we found that the mutant strains were more virulent in hamsters, indicating either that flagella are unnecessary for virulence or that repression of motility may be a pathogenic strategy employed byC. difficilein hamsters.


2017 ◽  
Vol 8 (2) ◽  
pp. 20 ◽  
Author(s):  
Supria Saha ◽  
Zohorul Islam ◽  
Sadequl Islam ◽  
Mirza Fida Hassan ◽  
Md. Shahadat Hossain ◽  
...  

A suitable plant regeneration system has been established using 3-4 weeks old calli derived from immature and mature seeds of four wheat varieties viz. Pavon 76, Akbar, Barkat, and Kanchan. As plant growth regulators, various auxins (2,4-D, BAP and IAA) either single or in combination were used in MS medium. The variety Pavon 76 showed maximum (72.25%) callus induction and Akbar exhibited the lowest (37.78%) from calli derived from immature seeds. Hormonal effects on callus induction were evaluated and significant results were found in case of genotypes at P <0.01. Out of four genotypes, the highest frequency of plant regeneration was recorded in Pavon 76 (67.00%) and lowest in Kanchan (43.10%) when 1.5 mg/l BAP and 0.5 mg/l IAA was added in the medium. It was observed that Pavon 76 produced highest number of green plants than others. For mature seeds all of the mentioned genotypes showed significant difference with maximum frequency of callusing in Pavon 76 (69.57%) in MS + 2.5 mg/l 2,4-D followed by Kanchan (60.84%), Barkat (52.73%), and Akbar (47.19%). For plant regeneration, Pavon 76 also showed best performance (64.36%) in MS + 2.0 BAP + 1.0 mg/l IAA, using calli derived from mature seeds. The other genotypes Barkat, Kanchan and Akbar exhibited 59.44, 52.71 and 52.32% regeneration in the same medium respectively. Here, the lowest regeneration (40.63%) was found in Akbar. In this case, it was aimed to establish a suitable protocol for in vitro callus induction and regeneration for advance biotechnological research on wheat in Bangladesh.


2018 ◽  
Vol 19 (1) ◽  
pp. 1-9
Author(s):  
Ali Ltifi ◽  
◽  
nissa Sahli ◽  
Wejden Brahmi ◽  
Insaf Nefzi ◽  
...  

This study focusedon wheat haploid production by anther culture. The main purpose wasto compare the in vitro androgenesis response often wheat Tunisian bread wheat varieties on two different induction media. The anthers were introduced in vitro when microspores were in the middle uninucleate stage and obtainedfrom treated spikes at 4° C for two weeks. The culture media 190-2 and BAC3 were used. Plants regenerated from induced embryos and calli were grown on the 190-2 medium without any growth regulators. The response to anther culture was different between the studied varieties. Androgenesis induction was better on the 190-2 medium than on BAC3 medium. In addition, the development of calli and the regeneration of embryos were better on 190-2 medium than on BAC3. Both green plantlets and albina were regenerated from induced embryos on the 190-2 medium, while no green plant regenerated from the embryos growingon BAC3 medium. Four varieties over ten studied gave good number of green plants. These results indicatedthat 190-2 medium was most favorable for the in vitro androgenesis of the Tunisian bread wheat varieties.


2018 ◽  
Vol 24 (2) ◽  
Author(s):  
J. D. BARSHILE

Present investigation was undertaken to standardize technique for in vitro micro-propagation of chickpea( Cicer arietinum ) cultivar Vishwas (Phule G 12). Micropropagation method for chickpea was established and this method enabled much more efficient propagation of plants. The present work was aimed at evolving a protocol for rapid multiplication of chickpea using micropropagation technique. Explants from shoot tip and node segment were cultured on MS medium supplemented with different concentrations of BAP and Kinetin (1.0 to 2.5 mg/l) and their growth responses like shooting were elucidated. The maximum multiple response was observed with 2 mg/l concentration of BAP from both types of explant. The highest number of shoots (12.5 ± 0.3) was achieved on MS medium with 2 mg/l BAP using node segments. The medium supplemented with 2 mg/l of BAP was found better than all other concentrations. Individual shoots were transferred to IBA and IAA (1.0-1.5 mg/l) for root induction. MS medium supplemented with 2 mg/l of IBA proved better for rooting. Rooted plantlets were successfully hardened in greenhouse and established in the pot.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Chuandong Song ◽  
Haifeng Wang

Emerging evidence demonstrates that post-translational modification plays an important role in several human complex diseases. Nevertheless, considering the inherent high cost and time consumption of classical and typical in vitro experiments, an increasing attention has been paid to the development of efficient and available computational tools to identify the potential modification sites in the level of protein. In this work, we propose a machine learning-based model called CirBiTree for identification the potential citrullination sites. More specifically, we initially utilize the biprofile Bayesian to extract peptide sequence information. Then, a flexible neural tree and fuzzy neural network are employed as the classification model. Finally, the most available length of identified peptides has been selected in this model. To evaluate the performance of the proposed methods, some state-of-the-art methods have been employed for comparison. The experimental results demonstrate that the proposed method is better than other methods. CirBiTree can achieve 83.07% in sn%, 80.50% in sp, 0.8201 in F1, and 0.6359 in MCC, respectively.


2021 ◽  
pp. 1-8
Author(s):  
Deep Shikha ◽  
Chandani Latwal ◽  
Elangbam Premabati Devi ◽  
Anupama Singh ◽  
Pawan K. Singh ◽  
...  

Abstract Genetic resources are of paramount importance for developing improved crop varieties, particularly for biotic and abiotic stress tolerance. Spot blotch (SB) is a destructive foliar disease of wheat prevalent in warm and humid regions of the world, especially in the eastern parts of South Asia. For the management of this disease, the most effective measure is the development of resistant cultivars. Thus, the present investigation was carried out to confirm SB resistance in 200 germplasm accessions based on phenotypic observations and molecular characterization. These elite breeding lines obtained from the International Centre for Maize and Wheat Improvement, Mexico, are developed deploying multiple parentages. These lines were screened for SB resistance in the field under artificially created epiphytotic conditions during 2014–15 and 2015–16 along with two susceptible checks (CIANO T79 and Sonalika) and two resistant checks (Chirya 3 and Francolin). Eighty-two out of 200 germplasm accessions were found resistant to SB and resistance in these lines was confirmed with a specific SSR marker Xgwm148. Three accessions, VORONA/CNO79, KAUZ*3//DOVE/BUC and JUP/BJY//URES/3/HD2206/HORK//BUC/BUL were observed possessing better resistance than the well-known SB-resistant genotype Chirya3. These newly identified resistant lines could be used by wheat breeders for developing SB-resistant wheat varieties.


2021 ◽  
Vol 22 (10) ◽  
pp. 5314
Author(s):  
Marlon-Schylor L. le Roux ◽  
Nicolas Francois V. Burger ◽  
Maré Vlok ◽  
Karl J. Kunert ◽  
Christopher A. Cullis ◽  
...  

Drought response in wheat is considered a highly complex process, since it is a multigenic trait; nevertheless, breeding programs are continuously searching for new wheat varieties with characteristics for drought tolerance. In a previous study, we demonstrated the effectiveness of a mutant known as RYNO3936 that could survive 14 days without water. In this study, we reveal another mutant known as BIG8-1 that can endure severe water deficit stress (21 days without water) with superior drought response characteristics. Phenotypically, the mutant plants had broader leaves, including a densely packed fibrous root architecture that was not visible in the WT parent plants. During mild (day 7) drought stress, the mutant could maintain its relative water content, chlorophyll content, maximum quantum yield of PSII (Fv/Fm) and stomatal conductance, with no phenotypic symptoms such as wilting or senescence despite a decrease in soil moisture content. It was only during moderate (day 14) and severe (day 21) water deficit stress that a decline in those variables was evident. Furthermore, the mutant plants also displayed a unique preservation of metabolic activity, which was confirmed by assessing the accumulation of free amino acids and increase of antioxidative enzymes (peroxidases and glutathione S-transferase). Proteome reshuffling was also observed, allowing slow degradation of essential proteins such as RuBisCO during water deficit stress. The LC-MS/MS data revealed a high abundance of proteins involved in energy and photosynthesis under well-watered conditions, particularly Serpin-Z2A and Z2B, SGT1 and Calnexin-like protein. However, after 21 days of water stress, the mutants expressed ABC transporter permeases and xylanase inhibitor protein, which are involved in the transport of amino acids and protecting cells, respectively. This study characterizes a new mutant BIG8-1 with drought-tolerant characteristics suited for breeding programs.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Basavalingayya K. Swamy ◽  
Ravikumar Hosamani ◽  
Malarvizhi Sathasivam ◽  
S. S. Chandrashekhar ◽  
Uday G. Reddy ◽  
...  

AbstractHypergravity—an evolutionarily novel environment has been exploited to comprehend the response of living organisms including plants in the context of extra-terrestrial applications. Recently, researchers have shown that hypergravity induces desired phenotypic variability in seedlings. In the present study, we tested the utility of hypergravity as a novel tool in inducing reliable phenotype/s for potential terrestrial crop improvement applications. To investigate, bread wheat seeds (UAS-375 genotype) were subjected to hypergravity treatment (10×g for 12, and 24 h), and evaluated for seedling vigor and plant growth parameters in both laboratory and greenhouse conditions. It was also attempted to elucidate the associated biochemical and hormonal changes at different stages of vegetative growth. Resultant data revealed that hypergravity treatment (10×g for 12 h) significantly enhanced root length, root volume, and root biomass in response to hypergravity. The robust seedling growth phenotype may be attributed to increased alpha-amylase and TDH enzyme activities observed in seeds treated with hypergravity. Elevated total chlorophyll content and Rubisco (55 kDa) protein expression across different stages of vegetative growth in response to hypergravity may impart physiological benefits to wheat growth. Further, hypergravity elicited robust endogenous phytohormones dynamics in root signifying altered phenotype/s. Collectively, this study for the first time describes the utility of hypergravity as a novel tool in inducing reliable root phenotype that could be potentially exploited for improving wheat varieties for better water usage management.


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