Transcription Factors and MicroRNA Interplay: A New Strategy for Crop Improvement

MicroRNAs (miRNAs) and transcription factors are master regulators of the cellular system. Plant genomes contain thousands of protein-coding and non-coding RNA genes; which are differentially expressed in different tissues at different times during growth and development. Complex regulatory networks that are controlled by transcription factors and microRNAs, which coordinate gene expression. Transcription factors, the key regulators of plant growth and development, are the targets of the miRNAs families. The combinatorial regulation of transcription factors and miRNAs guides the appropriate implementation of biological events and developmental processes. The resources on the regulatory cascades of transcription factors and miRNAs are available in the context of human diseases, but these resources are meager in case of plant diseases. On the other hand, it is also important to understand the cellular and physiological events needed to operate the miRNAs networks. The relationship between transcription factors and miRNA in different plant species described in this chapter will be of great interest to plant scientists, providing better insights into the mechanism of action and interactions among transcription factors (TFs) and miRNA networks culminating in improving key agronomic traits for crop improvement to meet the future global food demands

Optimization of recipe for development of Aonla squash- A Response surface methodology approach

Central Composite Design (CCD) was employed for optimizing the recipe for development of Aonla squash with juice content (25 to 40%), acidity (1.00 to 1.10%) as independent variables and adjusting 50% total soluble solids. Thirteen different experimental combinations given by RSM design were used to investigate the effect of independent process variables on four product responses developed squash. RSM evaluated responses of the 13 squash recipes by second order quadratic equations and found that pH ranged from 2.69-3.00, ascorbic acid from 102-212 mg/100ml, browning from 0.428- 0.579 and overall acceptability scores from 6.25-7.75. ANOVA analysis showed that the product responses of beverages were significantly affected (at 5%) by changes in juice and acidity of the squash recipes. Overall acceptability scores of the beverage increased with the increase in proportion of juice content from 25 to 40%. The coefficient of determination i.e., R2 for all responses was higher than 0.95 and nonsignificant lack of fit was observed for all models; which was desirable. Through numerical optimization, standardized recipe selected by RSM for aonla squash was with 40% juice and 1% acidity getting highest desirability of 0.991. The pH, ascorbic acid, browning and overall acceptability for the optimum recipe predicted by the design were 2.96, 197.8 mg/100 ml, 0.557 and 7.7, respectively. Thus, present study was first in its kind to optimize aonla squash recipe by using RSM as a tool which gave advantage of not only selecting best recipe but also provided impression of the influence of ingredients used in squash’s preparation on its physico-chemical profile

Development of promiscous rhizobia for diverse rabi legumes (Chickpea, Pea and Lentil)

Conjugation between microsymbiont was used to create genetic variations in rhizobia for diverse rabi legumes (chickpea, pea and lentil) with better characteristics in nodulation and nitrogen fixation process. Ten antibiotics were used as selectable markers for the screening of twenty four bacterial strains to be used in mating experiments for obtaining transconjugants. All bacterial strains were sensitive to gentamycin and resistant to streptomycin, kanamycin and sulphanilamide. Total five fusants were obtained from each rhizobial cross combination with the help of electro-poration. Modified transconjugants, rhizobial strains had promiscuous infection with 50-122% more nodules showed significant increase in shoot fresh weight, dry weight and total nitrogen content in chickpea, pea and lentil plants. Electrofusantsrhizobial strains improved shoot nitrogen content up to 67% in lentil and 54% in pea and chickpea plants. The amount of nitrogen fixed in chickpea was highest (3.71gm) by transconjugants DP-C6- HLN followed by DP-C6-HP14 (3.56gm). Transconjugants DP-HP14-HLN fixed the highest amount of nitrogen (3.92gm) in pea and 4.06gm in lentil plants. Plasmids were also analyzed in order to characterize their role in the evolution of rhizobial symbionts and their involvement in symbiotic behaviour. The developed Rhizobium strains with improved symbiotic association and ability to infect across strict specificity for host legumes would be of great help for the farming community at large

Statistical media optimization studies for growth and polydroxybutyrate (PHB) production by Pseudomonas spp.

Using glucose as carbon source and mustard cake and yeast extract as nitrogen sources bacterial isolate Pseudomonas B2 exhibited a maximum PHB recovery of 0.620 (in terms of O.D.) and PHB weight of 0.27g/L in 96 h. To determine the possibility of growth potential of Pseudomonas spp., it was grown in different carbon sources like fructose, glucose, maltose, mannitol etc. and it was found that glucose yielded good growth and PHB production. In order to incorporate cost effective nitrogen and carbon source, mustard cake and cotton cake as nitrogen source and molasses as carbon were used in medium. Statistical media optimization design was used to optimize the culture conditions for maximizing the PHB production. A maximum of 0.37 g/L of PHB and 0.746 (O.D.) PHB recoveries were obtained using optimized concentrations. Batch kinetics can be used for model development, which will make possible simulation of nutrient limited cultivation(s) for over accumulation of PHB. FTIR studies confirmed the presence of PHB

Reactivities of allenic and olefinic Michael acceptors towards phosphines

The kinetics of the reactions of tributylphosphine with allenic and olefinic Michael acceptors in dichloromethane at 20 °C was followed by photometric and NMR spectroscopic methods. Combination with DFT-calculated methyl anion affinities revealed the relevance of retroaddition barriers in phosphine-catalysed reactions when mixtures of allenic and olefinic substrates are used

Malignant mandibular tumors: two case reports of rare mandibular tumors in a single institution

Mandibular lesions can be benign or malignant, malignant being less common. The most common malignant tumor of mandible is squamous cell carcinoma. Others are ameloblastic carcinoma,  osteosarcoma, chondrosarcoma, fibrosarcoma, malignant fibrous histiocytoma and metastasis. Osteosarcoma is a bone tumor. It can occur in any bone, usually in the long bones of the extremities, but osteosarcoma of mandible is rare. In the initial phase, they may present as nondescript bony swellings with an indolent growth, only to become malignant towards the later stages. Osteosarcomas of the jaw are rare and they differ from osteosarcomas of the long bones in their biological behavior, even though they have the same histological appearance. Malignant fibrous histiocytoma (MFH) is the most common soft-­‐tissue sarcoma, but  relatively uncommon in head and neck region with only 30 reported cases till date. The purpose of this report is to present two cases of rare malignant mandibular tumors in a single institution.KEY WORDS: Osteosarcoma; Malignant fibrous histiocytoma; Mandibl

High precision temperature controlling AGPase in wheat affecting yield and quality traits

Adenosine diphosphate glucose pyrophosphorylase (AGPase) is the rate limiting enzyme of starch biosynthesis that directly affects the wheat productivity. AGPase and grain growth rate (GGR) discerned to be following strict temperature regimen in wheat disomic chromosome substitution (DCS) lines. The first half of grain filling period had chromosome 1B and 2D as prominent players, whereas second half was mainly controlled by chromosomes 6A and 5B. Chromosome 2D had major contribution towards yield in a specific temperature range of 23 ± 1.5 °C during initial stages of grain filling which can serve as an effective early screening tool for terminal heat tolerance in wheat. Chromosome 2D with highest amylose content can also be utilized to produce low digestibility flour. Grain yield was found to be significantly associated with spikes/plant, grains/spike, grain weight/spike and plant biomass. Further, path analysis indicated that though grains/spike had less direct effect on grain yield but its indirect impact on grain yield via AGPase-21 activity was high

Base Pairing between Hepatitis C Virus RNA and MicroRNA 122 3' of Its Seed Sequence Is Essential for Genome Stabilization and Production of Infectious Virus

MicroRNA 122 (miR-122) facilitates hepatitis C virus (HCV) replication by recruiting an RNA-induced silencing complex (RISC)-like complex containing argonaute 2 (Ago2) to the 5′ end of the HCV genome, thereby stabilizing the viral RNA. This requires base pairing between the miR-122 “seed sequence” (nucleotides [nt] 2 to 8) and two sequences near the 5′ end of the HCV RNA: S1 (nt 22 to 28) and S2 (nt 38 to 43). However, recent reports suggest that additional base pair interactions occur between HCV RNA and miR-122. We searched 606 sequences from a public database (genotypes 1 to 6) and identified two conserved, putatively single-stranded RNA segments, upstream of S1 (nt 2 and 3) and S2 (nt 30 to 34), with potential for base pairing to miR-122 (nt 15 and 16 and nt 13 to 16, respectively). Mutagenesis and genetic complementation experiments confirmed that HCV nt 2 and 3 pair with nt 15 and 16 of miR-122 bound to S1, while HCV nt 30 to 33 pair with nt 13 to 16 of miR-122 at S2. In genotype 1 and 6 HCV, nt 4 also base pairs with nt 14 of miR-122. These 3′ supplementary base pair interactions of miR-122 are functionally important and are required for Ago2 recruitment to HCV RNA by miR-122, miR-122-mediated stabilization of HCV RNA, and production of infectious virus. However, while complementary mutations at HCV nt 30 and 31 efficiently rescued the activity of a 15C,16C miR-122 mutant targeting S2, similar mutations at nt 2 and 3 failed to rescue Ago2 recruitment at S1. These data add to the current understanding of miR-122 interactions with HCV RNA but indicate that base pairing between miR-122 and the 5′ 43 nt of the HCV genome is more complex than suggested by existing models

Stabilization of hepatitis C virus RNA by an Ago2-miR-122 complex

MicroRNAs (miRNAs) are small noncoding RNAs that regulate eukaryotic gene expression by binding to regions of imperfect complementarity in mRNAs, typically in the 3′ UTR, recruiting an Argonaute (Ago) protein complex that usually results in translational repression or destabilization of the target RNA. The translation and decay of mRNAs are closely linked, competing processes, and whether the miRNA-induced silencing complex (RISC) acts primarily to reduce translation or stability of the mRNA remains controversial. miR-122 is an abundant, liver-specific miRNA that is an unusual host factor for hepatitis C virus (HCV), an important cause of liver disease in humans. Prior studies show that it binds the 5′ UTR of the messenger-sense HCV RNA genome, stimulating translation and promoting genome replication by an unknown mechanism. Here we show that miR-122 binds HCV RNA in association with Ago2 and that this slows decay of the viral genome in infected cells. The stabilizing action of miR-122 does not require the viral RNA to be translationally active nor engaged in replication, and can be functionally substituted by a nonmethylated 5′ cap. Our data demonstrate that a RISC-like complex mediates the stability of HCV RNA and suggest that Ago2 and miR-122 act coordinately to protect the viral genome from 5′ exonuclease activity of the host mRNA decay machinery. miR-122 thus acts in an unconventional fashion to stabilize HCV RNA and slow its decay, expanding the repertoire of mechanisms by which miRNAs modulate gene expression