Comparative transcriptome analysis of two contrasting genotypes provides new insights into the drought response mechanism in pigeon pea (Cajanus cajan L. Millsp.).

BACKGROUND: Despite plant's ability to adapt and withstand challenging environments, drought poses a severe threat to their growth and development. Although pigeon pea is already quite resistant to drought, the prolonged dehydration induced by the aberrant climate poses a serious threat to their survival and productivity. OBJECTIVE: Comparative physiological and transcriptome analyses of drought-tolerant (CO5) and drought-sensitive (CO1) pigeon pea genotypes subjected to drought stress were carried out in order to understand the molecular basis of drought tolerance in pigeon pea. METHODS: The transcriptomic analysis allowed us to examine how drought affects the gene expression of C. cajan. Using bioinformatics tools, the unigenes were de novo assembled, annotated, and functionally evaluated. Additionally, a homology-based sequence search against the droughtDB database was performed to identify the orthologs of the DEGs. RESULTS: 1102 potential drought-responsive genes were found to be differentially expressed genes (DEGs) between drought-tolerant and drought-sensitive genotypes. These included Abscisic acid insensitive 5 (ABI5), Nuclear transcription factor Y subunit A-7 (NF-YA7), WD40 repeat-containing protein 55 (WDR55), Anthocyanidin reductase (ANR) and Zinc-finger homeodomain protein 6 (ZF-HD6) and were highly expressed in the tolerant genotype. Further, GO analysis revealed that the most enriched classes belonged to biosynthetic and metabolic processes in the biological process category, binding and catalytic activity in the molecular function category and nucleus and protein-containing complex in the cellular component category. Results of KEGG pathway analysis revealed that the DEGs were significantly abundant in signalling pathways such as plant hormone signal transduction and MAPK signalling pathways. Consequently, in our investigation, we have identified and validated by qPCR a group of genes involved in signal reception and propagation, stress-specific TFs, and basal regulatory genes associated with drought response. CONCLUSION: In conclusion, our comprehensive transcriptome dataset enabled the discovery of candidate genes connected to pathways involved in pigeon pea drought response. Our research uncovered a number of unidentified genes and transcription factors that could be used to understand and improve susceptibility to drought.

Chitosan-Salicylic acid and Zinc sulphate nano-formulations defend against yellow rust in wheat by activating pathogenesis-related genes and enzymes.

Stripe rust instigated by Puccinia striiformis f. sp. tritici causes major yield loss in wheat. In this study, disease resistance was induced in wheat by pre-activation of pathogenesis related (PR) genes using two different nano-formulations (NFs) i.e. Chitosan- Salicylic acid (SA) NFs (CH-NFs) and Zinc sulphate NFs (Zn-NFs). These NFs were synthesized using green approach and were characterized using various techniques. Both NFs effectively controlled stripe rust in wheat genotypes (WH 711 and WH 1123) by significantly increasing activities of phenylalanine ammonia lyase, tyrosine ammonia lyase and polyphenol oxidase enzymes when compared with disease free-control and diseased plants. Total soluble sugar (TSS) level was highest in CH-NF treated plants. TSS was also relatively higher in diseased plants than disease free-control as well as Zn-NF treated plants. Both CH-NFs and Zn-NFs induced the expression of PR genes. In CH-NF treated plants, the relative expression of PR genes was higher on the 3rd day after spraying (DAS) of NFs as compared to diseased and Zn-NF treated plants in both the genotypes. While in case of Zn-NF treated plants, relative expression of PR genes was higher on 5th DAS as compared to diseased and disease free-control plants. Early rise in expression of PR genes due to NF treatments was responsible for disease resistance in both the wheat genotypes as evidenced by a lower average coefficient of infection. These NFs can be synthesized easily with low cost input, are eco-friendly and can be effectively used against yellow rust as well as other wheat diseases.

Abscisic Acid: Role in Fruit Development and Ripening.

Abscisic acid (ABA) is a plant growth regulator known for its functions, especially in seed maturation, seed dormancy, adaptive responses to biotic and abiotic stresses, and leaf and bud abscission. ABA activity is governed by multiple regulatory pathways that control ABA biosynthesis, signal transduction, and transport. The transport of the ABA signaling molecule occurs from the shoot (site of synthesis) to the fruit (site of action), where ABA receptors decode information as fruit maturation begins and is significantly promoted. The maximum amount of ABA is exported by the phloem from developing fruits during seed formation and initiation of fruit expansion. In the later stages of fruit ripening, ABA export from the phloem decreases significantly, leading to an accumulation of ABA in ripening fruit. Fruit growth, ripening, and senescence are under the control of ABA, and the mechanisms governing these processes are still unfolding. During the fruit ripening phase, interactions between ABA and ethylene are found in both climacteric and non-climacteric fruits. It is clear that ABA regulates ethylene biosynthesis and signaling during fruit ripening, but the molecular mechanism controlling the interaction between ABA and ethylene has not yet been discovered. The effects of ABA and ethylene on fruit ripening are synergistic, and the interaction of ABA with other plant hormones is an essential determinant of fruit growth and ripening. Reaction and biosynthetic mechanisms, signal transduction, and recognition of ABA receptors in fruits need to be elucidated by a more thorough study to understand the role of ABA in fruit ripening. Genetic modifications of ABA signaling can be used in commercial applications to increase fruit yield and quality. This review discusses the mechanism of ABA biosynthesis, its translocation, and signaling pathways, as well as the recent findings on ABA function in fruit development and ripening.

Scaffolds the backbone of tissue engineering: Advancements in use of polyhydroxyalkanoates (PHA).

Our body is built to heal from inside out naturally but wide-ranging medical conditions necessitate the need for artificial assistance, and therefore, something that can assist the body to heal wounds and damaged tissues quickly and efficiently is of utmost importance. Tissue engineering technology helps to regenerate new tissue to replace the diseased or injured one. The technology uses biodegradable porous three-dimensional scaffolds for mimicking the structure and functions of the natural extracellular matrix. The material and design of scaffolds are critical areas of biomaterial research. Biomaterial-based three-dimensional structures have been the most promising material to serve as scaffolds for seeding cells, both in vivo and in vitro. One such material is polyhydroxyalkanoates (PHAs) which are thermoplastic biopolyesters that are highly suitable for this purpose due to their enhanced biocompatibility, biodegradability, thermo-processability, diverse mechanical properties, non-toxicity and natural origin. Moreover, they have tremendous possibilities of customization through biological physical and chemical modification as well as blending with other materials. They are being used for several tissue engineering applications such as bone graft substitute, cardiovascular patches, stents, for nerve repair and in implantology as valves and sutures. The present review overviews usage of a multitude of PHA-based biomaterials for a wide range of tissue engineering applications, based on their properties suitable for the specific applications.

Evaluation of anti-inflammatory response of berberine-loaded gum nanocomplexes in carrageenan-induced acute paw edema in rats.

BACKGROUND: Berberine is a natural plant alkaloid and has been reported to possess anti-inflammatory activity. However, berberine's poor bioavailability and low solubility have limited its clinical applicability. Nanoencapsulation of berberine using a suitable carrier can be a promising strategy to improve its efficacy. Therefore, this study aimed to produce berberine-loaded gum nanocomplexes to evaluate their therapeutic effects in a carrageenan-induced rat model. METHODS: Berberine-loaded gum nanocomplexes were prepared by the ionic complexation between the negative charges of the gums (tragacanth and acacia gum) using a cross-linker for loading cationic berberine and their anti-inflammatory activity was evaluated against carrageenan-induced paw edema in rats. ELISA and qRT-PCR were employed to measure the concentration and mRNA expression level of inflammatory mediators in plasma and paw tissue, respectively. RESULTS: Berberine nanocomplexes were characterized for particle size (219.5 nm), zeta potential by the dynamic light scattering (DLS), and for entrapment efficiency (93.2%) Infrared spectroscopy affirmed the loading of berberine in gum nanocomplexes. Transmission electron microscopy of formulation showed the spherical shape of nanocomplexes and small particle size (100-150 nm). Pretreatment of rats with berberine nanocomplexes significantly reduced the paw edema in inflamed rat paws, decreased the production of nitrite and TNF-α in plasma and repressed the mRNA expression levels of TNF-α and IL-1ß in paw tissue in comparison to berberine per se treated rats. CONCLUSION: The obtained berberine-loaded gum nanocomplexes produced a better anti-inflammatory effect as compared to berberine alone and hence can be used as an efficient candidate in the treatment of inflammation. The schematic representation of the preparation of the preparation of berberine-loaded tragacanth/acacia gum nanocomplexes and the evaluation in vivo for anti-inflammatory effects.

Assessment of Antibacterial Activity of Biosynthesised ZnO Nanoparticles Against Xanthomonas axonopodis pv. malvacearum Causing Bacterial Blight in Cotton.

Cotton (Gossypium hirsutum L.), is an important fibre and oilseed crop of the world. India in particular has the largest area under cotton cultivation and around 60% proportion in the raw fibre textile industry is contributed by cotton alone. Cotton is affected by many diseases (bacterial blights, fungal leafspots, mildew) and pests (white flies, bollworms, aphids etc.). The bacterial blight disease caused by Xanthomonas axonopodis pv. malvacearum is considered as one of the most devastating one that cause huge losses in production every year. Due to systemic spread of this bacterial infection, combating this disease is slightly challenging. Spray of toxic chemicals like endosulfan, streptocycline and dimethoate is a common practice in fields but these chemicals are unable to control the disease spread substantially. Nanotechnology is a newly emerging technology that is being extensively exploited in the agriculture sector these days. Past studies have reported the antimicrobial effect of various metallic nanoparticles including zinc oxide nanoparticles which is known to possess antibacterial potential against both gram +ve and gram -ve bacteria. Based upon this, synthesis of ZnO nanoparticles was carried out using Morus alba plant leaf extract and the nanoparticles were characterised in detail using scanning electron microscopy, atomic force microscopy, X-ray diffraction analysis, electron dispersive X-ray spectroscopy study etc. The zinc oxide nanoparticles were found crystalline in nature and the size ranged between 10-50 nanometers. The efficacy of these nanoparticles was checked against Xanthomonas axonopodis pv. malvacearum under in vitro conditions and found to be very effective in controlling the bacterial spread in comparison to streptomycin that was used as control. Our results suggest that ZnO nanoparticles can be used as an effective antibacterial agent to control bacterial blight disease of cotton.

In Vitro Antifungal and Antibacterial Effects of Biosynthesized Zinc Oxide Nanoparticles Against Selected Pathogenic and Non-Pathogenic Strains.

We have developed a simple, robust environment-friendly and efficient method for ZnO nanoparticles biosynthesis using Dalbergia sissoo fresh leaf extract. Before using these nanoparticles for antimicrobial assay, a detailed characterization was performed using techniques like Ultraviolet/Visible (UV/Vis) spectroscopy, Particle size analysis (PSA), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM),Transmission electron microscopy (TEM) etc. The average size of biosynthesized ZnO nanoparticles was around 30 nm and they were pure and crystalline by nature. The effectiveness of these biosynthesized nanoparticles were checked against both pathogenic and non-pathogenic microbes. A total of eight bacterial strains-Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Klebsilla pneumoniae, Staphylococcus aureus, Streptococcus entericus, Bacillus cereus, Pantoea cypripedii and three fungal strains-Candida albicans, Aspergilus niger and Aspergilus flavus were studied to have a clear view of the spectrum of ZnO nanoparticles anti-microbial activity. The effectiveness of biosynthesized ZnO nanoparticles against the microbes was found to be better than the standard reference antibiotics used (streptomycin, chloramphenicol and rifampicin). The results seem to be very promising and can be used for some practical applications of ZnO nanoparticles in nearfuture.

Analysis of genetic control and QTL mapping of essential wheat grain quality traits in a recombinant inbred population.

Wheat cultivars are genetically crossed to improve end-use quality for traits as per demands of baking industry and broad consumer preferences. The processing and baking qualities of bread wheat are influenced by a variety of genetic make-ups, environmental factors and their interactions. Two wheat cultivars, WL711 and C306, derived recombinant inbred lines (RILs) with a population of 206, were used for phenotyping of quality-related traits. The genetic analysis of quality traits showed considerable variation for measurable quality traits, with normal distribution and transgressive segregation across the years. From the 206 RILs, few RILs were found to be superior to those of the parental cultivars for key quality traits, indicating their potential use for the improvement of end-use quality and suggesting the probability of finding new alleles and allelic combinations from the RIL population. Mapping analysis identified 38 putative QTLs for 13 quality-related traits, with QTLs explaining 7.9-16.8% phenotypic variation spanning over 14 chromosomes, i.e., 1A, 1B, 1D, 2A, 2D, 3B, 3D, 4A, 4B, 4D, 5D, 6A, 7A and 7B. In-silico analysis based on homology to the annotated wheat genes present in database, identified six putative candidate genes within QTL for total grain protein content, qGPC.1B.1 region. Major QTL regions for other quality traits such as TKW have been identified on 1B, 2A, and 7A chromosomes in the studied RIL population. This study revealed the importance of the combination of stable QTLs with region-specific QTLs for better phenotyping, and the QTLs presented in our study will be useful for the improvement of wheat grain and bread-making quality.

In vitro anti-inflammatory and antioxidant potential of thymol loaded bipolymeric (tragacanth gum/chitosan) nanocarrier.

Thymol is a natural bioactive agent which possesses various medicinal properties like antimicrobial, antifungal, anti-inflammatory, anticancer etc. and has been widely used in traditional medicine and food industries. It is eco-friendly, cheap, nontoxic and has been granted generally recognized as safe (GRAS) notation by USFDA. Its use is somewhat muted due to drawbacks like lesser bioavailability, comparatively poor solubility and low susceptibility to oxidation. In the present work, nanoformulation of thymol was prepared by ionic complexation of tragacanth gum and chitosan. Chitosan of different concentrations was used to obtain desired particle size and encapsulation efficiency. It was noted that a ratio of 1:2 (tragacanth gum:chitosan) yielded a minimum particle size along with higher encapsulation efficiency. Morphology of these optimized nanoparticles was found to be spherical using TEM. These particles were found in the size range of 150-200 nm. Further comparative study of the prepared nanoformulation and thymol for antioxidant and anti-inflammatory efficacy was done using DPPH method and HRBC (Human red blood cell) stabilization method. The results suggested an increase in both anti-inflammatory and antioxidant activity of thymol nanoformulation. This study will open up new avenues for application in the field of food and pharmaceutical industries.

Evaluation of HMW-GS 20 and 2.2 from near isogenic lines of wheat variety HD2329 for bread quality improvement.

BACKGROUND: Hexaploid wheat (Triticum aestivum L.) dominates the list of the most important human food sources ever. Its complex genetic background is the reason behind the wide diversity that exists in nutritional as well as food end-product quality. High-molecular-weight glutenin sub-units (HMW-GS) are the main grain storage proteins in the endosperm of wheat and related species. It is well established that the composition and quantity of allelic variation in HMW-GS genes substantially affect the taste and appearance of dough products and therefore work in this area is highly desired. RESULTS: A significant positive effect on wheat dough quality traits was observed among near isogenic lines of HMW-GS sub-units 20 and 2.2 in wheat variety HD2329 during quality evaluation of data generated over 2 years. A remarkably significant (P < 0.01) effect was observed on dough quality parameters like ratio of wet gluten/dry gluten, SDS sedimentation, farinogram parameters, and bread/chapatti traits whereas flour protein and dry gluten content showed an insignificant effect. CONCLUSION: HMW-GS 20 was found to be superior to HMW-GS 2.2 in terms of dough quality and both the near isogenic lines developed by us were found to be highly superior to the recurrent parent HD2329. As we know that the improvement of flour quality based on superior HMW-GS alleles is necessary to meet changing consumer demand, the study can be of immense use to future researchers who can target these HMW sub-units 20 and 2.2 in breeding programmes for the improvement of wheat end-product quality. © 2017 Society of Chemical Industry.