Synthesis of nanomaterials by biological approach is innovative, cheaper and environmental friendly and requires less-labor. In this regard, the present study focused on the synthesis of silver nanoparticles from the extract of Sargassum tenerrimum. Synthesized silver nanoparticles were wellcharacterized by UV-Visible Spectroscopy (UV-Vis), Fourier-Transform Infra-red Spectroscopy (FT-IR), Transmission Electron Microscopy analysis (TEM) and Dynamic Light Scattering (DLS). It was found that spherical shaped nanoparticles of size 20 nm were found in TEM analysis and showed effective anti-bacterial activity against standard reference strains. Altogether, extracts from seaweed were screened for phytochemicals followed by FT-IR prediction to reveal chemical functional groups present. The results showed that the anti-bacterial activity of silver nanoparticles was comparably higher than the phytochemicals present. Therefore, the present study elucidates silver nanoparticles can play a vital role in nano-based therapy in future. Citation: P. Kumar, et al. Synthesis of silver nanoparticles from Sargassum tenerrimum and screening phytochemicals for its anti-bacterial activity.

Pigeonpea is a major source of dietary protein to the vegetarian population of the Indian sub-continent. Crop improvement to mitigate biotic and abiotic stresses for realization of its potential yield and bridging yield gap is the need of the hour. Availability of limited genomic resources in the cultivated germplasm, however, is a serious bottleneck towards successful molecular breeding for the development of superior genotypes in pigeonpea. In view of this, improvement of pigeonpea can be attempted through transgenesis or by exploiting genetic resources from its wild relatives. Pigeonpea wild relatives are known to be bestowed with agronomic traits of importance; discovery and deployment of genes from them can provide a lucrative option for crop improvement. Understanding molecular signatures of wild relatives would not only provide information about the mechanism behind desired traits but also enable us to extrapolate the information to cultivated pigeonpea. The present study deals with the characterization of leaf transcriptomes of Cajanus cajan and one of its wild relatives, Cajanus platycarpus . Illumina sequencing revealed 0.11 million transcripts in both the species with an annotation of 0.09 million (82%) transcripts using BLASTX. Comparative transcriptome analyses on the whole, divulged cues about the wild relative being vigilant and agile. Gene ontology and Mapman analysis depicted higher number of transcripts in the wild relative pertaining to signaling, transcription factors and stress responsive genes. Further, networking between the differentially expressed MapMan bins demonstrated conspicuous interactions between different bins through 535 nodes (512 Genes and 23 Pathways) and 1857 edges. The authenticity of RNA-seq analysis was confirmed by qRT-PCR. The information emanating from this study can provide valuable information and resource for future translational research including genome editing to alleviate varied stresses. Further, this learning can be a platform for in-depth investigations to decipher molecular mechanisms for mitigation of various stresses in the wild relative.

Problem statement: The present investigation described a simple and reproducible protocol for transgenic cotton regeneration and characterization of chitinase (Chi II) gene expression against two different fungal pathogens in cotton. Approach: Transgenic cotton (Gossypium hirsutum cv. SVPR2) plants were produced by pCambia-bar-Chi II (13.8 kb) under the control of the CaMV 35S promoter, harbored in the strain LBA 4404 Agrobacterium tumefaciens by using shoot tip explants. Results: Finally, from the 10 experiments, 21.8% of transformation frequency was recorded. Segregation ratio of 3:1 was recorded in the T 0 plant seeds. Polymerase chain reaction and southern blotting analysis were used to confirm the integration of Chi II transgene in the T 0 plants genome of putative transgenics. Quantitiave and qualitative (SDS-PAGE) analyses were also carried out to confirm the expression of chitinase enzyme in T 0 plants. Further, randomly selected transgenic plants (T 0 ) were analyzed for disease tolerance by evaluating them with spores of Fusarium oxysporum and Alternaria macrospora. All the selected PCR positive plants showed enhanced disease resistance against Fusarium wilt. The plants selected randomly showed an enhanced survival rate compared with the control when they were grown in earthen pots inoculated with 1×10 5 spores 100 −1 g of soil mixture.Another four randomly selected plantlets were sprayed with spores of Alternaria macrospora in order to test their tolerance to Alternaria leaf spot disease. After 20 days of culture, the number of lesions per leaf and the lesion length per leaf spot in non-transferred leaves increased. In the case of transgenic plantlets, lesion formation was completely absent. Conclusion: The disease resistance against Fusarium wilt and Alternaria leaf spot in cotton strains would serve as good breeding materials for producing fungal disease resistant cotton varieties.

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