First report of pearl millet bacterial leaf blight caused by Pantoea stewartii subspecies indologenes in India.

Pearl millet (Cenchrus americanus L.) field-grown plants of cv. 7042S shown unusual water-soaked lesions on leaf tips spreading towards the leaf base from Manasagangothri region (12.31°N 76.61°E), Karnataka, a southern Indian state during March 2020. Later those infected plants showed extensive necrosis and typical leaf blight symptoms with 70% disease incidence and 59% severity. Surface sterilized (3 x 3 mm) infected leaf tissues were crushed in 1mL sterile distilled water and streaked onto nutrient agar media. Bright-yellowish, circular, mucoid single bacterial colonies (PPi-M1) with regular margin were recovered after 24 hours of incubation at 28oC, and the same bacterial colonies were used for further biochemical and molecular characterization. The isolate, PPi-M1 found as gram-negative rods, gelatin, starch hydrolysis negative, and catalase, indole production positive. The partial sequence of 16S rRNA gene (primers: 27F/1492R) of the isolate PPi-M1 was amplified, sequenced, and curated sequence submitted to NCBI GenBank (accession number: MN808555). In nucleotide BLAST search for homologous sequences, 99.5% nucleotide matching similarity (1410bp) was observed with other Pantoea stewartii subspecies indologenes strains (MF163274; NR_104928) at NCBI database indicating that our isolate PPi-M1 belongs to this species. In Phylogenetic analysis using the Maximum Likelihood method and Tamura Nei model (1993), PPi-M1 formed a distinct cluster with other Pantoea stewartii strains with bootstrap value >95 and it was distant from P. allii, P. ananatis, P. agglomerans, and P. dispera. Besides, the subspecies-specific PCR assay and subsequent sequencing of galE and recA genes (primers: 3614galE/3614galEc; 3614recA/3614recAc; 372 and 223 bp) also confirmed the identity of the isolate as Pantoea stewartii subspecies indologenes. Further, the pathogenicity test was performed in-planta on 21 days old seedlings of pearl millet cv. CO-10. The bacterial suspension of isolate PPi-M1 (1x108 CFU/ml) was used for inoculation by leaf clipping method (Ke et al. 2017). All the inoculated plants (n=4 leaves per plant; 15 plants) maintained under greenhouse conditions (Temp: 27-29oC; RH: 80-85%) except mock (sterile water inoculation) shown similar water-soaked lesions from the cut end of the leaf, with a definite spreading margin and a typical leaf blight symptom in 8 dpi, as observed in the field. Re-isolated bacterial colonies from infected leaves shared similar morphological characters and molecular identity with inoculated culture, thus proving Koch's postulates. This pearl millet leaf blight causing bacterial strain PPi-M1 was deposited in the National Agriculturally Important Microbial Culture Collection, Mau, India (accession no.: NAIMCC-B-02508). Previously, P. stewartii was reported to cause leaf blight and rot diseases on rice and maize (Kini et al. 2016; Roper et al. 2011), also the international seed federation has instigated the phytosanitary measures highlighting its true seed transmission ability (Pataky et al. 2003). This study will supplement future pearl millet breeding programs, and to our knowledge, this is the first report of P. s. subsp. indologenes inciting pearl millet leaf blight disease in India.

Exploration of Potent Multi-target-directed-ligands as Anti-alzheimer's Disease Agents: A Moiety Based Review.

Dementia is a chronic neurodegenerative disease, and a maximum number of the cases are directly related to Alzheimer's disease. More than 4 million people are living with Alzheimer's disease-related dementia in India, making it a national crisis. Alzheimer's disease deteriorates cognitive functions with the passage of time and consists of multi-faceted factors, such as the decline of acetylcholine level, amyloid ß-aggregation, tau hyperphosphorylation, oxidative stress, etc. The classical drugs used to date, are focused on only one target and are not serving the cause properly. Hence, the community of scientists is rigorously working on multi-target-directed agents that incorporate two or more active scaffolds in one compound or hybrid of active moieties. This article aims to evaluate novel potential compounds and moieties, such as quinolines, chalcones, coumarins, chromenes, piperazine, carbazoles, cinnamic acids, tacrine hybrids, donepezil hybrids, etc., that have been introduced as multi-target-directed agents in the recent five years.

Diversity Oriented Synthesis of 4H-Pyrimido[2,1-b]benzothiazole Derivatives via Biginellis Reaction: A Review.

BACKGROUND: Heterocycles have extended into widespread use for generating large collection of molecules in multi-component reactions. The development of new strategies for fused pyrimidobenzothiazole system has remained a highly attractive but challenging proposition for scientists working all around. OBJECTIVE: The main objective of this work is to explore the utility of different catalysts as an ecofriendly reaction medium for green Biginellis reaction. METHOD: A detailed study of Biginellis reactions using various catalysts was done using different research tools. The methods involved reaction of equimolar mixture of benzothiazole, 1,3-diketone and aldehyde as reactants by conventional and greener pathways via Knoevenagal condensation. RESULTS: The present review has several significant advantages for the scientists regarding green synthesis viz. green conditions, short reaction times, high yields, clean reaction conditions, easy isolation of products, simple work-up procedure and mild reaction conditions. CONCLUSION: Our report gives an overview of the combinatorial libraries for fused benzothiazole entities using metal catalyst, acid catalyst, ionic liquids, phase transfer catalyst, nano catalyst, etc.