Non-Targeted Metabolite Profiling Reveals Host Metabolomic Reprogramming during the Interaction of Black Pepper with Phytophthora capsici

Phytophthora capsici is one of the most destructive pathogens causing quick wilt (foot rot) disease in black pepper (Piper nigrum L.) to which no effective resistance has been defined. To better understand the P. nigrum–P. capsici pathosystem, we employed metabolomic approaches based on flow‐infusion electrospray–high‐resolution mass spectrometry. Changes in the leaf metabolome were assessed in infected and systemic tissues at 24 and 48 hpi. Principal Component Analysis of the derived data indicated that the infected leaves showed a rapid metabolic response by 24 hpi whereas the systemic leaves took 48 hpi to respond to the infection. The major sources of variations between infected leaf and systemic leaf were identified, and enrichment pathway analysis indicated, major shifts in amino acid, tricarboxylic acid cycle, nucleotide and vitamin B6 metabolism upon infection. Moreover, the individual metabolites involved in defensive phytohormone signalling were identified. RT‐qPCR analysis of key salicylate and jasmonate biosynthetic genes indicated a transient reduction of expression at 24 hpi but this increased subsequently. Exogenous application of jasmonate and salicylate reduced P. capsici disease symptoms, but this effect was suppressed with the co‐application of abscisic acid. The results are consistent with abscisic acid reprogramming, salicylate and jasmonate defences in infected leaves to facilitate the formation of disease. The augmentation of salicylate and jasmonate defences could represent an approach through which quick wilt disease could be controlled in black pepper

Genomic analysis of early SARS-CoV-2 breakthrough infections from the state of Kerala suggest a preponderance of variants of concern

The SARS-CoV-2 Variant of Concern, Delta (B.1.617.2) was first reported in December 2020 in India and has spread colossally throughout the globe. Owing to factors like increased transmissibility, immune escape, and virulence, the delta variant has been considered as a potential public health threat apart from other variants of concern like alpha, beta and gamma. Kerala was one of the first states in India to enroll in the systematic genomic surveillance. In the present report, vaccine breakthrough infections were followed up in 147 patients including 55 healthcare workers who had been vaccinated with ChAdOx1 nCoV- 19/BBV152 across eleven districts from the state of Kerala. The timeline of samples analysed were from April 2021 till June 2021. Severity of the infections reported in the enrolled patients found to be mildly symptomatic, majorly with only 0.7% (n=1) of the cohort to be asymptomatic. Genomic analysis of the samples revealed the Delta variant (B.1.617.2) to constitute about 81.6% (n=120) in the studied cohort. This was followed by the Kappa variant B.1.617.1 (8.35%, n=9), AY.1 (0.6%, n= 1), AY.12 (0.6%, n= 1), AY.4 (1.2%, n= 2), AY.9 (1.2%, n= 2) and Eta variant, B.1.525 (0.6%, n= 1). 11 samples were not assigned any lineage. Evidence from this study suggests the preponderance of the Delta variant in the samples analysed