The identification of deleterious mutations in different variants of SARS-CoV-2, and their roles in the morbidity of COVID-19 patients are yet to be explored. Analyzing 5,724 complete genomes of SARS-CoV-2, sequenced from deceased COVID-19 patients globally during January 2020 to February 2023, we found that SARS-CoV-2 genomes of the deceased belonged to 21 Nextstrain clades, of which clade 20I (Alpha variant) was the most predominating clade followed by clade 20H (Beta variant) and clade 20J (Gamma variant). The highest percentage (33.4%) of SARS-CoV-2 genomes from deceased patients were sequenced from North America, while the lowest (0.98%) was from Africa. The “G” clade was found to be predominated in the SARS-CoV-2 genomes Asian, African, and North American regions whereas “GRY” clade outweighed in Europe. We identified 35,799 nucleotide mutations throughout the genome keeping the highest (n = 11,402) frequency in the spike protein. More importantly, 4,150 point-specific amino acids (aa) mutations in SARS-CoV-2 genomes, and of them, D614G (20%) and N501Y (14%) deleterious mutations in the spike protein were found as the top two mutations worldwide. We also detected five frequent deleterious aa mutations such as G18V, W45S, I33T, P30L, and Q418H, responsible for defining each clade of the SARS-CoV-2. Our novel findings could therefore be useful for genomic surveillance and monitoring the integrated pattern of SARS-CoV-2 infection, its emerging variants, and their impacts on developing effective vaccination and control methodology.

Heat stress alters photosynthetic components and antioxidant scavenging system, negatively affecting plant growth and development. Plants overcome heat stress damage through an integrated network involving enzymatic and non-enzymatic antioxidants. The aim of the study was to assess physiological and biochemical responses in contrasting thermotolerant wheat varieties exposed to 25°C (control) and 35°C (heat stress), during seedling stage. Our results revealed a substantial decrease in the photosynthetic pigments, carotenoids, anthocyanin content, and increased membrane injury index, malondialdehyde, lipoxygenase, methylglyoxal and H2O2 contents compared to non-stress wheat seedlings. Comparatively the heat tolerant variety BG26 maintained a high level of stability compared to the heat susceptible variety Pavon, perpetuated by higher accumulation of proline, glycine betaine, ascorbate-glutathione cycle associated enzymes, reduced glutathione and ascorbate contents. In addition, significantly lower MG detoxification and activities of antioxidant system and ascorbate-glutathione cycle related enzymatic activities lead to increased susceptibility in Pavon. Hierarchical clustering and principal component analysis revealed BG26 possessing a combination of biochemical responses that induced higher level of tolerance. Taken together, our results provide a reference for utilizing BG26 and Pavon as highly contrasting heat-responsive varieties for comparative genomics and translational research to unravel underlying mechanisms to better adapt wheat to heat stress.