Omicron infection increases IgG binding to spike protein of predecessor variants.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission in India in 2020-2022 was driven predominantly by Wild (Wuhan-Hu-1 and D614G), Delta, and Omicron variants. The aim of this study was to examine the effect of infections on the humoral immune response and cross-reactivity to spike proteins of Wuhan-Hu-1, Delta, C.1.2., and Omicron. Residual archival sera (N = 81) received between January 2020 and March 2022 were included. Infection status was inferred by a positive SARS-CoV-2 RT-PCR and/or serology (anti-N and anti-S antibodies) and sequencing of contemporaneous samples (N = 18) to infer lineage. We estimated the levels and cross-reactivity of infection-induced sera including Wild, Delta, Omicron as well as vaccine breakthrough infections (Delta and Omicron). We found an approximately two-fold increase in spike-specific IgG antibody binding in post-Omicron infection compared with the pre-Omicron period, whilst the change in pre- and post-Delta infections were similar. Further investigation of Omicron-specific humoral responses revealed primary Omicron infection as an inducer of cross-reactive antibodies against predecessor variants, in spite of the weaker degree of humoral response compared to Wuhan-Hu-1 and Delta infection. Intriguingly, Omicron vaccine-breakthrough infections when compared with primary infections, exhibited increased humoral responses against RBD (7.7-fold) and Trimeric S (Trimeric form of spike protein) (34.6-fold) in addition to increased binding of IgGs towards previously circulating variants (4.2 - 6.5-fold). Despite Delta breakthrough infections showing a higher level of humoral response against RBD (2.9-fold) and Trimeric S (5.7-fold) compared to primary Delta sera, a demonstrably reduced binding (36%-49%) was observed to Omicron spike protein. Omicron vaccine breakthrough infection results in increased intensity of humoral response and wider breadth of IgG binding to spike proteins of antigenically-distinct, predecessor variants.

Marker-assisted backcross breeding for heat tolerance in bread wheat (Triticum aestivum L.).

Manipulation of flowering time for adaptation through natural or genetic approaches may combat heat-stress damage that occurs at the reproductive stages in production conditions. HD2733, a popular wheat variety of the eastern plains of India, is largely sensitive to heat stress. Therefore, the current study aims to improve heat tolerance of HD2733 by introgression of QTLs associated with early anthesis and high kernel weight linked to markers Xbarc186 and Xgwm190, respectively, through marker-assisted backcross breeding (MABB) from a tolerant donor, WH730. A total of 124 simple sequence repeat (SSR) markers distributed evenly across the genome were used for the background selection. The alleles of Xbarc186 and Xgwm190 were fixed in BC2F1 and BC1F2 generations by selecting individual plants heterozygous for both marker loci and backcrossed with HD2733 and simultaneously selfed to generate BC2F1 and BC1F2 populations, respectively. Furthermore, the selected BC1F2 were selfed to generate the BC1F4 population. By background screening, a total of 39 BC2F3 and 21 BC1F4 families homozygous for the targeted QTLs with 90.9-97.9% and 86.8-88.3% RPG recoveries were selected. The best performing 17 BC2F3 and 10 BC1F4 lines were evaluated for various morpho-physiological traits. Phenotypic evaluation and multi-location trials of the introgressed lines under late sown conditions led to the selection of three promising lines with early anthesis and higher grain yield. The improved lines will serve as an excellent genetic material for functional genomics and expression studies to understand the molecular mechanisms and pathways underlying the stress tolerance.

Development and genetic analysis of conspicuous purple coloured corolla lip flower with multicapsules genotype in sesame (Sesamum indicum L.).

The present investigation was framed to understand the genetics and development of conspicuous purple coloured corolla tip flower and multicapsules at axil in sesame (Sesamum indicum L.) from the cross between genotypes IC-205776 (♀) 9 EC-118591 (♂). The conspicuous corolla lip colour is recessive in expression and under digenic control, differing from the earlier reports. The ratio at F2 generation was best fit for 13:3 indicating inhibitory gene action for purple corolla lip colour. Among two genes, one acts as an inhibitory gene at recessive condition to produce conspicuous purple corolla lip colour. Multicapsules/axil is dominant in expression, controlled by more than one gene. The ratio of multiple capsules/axil and single capsules/axil at F2 generation was the best fit for the ratio 11:5 indicating dominance modification of duplicate genes for a number of capsules per axil. Single capsule/axil results due to dominance modification of duplicate genes where the homozygous condition of one gene reverses the dominance relation of another gene in heterozygous condition. Joint segregation analysis indicated independent segregation of corolla lip colour and capsule number per axil.

Effect of different cooking methods on loss of iron and zinc micronutrients in fortified and non-fortified rice.

Malnutrition is considered as major public health concern and is emerging challenge to food and nutrition security particularly in developing countries. Rice is the staple food and consumed by the half of the world's population which is the source of daily requirement of the nutrients. Attempts are being made to fortify rice with micronutrients, but the loss or retention of these micronutrients in different cooking methods is not well studied and documented especially in fortified rice. In the present study, paddy seeds of six Indian varieties were fortified with iron and zinc by parboiling process. Consequently, fortified polished rice had higher micronutrient contents (Fe, 106.31 ± 12.56; Zn, 97.72 ± 9.75) than non-fortified polished rice (Fe, 7.44 ± 1.05; Zn, 14.74 ± 2.94) expressed in ppm. Polished rice of both fortified and non-fortified were cooked under five different cooking conditions and analyzed for remaining iron and zinc content. Cooking rice in rice cooker without prior washing (NRC) retained highest concentration of Fe and Zinc in both fortified and non-fortified rice varieties. It also showed that fortified rice suffered higher percentage loss of micronutrient, than the non-fortified rice. But the average retained micronutrient amount measured in ppm, was higher in fortified rice (Fe, 43.54 ± 6.88; Zn, 36.7 ± 3.12) than in non-fortified rice (Fe, 4.24 ± 0.87; Zn, 9.3 ± 2.11). Hence, adopting appropriate cooking method, higher amount of micronutrients will be retained in the cooked food which will in turn help in combating the malnutrition and improve health.

Effect of sowing time and crop geometry on the Capsaicinoid content in Bhoot Jolokia (Capsicum chinense Jacq.).

Capsicum species are not only cultivated as vegetable and condiment crop but are also incorporated into a number of medicinal preparations in the ancient literature around the world. 'Naga chilli' or 'Bhoot Jolokia' (Capsicum chinense Jacq.) is a chilli variety indigenous to the northeast region of India and has been recognized as one of the hottest chilli in the world. It has also been used conventionally in treating various human ailments since time immemorial by the indigenous people of the northeast India. Capsaicin and dihydrocapsaicin are the two major members of the so-called capsaicinoid family, which includes other minor analogues, and usually account for at least 90 % of the pungency trait in chilli fruits. In the present study, determination of Capsaicinoid content of Bhoot Jolokia (Capsicum chinense Jacq.) under different sowing time and spacing was done. In the Scoville Organoleptic test, the highest Scoville Heat Unit (SHU) value was found in September 15 sowing fruits and the lowest in the February 15 sowing fruits. Fruit produced from spacing 105 cm × 105 cm showed highest Scoville Heat Unit. In High Performance Liquid Chromatography analysis, highest amount of capsaicinoid was also found in September 15 sowing while fruits produced from spacing 105 cm × 105 cm showed highest amount of capsaicinoid. Identification of Nordihydrocapsaicin, Capsaicin and Dihydrocapsaicin was done by comparing the retention time of sample with those of standard.