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Rice is the foremost crop catering to the major calorific requirement of the human population but has the disadvantage of having high glycaemic index (GI). The fine quality rice varieties, BPT and RNR have been recently identified as having low GI in nature and are grown mostly in southern parts of India. Starch (80%) is the major component of rice endosperm attributing to GI. The study aimed to unravel the molecular basis of low GI through targeted pooled amplicon sequencing of major starch biosynthetic genes. A total of 13 candidate genes involved in starch synthesis were amplified and pooled in equimolar proportion for sequencing. Single-nucleotide polymorphisms (SNPs) and insertions/deletions (Indels) were detected in both coding and noncoding regions. Among the genes that are under study, the highest number of variations were identified in starch synthase I (SSI) followed by starch synthase IIIA (SSIIIA) genes. Nonsynonymous SNPs with high probability of effecting gene function were validated by Sanger sequencing and molecular docking. Identified causative SNPs were mapped on 3000 rice genome database and their allele frequencies were obtained. The outcome of this study has a potential to be applied in breeding programmes to obtain low GI rice varieties with added beneficial traits.

Rice is the foremost crop catering to the major calorific requirement of the human population but has the disadvantage of having high glycaemic index (GI). The fine quality rice varieties, BPT and RNR have been recently identified as having low GI in nature and are grown mostly in southern parts of India. Starch (80%) is the major component of rice endosperm attributing to GI. The study aimed to unravel the molecular basis of low GI through targeted pooled amplicon sequencing of major starch biosynthetic genes. A total of 13 candidate genes involved in starch synthesis were amplified and pooled in equimolar proportion for sequencing. Single-nucleotide polymorphisms (SNPs) and insertions/deletions (Indels) were detected in both coding and noncoding regions. Among the genes that are under study, the highest number of variations were identified in starch synthase I (SSI) followed by starch synthase IIIA (SSIIIA) genes. Nonsynonymous SNPs with high probability of effecting gene function were validated by Sanger sequencing and molecular docking. Identified causative SNPs were mapped on 3000 rice genome database and their allele frequencies were obtained. The outcome of this study has a potential to be applied in breeding programmes to obtain low GI rice varieties with added beneficial traits.

Cytoplasmic male sterility (CMS) is an important trait for large-scale hybrid seed production which avoids manual emasculation and undesired horizontal spread of pollen. Rearrangements in mitochondrial genome in terms of deletions and insertions are frequent causes leading to CMS. Mitochondrial ATP synthase is a multisubunit molecular machine which is involved in synthesis of ATP. In this study, three mutations in ATPase subunit 6 were identified and their cosegregation with male sterility was established using tobacco male sterile hybrids and

Cytoplasmic male sterility (CMS) is an important trait for large-scale hybrid seed production which avoids manual emasculation and undesired horizontal spread of pollen. Rearrangements in mitochondrial genome in terms of deletions and insertions are frequent causes leading to CMS. Mitochondrial ATP synthase is a multisubunit molecular machine which is involved in synthesis of ATP. In this study, three mutations in ATPase subunit 6 were identified and their cosegregation with male sterility was established using tobacco male sterile hybrids and Nicotiana suvaolensis. A breeder friendly Kompetitive allele specific polymerase chain reaction (KASP) SNP marker was developed for high throughput and quick genotyping. Introgression of this trait into selected germplasm lines (n = 9) was achieved based on foreground for CMS and background selection for recurrent parent using KASP marker and 50K custom tobacco SNP array, respectively. Analysis of genotyping data from SNP array revealed the presence of 88-99% of recurrent parent genome in BC3F1 plants. The selected BC3F1 plants exhibit CMS and are indistinguishable from the fertile recurrent parent (germplasm) in terms of plant morphology.

Potassium (K), one of the essential elements required for plant growth and development, determines leaf quality in tobacco (Nicotiana tabacum L.). Potassium (K) levels are relatively high in black soils (vertisols), but K uptake is severely hindered by the presence of remarkably high levels of calcium and magnesium. Our major objective was to enhance potassium uptake in black soils, which cover the major tobacco growing regions of Andhra Pradesh, India. Among several agronomic inputs such as soil amendments, fertilizer application, and plant growth regulators, we found that foliar application of fulvic acid (FA), one of the most bioactive humate molecules, enhanced K levels in leaves. Using next-generation sequencing (NGS), we identified changes in expression levels of a number of genes related to metabolic pathways implicated in plant growth and nutrient uptake upon FA application. Interestingly, starch levels in leaves were reduced concomitant with an increase in K attributable to FA application. We att...