Discovery of genomic regions and candidate genes for grain weight employing next generation sequencing based QTL-seq approach in rice (Oryza sativa L.).

Rice (Oryza sativa L.) yield enhancement is one of the prime objectives of plant breeders. Elucidation of the inheritance of grain weight, a key yield component trait, is of paramount importance for raising the yield thresholds in rice. In the present investigation, we employed Next-Generation Sequencing based QTL-seq approach to identify major genomic regions associated with grain weight using mapping populations derived from a cross between BPT5204 and MTU3626. QTL-seq analysis identified three grain weight quantitative trait loci (QTL) viz., qGW1 (35-40 Mb), qGW7 (10-18 Mb), and qGW8 (2-5 Mb) on chromosomes 1, 7 and 8, respectively and all are found to be novel. Further, qGW8 was confirmed through conventional QTL mapping in F2, F3 and BC1F2 populations and found to explain the phenotypic variance of 17.88%, 16.70% and 15.00%, respectively, indicating a major QTL for grain weight. Based on previous reports, two candidate genes in the qGW8 QTL were predicted i.e., LOC_Os08g01490 (Cytochrome P450), and LOC_Os08g01680 (WD domain, G-beta repeat domain containing protein) and through in silico analysis they were found to be highly expressed in reproductive organs during different stages of grain development. Here, we have demonstrated that QTL-seq is one of the rapid approaches to uncover novel QTLs controlling complex traits. The candidate genes identified in the present study undoubtedly enhance our understanding of the mechanism and inheritance of the grain weight. These candidate genes can be exploited for yield enhancement after confirmation through complementary studies.

Antioxidants and lipid peroxidation status in diabetic patients with and without complications.

BACKGROUND: Oxidative stress is involved in the pathophysiology of diabetes mellitus. METHODS: In the present study, 68 patients with type 2 diabetes mellitus and 31 clinically healthy individuals were evaluated. The patients were divided into two groups. Group 1 included 29 patients without diabetic complications and group 2 consisted of 39 patients with diabetic complications. Erythrocyte glutathione, superoxide dismutase, and thiobarbituric acid-reactive substance levels as well as plasma antioxidant vitamins C and E, and serum total glutathione-S-transferase, ceruloplasmin, and protein thiols were estimated by using spectro-photometer. RESULTS: A significant decrease of erythrocyte glutathione was observed in group 1 when compared with the controls. Thiols decreased in group 2. An increase in glutathione-S-transferase, ceruloplasmin, superoxide dismutase, and vitamins C and E levels was noted in patients with diabetes mellitus. Thiobarbituric acid-reactive substance levels decreased in group 1 but increased in group 2 when compared with the controls. CONCLUSION: In the present study, tendency of most of the antioxidants to rise in diabetes could probably be due to an adaptive response to the pro-oxidant milieu of the diabetic state. Hence, we suggest that supplementation with dietary antioxidants especially antioxidant vitamins accompanied by change in lifestyle might help to reduce damage brought about by free radical toxicity in diabetes mellitus.