Jawaharlal Nehru University

About: Jawaharlal Nehru University is a education organization based out in New Delhi, India. It is known for research contribution in the topics: Population & Politics. The organization has 6082 authors who have published 13455 publications receiving 245407 citations. The organization is also known as: JNU.

Petrology and geochemistry of metamorphosed basaltic pillow lava and basaltic komatiite in the Mauranipur area: subduction related volcanism in the Archean Bundelkhand craton, Central India

Abstract: The occurrence of metamorphosed basaltic pillow lava in close association with serpentinized ultramafic rock, metamorphosed basaltic komatiite, volcaniclastic metasediment, and banded iron formation (BIF) in the Mauranipur area is the first explicit evidence for subduction related submarine volcanism in the Archean Bundelkhand craton, Central India. The Mauranipur pillow lava underwent greenschist to amphibolite facies metamorphism while retaining a geochemical signature of its igneous protolith. The pillow lava and associated massive volcanic rock is subalkalic, low-K tholeiitic basalt to basaltic andesite with SiO2 = 51.9-55.9 wt% and Mg/(Mg + Fetotal) × 100 = 63.4-67.2. The rock shows depletion in HFS elements with Nb/Nb* (0.07-0.17), and LIL elements are relatively enriched compared with present-day N-MORB compositions. Chondrite normalized REE patterns for the Mauranipur pillow lava are nearly flat with (La/Sm)N = 0.9-1.5, (Gd/Yb)N = 1.0-1.1, and Eu/Eu* = 0.81-1.10. The geochemical characteristics of the pillow lava are similar to those of low-K tholeiitic basalt reported from modern intra-oceanic arcs. The associated high-Mg andesite is compositionally similar to basaltic komatiite, enriched in LREE, with (La/Sm)N = 2.95-6.44, and depicts a nearly flat chondrite normalized HREE pattern with a low MREE/HREE ratio (Gd/Yb)N = 1.24-1.58. The basaltic komatiite displays remarkably similar geochemical characteristics to modern boninite. The present study, combined with available geological data, suggests that the supracrustal rocks of the Mauranipur area represent an Archean ophiolite sequence formed in a plate convergent setting.

Presence of unique glyoxalase III proteins in plants indicates the existence of shorter route for methylglyoxal detoxification

Abstract: Glyoxalase pathway, comprising glyoxalase I (GLY I) and glyoxalase II (GLY II) enzymes, is the major pathway for detoxification of methylglyoxal (MG) into D-lactate involving reduced glutathione (GSH). However, in bacteria, glyoxalase III (GLY III) with DJ-1/PfpI domain(s) can do the same conversion in a single step without GSH. Our investigations for the presence of DJ-1/PfpI domain containing proteins in plants have indicated the existence of GLY III-like proteins in monocots, dicots, lycopods, gymnosperm and bryophytes. A deeper in silico analysis of rice genome identified twelve DJ-1 proteins encoded by six genes. Detailed analysis has been carried out including their chromosomal distribution, genomic architecture and localization. Transcript profiling under multiple stress conditions indicated strong induction of OsDJ-1 in response to exogenous MG. A member of OsDJ-1 family, OsDJ-1C, showed high constitutive expression at all developmental stages and tissues of rice. MG depletion study complemented by simultaneous formation of D-lactate proved OsDJ-1C to be a GLY III enzyme that converts MG directly into D-lactate in a GSH-independent manner. Site directed mutagenesis of Cys-119 to Alanine significantly reduces its GLY III activity indicating towards the existence of functional GLY III enzyme in rice-a shorter route for MG detoxification.

Association mapping in plants in the post-GWAS genomics era.

Abstract: With the availability of DNA-based molecular markers during early 1980s and that of sophisticated statistical tools in late 1980s and later, it became possible to identify genomic regions that control a quantitative trait. The two methods used for this purpose included quantitative trait loci (QTL) interval mapping and genome-wide association mapping/studies (GWAS). Both these methods have their own merits and demerits, so that newer approaches were developed in order to deal with the demerits. We have now entered a post-GWAS era, where either the original data on individual genotypes are being used again keeping in view the results of GWAS or else summary statistics obtained through GWAS is subjected to further analysis. The first half of this review briefly deals with the approaches that were used for GWAS, the GWAS results obtained in some major crops (maize, wheat, rice, sorghum and soybean), their utilization for crop improvement and the improvements made to address the limitations of original GWA studies (computational demand, multiple testing and false discovery, rare marker alleles, etc.). These improvements included the development of multi-locus and multi-trait analysis, joint linkage association mapping, etc. Since originally GWA studies were used for mere identification of marker-trait association for marker-assisted selection, the second half of the review is devoted to activities in post-GWAS era, which include different methods that are being used for identification of causal variants and their prioritization (meta-analysis, pathway-based analysis, methylation QTL), functional characterization of candidate signals, gene- and gene-set based association mapping, GWAS using high dimensional data through machine learning, etc. The last section deals with popular resources available for GWAS in plants in the post-GWAS era and the implications of the results of post-GWAS for crop improvement.

Fungal association and utilization of phosphate by plants: success, limitations, and future prospects

Abstract: Phosphorus (P) is a major macronutrient for plant health and development. The available form of P is generally low in the rhizosphere even in fertile soils. A major proportion of applied phosphate (Pi) fertilizers in the soil become fixed into insoluble, unavailable forms, which restricts crop production throughout the world. Roots possess two distinct modes of P uptake from the soil, direct and indirect uptake. The direct uptake of P is facilitated by the plant's own Pi transporters while indirect uptake occurs via mycorrhizal symbiosis, where the host plant obtains P primarily from the fungal partner, while the fungus benefits from plant-derived reduced carbon. So far, only one Pi transporter has been characterized from the mycorrhizal fungus Glomus versiforme. As arbuscular mycorrhizal fungi cannot be cultured axenically, their Pi transporter network is difficult to exploite for large scale sustainable agriculture. Alternatively, the root-colonizing endophytic fungus Piriformospora indica can grow axenically and provides strong growth-promoting activity during its symbiosis with a broad spectrum of plants. P. indica contains a high affinity Pi transporter (PiPT) involved in improving Pi nutrition levels in the host plant under P limiting conditions. As P. indica can be manipulated genetically, it opens new vistas to be used in P deficient fields.