Chugh, J. | bioRxiv Science

bioRxiv2019

Cold storage reveals distinct metabolic perturbations in processing and non-processing cultivars of potato

Cold-induced sweetening (CIS) causes a great loss to the potato (Solanum tuberosum L.) processing industry wherein selection of potato genotypes using biochemical information through marker-trait associations has found to be advantageous. In the present study, we have performed nuclear magnetic resonance (NMR) spectroscopy-based metabolite profiling on tubers from five potato cultivars (Atlantic, Frito Lay-1533, Kufri Jyoti, Kufri Pukhraj, and PU1) differing in their CIS ability and processing characteristics at harvest and after one month of cold storage at 4{degrees}C. A total of 39 water-soluble metabolites were detected using 1H NMR. Multivariate statistical analysis indicated significant differences in metabolite profiles between processing and non-processing potato cultivars. Further analysis revealed distinct metabolite perturbations as induced by cold storage in both types of cultivars wherein significantly affected metabolites were categorized mainly as sugars, sugar alcohols, amino acids, and organic acids. Significant metabolic perturbations were used to carry out metabolic pathway analysis that in turn tracked 130 genes encoding enzymes (involved directly and/or indirectly) involved in CIS pathway using potato genome sequence survey data. Based on the metabolite perturbations, the possible relevant metabolite biomarkers, significantly affected metabolic pathways, and key candidate genes responsible for the observed metabolite variation were identified. Overall, studies provided new insights in further manipulation of specific metabolites playing a crucial role in determining the cold-induced ability and processing quality of potato cultivars for improved quality traits.\n\nHighlightMetabolomic profiling using 1D 1H-NMR and bioinformatics analysis of potato cultivars for the identification of metabolites and genes controlling biochemical pathways in cold-stored potato tubers

plant biology↗

bioRxiv2019

NMR-based analysis of nucleotide π-stacking in a crowded environment: Implications for prebiotic reactions

The inherent heterogeneity of the prebiotic milieu is often overlooked when studying nonenzymatic reactions. However, it is important to note that the prebiotic soup of a putative RNA World would have been replete with a plethora of molecules resulting from complex chemical syntheses, as well as exogeneous delivery. The presence of such background molecules could lead to pertinent phenomenon such as molecular crowding, which can potentially affect how a reaction would advent in a crowded milieu. In the current study, we have analyzed the effect of crowding on the stacking ability of the RNA monomers, using Nuclear Magnetic Resonance (NMR) spectroscopy. Our findings corroborate that the purine monomers possess better stacking efficiency than pyrimidine based monomers. Significantly, this competence is further enhanced in the presence of a crowding agent. Interestingly, this enhanced stacking could result in higher sequestration of the purine monomers, putting their ready availability for relevant nonenzymatic polymerization and replication reactions into question. Taken together, this study demonstrates the need for systematic biophysical characterization of molecular crowding in the context of prebiotically pertinent processes. Unravelling such phenomena is essential to gather a real understanding of how the transition from abiotic to biotic, would have happened during the origin of life.

biophysics↗