Ribosomal proteins are an integral part of ribosomes and are involved in their biogenesis and assembly, thus regulating protein synthesis. It is difficult to attribute an individual function of translational activity to a single ribosomal protein. This difficulty is rooted in the highly cooperative nature of the interactions between ribosomal ribonucleic acid (rRNA) and ribosomal proteins. Ribosomal proteins regulate their own synthesis by controlling the expression of their transcripts in association with transcription factors. The ribosome consists of large and small subunits. In eukaryotes, 47 ribosomal protein large (RPL) subunits and 32 ribosomal protein small (RPS) subunits form a ribosome complex with rRNAs (Ben-Shem et al., 2011). Interestingly, extraribosomal functions of many ribosomal proteins have been reported (Wool, 1996; Freed et al., 2010). Several ribosomal protein-encoding genes are shown to be differentially

Reactive carbonyl compounds (RCCs) such as hydroxynonenol, malondialdehyde, acrolein, crotonaldehyde, methylglyoxal, and glyoxal accumulate at higher levels under stress in plants and damage the cell metabolic activities. Plants have evolved several detoxifying enzymes such as aldo−keto reductases (AKRs), aldehyde/alcohol dehydrogenases (ALDH/ADH), and glyoxalases. We report the phylogenetic relationship of these proteins and in silico analysis of rice-detoxifying protein structures and their substrate affinity with cofactors using docking and molecular simulation studies. Molecular simulations with nicotinamide adenine dinucleotide phosphate or glutathione cofactor docking with commonly known reactive substrates suggests that the AKRs, ALDH, and ADH proteins attain maximum conformational changes, whereas glyoxalase has fewer conformational changes with cofactor binding. Several AKRs showed a significant binding affinity with many RCCs. The rice microarray studies showed enhanced expression of many AKRs in resistant genotypes, which also showed higher affinity to RCCs, signifying their importance in managing carbonyl stress. The higher expression of AKRs is regulated by stress-responsive transcription factors (TFs) as we identified stress-specific cis-elements in their promoters. The study reports the stress-responsive nature of AKRs, their regulatory TFs, and their best RCC targets, which may be used for crop improvement programs.

Background The unprecedented drought and frequent occurrence of pathogen infection in rice is becoming more due to climate change. Simultaneous occurrence of stresses lead to more crop loss. To cope up multiple stresses, the durable resistant cultivars needs to be developed, by identifying relevant genes from combined biotic and abiotic stress exposed plants. Results We studied the effect of drought stress, bacterial leaf blight disease causing Xanthomonas oryzae pv. oryzae (Xoo) pathogen infection and combined stress in contrasting BPT5204 and TN1 rice genotypes. Mild drought stress increased Xoo infection irrespective of the genotype. To identify relevant genes that could be used to develop multi-stress tolerant rice, RNA sequencing from individual drought, pathogen and combined stresses in contrasting genotypes has been developed. Many important genes are identified from resistant genotype and diverse group of genes are differentially expressed in contrasting genotypes under combined stress. Further, a meta-analysis from individual drought and Xoo pathogen stress from public domain data sets narrowed- down candidate differentially expressed genes. Many translation associated genes are differentially expressed suggesting their extra-ribosomal function in multi-stress adaptation. Overexpression of many of these genes showed their relevance in improving stress tolerance in rice by different scientific groups. In combined stress, many downregulated genes also showed their relevance in stress adaptation when they were over-expressed. Conclusions Our study identifies many important genes, which can be used as molecular markers and targets for genetic manipulation to develop durable resistant rice cultivars. Strategies should be developed to activate downregulated genes, to improve multi-stress tolerance in plants.

Drought-induced abscisic acid (ABA) accumulation plays a key role in plant water relations by regulating stomatal movements. Although ABA helps in the survival of the plants, reduced carbon gain affects plant productivity. To improve crop productivity under mild drought stress conditions, it is necessary to manipulate ABA responses. Other research groups have used forward chemical genomics for the identification of ABA agonists and antagonists aiming to manipulate ABA biosynthesis and signalling. In the present study, we identified indolyl-ethyl amine and serotonin small molecules using a reverse chemical genomics approach, with these acting as potent inhibitors of ABA biosynthesis through transient regulation of bZIP23 transcription factor activity. In rice, wheat and soybean, each of the small molecules enhanced the germination of seeds, even in the presence of ABA. These molecules nullified the effect of ABA on intact and detached leaves, resulting in higher photosynthesis. Furthermore, these small molecules effectively reduced the transcription levels of bZIP23 targeting NCED4, PP2C49 and CO3 genes. Rice plants treated with the small molecules were found to have improved stomatal conductance, spikelet fertility and yield compared to untreated plants under mild drought stress conditions. Our results suggest that indolyl-ethyl amine and serotonin small molecules could be utilized to improve yield under mild drought conditions.