Ramanjulu Sunkar

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MicroRNAs (miRNAs) and short interfering RNAs (siRNAs) are small noncoding RNAs that have recently emerged as important regulators of mRNA degradation, translational repression, and chromatin modification. In Arabidopsis thaliana, 43 miRNAs comprising 15 families have been reported thus far. In an attempt to identify novel and abiotic stress regulated(More)
MicroRNAs (miRNAs) are a class of regulatory RNAs of approximately 21 nucleotides that posttranscriptionally regulate gene expression by directing mRNA cleavage or translational inhibition. Increasing evidence points to a potential role of miRNAs in diverse physiological processes. miR398 targets two closely related Cu/Zn superoxide dismutases (cytosolic(More)
In higher eukaryotes, miRNAs and siRNAs guide translational inhibition, mRNA cleavage, or chromatin regulation. We found that the antisense overlapping gene pair of Delta(1)-pyrroline-5-carboxylate dehydrogenase (P5CDH), a stress-related gene, and SRO5, a gene of unknown function, generates two types of siRNAs. When both transcripts are present, a 24-nt(More)
Small RNA-guided gene silencing at the transcriptional and post-transcriptional levels has emerged as an important mode of gene regulation in plants and animals. Thus far, conventional sequencing of small RNA libraries from rice led to the identification of most of the conserved miRNAs. Deep sequencing of small RNA libraries is an effective approach to(More)
MicroRNAs (miRNAs) are a growing family of small noncoding RNAs that downregulate gene expression in a sequence-specific manner. The identification of the entire set of miRNAs from a model organism is a critical step toward understanding miRNA-guided gene regulation. Rice (Oryza sativa) and Arabidopsis thaliana, two plant model species with fully sequenced(More)
MicroRNA (miRNA)-guided target RNA expression is vital for a wide variety of biological processes in eukaryotes. Currently, miRBase (version 13) lists 142 and 353 miRNAs from Arabidopsis and rice (Oryza sativa), respectively. The integration of miRNAs in diverse biological networks relies upon the confirmation of their RNA targets. In contrast with the(More)
Abiotic stress is one of the primary causes of crop losses worldwide. Much progress has been made in unraveling the complex stress response mechanisms, particularly in the identification of stress responsive protein-coding genes. In addition to protein coding genes, recently discovered microRNAs (miRNAs) and endogenous small interfering RNAs (siRNAs) have(More)
In plants, oxidative stress is one of the major causes of damage as a result of various environmental stresses. Oxidative stress is primarily because of the excessive accumulation of reactive oxygen species (ROS). The amplification of ROS damage is further stimulated by the accumulation of toxic degradation products, i.e. aldehydes, arising from reactions(More)
MicroRNA398 targets two Cu/Zn superoxide dismutases (CSD1 and CSD2) in higher plants. Previous investigations revealed both decreased miR398 expression during high Cu2+ or paraquat stress and increased expression under low Cu2+ or high sucrose in the growth medium. Here, we show that additional abiotic stresses such as ozone and salinity also affect miR398(More)
The discovery of microRNAs (miRNAs) as gene regulators has led to a paradigm shift in the understanding of post-transcriptional gene regulation in plants and animals. miRNAs have emerged as master regulators of plant growth and development. Evidence suggesting that miRNAs play a role in plant stress responses arises from the discovery that miR398 targets(More)