S-nitrosocysteine-responsive genes modulate diverse regulatory pathways in Oryza sativa: a transcriptome profiling study.

Rice (Oryza sativa L.) is a major food crop and also a well-established genetic model. Nitric oxide (NO) and its derivatives are important signalling molecules that actively participate in various signalling pathways in response to different stresses. In this study, we performed RNA-seq mediated transcriptomic analysis of rice after treatment with the nitric oxide donor, S-nitroso-L-cysteine (CySNO), generating an average of 37.5 and 41.5 million reads from control and treated leaf samples respectively. More than 95% of the reads were successfully mapped to the O. sativa reference genome yielding a total of 33539 differentially expressed genes (DEGs, P < 0.05). Further analyses identified 825 genes with at least 2-fold change in the expression following treatment with CySNO (P < 0.01). The DEGs identified were involved in diverse molecular functions such as catalytic activity, binding, transport, and receptor activity and were mostly located in the membrane, organelles such as nucleus, Golgi apparatus and mitochondria. DEGs also contained several genes that regulate responses to abiotic stresses such as drought, heat, cold and salt stress and biotic stresses. We also found significantly similar expression patterns of CySNO-responsive DEGs of rice with the CySNO-responsive DEGs of Arabidopsis in a previous study. Expression patterns of genes involved in key biological functions were verified using quantitative real time (qRT)-PCR. The findings of this study suggest that NO regulates the transcriptional control of genes involved in a wide variety of physiological functions in rice, and that NO-mediated transcriptional networks are highly conserved across the plant kingdom. This study provides useful information regarding the transcriptional response of plants to nitrosative stress.