Global transcriptome analysis of novel stress associated protein (<i>SAP</i>) genes expression dynamism of combined abiotic stresses in <i>Oryza sativa</i> (L.)

Genes encoding proteins with A20/AN1 zinc-finger domains, belonging to the stress associated protein (SAP) gene family, are present in all eukaryotes and play a decisive role in plant response to diverse physiological and molecular activities particularly on biotic and abiotic stresses (AbS). In this first and foremost study, global transcriptome analysis of members of the <i>SAP</i> gene family was carried out in C3 model-<i>Oryza sativa</i> (<i>OsSAP</i>) aiming at the identification of <i>OsSAP</i> genes activated in response to unique or Combined AbS (CAbS). Based on the available spatio-temporal and phytohormonal RNA-Seq expression profile datasets, nine <i>OsSAP</i> genes were filtered out and identified by a differential expression signature noted in various tissues as well as plant hormones. Comparative genome ideogram of <i>OsSAP</i> genes confirmed the orthologous collinearity with C4 panicoid genomes. Interactome of these genes, revealed the molecular cross-talks of <i>OsSAP</i>. Thus, the computational expression signature of <i>OsSAP</i> genes led to a better understanding of gene dynamism in diverse developmental tissues/organs. Transcriptional regulation analysis of key <i>OsSAP</i> genes in response to stress (drought and salinity) suggested the novel role of <i>OsSAP1</i>, <i>OsSAP2</i>, <i>OsSAP5, OsSAP7</i>, <i>OsSAP8</i> and <i>OsSAP11</i> in AbS. Altogether, the study provides deeper insights on molecular characteristics of <i>OsSAP</i> genes, which could be deployed further to decipher their precise functional roles in AbS responses. Communicated by Ramaswamy H. Sarma