Ca²⁺is an essential inorganic macronutrient, involved in regulating major physiological processes inplants. It has been well established as a second messenger and is predominantly stored in the cell wall,endoplasmic reticulum, mitochondria and vacuoles. In the cytosol, the concentration of this ion is main-tained at nano-molar range. Upon requirement, Ca²⁺is released from intra-cellular as well as extracellularcompartments such as organelles and cell wall. In this study, we report for the first time, a whole genometranscriptome response to short (5 D) and long (14 D) term Ca²⁺starvation and restoration in rice. Ourresults manifest that short and long term Ca2+starvation involves a very different response in gene expres-sion with respect to both the number and function of genes involved. A larger number of genes were up-or down-regulated after 14 D (5588 genes) than after 5 D (798 genes) of Ca²⁺starvation. The functionalclassification of these genes indicated their connection with various metabolic pathways, ion transport,signal transduction, transcriptional regulation, and other processes related to growth and development.The results obtained here will enable to understand how changes in Ca²⁺concentration or availabilityare interpreted into adaptive responses in plants