Calcium deficient transcriptome analysis of rice

Calcium is an essential macronutrient and plant requires it in large amounts for normal growth and development. This ion participated in innumerable processes and affects nearly all aspects of plant growth and development such as signal transduction, metabolism of lipids, proteins, and carbohydrates, cell growth, cell wall and membrane stabilization. We used whole genome microarrays to determine the transcriptomic profile of rice seedlings exposed to short-term and long term Ca2+ deficiency followed by Ca2+ resupply. Calcium treated seedlings were used for for RNA extraction and hybridization on Agilent microarray platform. Three biological replicates of each sample were used for microarray analysis. We wanted to know the altered expression patterns of calcium-responsive genes majorly involved in metabolic processes, signal transdction pathways, transcriptional regulation, and transport of multiple molecules including Ca2+. Seeds of indica rice were surface sterilized and grown hydroponically in rice growing medium. Plants were grown in the rice growth room under the condition of 16 h light/8 h dark (28°C) photoperiod with 70 % humidity. After 5 days of normal growth, some of the seedlings were transferred to nutrient solution lacking CaCl2 (-Ca2+). After 5 and 14 days, calcium (0.798 mM CaCl2) was resupplied to the plants grown in -Ca2+ medium for 6 h.