Cytosolic calcium and nuclear calcium-regulated transcription networks in response to ABA and JA

Calcium acts as a universal second messenger to regulate gene expression in both developmental processes and responses to environmental stresses. Previous studies showed that a number of stimuli can induce calcium increases in the cytoplasm and nucleus, independently. However, the gene expression network deciphering [Ca2+]cyt and/or [Ca2+]nuc signaling pathway remain obscure. Using transgenic Arabidopsis containing a fusion protein, comprising rat parvalbumin (PV) with either a nuclear export sequence (PV-NES) or a nuclear localization sequence (NLS-PV), to selectively buffer the cytosolic or nucleosolic calcium, we identified the [Ca2+]cyt- or /and [Ca2+]nuc-regulated ABA- and MeJA-responsible genes with the Arabidopsis Genome Oligo array. Three day-old seedlings of wild type (Col-0) , the transgenic plants PV-NES and NLS-PV were transferred onto medium with or without 10 μM ABA or 50 μM MeAJ for growing additional 5 days. Then RNA was extracted from those seedlings .