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Phospholipase C (PLC), a major membrane phospholipid hydrolyzing enzyme generates signaling messengers such as diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) in animals, and their phosphorylated forms such as phosphatidic acid (PA) and inositol hexakisphosphate (IP6) are thought to regulate various cellular processes in plants. Based on substrate specificity, plant PLC family is sub-divided into phosphatidylinositol-PLC (PI-PLC) and phosphatidylcholine-PLC (PC-PLC) groups. The activity of plant PLCs is regulated by various factors and the major ones include, Ca(2+) concentration, phospholipid substrate, post-translational modifications and interacting proteins. Most of the PLC members have been localized at the plasma membrane, suited for their function of membrane lipid hydrolysis. Several PLC members have been implicated in various cellular processes and signaling networks, triggered in response to a number of environmental cues and developmental events in different plant species, which makes them potential candidates for genetically engineering the crop plants for stress tolerance and enhancing the crop productivity. In this review article, we are focusing mainly on the plant PLC signaling and regulation, potential cellular and physiological role in different abiotic and biotic stresses, nutrient deficiency, growth and development., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Calcium ion is involved in diverse physiological and developmental pathways. One of the important roles of calcium is a signaling messenger, which regulates signal transduction in plants. CBL (calcineurin B-like protein) is one of the calcium sensors that specifically interact with a family of serine-threonine protein kinases designated as CBL-interacting protein kinases (CIPKs). The coordination of these two gene families defines complexity of the signaling networks in several stimulus-response-coupling during various environmental stresses. In Arabidopsis, both of these gene families have been extensively studied. To understand in-depth mechanistic interplay of CBL-CIPK mediated signaling pathways, expression analysis of entire set of CBL and CIPK genes in rice genome under three abiotic stresses (salt, cold and drought) and different developmental stages (3-vegetative stages and 11-reproductive stages) were done using microarray expression data. Interestingly, expression analysis showed that rice CBLs and CIPKs are not only involved in the abiotic stress but their significant role is also speculated in the developmental processes. Chromosomal localization of rice CBL and CIPK genes reveals that only OsCBL7 and OsCBL8 shows tandem duplication among CBLs whereas CIPKs were evolved by many tandem as well as segmental duplications. Duplicated OsCIPK genes showed variable expression pattern indicating the role of gene duplication in the extension and functional diversification of CIPK gene family in rice. Arabidopsis SOS3/CBL4 related genes in rice (OsCBL4, OsCBL5, OsCBL7 and OsCBL8) were employed for interaction studies with rice and Arabidopsis CIPKs. OsCBLs and OsCIPKs are not only found structurally similar but likely to be functionally equivalent to Arabidopsis CBLs and CIPKs genes since SOS3/CBL4 related OsCBLs interact with more or less similarly to rice and Arabidopsis CIPKs and exhibited an interaction pattern comparable with Arabidopsis SOS3/CBL4., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Ca(2+) is an essential inorganic macronutrient, involved in regulating major physiological processes in plants. 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 maintained at nano-molar range. Upon requirement, Ca(2+) is released from intra-cellular as well as extracellular compartments such as organelles and cell wall. In this study, we report for the first time, a whole genome transcriptome response to short (5 D) and long (14 D) term Ca(2+) starvation and restoration in rice. Our results manifest that short and long term Ca(2+) starvation involves a very different response in gene expression 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 Ca(2+) starvation. The functional classification 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 Ca(2+) concentration or availability are interpreted into adaptive responses in plants., (Copyright © 2014 Elsevier Ltd. All rights reserved.)