Overexpression of PLC increases drought tolerance

ZHANG, QIANQIAN; VAN WIJK, RINGO; GUARDIA, AISHA; SCUFFI, DENISE; GARCÍA-MATA, CARLOS; HARING, MICHEL A.; LAXALT, ANA MARÍA; MUNNIK, TEUN

Lunteren

Congreso; Dutch Society of Biochemestry. Lunteren, The Netherlands; 2015

Drought is one of the most important environmental stresses that limit plant growth and crop yield. Recently,overexpression of phosphoinositide-specific phospholipase C (PLC) in maize (Wang et al. 2008) and canola (Georges et al. 2009) generated plants with increased drought tolerance. In animals, PLC is an enzyme that hydrolyses membrane-bound phosphatidylinositol 4,5-bisphosphate (PIP2) to generate two second messengers, diacylglycerol (DAG) and inositol trisphosphate (InsP3). These second messengers cause the release of Ca2+ from intracellular stores and activate members of the protein kinase C (PKC) family. Plants,however, lack homologs for the InsP3 receptor and PKC. Furthermore, plants display extremely low PIP2 levels in their membranes under normal conditions. Plants do have genes encoding for phosphatidylinositol kinase(PIK), which generate phosphatidylinositol phosphate (PIP), and PIP kinase (PIPK) to synthesize PIP2. Recent data suggests that not DAG and InsP3 but their phosphorylated products, i.e. InsP5 and InsP6, and phosphatidic acid (PA) function as plant signalling molecules (Munnik 2014). Both InsP6 (Lemtiri-Chlieh et al. 2003) and PA (Zhang et al. 2009) have been implicated in guard cell signalling and regulation of stomatal aperture. Arabidopsis contains nine PLCs. Here we show that four PLCs, namely PLC2 (At3g08510), PLC3 (At4g38530),PLC5 (At5g58690) and PLC7 (At5g55940), belonging to different clades (Hunt 2004, Fig. 1), all exhibit increased tolerance to drought.