Genomic-Wide Analysis Identifies the PI-PLC Gene Family and Expression of Its Member PsnPI-PLC6 Confers Cadmium Tolerance in Transgenic Tobacco Plants.

The phospholipase C are key enzymes in phospholipid signaling in plant growth, development, biotic, and abiotic stress responses. So far, many PI-PLC (phosphoinositide-specific PLC) genes have been cloned from various plant species and their functions have been analyzed. However, the current understanding of the PI-PLC signal transduction pathway in woody plants is limited, and the function of PI-PLC in plant abiotic stress responses still needs to be experimentally verified. In order to explore the evolution and function of the poplar PI-PLC gene family, 7 PI-PLC genes were identified through genome-wide analysis. The encoded proteins all had X and Y conserved catalytic domains and C2 domain. Chromosomal location analysis showed that the PtPI-PLCs were located on 4 of the 19 poplar chromosomes. Phylogenetic relationship analysis showed that the poplar PtPI-PLC gene family had high similarity with the PLC sequences in other plants. Expression pattern analysis showed that PsnPI-PLC6 was transiently up-regulated under cadmium stress conditions in the root, stems, and leaves of Populus simonii × P. nigra. Physiological and biochemical results showed that the SOD activities were increased under cadmium stress, implying that expression of PsnPI-PLC6 in tobacco increased ROS scavenging ability. This study provides new insights into the functional analysis of poplar PI-PLC genes in response to abiotic stress. [ABSTRACT FROM AUTHOR]