Genome-Wide Analysis and Expression Profiling of the Phospholipase C Gene Family in Soybean (Glycine max)

Abstract

Phosphatidylinositol-specific phospholipase C (PI-PLC) hydrolyses phosphatidylinositol-4,5-bisphosphate to produce diacylglycerol and inositol 1,4,5-trisphosphate. It plays an important role in plant development and abiotic stress responses. However, systematic analysis and expression profiling of the phospholipase C (PLC) gene family in soybean have not been reported. In this study, 12 putative PLC genes were identified in the soybean genome. Soybean PLCs were found on chromosomes 2, 11, 14 and 18 and encoded 58.8-70.06 kD proteins. Expression pattern analysis by RT-PCR demonstrated that expression of the GmPLCs was induced by PEG, NaCl and saline-alkali treatments in roots and leaves. GmPLC transcripts accumulated specifically in roots after ABA treatment. Furthermore, GmPLC transcripts were analyzed in various tissues. The results showed that GmPLC7 was highly expressed in most tissues, whereas GmPLC12 was expressed in early pods specifically. In addition, subcellular localization analysis was carried out and confirmed that GmPLC10 was localized in the plasma membrane in Nicotiana benthamiana. Our genomic analysis of the soybean PLC family provides an insight into the regulation of abiotic stress responses and development. It also provides a solid foundation for the functional characterization of the soybean PLC gene family.

Fig 1. Domain analysis of soybean PLCs.

Fig 2. Phylogenetic analysis of the PLC family in soybean, Arabidopsis and rice.

Fig 3. Expression of soybean PLCs in leaves under abiotic stress.

The expression levels of soybean PLCs, which were shown in Y-axis, were compared with the control (0 h). Please note that the expression levels of different PLCs are scaled differently.

Fig 4. Expression of soybean PLCs in roots under abiotic stress.

The expression levels of soybean PLCs, which were shown in Y-axis, were compared with the control (0 h). Please note that the expression levels of different PLCs are scaled differently.

Fig 5. Expression of GmPLCs in various organs.

The expression levels of soybean PLCs was compared with EF1A which the expression level of EF1A was defined as “1”. a: expression level > 0.1; b: expression level from 0.01 to 0.1; c: expression level from 0.001 to 0.01; d: expression level < 0.001. Please note that the expression levels of different PLCs are scaled differently.

Fig 6. Cis-regulatory elements in the promoters of the soybean PLC gene family.

The values of -900 to -100 represent the upstream region (from translation start site) of the promoter of all the PLC genes. Various elements such as ABRE, MBS, TC-rich, Skn-1 and GCN4 are present in the promoter.

Fig 7. Subcellular localization of GmPLC10 in Nicotiana benthamiana cells.

Bar = 20 μm.