Function Analysis Of AtPLC14 Regulation Pollen Germination And Development In Arabidopsis

The phospholipases C are characterized by hydrolyzing phospholipids.It is a super family that contains much subtype.Accroding to the different substrates,it can be devided into Phosphoinositide-specific phospholipase C(PI-PLC),Phosphatidylcholine- specific phospholipase C(PC-PLC) and so on.PI-PLC universally consists in mammal and plant, which plays a key role in the phosphoinositide signaling transduction pathway,which has been proposed to be important in regulating many physiological processes.PI-PLC and some signal molecules such as Phosphatidylinositol bisphosphate(PIP₂),Inositol 1,4,5-trisphosphate (IP3),Diacylglycerol(DAG),Ca²⁺ were found invoved in the pollen germination and pollen tuble growth processes in plants.A novel phospholipase C that can hydrolyze phosphatidylcholine has been found in plant nowdays.It has been reported that PC-PLC had relatively high expression levels in nonphotosynthetic organs like floral organs and roots.The expression of PC-PLC in roots is related to phosphate supplementation and the replacement of polar lipids during phosphate deprivation.After the accomplishment of Arabidopsis genome sequencing,we have known that there are about 17 classes of PLC subtype in Arabidopsis,and all of them might have their own functions in different physiological process.Here,we use one subtype of Arabidopsis PLC-like gene(AtPLC14) T-DNA insertion mutants,anastates and overexpression as material,and we used wide-type Arabidopsis as comparison,providing molecular evidences of this gene in vivo during the pollen germination and development.We found that AtPLC14 is highly expressed in mature pollen by RT-PCR and GUS-staining.Then we detected the phenotype and germinant character of mutant pollen using wide-type Arabidopsis as comparison.The results showed that the defect of AtPLC14 could cause the decrease in the pollen germination and pollen tube growth.Through the transient expression results of the gene AtPLC14 and eYFP fusion gene in onion epidermal cell,we found that the subcellular expression site of the gene AtPLC14 located on and outside the plasma membrane.We tested the prokaryotic expression product of the gene AtPLC14 by high efficiency liquid chromatography,we found the function of the expression product is hydrolyzing the phosphatidylcholine(PC).These rusults suggested that the product of AtPLC14 is a kind of hydrolase that can hydrolyze PC. It locates outside the plasma membrane,involves in the regulation of the pollen tube germ-ination and growth.