Abstract
Phospholipase A2 (PLA2) hydrolyzes the fatty acyl ester bond at the sn-2 position of glycerophospholipids. In many plant species, the existence of PLA2 has been ascertained by advance in genome project and molecular biology. However, there is little information on the physiological role of plant PLA2, in contrast to many reports on the functions of animal PLA2. We have recently cloned two putative secretory PLA2 (sPLA2) cDNAs from tobacco. However, it was difficult to analyze mRNA expression because of small amount of their transcripts. In this study, we investigated the tissue specificity of mRNA expression by using a quantitative RT-PCR. Both sPLA2 mRNA expressions were high in flower, while they were low in root, leaf and stem. Furthermore, PLA2 activity was also much higher in flower than in other tissues. We now investigate the response of both sPLA2 to stress on tobacco plant and cultured cells.
