| Abstract Detail
Lipids Kim, Eun Yu [1], Seo, Young Sam [2], Mang, Hyung Gon [2], Son, ORa [2], Kim, Woo Taek [2]. Heterologous Expression and Biochemical and Cellular Characterization of CaPLA1 Encoding a Hot Pepper Phospholipase A1 homolog. Phospholipid-derived products generated by phospholipase A (PLA) play an important role in plant growth and development. The CaPLA1 encoding a putative phospholipase A1 was isolated from the cDNA library prepared from hot pepper (Capsicum annuum L.) at the stage of root hair formation. RNA gel blot analysis confirmed that CaPLA1 was specifically expressed at the root hair forming stage. CaPLA1 shows a high sequence identity to a phosphatidylcholin-hydrolyzing PLA1 and has no signal peptide, which indicates its cytosolic location. Recombinant CaPLA1 hydrolyzed phospholipids specifically. For the purpose of studying in vivo function of CaPLA1, we established transgenic Arabidopsis plants that overexpressed CaPLA1. The plants showed rapid growth phenotypes. These lines had not only longer root in early developmental stage but larger leaf and longer inflorescence in adult stage compared to wild type. Also, it took shorter developmental time to reach the bolting stage than that of wild type. Microscopic analysis showed that overexpressed CaPLA1 roots had increased numbers of cortex, epidermis cells, resulting increased populated cell layers in the endodermis and stele. In addition, rosette leaf of CaPLA1 - overexpressing plants had smaller and many numbers of adaxial epidermis, palisade mesophyll cells and abaxial epidermis as compared to the wild type. To investigate the molecular mechanism representing these phenotypes, we performed semi-quantitative RT-PCR experiment using the primers of cell cycle-, cell expansion- and lipid metabolism-associated genes in transgenic Arabidopsis. Cell cycle-associated genes were induced whereas the expression level of cell expansion-related genes was unchanged. Also, lipid metabolism-related genes were induced in overexpressed CaPLA1 plants. From these transgenic Arabidopsis studies, we expect to find the influence of phospholipid generated by CaPLA1 on the plants.
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1 - Yonsei University, Department of Biology, 134, Sinchon-dong, Seodaemun-gu, Seoul, 120-749, Korea
2 - YONSEI UNIVERSITY, Department of Biology
Keywords:
phospholipase A1
root growth
cell cycle
lipid metabolism
Hot pepper
Arabidopsis.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P21009
Abstract ID:1330 |
