Poster: Integrated Plant Biology

Abs # 74: Characterization of PLC1 encoding a novel lipocalin protein of pepper

Presenter:	Harn, Chee , chharn@nongwoobio.co.kr
Authors	Harn, Chee  (A)   Lee, Sang Jik  (A)   Lee, Mi Yeon  (A)   Lee, Phil Sik  (A)   Choi, Sooh Ho  (A)   Yang, Seung Gyun  (A)
Affiliations:	(A): Nong Woo Bio Co.

To investigate the molecular mechanism controlling fruit ripening, we have isolated an expressed sequence tag (EST) collection that are differentially expressed in red ripe fruit of Capsicum annuum cv. SIRO by suppression subtractive hybridization (SSH). One of the clones, named PLC1 (pepper lipocalin 1; accession no. CB165063), was sequenced completely. PLC1 was 555 bp in length and the open reading frame predicted a polypeptide of 184 amino acids with a calculated molecular mass of 20 kDa. Southern blot showed that the pepper genome contained a single copy of the PLC1 gene. Surprisingly, PLC1 was only expressed in pericarp and placenta of red ripe fruit indicating that it is regulated tissue specifically. In addition, the PLC1 transcripts were detected in breaker fruits (green and red stage) and red ripe fruits along fruit ripening and not detected during green fruit development indicating that it is regulated red fruit developmentally. Several phytohormones such as ethylene and ABA did not induce the PLC1 expression, suggesting that induction of PLC1 expression was limited to fruit ripening only. The PLC1::smGFP fusion protein was observed at the memebrane, but not in the cytoplasm, indicating that PLC1 is a plasma membrane protein. We report here that the PLC1 represents the first plant lipocalin that probably plays a role in fruit maturation.