A lily (Lilium longiflorum) pollen-specific gene encoding a novel proline, glycine and serine-rich protien

• Main Authors: Ssu-Wei Hsu, 徐思維
• Other Authors: Co-Shine Wang
• Format: Others
• Language: en_US
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/32088695282104170091

碩士 === 國立中興大學 === 生物科技學研究所 === 91 === LLP-12-2 is a gene that expresses specifically in the late stage of pollen development in lily (Lilium longiflorum) plants. Using the lily leaf genomic DNA as a template, polymerase chain reaction revealed that the LLP12-2 gene includes the coding region of 669 bp interrupted by two introns of 72 bp and 98 bp, respectively, near the 5’ end of the gene. The gene encodes a protein that has 222 amino acid residues containing a couple of (Gly-X)n motifs, a characteristic of cell wall proteins, which is similar to the glycine-rich proteins (GRPs). The LLP12-2 protein is rich in proline (15.8 %), glycine (11.3 %) and serine (10.8 %). Amino acid sequence alignment indicated that LLP12-2 protein is an unknown protein because no significant similarity between LLP12-2 and other known proteins. Genomic Southern of lily leaf DNA indicated that LLP12-2 is a single gene. To obtain anti-LLP12-2 antiserum, the coding region of LLP12-2 cDNA was introduced into pET32a and expressed in the Escherichia coli. The overexpressed protein was purified by the Ni-NTA agarose. Using the blot-affinity purified anti-LLP12-2 antibody, the immunoblots indicated the LLP12-2 is a pollen-specific protein, which exists only in the pollen, but not in any other floral organs and vegetative organs of lily plants. Premature-drying suggested that the LLP12-2 protein is also a dehydration-induced protein. The LLP12-2 protein appeared in the late stage of pollen development and accumulated rapidly as pollen grew to mature prior to desiccation. The function of LLP12-2 protein may be involved in the pollen germination and pollen tube growth because it still exists in the pollen or pollen tube after germination. In addition, subcellular immunodetection of the LLP12-2 protein indicated that the protein may exist in the cytoplasm.