| Summary: | 碩士 === 國立中興大學 === 生命科學系 === 93 === Our previous study showed that the germination and growth rates of lily (Lilium longiflorum Thumb. cv Avita) pollen were significantly retarded after -20°C storage for certain periods. Some pre-synthesized mRNAs stored in mature pollen might have degraded gradually during cold storage. After suppression subtractive hybridization screening, thousands of clones were obtained, 99 cDNAs were enriched in the fresh mature pollen and one of them is H+ (or Na+)/myo-inositol symporter (LLPD5). The corresponding full length cDNA with 1972 nucleotides were obtained after 5’- and 3’-RACE. The cDNA encodes a 582 amino acids polypeptide with estimated molecular mass and PI being 63 kDa and 7.9, respectively. Its pollen and late developmental stage specific expression patterns were confirmed by RT-PCR. The possible function of H+(or Na+)/myo-inositol symporter in germinating pollen tube may transport tapetum secreted myo-inositol into developmental microspore for pollen wall synthesis and stylar secreted myo-inositol into pollen tube used for pollen tube wall synthesis during pollination. To isolate and characterize the de novo synthesized proteins form pollen tube induced by developmental progress or gynoecium during pollination, a proteomic study were conducted. Comparing the total protein profiles revealed by 2-D PAGE of pollen grain, in vitro- and in vivo-grown 24 hr pollen tube, several novel proteins were identified. 15 proteins enriched in proteins profile of in vitro-grown 24 hr pollen tube were found . Lots of proteins appear in 2-D profile of all samples, but only 12 of them were riched in the in vitro-grown or in vivo-grown 24 hr pollen tubes. Additional 9 proteins specifically present in proteins profile of in vivo-grown 24 hr pollen tube were identified as compared to that of in vitro-grown 24 hr pollen tube. One of them was chosen for N-terminal sequencing analysis and no homologous protein was found from the available databases. To further investigate the reality of gynoecium-induced character of those proteins or simply caused the contamination of stigma/stylar exudates adhered on the in vivo-grown pollen tubes, self- and cross-pollinated in vivo-grown pollen tubes were used for comparison by 2-D PAGE. Our results suggest that those in vivo-grown pollen tubes specific and enriched proteins are induced by gynoecium during pollination.
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