A full—lerlgth cDNA(L／pCe／／)encoding an endo-1，4-β-glucanase(EGase)was isolated from pollen tubes of Lilium longiflorum Thunb．by RT-PCR and RACE．The deduced protein，which iS predicted to be a compact globular...A full—lerlgth cDNA(L／pCe／／)encoding an endo-1，4-β-glucanase(EGase)was isolated from pollen tubes of Lilium longiflorum Thunb．by RT-PCR and RACE．The deduced protein，which iS predicted to be a compact globular protein，is of 490 amino acids．in cluding a putative 21 amino acid-signal peptide．LlpCell shares high level of homology(about50％)with plant secreted EGases，which bear apparently neither trans-membrane domain．nor cellulose—binding domain(CBD)．LIpCell belongs to gycosyl hydrolase family 9．LlpOell transcripts were detected in pollen grains．germinating pollen and elongating pollen tubes with a similar level．whereas LlpCell transcripts were not detectable in all other lily tissues examined．The specific expression pattern suggests that LlpCell is confined to lily pollen germination and pollen tube elongation．展开更多
The stigma initiation and development of Cucumis sativus L female flower was studied usingelectron microscopy. The differentiation of stigmatic cells could be recognized when the floral bud wasabout 1 mm in length. Af...The stigma initiation and development of Cucumis sativus L female flower was studied usingelectron microscopy. The differentiation of stigmatic cells could be recognized when the floral bud wasabout 1 mm in length. After the pinnate structure of the stigma appeared, three regions indicating thepapillae, the transmitting tissue and the secretory tissue were observed. The pinnate stigma wascharacterized as a partition structure for naming immature and mature stigma in the following investigation.The ultrastructure of various tissue cells of the stigma during the development was observed usingtransmission electron microscopy. Throughout the whole developmental process the cytoplasm of papillaeand secretory tissue cells was filled with many endoplasmic reticula (ER). Most of the ER was tube-like andrough with enlarged cisterna from which many vesicles were produced. |n the mature stigma, numbers ofplasmodesmata were found between the secretory and the transmitting tissue cells. The papillae andsecretory tissue cells are highly vacuolated and the plasmalemma was invaginated or exvaginated. Thenuclear envelope of secretory tissue cells was enlarged, which led to the formation of plurivalvis nucleusduring stigma development, Apparently, nuclear envelope became more strongly lamellate at mature stage.In different tissue cells of mature stigma, ATPase activity was localized along the plasmalemma andvacuole membrane. The PM-H*-ATPase specific activity increased during stigma deve{opment. Ourresults revealed the glandular characteristics of the developing stigma of cucumber female flowers.展开更多
Abstract: Arabinogalactan proteins (AGPs) and pectins were detected in the floral buds of cucumber (Cucumis sativus L.) during its sex determination using the following monoclonal antibodies: MAC 207 (recognizes AGP e...Abstract: Arabinogalactan proteins (AGPs) and pectins were detected in the floral buds of cucumber (Cucumis sativus L.) during its sex determination using the following monoclonal antibodies: MAC 207 (recognizes AGP epitopes); JIM 8 (recognizes a subset of AGP epitopes); and JIM 5 and JIM 7 (epitopes of pectins esterified to various degrees). In the stem apex meristem (SAM) of the cucumber, epitopes of MAC 207, JIM 7, and JIM 5 were localized in the cells from second to third peripheral layers when the sex organ primodium began to differentiate; epitopes of MAC 207 and JIM 5 were also detected in the ragged edge cells. A very dense labeling signal with MAC 207 was observed in the carpel and pistil primodium. The AGP epitopes recognized by JIM 8 were localized in the anther of the male flower and the anther-like portion of the stagnant stamen of the female flower. This suggests that the AGPs and pectins in the SAM of the cucumber are closely associated with the differentiation of the SAM, from meristematic cells to floral primodium. The subset of AGPs recognized by JIM 8 may play an important role in stamen formation.展开更多
文摘A full—lerlgth cDNA(L／pCe／／)encoding an endo-1，4-β-glucanase(EGase)was isolated from pollen tubes of Lilium longiflorum Thunb．by RT-PCR and RACE．The deduced protein，which iS predicted to be a compact globular protein，is of 490 amino acids．in cluding a putative 21 amino acid-signal peptide．LlpCell shares high level of homology(about50％)with plant secreted EGases，which bear apparently neither trans-membrane domain．nor cellulose—binding domain(CBD)．LIpCell belongs to gycosyl hydrolase family 9．LlpOell transcripts were detected in pollen grains．germinating pollen and elongating pollen tubes with a similar level．whereas LlpCell transcripts were not detectable in all other lily tissues examined．The specific expression pattern suggests that LlpCell is confined to lily pollen germination and pollen tube elongation．
文摘The stigma initiation and development of Cucumis sativus L female flower was studied usingelectron microscopy. The differentiation of stigmatic cells could be recognized when the floral bud wasabout 1 mm in length. After the pinnate structure of the stigma appeared, three regions indicating thepapillae, the transmitting tissue and the secretory tissue were observed. The pinnate stigma wascharacterized as a partition structure for naming immature and mature stigma in the following investigation.The ultrastructure of various tissue cells of the stigma during the development was observed usingtransmission electron microscopy. Throughout the whole developmental process the cytoplasm of papillaeand secretory tissue cells was filled with many endoplasmic reticula (ER). Most of the ER was tube-like andrough with enlarged cisterna from which many vesicles were produced. |n the mature stigma, numbers ofplasmodesmata were found between the secretory and the transmitting tissue cells. The papillae andsecretory tissue cells are highly vacuolated and the plasmalemma was invaginated or exvaginated. Thenuclear envelope of secretory tissue cells was enlarged, which led to the formation of plurivalvis nucleusduring stigma development, Apparently, nuclear envelope became more strongly lamellate at mature stage.In different tissue cells of mature stigma, ATPase activity was localized along the plasmalemma andvacuole membrane. The PM-H*-ATPase specific activity increased during stigma deve{opment. Ourresults revealed the glandular characteristics of the developing stigma of cucumber female flowers.
文摘Abstract: Arabinogalactan proteins (AGPs) and pectins were detected in the floral buds of cucumber (Cucumis sativus L.) during its sex determination using the following monoclonal antibodies: MAC 207 (recognizes AGP epitopes); JIM 8 (recognizes a subset of AGP epitopes); and JIM 5 and JIM 7 (epitopes of pectins esterified to various degrees). In the stem apex meristem (SAM) of the cucumber, epitopes of MAC 207, JIM 7, and JIM 5 were localized in the cells from second to third peripheral layers when the sex organ primodium began to differentiate; epitopes of MAC 207 and JIM 5 were also detected in the ragged edge cells. A very dense labeling signal with MAC 207 was observed in the carpel and pistil primodium. The AGP epitopes recognized by JIM 8 were localized in the anther of the male flower and the anther-like portion of the stagnant stamen of the female flower. This suggests that the AGPs and pectins in the SAM of the cucumber are closely associated with the differentiation of the SAM, from meristematic cells to floral primodium. The subset of AGPs recognized by JIM 8 may play an important role in stamen formation.
