Serine esterases are required for pollen tube penetration of the stigma in Brassica
We have investigated the diversity of serine esterases in pollen and stigma tissues of Brassica napus and the role of these enzymes in pollen germination and pollen tube penetration of the stigma. The serine esterase-specific inhibitor diisopropyl fluorophosphate was used as a probe in a tritiated f...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
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2002
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| _version_ | 1826304065630371840 |
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| author | Hiscock, S Bown, D Gurr, S Dickinson, H |
| author_facet | Hiscock, S Bown, D Gurr, S Dickinson, H |
| author_sort | Hiscock, S |
| collection | OXFORD |
| description | We have investigated the diversity of serine esterases in pollen and stigma tissues of Brassica napus and the role of these enzymes in pollen germination and pollen tube penetration of the stigma. The serine esterase-specific inhibitor diisopropyl fluorophosphate was used as a probe in a tritiated form, [3H]-DIPF, to determine the number and diversity of serine esterases in crude protein extracts from pollen and stigma. Seven serine esterases were identified in pollen and at least seven serine esterases were identified in stigma. The most abundant enzymes had molecular weights of 30-50 kDa. In the pollen extract a serine esterase was detected with the same molecular weight, 22 kDa, as an esterase previously shown to be a cutinase. Only one serine esterase (40 kDa) appeared to be shared between pollen and stigma extracts. Butyrate esterase activity in pollen and stigma extracts was assayed using p-nitrophenyl butyrate (PNB), an ester substrate frequently used in 'cutinase' assays. Total PNBase activity in pollen and stigma extracts was shown to be significantly reduced by the serine esterase inhibitors DIPF and ebelactone B. When DIPF and ebelactone B were applied to stigmas prior to pollination, pollen germination was not significantly affected but, at the highest inhibitor concentrations, up to 70% of germinating pollen tubes failed to penetrate the stigma surface. These data demonstrate that serine esterases, most probably cutinase(s), are required for pollen tube penetration of the dry cuticularised Brassica stigma. |
| first_indexed | 2024-03-07T06:12:10Z |
| format | Journal article |
| id | oxford-uuid:efe4387c-5a32-478b-b55b-7e4e1ca88655 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T06:12:10Z |
| publishDate | 2002 |
| record_format | dspace |
| spelling | oxford-uuid:efe4387c-5a32-478b-b55b-7e4e1ca886552022-03-27T11:43:30ZSerine esterases are required for pollen tube penetration of the stigma in BrassicaJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:efe4387c-5a32-478b-b55b-7e4e1ca88655EnglishSymplectic Elements at Oxford2002Hiscock, SBown, DGurr, SDickinson, HWe have investigated the diversity of serine esterases in pollen and stigma tissues of Brassica napus and the role of these enzymes in pollen germination and pollen tube penetration of the stigma. The serine esterase-specific inhibitor diisopropyl fluorophosphate was used as a probe in a tritiated form, [3H]-DIPF, to determine the number and diversity of serine esterases in crude protein extracts from pollen and stigma. Seven serine esterases were identified in pollen and at least seven serine esterases were identified in stigma. The most abundant enzymes had molecular weights of 30-50 kDa. In the pollen extract a serine esterase was detected with the same molecular weight, 22 kDa, as an esterase previously shown to be a cutinase. Only one serine esterase (40 kDa) appeared to be shared between pollen and stigma extracts. Butyrate esterase activity in pollen and stigma extracts was assayed using p-nitrophenyl butyrate (PNB), an ester substrate frequently used in 'cutinase' assays. Total PNBase activity in pollen and stigma extracts was shown to be significantly reduced by the serine esterase inhibitors DIPF and ebelactone B. When DIPF and ebelactone B were applied to stigmas prior to pollination, pollen germination was not significantly affected but, at the highest inhibitor concentrations, up to 70% of germinating pollen tubes failed to penetrate the stigma surface. These data demonstrate that serine esterases, most probably cutinase(s), are required for pollen tube penetration of the dry cuticularised Brassica stigma. |
| spellingShingle | Hiscock, S Bown, D Gurr, S Dickinson, H Serine esterases are required for pollen tube penetration of the stigma in Brassica |
| title | Serine esterases are required for pollen tube penetration of the stigma in Brassica |
| title_full | Serine esterases are required for pollen tube penetration of the stigma in Brassica |
| title_fullStr | Serine esterases are required for pollen tube penetration of the stigma in Brassica |
| title_full_unstemmed | Serine esterases are required for pollen tube penetration of the stigma in Brassica |
| title_short | Serine esterases are required for pollen tube penetration of the stigma in Brassica |
| title_sort | serine esterases are required for pollen tube penetration of the stigma in brassica |
| work_keys_str_mv | AT hiscocks serineesterasesarerequiredforpollentubepenetrationofthestigmainbrassica AT bownd serineesterasesarerequiredforpollentubepenetrationofthestigmainbrassica AT gurrs serineesterasesarerequiredforpollentubepenetrationofthestigmainbrassica AT dickinsonh serineesterasesarerequiredforpollentubepenetrationofthestigmainbrassica |