Mir1 is Highly Upregulated and Localized to Nuclei During Infectious Hyphal Growth in the Rice Blast Fungus
Rice blast, caused by Magnaporthe grisea, is a devastating disease of rice throughout the world. Many recent molecular studies have focused on the early infection stages, but our knowledge about molecular events at the infectious hyphae stage is limited. In this study, 750 hygromycin-resistant trans...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
The American Phytopathological Society
2007-04-01
|
| Series: | Molecular Plant-Microbe Interactions |
| Subjects: | |
| Online Access: | https://apsjournals.apsnet.org/doi/10.1094/MPMI-20-4-0448 |
| _version_ | 1811278081176895488 |
|---|---|
| author | Lei Li Sheng-Li Ding Amir Sharon Marc Orbach Jin-Rong Xu |
| author_facet | Lei Li Sheng-Li Ding Amir Sharon Marc Orbach Jin-Rong Xu |
| author_sort | Lei Li |
| collection | DOAJ |
| description | Rice blast, caused by Magnaporthe grisea, is a devastating disease of rice throughout the world. Many recent molecular studies have focused on the early infection stages, but our knowledge about molecular events at the infectious hyphae stage is limited. In this study, 750 hygromycin-resistant transformants were isolated by transforming M. grisea Guy11 with a promoterless enhanced green fluorescent protein (EGFP) construct. In one of the transformants, L1320, EGFP signals were observed in the nuclei of infectious hyphae. The transforming vector was inserted in a predicted gene named MIR1 and resulted in a Mir11–107-EGFP fusion. Mir1 is a low-complexity protein with no known protein domain and has no homolog in GenBank or other sequenced fungal genomes. Quantitative real-time reverse-transcriptase polymerase chain reaction analysis and expression assays of MIR1-EGFP fusion constructs indicated that the expression of MIR1 was highly induced during plant infection. Deletion analyses identified a 458-bp region that was sufficient for the MIR1 promoter activity. Further characterization revealed that a 96-bp sequence was essential for the enhanced in planta expression. MIR1 is an M. grisea-specific gene that is highly conserved among the field isolates belonging to the M. grisea species complex. The mir1 mutants had no obvious defects in appressorial penetration and rice infection. When overexpressed with the RP27 promoter, nuclear localization of the Mir1-EGFP fusion was observed in conidia and vegetative hyphae. These data suggest that the expression but not the nuclear localization of MIR1 is specific to infectious hyphae and that reporter genes based on MIR1 may be suitable for monitoring infectious growth in M. grisea. |
| first_indexed | 2024-04-13T00:29:22Z |
| format | Article |
| id | doaj.art-d65eda5a7bb849278675d526289b3859 |
| institution | Directory Open Access Journal |
| issn | 0894-0282 1943-7706 |
| language | English |
| last_indexed | 2024-04-13T00:29:22Z |
| publishDate | 2007-04-01 |
| publisher | The American Phytopathological Society |
| record_format | Article |
| series | Molecular Plant-Microbe Interactions |
| spelling | doaj.art-d65eda5a7bb849278675d526289b38592022-12-22T03:10:32ZengThe American Phytopathological SocietyMolecular Plant-Microbe Interactions0894-02821943-77062007-04-0120444845810.1094/MPMI-20-4-0448Mir1 is Highly Upregulated and Localized to Nuclei During Infectious Hyphal Growth in the Rice Blast FungusLei LiSheng-Li DingAmir SharonMarc OrbachJin-Rong XuRice blast, caused by Magnaporthe grisea, is a devastating disease of rice throughout the world. Many recent molecular studies have focused on the early infection stages, but our knowledge about molecular events at the infectious hyphae stage is limited. In this study, 750 hygromycin-resistant transformants were isolated by transforming M. grisea Guy11 with a promoterless enhanced green fluorescent protein (EGFP) construct. In one of the transformants, L1320, EGFP signals were observed in the nuclei of infectious hyphae. The transforming vector was inserted in a predicted gene named MIR1 and resulted in a Mir11–107-EGFP fusion. Mir1 is a low-complexity protein with no known protein domain and has no homolog in GenBank or other sequenced fungal genomes. Quantitative real-time reverse-transcriptase polymerase chain reaction analysis and expression assays of MIR1-EGFP fusion constructs indicated that the expression of MIR1 was highly induced during plant infection. Deletion analyses identified a 458-bp region that was sufficient for the MIR1 promoter activity. Further characterization revealed that a 96-bp sequence was essential for the enhanced in planta expression. MIR1 is an M. grisea-specific gene that is highly conserved among the field isolates belonging to the M. grisea species complex. The mir1 mutants had no obvious defects in appressorial penetration and rice infection. When overexpressed with the RP27 promoter, nuclear localization of the Mir1-EGFP fusion was observed in conidia and vegetative hyphae. These data suggest that the expression but not the nuclear localization of MIR1 is specific to infectious hyphae and that reporter genes based on MIR1 may be suitable for monitoring infectious growth in M. grisea.https://apsjournals.apsnet.org/doi/10.1094/MPMI-20-4-0448appressoriumfungus-plant interactionpathogenesis |
| spellingShingle | Lei Li Sheng-Li Ding Amir Sharon Marc Orbach Jin-Rong Xu Mir1 is Highly Upregulated and Localized to Nuclei During Infectious Hyphal Growth in the Rice Blast Fungus Molecular Plant-Microbe Interactions appressorium fungus-plant interaction pathogenesis |
| title | Mir1 is Highly Upregulated and Localized to Nuclei During Infectious Hyphal Growth in the Rice Blast Fungus |
| title_full | Mir1 is Highly Upregulated and Localized to Nuclei During Infectious Hyphal Growth in the Rice Blast Fungus |
| title_fullStr | Mir1 is Highly Upregulated and Localized to Nuclei During Infectious Hyphal Growth in the Rice Blast Fungus |
| title_full_unstemmed | Mir1 is Highly Upregulated and Localized to Nuclei During Infectious Hyphal Growth in the Rice Blast Fungus |
| title_short | Mir1 is Highly Upregulated and Localized to Nuclei During Infectious Hyphal Growth in the Rice Blast Fungus |
| title_sort | mir1 is highly upregulated and localized to nuclei during infectious hyphal growth in the rice blast fungus |
| topic | appressorium fungus-plant interaction pathogenesis |
| url | https://apsjournals.apsnet.org/doi/10.1094/MPMI-20-4-0448 |
| work_keys_str_mv | AT leili mir1ishighlyupregulatedandlocalizedtonucleiduringinfectioushyphalgrowthinthericeblastfungus AT shengliding mir1ishighlyupregulatedandlocalizedtonucleiduringinfectioushyphalgrowthinthericeblastfungus AT amirsharon mir1ishighlyupregulatedandlocalizedtonucleiduringinfectioushyphalgrowthinthericeblastfungus AT marcorbach mir1ishighlyupregulatedandlocalizedtonucleiduringinfectioushyphalgrowthinthericeblastfungus AT jinrongxu mir1ishighlyupregulatedandlocalizedtonucleiduringinfectioushyphalgrowthinthericeblastfungus |