Systematic Characterization of bZIP Transcription Factors Required for Development and Aflatoxin Generation by High-Throughput Gene Knockout in <i>Aspergillus flavus</i>
The basic leucine zipper (bZIP) is an important transcription factor required for fungal development, nutrient utilization, biosynthesis of secondary metabolites, and defense against various stresses. <i>Aspergillus flavus</i> is a major producer of aflatoxin and an opportunistic fungus...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-03-01
|
| Series: | Journal of Fungi |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2309-608X/8/4/356 |
| _version_ | 1827600223694749696 |
|---|---|
| author | Qianqian Zhao Hao Pei Xiaoling Zhou Kai Zhao Min Yu Guomin Han Jun Fan Fang Tao |
| author_facet | Qianqian Zhao Hao Pei Xiaoling Zhou Kai Zhao Min Yu Guomin Han Jun Fan Fang Tao |
| author_sort | Qianqian Zhao |
| collection | DOAJ |
| description | The basic leucine zipper (bZIP) is an important transcription factor required for fungal development, nutrient utilization, biosynthesis of secondary metabolites, and defense against various stresses. <i>Aspergillus flavus</i> is a major producer of aflatoxin and an opportunistic fungus on a wide range of hosts. However, little is known about the role of most bZIP genes in <i>A. flavus</i>. In this study, we developed a high-throughput gene knockout method based on an <i>Agrobacterium</i>-mediated transformation system. Gene knockout construction by yeast recombinational cloning and screening of the null mutants by double fluorescence provides an efficient way to construct gene-deleted mutants for this multinucleate fungus. We deleted 15 bZIP genes in <i>A. flavus</i>. Twelve of these genes were identified and characterized in this strain for the first time. The phenotypic analysis of these mutants showed that the 15 bZIP genes play a diverse role in mycelial growth (eight genes), conidiation (13 genes), aflatoxin biosynthesis (10 genes), oxidative stress response (11 genes), cell wall stress (five genes), osmotic stress (three genes), acid and alkali stress (four genes), and virulence to kernels (nine genes). Impressively, all 15 genes were involved in the development of sclerotia, and the respective deletion mutants of five of them did not produce sclerotia. Moreover, MetR was involved in this biological process. In addition, <i>HapX</i> and <i>MetR</i> play important roles in the adaptation to excessive iron and sulfur metabolism, respectively. These studies provide comprehensive insights into the role of bZIP transcription factors in this aflatoxigenic fungus of global significance. |
| first_indexed | 2024-03-09T04:32:04Z |
| format | Article |
| id | doaj.art-89d2909825c64e199d56fc65c0fa623c |
| institution | Directory Open Access Journal |
| issn | 2309-608X |
| language | English |
| last_indexed | 2024-03-09T04:32:04Z |
| publishDate | 2022-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Journal of Fungi |
| spelling | doaj.art-89d2909825c64e199d56fc65c0fa623c2023-12-03T13:34:32ZengMDPI AGJournal of Fungi2309-608X2022-03-018435610.3390/jof8040356Systematic Characterization of bZIP Transcription Factors Required for Development and Aflatoxin Generation by High-Throughput Gene Knockout in <i>Aspergillus flavus</i>Qianqian Zhao0Hao Pei1Xiaoling Zhou2Kai Zhao3Min Yu4Guomin Han5Jun Fan6Fang Tao7School of Life Sciences, Anhui Agricultural University, Hefei 230036, ChinaSchool of Life Sciences, Anhui Agricultural University, Hefei 230036, ChinaSchool of Life Sciences, Anhui Agricultural University, Hefei 230036, ChinaThe National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei 230036, ChinaSchool of Life Sciences, Anhui Agricultural University, Hefei 230036, ChinaThe National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei 230036, ChinaThe National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei 230036, ChinaSchool of Life Sciences, Anhui Agricultural University, Hefei 230036, ChinaThe basic leucine zipper (bZIP) is an important transcription factor required for fungal development, nutrient utilization, biosynthesis of secondary metabolites, and defense against various stresses. <i>Aspergillus flavus</i> is a major producer of aflatoxin and an opportunistic fungus on a wide range of hosts. However, little is known about the role of most bZIP genes in <i>A. flavus</i>. In this study, we developed a high-throughput gene knockout method based on an <i>Agrobacterium</i>-mediated transformation system. Gene knockout construction by yeast recombinational cloning and screening of the null mutants by double fluorescence provides an efficient way to construct gene-deleted mutants for this multinucleate fungus. We deleted 15 bZIP genes in <i>A. flavus</i>. Twelve of these genes were identified and characterized in this strain for the first time. The phenotypic analysis of these mutants showed that the 15 bZIP genes play a diverse role in mycelial growth (eight genes), conidiation (13 genes), aflatoxin biosynthesis (10 genes), oxidative stress response (11 genes), cell wall stress (five genes), osmotic stress (three genes), acid and alkali stress (four genes), and virulence to kernels (nine genes). Impressively, all 15 genes were involved in the development of sclerotia, and the respective deletion mutants of five of them did not produce sclerotia. Moreover, MetR was involved in this biological process. In addition, <i>HapX</i> and <i>MetR</i> play important roles in the adaptation to excessive iron and sulfur metabolism, respectively. These studies provide comprehensive insights into the role of bZIP transcription factors in this aflatoxigenic fungus of global significance.https://www.mdpi.com/2309-608X/8/4/356<i>Aspergillus flavus</i>bZIP transcription factorsmycelial growthconidiationsclerotiaaflatoxin |
| spellingShingle | Qianqian Zhao Hao Pei Xiaoling Zhou Kai Zhao Min Yu Guomin Han Jun Fan Fang Tao Systematic Characterization of bZIP Transcription Factors Required for Development and Aflatoxin Generation by High-Throughput Gene Knockout in <i>Aspergillus flavus</i> Journal of Fungi <i>Aspergillus flavus</i> bZIP transcription factors mycelial growth conidiation sclerotia aflatoxin |
| title | Systematic Characterization of bZIP Transcription Factors Required for Development and Aflatoxin Generation by High-Throughput Gene Knockout in <i>Aspergillus flavus</i> |
| title_full | Systematic Characterization of bZIP Transcription Factors Required for Development and Aflatoxin Generation by High-Throughput Gene Knockout in <i>Aspergillus flavus</i> |
| title_fullStr | Systematic Characterization of bZIP Transcription Factors Required for Development and Aflatoxin Generation by High-Throughput Gene Knockout in <i>Aspergillus flavus</i> |
| title_full_unstemmed | Systematic Characterization of bZIP Transcription Factors Required for Development and Aflatoxin Generation by High-Throughput Gene Knockout in <i>Aspergillus flavus</i> |
| title_short | Systematic Characterization of bZIP Transcription Factors Required for Development and Aflatoxin Generation by High-Throughput Gene Knockout in <i>Aspergillus flavus</i> |
| title_sort | systematic characterization of bzip transcription factors required for development and aflatoxin generation by high throughput gene knockout in i aspergillus flavus i |
| topic | <i>Aspergillus flavus</i> bZIP transcription factors mycelial growth conidiation sclerotia aflatoxin |
| url | https://www.mdpi.com/2309-608X/8/4/356 |
| work_keys_str_mv | AT qianqianzhao systematiccharacterizationofbziptranscriptionfactorsrequiredfordevelopmentandaflatoxingenerationbyhighthroughputgeneknockoutiniaspergillusflavusi AT haopei systematiccharacterizationofbziptranscriptionfactorsrequiredfordevelopmentandaflatoxingenerationbyhighthroughputgeneknockoutiniaspergillusflavusi AT xiaolingzhou systematiccharacterizationofbziptranscriptionfactorsrequiredfordevelopmentandaflatoxingenerationbyhighthroughputgeneknockoutiniaspergillusflavusi AT kaizhao systematiccharacterizationofbziptranscriptionfactorsrequiredfordevelopmentandaflatoxingenerationbyhighthroughputgeneknockoutiniaspergillusflavusi AT minyu systematiccharacterizationofbziptranscriptionfactorsrequiredfordevelopmentandaflatoxingenerationbyhighthroughputgeneknockoutiniaspergillusflavusi AT guominhan systematiccharacterizationofbziptranscriptionfactorsrequiredfordevelopmentandaflatoxingenerationbyhighthroughputgeneknockoutiniaspergillusflavusi AT junfan systematiccharacterizationofbziptranscriptionfactorsrequiredfordevelopmentandaflatoxingenerationbyhighthroughputgeneknockoutiniaspergillusflavusi AT fangtao systematiccharacterizationofbziptranscriptionfactorsrequiredfordevelopmentandaflatoxingenerationbyhighthroughputgeneknockoutiniaspergillusflavusi |