The Photodegradation of Lignin Methoxyl C Promotes Fungal Decomposition of Lignin Aromatic C Measured with <sup>13</sup>C-CPMAS NMR
Solar radiation has been regarded as a driver of litter decomposition in arid and semiarid ecosystems. Photodegradation of litter organic carbon (C) depends on chemical composition and water availability. However, the chemical changes in organic C that respond to solar radiation interacting with wat...
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| Format: | Article |
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MDPI AG
2022-08-01
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| Series: | Journal of Fungi |
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| Online Access: | https://www.mdpi.com/2309-608X/8/9/900 |
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| author | Bei Yao Xiaoyi Zeng Lu Pang Xiangshi Kong Kai Tian Yanli Ji Shucun Sun Xingjun Tian |
| author_facet | Bei Yao Xiaoyi Zeng Lu Pang Xiangshi Kong Kai Tian Yanli Ji Shucun Sun Xingjun Tian |
| author_sort | Bei Yao |
| collection | DOAJ |
| description | Solar radiation has been regarded as a driver of litter decomposition in arid and semiarid ecosystems. Photodegradation of litter organic carbon (C) depends on chemical composition and water availability. However, the chemical changes in organic C that respond to solar radiation interacting with water pulses remain unknown. To explain changes in the chemical components of litter organic C exposed to UV-B, UV-A, and photosynthetically active radiation (PAR) mediated by water pulses, we measured the chemistry of marcescent <i>Lindera glauca</i> leaf litter by solid-state <sup>13</sup>C cross-polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) over 494 days of litter decomposition with a microcosm experiment. Abiotic and biotic factors regulated litter decomposition via three pathways: first, photochemical mineralization of lignin methoxyl C rather than aromatic C exposed to UV radiation; second, the biological oxidation and leaching of cellulose O-alkyl C exposed to PAR and UV radiation interacts with water pulses; and third, the photopriming effect of UV radiation on lignin aromatic C rather than cellulose O-alkyl C under the interaction between radiation and water pulses. The robust decomposition index that explained the changes in the mass loss was the ratio of aromatic C to O-alkyl C (AR/OA) under radiation, but the ratio of hydrophobic to hydrophilic C (hydrophobicity), the carbohydrate C to methoxyl C ratio (CC/MC), and the alkyl C to O-alkyl C ratio (A/OA) under radiation were mediated by water pulses. Moreover, the photopriming effect and water availability promoted the potential activities of peroxidase and phenol oxidase associated with lignin degradation secreted by fungi. Our results suggest that direct photodegradation of lignin methoxyl C increases microbial accessibility to lignin aromatic C. Photo-oxidized compounds might be an additional C pool to regulate the stability of the soil C pool derived from plant litter by degrading lignin methoxyl and aromatic C. |
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| language | English |
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| publishDate | 2022-08-01 |
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| series | Journal of Fungi |
| spelling | doaj.art-27b3a83e8d8b4be19f9d733c87810b9f2023-11-23T17:08:56ZengMDPI AGJournal of Fungi2309-608X2022-08-018990010.3390/jof8090900The Photodegradation of Lignin Methoxyl C Promotes Fungal Decomposition of Lignin Aromatic C Measured with <sup>13</sup>C-CPMAS NMRBei Yao0Xiaoyi Zeng1Lu Pang2Xiangshi Kong3Kai Tian4Yanli Ji5Shucun Sun6Xingjun Tian7School of Life Sciences, Nanjing University, Nanjing 210023, ChinaSchool of Life Sciences, Nanjing University, Nanjing 210023, ChinaSchool of Life Sciences, Nanjing University, Nanjing 210023, ChinaSchool of Life Sciences, Nanjing University, Nanjing 210023, ChinaSchool of Life Sciences, Nanjing University, Nanjing 210023, ChinaSchool of Life Sciences, Nanjing University, Nanjing 210023, ChinaSchool of Life Sciences, Nanjing University, Nanjing 210023, ChinaSchool of Life Sciences, Nanjing University, Nanjing 210023, ChinaSolar radiation has been regarded as a driver of litter decomposition in arid and semiarid ecosystems. Photodegradation of litter organic carbon (C) depends on chemical composition and water availability. However, the chemical changes in organic C that respond to solar radiation interacting with water pulses remain unknown. To explain changes in the chemical components of litter organic C exposed to UV-B, UV-A, and photosynthetically active radiation (PAR) mediated by water pulses, we measured the chemistry of marcescent <i>Lindera glauca</i> leaf litter by solid-state <sup>13</sup>C cross-polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) over 494 days of litter decomposition with a microcosm experiment. Abiotic and biotic factors regulated litter decomposition via three pathways: first, photochemical mineralization of lignin methoxyl C rather than aromatic C exposed to UV radiation; second, the biological oxidation and leaching of cellulose O-alkyl C exposed to PAR and UV radiation interacts with water pulses; and third, the photopriming effect of UV radiation on lignin aromatic C rather than cellulose O-alkyl C under the interaction between radiation and water pulses. The robust decomposition index that explained the changes in the mass loss was the ratio of aromatic C to O-alkyl C (AR/OA) under radiation, but the ratio of hydrophobic to hydrophilic C (hydrophobicity), the carbohydrate C to methoxyl C ratio (CC/MC), and the alkyl C to O-alkyl C ratio (A/OA) under radiation were mediated by water pulses. Moreover, the photopriming effect and water availability promoted the potential activities of peroxidase and phenol oxidase associated with lignin degradation secreted by fungi. Our results suggest that direct photodegradation of lignin methoxyl C increases microbial accessibility to lignin aromatic C. Photo-oxidized compounds might be an additional C pool to regulate the stability of the soil C pool derived from plant litter by degrading lignin methoxyl and aromatic C.https://www.mdpi.com/2309-608X/8/9/900photodegradationlitterUVligninfungal decomposition<sup>13</sup>C-CPMAS NMR |
| spellingShingle | Bei Yao Xiaoyi Zeng Lu Pang Xiangshi Kong Kai Tian Yanli Ji Shucun Sun Xingjun Tian The Photodegradation of Lignin Methoxyl C Promotes Fungal Decomposition of Lignin Aromatic C Measured with <sup>13</sup>C-CPMAS NMR Journal of Fungi photodegradation litter UV lignin fungal decomposition <sup>13</sup>C-CPMAS NMR |
| title | The Photodegradation of Lignin Methoxyl C Promotes Fungal Decomposition of Lignin Aromatic C Measured with <sup>13</sup>C-CPMAS NMR |
| title_full | The Photodegradation of Lignin Methoxyl C Promotes Fungal Decomposition of Lignin Aromatic C Measured with <sup>13</sup>C-CPMAS NMR |
| title_fullStr | The Photodegradation of Lignin Methoxyl C Promotes Fungal Decomposition of Lignin Aromatic C Measured with <sup>13</sup>C-CPMAS NMR |
| title_full_unstemmed | The Photodegradation of Lignin Methoxyl C Promotes Fungal Decomposition of Lignin Aromatic C Measured with <sup>13</sup>C-CPMAS NMR |
| title_short | The Photodegradation of Lignin Methoxyl C Promotes Fungal Decomposition of Lignin Aromatic C Measured with <sup>13</sup>C-CPMAS NMR |
| title_sort | photodegradation of lignin methoxyl c promotes fungal decomposition of lignin aromatic c measured with sup 13 sup c cpmas nmr |
| topic | photodegradation litter UV lignin fungal decomposition <sup>13</sup>C-CPMAS NMR |
| url | https://www.mdpi.com/2309-608X/8/9/900 |
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