論文 - 詳細
| RRC ID | 61742 |
|---|---|
| 著者 | Brightly WH, Hartley SE, Osborne CP, Simpson KJ, Strömberg CAE. |
| タイトル | High silicon concentrations in grasses are linked to environmental conditions and not associated with C4 photosynthesis. |
| ジャーナル | Glob Chang Biol |
| Abstract |
The uptake and deposition of silicon (Si) as silica phytoliths is common among land plants and is associated with a variety of functions. Among these, herbivore defense has received significant attention, particularly with regard to grasses and grasslands. Grasses are well known for their high silica content, a trait which has important implications ranging from defense to global Si cycling. Here, we test the classic hypothesis that C4 grasses evolved stronger mechanical defenses than C3 grasses through increased phytolith deposition, in response to extensive ungulate herbivory ("C4 -grazer hypothesis"). Despite mixed support, this hypothesis has received broad attention, even outside the realm of plant biology. Because C3 and C4 grasses typically dominate in different climates, with the latter more abundant in hot, dry regions, we also investigated the effects of water availability and temperature on Si deposition. We compiled a large dataset of grasses grown under controlled environmental conditions. Using phylogenetically informed generalized linear mixed models and character evolution models, we evaluated whether photosynthetic pathway or growth condition influenced Si concentration. We found that C4 grasses did not show consistently elevated Si concentrations compared with C3 grasses. High temperature treatments were associated with increased concentration, especially in taxa adapted to warm regions. Although the effect was less pronounced, reduced water treatment also promoted silica deposition, with slightly stronger response in dry habitat species. The evidence presented here rejects the "C4 -grazer hypothesis." Instead, we propose that the tendency for C4 grasses to outcompete C3 species under hot, dry conditions explains previous observations supporting this hypothesis. These findings also suggest a mechanism via which anthropogenic climate change may influence silica deposition in grasses and, by extension, alter the important ecological and geochemical processes it affects. |
| 巻・号 | 26(12) |
| ページ | 7128-7143 |
| 公開日 | 2020-9-8 |
| DOI | 10.1111/gcb.15343 |
| PMID | 32897634 |
| MeSH | Climate Change Photosynthesis Poaceae* Silicon* Temperature |
| IF | 8.555 |
| リソース情報 | |
| GBIF | Plant specimens of Ishikawa Museum of Natural History Plant Specimens of The Cattle Museum Plant specimens of Toyota City Nature Sanctuary Spermatophyta Specimens of Kawasaki Municipal Science Museum Plant specimens of Otaru Museum Plant specimens of Komatsu City Museum Vascular Plant Specimens of Yamagata Prefectural Museum Vascular plant specimens of Omachi Alpine Museum Vascular plant specimens of Akita Prefectural Museum Herbarium, University Archives and Collections, Fukushima University, Japan (FKSE) Angiospermatatophytina Collection of Saitama Museum of Natural History Plant specimens of Oiso Municipal Museum Vascular Plant Collection of Natural History Museum and Institute, Chiba Herbarium Specimens of Museum of Nature and Human Activities, Hyogo Pref., Japan Ibaraki Nature Museum, Vascular Plants collection Vascular plant specimens of National Museum of Nature and Science (TNS) Plant Specimens of Kurashiki Museum of Natural History Herbarium Specimens of Tokushima Prefectural Museum, Japan Spermatophyta specimens of Iwate Prefectural Museum Vascular Plants Collection of Sagamihara City Museum Plant specimens in the Museum of Nature and Human Activities, Hyogo Prefecture, Japan Plant specimens deposited in Osaka Museum of Natural History, Japan Vascular Plant Specimens of Kochi Prefectural Makino Botanical Garden Plant specimens of Kiritappu Wetland Center Vascular Plant Specimen database of Kanagawa Prefectural Museum of Natural History Gunma Museum of Natural History, Vascular Plant Specimen Vascular plants collection of Hiratsuka City Museum Plant specimens of Kushiro City Museum Herbarium Specimens of Bonin and Ryukyu Islands Vascular plant specimens of Sugadaira Research Station, Mountain Science Center, University of Tsukuba Herbarium of Shinshu University Plant specimens of Parthenon Tama Museum (PTHM) Plant specimens of Obihiro Centennial City Museum Vascular plant specimens of Nagano Environmental Conservation Research Institute, Nagano Prefecture Vascular plant specimens of The Shirakami Research Center for Environmental Sciences, Hirosaki University Plant specimens of Toyota City Nature Sanctuary (from non-museum circle) Vascular plant specimens of Toyama Science Museum |