Newsham Kevin K
British Antarctic Survey, NERC, High Cross, Madingley Road, Cambridge, CB3 0ET, UK.
Fungal Biol. 2024 Dec;128(8 Pt B):2365-2371. doi: 10.1016/j.funbio.2023.12.003. Epub 2023 Dec 24.
The surface temperatures of Antarctic soils and bryophyte colonies can fluctuate from close to freezing point to approximately 20 °C under clear skies around solar noon during midsummer. However, whether diurnally fluctuating temperatures influence the growth and metabolic activities of fungi inhabiting these substrates remains unknown. Here, 10 isolates of Pseudogymnoascus roseus, an ascomycete that is widespread in Antarctica, were exposed in vitro to temperatures fluctuating daily from 2 °C to 15-24 °C. Relative to controls incubated at the constant mean temperature of each treatment, temperatures fluctuating from 2 °C to ≥18 °C inhibited the growth of all isolates by 10-51% at 24 h and 48 h, and by up to 79% for individual isolates. Over a period of 21 days, all fluctuating temperature treatments reduced mean growth rates by between 3% and 48%, but had few effects on specific β-glucosidase activity, a proxy measure for metabolic activity. It is concluded that temperatures fluctuating diurnally to ≥18 °C during summer in mesic Antarctic soils and bryophyte colonies, exacerbated by the occurrence of climate-change associated heatwaves, are likely to inhibit the growth of P. roseus and perhaps also other ecologically important fungi.
在仲夏的晴朗天空下，接近中午时分，南极土壤和苔藓植物群落的表面温度可在接近冰点到约20°C之间波动。然而，昼夜波动的温度是否会影响栖息在这些基质上的真菌的生长和代谢活动仍不清楚。在这里，10株玫瑰拟裸囊菌（一种在南极洲广泛分布的子囊菌）的分离株在体外暴露于每日从2°C波动到15 - 24°C的温度下。相对于在每种处理的恒定平均温度下培养的对照，从2°C波动到≥18°C的温度在24小时和48小时时抑制了所有分离株的生长10% - 51%，个别分离株的抑制率高达79%。在21天的时间里，所有波动温度处理使平均生长速率降低了3%至48%，但对作为代谢活动替代指标的特定β - 葡萄糖苷酶活性影响很小。研究得出结论，在南极湿润土壤和苔藓植物群落中，夏季昼夜波动至≥18°C的温度，因与气候变化相关的热浪的出现而加剧，可能会抑制玫瑰拟裸囊菌以及其他一些具有重要生态意义的真菌的生长。
