Lifecycle of Pyrenopeziza protrusa (Helotiales, Dermateaceae sensu lato) in Magnolia obovata revealed by field observation and molecular quantification.
Lifecycle of Pyrenopeziza protrusa (Helotiales, Dermateaceae sensu lato) in Magnolia obovata revealed by field observation and molecular quantification.
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DOI：
10.47371/mycosci.2021.08.001
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发表时间：
2021
期刊：
影响因子：
1.4
通讯作者：
Hosoya T
中科院分区：
文献类型：
--
作者：
Itagaki H;Hosoya T
真菌表现出腐生、寄生和共生的生活方式，并随着环境变化和寄主条件的变化而灵活切换。然而，只有少数研究阐明了真菌DNA或形态的详细变化，包括随着生活方式的改变而形成的生殖结构。我们推测，作为腐生植物大量和专门存在于倒卵白玉兰上的白玉兰，也与活的寄主有关，并作为其生活史的一部分而改变其生活方式。为了阐明这一假设，我们定期采集倒卵黄瓜的新鲜/落叶标本，以观察繁殖结构的季节性发生，以便利用新开发的物种特异性引物分离和检测/定量P.protrusa DNA。在秋季落叶前的鲜叶中，Protrusa DNA的分离率和数量急剧增加，但从秋季到春季，落叶中Protrusa DNA的分离率和数量仍然很高。随着DNA含量的增加，落叶中也出现了大量的分生孢子和子囊群。这些结果阐明了Protrusa生活史的很大一部分，表明生活方式从共生阶段转变为腐生阶段，根据季节变化显著增加了DNA含量以响应寄主条件。
Fungi exhibit saprophytic, parasitic, and symbiotic lifestyles, and flexibly switching between them by the environmental changes and host conditions. However, only a few studies have elucidated the detailed changes in fungal DNA or morphology, including the formation of reproductive structures along with lifestyle switching. We hypothesized that Pyrenopeziza protrusa, which occurs abundantly and specifically on Magnolia obovata as a saprophyte, is also associated with living hosts and switches its lifestyles as part of its lifecycle. To elucidate this hypothesis, we periodically sampled the fresh/fallen leaves of M. obovata to observe the seasonal occurrence of reproductive structures for the isolation and detection/quantification of P. protrusa DNA with newly developed species-specific primers. The isolation frequency and amount of P. protrusa DNA drastically increased in the fresh leaves just before defoliation in autumn, but remained high in fallen leaves from autumn to spring. Abundant production of conidiomata and apothecia was also observed in the fallen leaves with increasing DNA content. These results clarified a large part of the lifecycle of P. protrusa, suggesting that the lifestyle is switched from symbiotic to saprophytic stage by significantly increasing the amount of DNA in response to host conditions according to the seasonal variations.