Li Shiyu, Yang Mengfei, Yao Tongfu, Xia Wenqiang, Ye Zihong, Zhang Shangfa, Li Yipeng, Zhang Zhongjin, Song Ruiqi
Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, Zhejiang, China.
Zhejiang Provincial Key Laboratory of Characteristic Aquatic Vegetable Breeding and Cultivation, Jinhua Academy of Agricultural Sciences, Jinhua, Zhejiang, China.
Front Microbiol. 2023 Jul 24;14:1199907. doi: 10.3389/fmicb.2023.1199907. eCollection 2023.
Smut fungi display a uniform life cycle including two phases: a saprophytic phase and a parasitic phase in host plants. Several apathogenic smut fungi are found, lacking suitable hosts in their habitat. Interestingly, MT-type was found to maintain a parasitic life, lacking the saprophytic phase. Its long period of asexual proliferation in plant tissue results in severe defects in certain functions. In this study, the growth dynamics of in plant tissues were carefully observed. The mycelia of T- and MT-type exhibit rapid growth after karyogamy and aggregate between cells. While T-type successfully forms teliospores after aggregation, the aggregated mycelia of MT-type gradually disappeared after a short period of massive proliferation. It may be resulted by the lack of nutrition such as glucose and sucrose. After overwintering, infected plants no longer contained diploid mycelia resulting from karyogamy. This indicated that diploid mycelia failed to survive in plant tissues. It seems that diploid mycelium only serves to generate teliospores. Notably, MT-type keeps the normal function of karyogamy, though it is not necessary for its asexual life in plant tissue. Further investigations are required to uncover the underlying mechanism, which would improve our understanding of the life cycle of smut fungi and help the breeding of .
黑粉菌表现出统一的生命周期，包括两个阶段：腐生阶段和在寄主植物中的寄生阶段。发现了几种无致病性的黑粉菌，在其栖息地缺乏合适的寄主。有趣的是，MT型黑粉菌被发现维持寄生生活，缺乏腐生阶段。它在植物组织中长时间的无性增殖导致某些功能出现严重缺陷。在本研究中，仔细观察了黑粉菌在植物组织中的生长动态。T型和MT型黑粉菌的菌丝体在核配后迅速生长并在细胞间聚集。虽然T型黑粉菌在聚集后成功形成冬孢子，但MT型黑粉菌的聚集菌丝体在短时间大量增殖后逐渐消失。这可能是由于缺乏葡萄糖和蔗糖等营养物质所致。越冬后，受感染的植物不再含有核配产生的二倍体菌丝体。这表明二倍体菌丝体无法在植物组织中存活。似乎二倍体菌丝体仅用于产生冬孢子。值得注意的是，MT型黑粉菌保持核配的正常功能，尽管这对其在植物组织中的无性生活并非必需。需要进一步研究以揭示潜在机制，这将增进我们对黑粉菌生命周期的理解并有助于黑粉菌的育种。
