Asseri Ashwag A, Coello-Camba Alexandra, Agustí Susana
Marine Science Program, The Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
Front Microbiol. 2025 Jan 29;16:1435925. doi: 10.3389/fmicb.2025.1435925. eCollection 2025.
Marine fungi play a crucial role in carbon cycling and food webs by acting as saprophytes or parasites and shaping host communities. However, our knowledge of these fungi in the marine ecosystem remains limited. To address this gap, we conducted a study to investigate the diversity of planktonic fungal communities in the Red Sea, a warm and oligotrophic sea. We collected water samples from the photic layer at six sites along the Red Sea basin and analyzed the fungal community by targeting the 28S rRNA gene. Our results showed that Chytridiomycota dominated these communities, accounting for 85% of reads, followed by members of the divisions Basidiomycota (4.7%) and Cryptomycota (4.13%). Interestingly, we found that fungal communities did not exhibit significant changes with depth or chlorophyll concentration. However, they did vary with the latitudinal gradient in environmental conditions, which is characterized by high temperature (ranging from 22.3 to 27.0°C) and salinity (ranging from 38.0 to 40.4 PSU). Specifically, the proportions of Chytridomycetes and Neocallimastigomycetes (the two dominant classes of Chytridiomycota) were negatively correlated between themselves. Chytridomycetes exhibited a negative correlation with temperature (R = 0.60, = 0.0028) and a positive correlation with salinity (R = 0.49, = 0.010), being more abundant in the northern Red Sea. Conversely, Neocallimastigomycetes showed an increase in abundance with increasing temperature (R = 0.61, = 0.0026) and a decrease with increasing salinity (R = 0.40, = 0.026), making them more prevalent in the southern Red Sea. Overall, our study described a differential distribution of the most dominant fungal classes, with potential significance in their control of planktonic populations and consequent influence in the carbon cycle in the Red Sea ecosystem. These findings underscore the importance of further research to better understand the role of marine fungi in ecosystem functioning.
海洋真菌通过充当腐生菌或寄生菌以及塑造宿主群落，在碳循环和食物网中发挥着关键作用。然而，我们对海洋生态系统中这些真菌的了解仍然有限。为了填补这一空白，我们开展了一项研究，以调查红海（一个温暖且贫营养的海域）中浮游真菌群落的多样性。我们从红海盆地沿线的六个地点采集了光合层的水样，并通过靶向28S rRNA基因来分析真菌群落。我们的结果表明，壶菌门在这些群落中占主导地位，占读数的85%，其次是担子菌门（4.7%）和隐真菌门（4.13%）的成员。有趣的是，我们发现真菌群落并未随深度或叶绿素浓度呈现出显著变化。然而，它们确实随环境条件的纬度梯度而变化，该梯度的特征是高温（范围为22.3至27.0°C）和高盐度（范围为38.0至40.4 PSU）。具体而言，壶菌纲和新美鞭菌纲（壶菌门的两个主要类群）的比例彼此呈负相关。壶菌纲与温度呈负相关（R = 0.60，P = 0.0028），与盐度呈正相关（R = 0.49，P = 0.010），在红海北部更为丰富。相反，新美鞭菌纲的丰度随温度升高而增加（R = 0.61，P = 0.0026），随盐度升高而降低（R = 0.40，P = 0.026），使其在红海南部更为普遍。总体而言，我们的研究描述了最主要真菌类群的差异分布，这对于它们控制浮游生物种群以及进而影响红海生态系统中的碳循环具有潜在意义。这些发现强调了进一步开展研究以更好地理解海洋真菌在生态系统功能中作用的重要性。
