Differential expression of different sex Taxus. mairei under UV-B

Dioecious plants have sex-specific adaptions to constantly changing environments. Ancient gymnosperms have coevolved with diverse endophytic fungi that are essential for the fitness and adaptability of plant host. However, sex-specific impacts on plant-endophyte interaction that affect the environmental stress response are largely unknown. In our study, integrated RNA-seq and ITS analysis was applied to reveal the potential mechanisms underlying the sex-specific UV-B radiation response. RNA-seq data screened a number of differentially expressed genes (DEGs) responsive to UV-B radiation. Enrichment analysis of the DEGs suggested that female T. mairei trees have a slightly stronger response to light stress at transcriptional level. The endophytic fungal communities in T. mairei were significantly affected by both of sex and UV-B radiation. Diversity and hierarchical clustering analyses showed that UV-B radiation was the greater factor in driving differences of fungal communities than sex. Under control condition, the most significant fungal biomarker taxon Pestalotiopsis/Alternaria and Herpotrichiellaceae/Cyphellophora in the female and male trees, respectively. Under UV-B radiation, the genus Guignardia was identified as significant fungal biomarker taxon. To simply the complexity of endophytic fungal communities, 31 genus indicators were identified, including Guignardia and Alternaria.

雌雄异株植物（Dioecious plants）演化出性别特异性适应策略以应对持续变化的环境。古老裸子植物（gymnosperms）已与多样的内生真菌（endophytic fungi）协同演化，这类真菌对于植物宿主的适合度与适应性至关重要。然而，性别对调控环境胁迫响应的植物-内生真菌互作所产生的特异性影响，目前仍知之甚少。
本研究整合RNA测序（RNA-seq）与内转录间隔区（ITS）分析，旨在揭示T. mairei响应紫外-B（UV-B）辐射的性别特异性潜在机制。
RNA测序数据筛选得到一批响应UV-B辐射的差异表达基因（differentially expressed genes, DEGs）。对上述DEGs的富集分析结果显示，雌性T. mairei植株在转录水平上对光胁迫的响应强度略高于雄性植株。
T. mairei的内生真菌群落同时受到性别与UV-B辐射的显著影响。多样性分析与层次聚类分析表明，相较于性别因素，UV-B辐射是驱动真菌群落结构差异的更主导因子。
在对照条件下，雌性植株中最显著的真菌生物标记类群为Pestalotiopsis（拟盘多毛孢属）/Alternaria（链格孢属），而雄性植株中则为Herpotrichiellaceae（毛球壳科）/Cyphellophora（瓶霉属）。
在UV-B辐射处理条件下，Guignardia（球座菌属）被鉴定为显著的真菌生物标记类群。为简化内生真菌群落的分析复杂度，本研究共鉴定出31个属水平指示类群，其中包含球座菌属与链格孢属。