Facultative symbiosis with a saprotrophic soil fungus promotes potassium uptake in American sweetgum trees
Facultative symbiosis with a saprotrophic soil fungus promotes potassium uptake in American sweetgum trees
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与腐生土壤真菌的兼性共生促进美国枫香树对钾的吸收
DOI：
10.1111/pce.14053
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Zhilin Yuan
中科院分区：
文献类型：
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作者：
Long Peng;Xiaoliang Shan;Yuzhan Yang;Yuchen Wang;Irina S. Druzhinina;Xueyu Pan;Wei Jin;Xinghua He;Xinyu Wang;Xiaoguo Zhang;Francis M. Martin;Zhilin Yuan
几种自由生活的土壤腐生生物有时可以与植物建立生物营养共生关系，但这种共生关系的基础生物学在很大程度上仍不清楚。在这里，我们研究了一种常见的土壤腐生生物霍布松乳杆菌(蘑菇)和美国香胶(枫香)之间的共生相互作用。定植的根皮质细胞含有大量的微菌核样结构。真菌侵染促进了植株的生长和钾素的吸收，特别是在钾素限制下(0.05 mm K+)。共生没有改变植物吸收钾相关基因的表达，但定植根中含有3个与K+转运体(ACU和HAK)和通道(SKC)同源的真菌基因的转录本。异源表达ChACU和ChSKCreate酵母K+摄取缺陷突变体的生长。与对照(5 mm K+)相比，低K+(0和0.0 5 mm K+)条件下ChACU转录本在植物和体外均有上调。在0.0 5 mm K+浓度下，侵染植株的可溶性糖积累量高于未侵染植株。目前的研究表明，这种新型的树木-真菌共生在钾限制下的互惠互利，主要是通过双方之间额外的碳和钾交换实现的。
Several species of soil free‐living saprotrophs can sometimes establish biotrophic symbiosis with plants, but the basic biology of this association remains largely unknown. Here, we investigate the symbiotic interaction between a common soil saprotroph,Clitopilus hobsonii(Agaricomycetes), and the American sweetgum (Liquidambar styraciflua). The colonized root cortical cells were found to contain numerous microsclerotia‐like structures. Fungal colonization led to increased plant growth and facilitated potassium uptake, particularly under potassium limitation (0.05 mM K+). The expression of plant genes related to potassium uptake was not altered by the symbiosis, but colonized roots contained the transcripts of three fungal genes with homology to K+transporters (ACU and HAK) and channel (SKC). Heterologously expressedChACUandChSKCrestored the growth of a yeast K+‐uptake‐defective mutant. Upregulation ofChACUtranscript under low K+conditions (0 and 0.05 mM K+) compared to control (5 mM K+) was demonstrated in planta and in vitro. Colonized plants displayed a larger accumulation of soluble sugars under 0.05 mM K+than non‐colonized plants. The present study suggests reciprocal benefits of this novel tree‐fungus symbiosis under potassium limitation mainly through an exchange of additional carbon and potassium between both partners.