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(单词翻译:双击或拖选)
If I told you there was a large mass of fungus1 infecting the roots of that lovely pine tree which shades your front lawn, would you be worried? Would you buy a strong fungicide if I said that this fungus survived by sucking valuable sugars, vitamins, and other nutrients3 out of your tree’s roots? Actually, most species of tree and plant are routinely infected by what’s known as “mycorrhizal fungi2,” but this is no cause for alarm. We'll learn how trees can actually benefit from their fungal friends on today's moment of science. Many trees and plants not only host mycorrhizal fungi–they have actually come to depend on them. As the fungi grow, they send fine tentacles4 streaming into the soil. These tentacles help channel large amounts of water and nutrients back to the host tree, far more water than the tree would be able to trap with its roots alone. One study found that conifers with the fungus are twice as likely to survive a drought as those without. Some mycorrhizal fungi help their host tree in other ways too, secreting5 a tree hormone6 that causes the roots to grow new root tips, and a hormone that increases the longevity7 of these new roots. Other fungi release natural antibiotics8 into the soil, further protecting the tree. In fact, the seedlings9 of many tree species will die if fungus does not develop around their roots during their first year of growth. This is a striking example of the biological concept of symbiosis10, in which two or more unrelated species have co-evolved and now depend on each other for survival. It shows us just how interconnected the delicate web of life is.Which covers our planting earth.
1 fungus | |
n.真菌,真菌类植物 | |
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2 fungi | |
n.真菌,霉菌 | |
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3 nutrients | |
n.(食品或化学品)营养物,营养品( nutrient的名词复数 ) | |
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4 tentacles | |
n.触手( tentacle的名词复数 );触角;触须;触毛 | |
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5 secreting | |
v.(尤指动物或植物器官)分泌( secrete的现在分词 );隐匿,隐藏 | |
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6 hormone | |
n.荷尔蒙,激素,内分泌 | |
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7 longevity | |
n.长命;长寿 | |
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8 antibiotics | |
n.(用作复数)抗生素;(用作单数)抗生物质的研究;抗生素,抗菌素( antibiotic的名词复数 ) | |
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9 seedlings | |
n.刚出芽的幼苗( seedling的名词复数 ) | |
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10 symbiosis | |
n.共生(关系),共栖 | |
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