There was a negative correlation between the nitrogenase activities of nitrogen fixing bacteria in root and that in leaf and stem.

此外，甘蔗根、茎、叶中固氮菌的固氮酶活性之间关系较为密切，根中固氮菌的固氮酶活性与叶片和茎中的都呈负相关。

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Although there is 34,500 tons of gaseous nitrogen in the air column above each acre of the earth's surface, this cannot be used by plants until it has been fixed by nitrogen-fixing bacteria and algae.

虽然在地球表面每英亩空气柱中有34,500吨气态氮，但是如果这些气态氮不被固氮菌和藻类固定，是不能被植物利用的。

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Symbiotic nitrogen-fixing bacteria invade the root hairs of host plants, where they multiply and stimulate the formation of root nodules, enlargements of plant cells and bacteria in close association.

共生的固氮菌侵袭宿主植物的根毛，并在此繁殖和促进根瘤的形成、植物细胞和亲密共生细菌的扩大。

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