酸沉降对马尾松菌根共生蛋白及营养关系影响

Effects of Artificial Acid Rain and Different Ca/Al Ratios on the Symbiosis and Nutrient Relationship in Mycorrhizae of Pinus massoniana *

研究模拟酸雨及不同Ｃａ／Ａｌ比对马尾松（Ｐｉｎｕｓｍ ａｓｓｏｎｉａｎａ Ｌａｍ ｂ．）菌根中真菌与植物共生及营养关系的影响，在分子水平上揭示污染对生物的作用和生物抗性机理．当ｐＨ２０ 的模拟酸雨与铝共同作用时，马尾松菌根中酸性磷酸酶、硝酸还原酶以及海藻糖酶和甘露醇脱氢酶活性明显下降，即ｐＨ２０ 的模拟酸雨及铝离子对马尾松幼苗根的磷、氮吸收以及两共生生物之间的营养物质交换过程产生了影响，且铝离子在ｐＨ值低的情况下毒性作用更强；而钙能有效地缓解铝的毒性⒚在本实验中当Ｃａ／Ａｌ比为１／１ 时，缓解能力最强；在接种外生菌根真菌彩色豆马勃（Ｐｉｓｏｌｉｔｈｕｓｔｉｎｃｔｏｒｉｕｓ）后，马尾松幼苗根部酶活性仍能保持一定水平，植物对模拟酸雨及铝毒的抗性增强．菌根形成初期，经等点聚焦电泳后分离出在植物及真菌纯培养中均不存在的共生蛋白，其等电点为４７０。

Protein synthesis, acid phosphatase, nitrate reductase, mannitol dehydrogenase and trehalase activities in Pinus massoniana Lamb., were obviously inhibited by the artificial acid rain and Al. In other words, the artificial acid rain and Al could affect the uptake of phosphorous, nitrogen and the exchange of nutrient between symbionts in mycorrhizae. From the results of this study, it could be concluded that the combination of lower pH and Al was more toxic. Al toxicity could be ameliorated by Ca and the amelioration of Al toxicity was the most when Ca/Al ratio was 1/1. Inoculation of P. tinctorius at the root of Pinus massoniana Lamb. increased the ability of the plant to resist the toxicity of artificial acid rain and Al. During the formation of mycorrhizae, one kind of specific protein, whose isoelectric point was 4 70, was isolated. This protein did not exist in either the pure culture of fungus or root. Moreover, this protein did not disappear after the treatment with artificial acid rain.