稻瘟菌诱导的水稻过氧羟基脂肪酸分解酶的分离

ISOLATION OF LIPID HYDROPEROXIDE-DECOMPOSING ENZYME IN RICE INDUCED BY INFECTION OF BLAST FUNGUS

水稻叶片接种稻瘟病菌后，在非亲和性组合稻叶（１３１小种接种稻叶）中，过氧羟基脂肪酸分解酶（ＬｉｐｉｄＨｙｄｒｏｐｅｒｏｘｉｄｅ－ＤｅｃｏｍｐｏｓｉｎｇＥｎｚｙｍｅ，简称ＬＨＤＥ）活性在接种３６ｈ后显著增加，６０ｈ增加到最大；在亲和性组合稻叶（００７小种接种稻叶）和健康稻叶中，ＬＨＤＥ活性在接种３６、４８和６０ｈ后无显著增加。接种后４８ｈ的稻叶中的ＬＨＤＥ活性分别是亲和性组合稻叶和健康稻叶中ＬＨＤＥ活性的４．３和６．０倍。通过ＤＥＡＥ－Ｓｅｐｈａｒｏｓｅ阴离子交换层析，接种后４８ｈ的稻叶中的ＬＨＤＥ分为ＬＨＤＥ１和ＬＨＤＥ２两个组分。ＬＨＤＥ１组分在健康稻叶、亲和性组合稻叶和非亲和性组合稻叶中变化不大，总活性分别为０．０８Ｕ、０．０９Ｕ和０．１０Ｕ；但ＬＨＤＥ２组分在非亲和性组合稻叶中显著增加，而在亲和性组合稻叶和健康稻叶中变化不大，总活性分别为８．７２Ｕ、１．３０Ｕ和１．９０Ｕ。由此说明ＬＨＤＥ２是侵染诱导性ＬＨＤＥ，可能参与水稻对稻瘟病的抗性反应。

Lipid Hydroperoxide-Decomposing Enzyme(LHDE)was related to rice resistance to the blast fungus(Magnaporthe grisen).LHDE activity in rice leaves in fected by incompatible race 131 of the fungus increased significantly at 36h and reached maximun at 60h after inoculation,whearas it only increased slightly in compatible race 007-infected leaves and healthy leaves at 36,48,60h after inoculation.The LHDE activity at 48h after inoculation in the race 131-infected leaves was 4.3 times and 6.0 times higher than that in healthy leaves and the race 007-infceted leaves,respectivily.Using ionexchange chromatography,two LHDE components(LHDE 1 and LHDE 2)were separated from both uninoculated and infected leaves.There was little difference in LHDE 1 activity in healthy leaves,race 007-infected leaves and race 131-infected leaves;but apparent differenec in LHDE 2 was found in these rice leaves.LHDE 2 activity in healthy leaves,race 007-infected leaves and race 131-infceted leaves was 8.27U,1.30U and 1.90U,respectively.The result showed LHDE 2 may be involved in resistance induction in rice by the blast fungus infcetion.