【作者】 张春燕；

【导师】 章文华；

【作者基本信息】 南京农业大学 ， 细胞生物学， 2008， 硕士

【摘要】 以真菌激发子木聚糖酶（xylanase）和稻瘟病菌提取物对水稻悬浮细胞和愈伤组织做处理试验,结果发现:（1）xylanase可显著诱导水稻悬浮细胞H₂O₂和O₂的产生;处理1h后,编码几丁质酶的基因Chitinase表达明显增加,而编码病程相关蛋白的PR10基因没有表达,但处理12h,后者表达明显增加;处理24h,诱导80%的悬浮细胞死亡;处理24h至72h,诱导愈伤组织中抗毒素樱花素的生成;处理20d,导致愈伤组织褐化、生长量减低、愈伤组织从致密状变为镂空状。（2）稻瘟病菌提取物处理引起的抗病防卫反应与xylanase一致。稻瘟病菌提取物处理诱导悬浮细胞中基因PR10及基因Chitinase表达,诱导愈伤组织中sakuranetin生成,导致愈伤组织褐化、生长量减低、愈伤组织从致密状变为镂空状。上述试验结果表明,水稻悬浮细胞和愈伤组织是研究抗稻瘟病机制方便、合适的实验材料,xylanase和稻瘟病菌提取物都能够诱水稻悬浮细胞和愈伤组织产生抗病防卫反应。磷脂酶D/磷脂酸信号是植物信号转导途径中一个极为重要的组分,在植物生长发育、逆境与激素反应以及抗病反应的信号传导途径中具有重要作用。以水稻悬浮细胞和愈伤组织为实验材料,初步研究了PLD在xylanase或稻瘟病菌提取物引起的水稻抗病防卫反应中的作用机理。试验发现:（1）xylanase和稻瘟病菌提取物均迅速激活水稻细胞PLDα,但未诱导PLDα1基因及PLDα蛋白表达。（2）1-But抑制xylanase引起的H₂O₂第二个峰形成、抗毒素产生和细胞死亡。（3）外施PA能诱导H₂O₂第二个峰的形成、水稻抗毒素的产生和细胞死亡。（4）xylanase引起的细胞死亡需要H₂O₂信号的参与,清除H₂O₂抑制了xylanase或PA引起的水稻细胞死亡。试验结果初步表明,PLD/PA参与了xylanase和EFM诱导水稻细胞抗病防卫反应这一过程。更多还原

【Abstract】 Rice suspension cell and callus were treated with fungal elicitor-xylanase or the extract from Magnaporthe grisea.We found:（1） Xylanase treatment induced rapid accumulation of H₂O₂ and O₂^- in rice suspension cells.Xylanase also induced the expression of defense genes.The expression of chitinase was induced obviously in suspension cells after 1h treatment while the expression of PR10 was induced after 12h treatment.Xylanase treatment induced 80%cell death in 24h.Xylanase induced the synthesis of sakuranetin in callus after 24h to 72h treatment.Then callus turned brown,decreased in fresh weight and declined the density of callus when treated with xylanase in 20d.（2） EFM treatment induced the expression of PR10 and chitinase,the production of sakuranetin,and calli turned brown,decreased in fresh weight and declined the density of callus.The preliminary results showed that suspension cell and callus are convenient and suitable plant materials for studying the mechanisms of the resistance to Magnaporthe grisea in rice.Both xylanase and EFM induced rice resistance response.Phospholipase D（PLD） and phosphatidic acid（PA） are essential signal molecules in the plant responses to various biotic and abiotic cues.Using suspension cell and callus,we study the mechanism of rice blast resistance and the PLD effects.We found:（1） Xylanase elicitor and EFM activates PLDα,but not increase the content of PLDαand the expression of plda gene.（2） In the presence of 1-butanol,the second phase generation of H₂O₂ was no longer detected;the sakuranetin production and cell death was clearly suppressed.（3） Exogenously applied PA itself induced the second phase generation of H₂O₂,the sakuranetin production and cell death.（4） H₂O₂ was involved in cell death induced by xylanase.Scavenging of H₂O₂ suppressed the cell death induced by xylanase or PA.The preliminary results showed that Phospholipase D and phosphatidic acid are involved in the responses of rice cells to xylanase elicitor or EFM.更多还原