Increased Activity of a Cationic Peroxidase Associated with an Incompatible Interaction Between Xanthomonas oryzae pv oryzae and Rice (Oryza sativa).
Increased Activity of a Cationic Peroxidase Associated with an Incompatible Interaction Between Xanthomonas oryzae pv oryzae and Rice (Oryza sativa).
复制标题
与米黄单胞菌 pv oryzae 和水稻 (Oryza sativa) 之间不相容相互作用相关的阳离子过氧化物酶活性增加。
作者：
P. Reimers;A. Guo;J. Leach
水稻（Oryza sativa L.）品种Cas 209携带抗水稻黄单胞菌（Xanthomonas oryzae pv oryzae） 2小种的Xa-10基因。用PXO86（Rif）菌株（2种，不相容）的细菌细胞悬浮液侵染Cas 209幼苗叶片，接种后16 ~ 24小时，细胞外空间提取物的总过氧化物酶活性增加了近3倍。细胞外提取物中总过氧化物酶活性的增加与43千道尔顿过氧化物酶同工酶的出现有关，等电点为8.6。两种阴离子过氧化物酶同工酶活性的增加也与不相容相互作用有关。在互作后期，亲和处理（cv Cas 209与1号小种PXO61（Sm）浸润）和对照处理（Cas 209与水浸润）的总过氧化物酶活性均有所增加，但最终活性水平低于不亲和处理。同样，在浸润后48小时，所有三个处理都检测到阳离子过氧化物酶，但相对于不相容组合，相容处理和水浸润对照处理的阳离子过氧化物酶水平较低。这种过氧化物酶在细胞外空间的积累可能在cas209的防御反应中起作用。
Rice (Oryza sativa L.) cultivar Cas 209 carries the gene Xa-10 for resistance to race 2 of Xanthomonas oryzae pv oryzae, the bacterial blight pathogen. When seedling leaves of Cas 209 plants were infiltrated with bacterial cell suspensions of strain PXO86(Rif) (race 2, incompatible), total peroxidase activity in extracts from extracellular spaces increased almost threefold between 16 and 24 hours after inoculation. The increase in total peroxidase activity in extracellular extracts was correlated with the appearance of a 43-kilodalton peroxidase isoenzyme with an isoelectric point of 8.6. Increases in the activities of two anionic peroxidase isoenzymes also were associated with the incompatible interaction. Later during the interactions, total peroxidase activities increased in both compatible (cv Cas 209 infiltrated with race 1, PXO61(Sm)) and control (Cas 209 infiltrated with water) treatments, but final activity levels were less than that observed in the incompatible combination. Similarly, the cationic peroxidase was detected in all three treatments by 48 hours after infiltration, but at reduced levels in compatible and water-infiltrated control treatments relative to the incompatible combination. Accumulation of this peroxidase in extracellular spaces thus may play a role in the defense response in cultivar Cas 209.