Pea extracellular Cu/Zn-superoxide dismutase responsive to signal molecules from a fungal pathogen
Pea extracellular Cu/Zn-superoxide dismutase responsive to signal molecules from a fungal pathogen
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DOI：
10.1007/s10327-006-0283-y
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发表时间：
2006-10-01
影响因子：
1.2
通讯作者：
Shiraishi, Tomonori
中科院分区：
文献类型：
--
作者：
Kasai, Tomonari;Suzuki, Tomoko;Shiraishi, Tomonori
我们之前报道过一个70 kda的糖蛋白激发子可以促进O-2（-）从分离的豌豆细胞壁释放，但被从豌豆枯萎病的病原菌pinodemycosphaerella pinodedes的孢子萌发液中制备的粘蛋白型糖肽抑制物（抑制素a和抑制素B）抑制。在这里，我们发现豌豆幼苗外质体液/细胞壁中的超氧化物歧化酶（SOD）对真菌激发子和抑制分子有反应。在药理学研究和内部氨基酸测序中，发现豌豆品种Midoriusui的外质体SOD为Cu/Zn型SOD。我们克隆了Cu/Zn-SOD的全长cDNA，并将其命名为PsCu/Zn-SOD1。诱导子对PsCu/Zn-SOD1 mRNA和PsCu/Zn-SOD1蛋白表达的诱导作用强于损伤处理。然而，激发剂或损伤的这种诱导被伴随存在的抑制因子所抑制。重组PsCu/Zn-SOD1的SOD活性是由这些信号分子直接调控的，其作用方式类似于它们对胞外液和细胞壁结合蛋白中SOD活性的影响。基于这些发现，我们讨论了PsCu/Zn-SOD1在豌豆防御反应中的作用。
We previously reported that the release of O-2(-) from isolated pea cell walls was enhanced by a 70-kDa glycoprotein elicitor but was suppressed by mucin-type glycopeptide suppressors (supprescins A and B) prepared from pycnospore germination fluid of Mycosphaerella pinodes, causal agent of Mycosphaerella blight of pea. Here, we show that superoxide dismutase (SOD) in the apoplast fluid/cell wall of pea seedlings responds to the fungal elicitor and suppressor molecules. In a pharmacological study and with internal amino acid sequencing, the apoplastic SOD in a pea cultivar Midoriusui was found to be a Cu/Zn type SOD. We cloned a full-length cDNA of the Cu/Zn-SOD and designated it as PsCu/Zn-SOD1. An increase in PsCu/Zn-SOD1 mRNA and the PsCu/Zn-SOD1 protein was induced by treatment with the elicitor more intensively than by wounding. Such induction by the elicitor or wounding, however, was inhibited by the concomitant presence of supprescins. The SOD activity of recombinant PsCu/Zn-SOD1 was regulated directly by these signal molecules in a manner similar to their effect on the SOD activity in the apoplastic fluid and in the cell wall-bound proteins. Based on these findings, we discuss a role for PsCu/Zn-SOD1 in the pea defense response.