A Maize Lectin-Like Protein with Antifungal Activity against Aspergillus flavus
A Maize Lectin-Like Protein with Antifungal Activity against Aspergillus flavus
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DOI：
10.4315/0362-028x-72.1.120
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发表时间：
2009-01-01
影响因子：
2
通讯作者：
Fakhoury, A. M.
中科院分区：
文献类型：
--
作者：
Baker, R. L.;Brown, R. L.;Fakhoury, A. M.
丝状真菌黄曲霉引起玉米穗腐病，并在定植的玉米粒中产生真菌毒素（黄曲霉毒素）。黄曲霉毒素在摄入后对人类和动物具有致癌性。黄曲霉毒素污染导致农民每年损失大量利润和可销售的产量。几个研究小组致力于查明抗A.黄曲霉菌和由此产生的玉米黄曲霉毒素污染。一些玉米基因型比其他基因型表现出更大的抗性。蛋白质组学方法最近已被用于鉴定可能与抗真菌性相关的内源玉米蛋白质。已经对一种这样的蛋白质的克隆、表达和部分表征进行了研究，该蛋白质具有与冷调节蛋白质相似的序列。表达的ZmCORp蛋白对真菌分生孢子和绵羊红细胞具有凝集素样的血凝活性。实时荧光定量PCR分析表明，ZmCOR在来自Mp420系的玉米籽粒中的表达量高出50%，Mp420系是一种抗A.与感病品系B73相比，该基因的表达水平显著降低。ZmCORp对A. ZmCORp在18mM的终浓度下对黄曲霉分生孢子萌发的抑制率达80%。当萌发的分生孢子与蛋白质一起孵育时，菌丝生长减少50%。ZmCORp蛋白的部分特性表明，该蛋白可能在提高籽粒对A.黄曲霉感染和黄曲霉毒素积累。
The filamentous fungus Aspergillus flavus causes an ear rot on maize and produces a mycotoxin (aflatoxin) in colonized maize kernels. Aflatoxins are carcinogenic to humans and animals upon ingestion. Aflatoxin contamination results in a large loss of profits and marketable yields for farmers each year. Several research groups have worked to pinpoint sources of resistance to A. flavus and the resulting aflatoxin contamination in maize. Some maize genotypes exhibit greater resistance than others. A proteomics approach has recently been used to identify endogenous maize proteins that may be associated with resistance to the fungus. Research has been conducted on cloning, expression, and partial characterization of one such protein, which has a sequence similar to that of cold-regulated proteins. The expressed protein, ZmCORp, exhibited lectin-like hemagglutination activity against fungal conidia and sheep erythrocytes. Quantitative real-time PCR assays revealed that ZmCOR is expressed 50% more in maize kernels from the Mp420 line, a type of maize resistant to A. flavus, compared with the expression level of the gene in the susceptible B73 line. ZmCORp exhibited fungistatic activity when conidia from A. flavus were exposed to the protein at a final concentration of 18 mM. ZmCORp inhibited the germination of conidia by 80%. A 50% decrease in mycelial growth resulted when germinated conidia were incubated with the protein. The partial characterization of ZmCORp suggests that this protein may play an important role in enhancing kernel resistance to A. flavus infection and aflatoxin accumulation.