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脱氧血腐镰刀菌烯醇(deoxynivalenol,DON)在小麦赤霉病发病过程中起重要作用,是一种毒性因子.禾谷镰刀菌的侵染能力依赖于其产生DON的能力,抗病品种能显著降低病穗组织中DON的含量.本研究利用Affymetrix小麦基因组芯片,对抗赤霉病小麦品种望水白经DON诱导后的穗组织基因表达特点进行了分析,结果发现,一个编码PDR型转运蛋白的EST受DON诱导后上调表达45倍.根据该EST设计引物筛选小麦基因组TAC文库,得到一个包含该基因的TAC单克隆.利用染色体walking对该单克隆测序,用Softberry软件进行基因预测,根据预测基因的5′和3′非翻译区设计引物,从DON诱导的小麦望水白穗组织cDNA中克隆出该转运蛋白基因.该基因组全长7377bp,包含19个外显子,CDS长度为4308bp,编码长1435aa且分子量161kD的蛋白.蛋白序列比对表明,该基因属于PDR蛋白家族,命名为TaPDR1(Triticum asetivum Pleiotropic Drug Resistance).利用一套中国春缺体-四体系将TaPDR1基因定位在小麦5A染色体上.半定量RT-PCR表明,TaPDR1在望水白穗中受DON和禾谷镰刀菌诱导表达,表明其参与了植物抗病防御反应.该基因在望水白感病突变体中低水平表达,进一步证明TaPDR1与赤霉病抗性有关.TaPDR1的表达不受与生物胁迫相关的激素(JA和SA)和非生物胁迫因子(热、冷、伤害和NaCl)的诱导,但受到Al3+和游离Ca2+的诱导表达,推测[Ca2+]i介导了TaPDR1的表达信号.
Deoxynivalenol (DON) plays an important role in the pathogenesis of wheat scab and it is a virulence factor. The infectivity of Fusarium graminearum depends on its ability to produce DON, Significantly reduce the content of DON in diseased ear tissues.In this study, Affymetrix wheat genome chip was used to analyze the gene expression characteristics of spike tissue induced by DON in Shui Shui Bai Hei of Fusarium head blight. The results showed that a gene encoding PDR-type transporter Of ESTs were upregulated 45-fold after DON induction.According to the EST design primers screening of wheat genomic TAC library to obtain a TAC-containing monoclonal cloning of the gene using chromosome walking sequencing of the monoclonal with Softberry software for gene prediction, according to the prediction This gene was cloned from cDNA of DON-induced wheat ear panicle tissue by PCR using the primers designed in 5 ’and 3’ untranslated regions of the gene. The full length of this gene is 7377bp and contains 19 exons with a CDS length of 4308bp, Encoding a protein with a length of 1435aa and a molecular weight of 161kD.The protein sequence alignment indicated that this gene belongs to the PDR protein family and named as Triticum asetivum Pleiotropic Drug Resistance. TaPDR1 gene was mapped on chromosome 5A of wheat using a set of Chinese springbody-quaternary system.The semi-quantitative RT-PCR showed that TaPDR1 was induced by DON and Fusarium graminearum in Wangshui white spike, indicating that it is involved in plant disease resistance Defense response.The expression of TaPDR1 in Fusarium graminearum was low, which further proved that TaPDR1 was related to the resistance to Fusarium head blight.The expression of TaPDR1 was not affected by hormones (JA and SA) and abiotic stress factors Induced by Al3 + and free Ca2 +, suggesting that [Ca2 +] i mediates the expression of TaPDR1.