Niu Ji-Shan, Zhang Li-Na, Hong De-Feng, Wang Ying-Hong
National Center of Engineering and Technological Research for Wheat, Henan Agricultural University, Zhengzhou 450002, China.
Zhi Wu Sheng Li Yu Fen Zi Sheng Wu Xue Xue Bao. 2005 Oct;31(5):477-84.
To investigate if there is an EDR1 pathway in wheat (Triticum aestivum L.), a pair of degenerate primers was designed according to the cDNAs of Arabidopsis thaliana EDR1 gene and its homologs were used to isolate EDR1 gene homologs from wheat. RT-PCR was conducted on the cDNA template synthesized with RNA of wheat leaves. A 627-bp cDNA fragment representing an EDR1 gene (named as TaEDR1) was isolated (GenBank accession number: AY743662). Subsequently, the 3050-bp full-length cDNA sequence of TaEDR1, which encodes a polypeptide consisting of 959 amino acid residues, was obtained by RACE technique. The amino acid sequence of TaEDR1 and that of barley (Hordeum vulgare) EDR1 (signed as HvEDR1) show 92% identity. There is a highly conserved catalytic domain of serine/threonine protein kinases in the C-terminus of TaEDR1. Because this protein has a putative nuclear localization motif, it probably functions in the nucleus. This study provides the first molecular biological evidence of the presence of an EDR1 homolog in common wheat. The transcription pattern of TaEDR1 was investigated in leaves after inoculation with Blumeria graminis (DC.) E.O. Speer f. sp. tritici Em. Marchal (Bgt) through semi-quantitative RT-PCR (semi-QRT-PCR). The result showed that the transcribing of TaEDR1 was enhanced by Bgt. The expression pattern of the TaEDR1 gene in different tissues showed that it expressed in leaves, stems, spikes and roots. This study suggests that the TaEDR1, a MAP kinase kinase kinase, may function in wheat defense responses.
为了研究小麦（Triticum aestivum L.）中是否存在EDR1途径，根据拟南芥EDR1基因的cDNA设计了一对简并引物，并用于从小麦中分离EDR1基因同源物。以小麦叶片RNA合成的cDNA为模板进行RT-PCR。分离出一个代表EDR1基因的627 bp cDNA片段（命名为TaEDR1）（GenBank登录号：AY743662）。随后，通过RACE技术获得了TaEDR1的3050 bp全长cDNA序列，该序列编码一个由959个氨基酸残基组成的多肽。TaEDR1的氨基酸序列与大麦（Hordeum vulgare）EDR1（命名为HvEDR1）的氨基酸序列具有92%的同一性。TaEDR1的C末端存在丝氨酸/苏氨酸蛋白激酶的高度保守催化结构域。由于该蛋白具有推定的核定位基序，它可能在细胞核中发挥作用。本研究提供了普通小麦中存在EDR1同源物的首个分子生物学证据。通过半定量RT-PCR（semi-QRT-PCR）研究了接种小麦白粉病菌（Blumeria graminis (DC.) E.O. Speer f. sp. tritici Em. Marchal (Bgt)）后TaEDR1在叶片中的转录模式。结果表明，Bgt可增强TaEDR1的转录。TaEDR1基因在不同组织中的表达模式表明，它在叶片、茎、穗和根中均有表达。本研究表明，TaEDR1作为一种促分裂原活化蛋白激酶激酶激酶，可能在小麦防御反应中发挥作用。
