Identification and characterization of a barley yellow dwarf virus resistance gene in maize

大麦黄矮病是大麦中传播最广的一种病毒性病害。它是由大麦黄矮病毒（BYDV）和谷物黄矮病毒（CYDV）引起的，其中第一种病毒比第二种病毒造成的危害更严重。玉米在BYDV流行病学中起着重要作用，也受到病毒的破坏。随着全球气温的升高，预计病毒病和BYDV将成为谷物和玉米种植中的突出问题。控制病毒本身是不可能的，用于控制传播bydv的蚜虫的杀虫剂在德国没有得到认证。抗性玉米可以打破BYDV的传播循环，从而也有助于减少其他谷物中的BYDV问题。在早期的研究中，我们在10号染色体底部检测到一个BYDV抗性因子，这解释了相当大比例的性状表型变异，病毒浓度和疾病症状。综合以上试验结果，GRMZM2G018027基因为最佳候选BYDV抗性基因。该基因在拟南芥中的同源基因是OXS3，被描述参与H2O2的产生。由于已知H2O2在病原体防御中起重要作用，GRMZM2G018027可能参与一般的病原体防御反应。该项目的目标之一是鉴定和验证玉米中抗BYDV的基因。这将在5个所谓的异种近交家族的帮助下实现。通过人工接种实验和蚜虫对异种自交系重组植株的吸虫行为实验，以及用GRMZM2G018027的不同等位基因改造玉米自交系A188所形成的基因型，将有助于进一步了解BYDV抗性基因的分子功能。此外，我们计划量化BYDV抗性基因对其他病毒性疾病变异的贡献。

Barley yellow dwarf is the most widely spread viral disease of cereals. It is caused by the Barley yellow dwarf virus (BYDV) and the Cereal yellow dwarf virus (CYDV), where the first is causing more severe damages than the second. Maize plays an important role in the epidemiology of BYDV and is as well damaged by the virus. With increasing global temperatures, viral diseases in general and BYDV in specific are expected to become prominent problems in cereal and maize cultivation. The control of the virus itself is not possible and insecticides to control the BYDV-transmitting aphids are not certificated in Germany. Resistant maize can break the transmission cycle of BYDV and therewith could as well contribute to a reduction of the BYDV problems in other cereals. In an earlier study, we detected a BYDV resistance factor at the bottom of chromosome ten, which explained considerable proportions of the phenotypic variance of the traits virus concentration and disease symptoms. Based on these experiments, the gene GRMZM2G018027 is the best candidate as BYDV resistance gene. The homolog of this gene in Arabidopsis thaliana is OXS3 that is described to be involved in the production of H2O2. As H2O2 is known to play an important role in pathogen defense, GRMZM2G018027 could be involved in a general pathogen defense reaction. One of the objectives of the proposed project is to identify and validate the BYDV resistance gene in maize. This will be reached with the help of five so called heterogeneous inbred families. Artificial inoculation experiments and experiments characterizing the sucking behavior of aphids on recombinant plants of the heterogeneous inbred families as well as genotypes that were created by transforming the maize inbred A188 with different alleles of GRMZM2G018027 will be used to improve our understanding of the molecular function of the BYDV resistance gene. Furthermore, we plan to quantify the contribution of the BYDV resistance gene to variation of other viral diseases.