Jin Jing, Kong Jingjing, Qiu Jianle, Zhu Huasheng, Peng Yuancheng, Jiang Haiyang
Key Laboratory of Crop Biology of Anhui Province, Collaborative Innovation Center of Anhui Grain Crops, Anhui Agricultural University, Hefei, China.
Dev Genes Evol. 2016 Jan;226(1):15-25. doi: 10.1007/s00427-015-0523-2. Epub 2016 Jan 11.
The WRKY gene family, which encodes proteins in the regulation processes of diverse developmental stages, is one of the largest families of transcription factors in higher plants. In this study, by searching for interspecies gene colinearity (microsynteny) and dating the age distributions of duplicated genes, we found 35 chromosomal segments of subgroup I genes of WRKY family (WRKY I) in four Gramineae species (Brachypodium, rice, sorghum, and maize) formed eight orthologous groups. After a stepwise gene-by-gene reciprocal comparison of all the protein sequences in the WRKY I gene flanking areas, highly conserved regions of microsynteny were found in the four Gramineae species. Most gene pairs showed conserved orientation within syntenic genome regions. Furthermore, tandem duplication events played the leading role in gene expansion. Eventually, environmental selection pressure analysis indicated strong purifying selection for the WRKY I genes in Gramineae, which may have been followed by gene loss and rearrangement. The results presented in this study provide basic information of Gramineae WRKY I genes and form the foundation for future functional studies of these genes. High level of microsynteny in the four grass species provides further evidence that a large-scale genome duplication event predated speciation.
WRKY基因家族在植物不同发育阶段的调控过程中编码蛋白质,是高等植物中最大的转录因子家族之一。在本研究中,通过搜索种间基因共线性(微共线性)并确定重复基因的年龄分布,我们发现在四个禾本科物种(短柄草、水稻、高粱和玉米)中,WRKY家族I亚组基因(WRKY I)的35个染色体片段形成了八个直系同源组。在对WRKY I基因侧翼区域的所有蛋白质序列进行逐基因的逐步相互比较后,在这四个禾本科物种中发现了高度保守的微共线性区域。大多数基因对在同线基因组区域内显示出保守的方向。此外,串联重复事件在基因扩张中起主导作用。最终,环境选择压力分析表明禾本科中WRKY I基因受到强烈的纯化选择,随后可能发生了基因丢失和重排。本研究结果提供了禾本科WRKY I基因的基本信息,为这些基因未来的功能研究奠定了基础。这四个禾本科物种中高度的微共线性进一步证明了大规模基因组复制事件早于物种形成。