The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.
Funct Integr Genomics. 2011 Sep;11(3):431-43. doi: 10.1007/s10142-011-0228-1. Epub 2011 May 20.
MYB transcription factors play diverse roles in plant growth, developmental processes and stress responses. A full-length cDNA sequence of a MYB gene, namely TaPIMP1, was isolated from wheat (Triticum aestivum L.). The TaPIMP1 transcript level was significantly up-regulated by inoculation with a fungal pathogen Bipolaris sorokiniana and by drought treatment. TaPIMP1 encodes the MYB protein TaPIMP1 consisting of 323 amino acids. TaPIMP1 contains two MYB DNA binding domains (R2, R3), two putative nuclear localization sites and two putative transcription activation domains. TaPIMP1 is a new member of the R2R3-MYB transcription factor subfamily. Transient expression in onion epidermal cells of GFP fused with TaPIMP1 proved that subcellular localization of TaPIMP1 occurred in the nucleus. The TaPIMP1 gene was transferred into tobacco (Nicotiana tabacum L.) cultivar W38 by Agrobacterium-mediated transformation. After screening through PCR and RT-PCR analyses, transgenic tobacco lines expressing TaPIMP1 were identified and evaluated for pathogen resistance, and drought and salt tolerance. Compared to untransformed tobacco host plants, TaPIMP1 expressing plants displayed significantly enhanced resistance to Ralstonia solanacearum and exhibited improved tolerances to drought and salt stresses. In these transgenic lines, the activities of phenylalanine ammonia-lyase (PAL) and superoxide dismutase (SOD) were significantly increased relative to wild-type tobacco plants. The results suggested that the wheat R2R3-MYB transcription factor plays an important role in modulating responses to biotic and abiotic stresses.
MYB 转录因子在植物生长、发育过程和应激反应中发挥着多样化的作用。本研究从小麦（Triticum aestivum L.）中分离到一个 MYB 基因 TaPIMP1 的全长 cDNA 序列。TaPIMP1 的转录水平在接种真菌病原菌双极镰刀菌和干旱处理后显著上调。TaPIMP1 编码 MYB 蛋白 TaPIMP1，由 323 个氨基酸组成。TaPIMP1 包含两个 MYB DNA 结合域（R2、R3）、两个假定的核定位位点和两个假定的转录激活域。TaPIMP1 是 R2R3-MYB 转录因子亚家族的新成员。TaPIMP1 与 GFP 融合的瞬时表达在洋葱表皮细胞中证明了 TaPIMP1 的亚细胞定位发生在细胞核中。通过农杆菌介导的转化将 TaPIMP1 基因转入烟草（Nicotiana tabacum L.）品种 W38。通过 PCR 和 RT-PCR 分析筛选后，鉴定并评价了表达 TaPIMP1 的转基因烟草系对病原体的抗性以及对干旱和盐胁迫的耐受性。与未转化的烟草宿主植物相比，表达 TaPIMP1 的烟草植物对茄青枯病菌的抗性显著增强，并表现出对干旱和盐胁迫的耐受性提高。在这些转基因系中，苯丙氨酸解氨酶（PAL）和超氧化物歧化酶（SOD）的活性与野生型烟草植物相比显著增加。结果表明，小麦 R2R3-MYB 转录因子在调节生物和非生物胁迫反应中起着重要作用。
