Roothairless5, which functions in maize (Zea mays L.) root hair initiation and elongation encodes a monocot-specific NADPH oxidase
Roothairless5, which functions in maize (Zea mays L.) root hair initiation and elongation encodes a monocot-specific NADPH oxidase
复制标题
DOI：
10.1111/tpj.12578
复制
发表时间：
2014-09-01
期刊：
影响因子：
7.2
通讯作者：
Hochholdinger, Frank
中科院分区：
文献类型：
--
作者：
Nestler, Josefine;Liu, Sanzhen;Hochholdinger, Frank
根毛有助于单子叶植物谷物的营养吸收。玉米 (Zea mays L.) roothairless5 (rth5) 突变体在根毛起始和伸长方面表现出缺陷，表现为根毛密度和长度降低。基于图谱的克隆揭示了 rth5 基因编码单子叶植物特异性 NADPH 氧化酶。 RNA-Seq、原位杂交和 qRT-PCR 实验表明，rth5 基因在根毛中优先表达，但在其他组织中也积累到低水平。免疫定位在初生根伸长和分化区的表皮中检测到RTH5蛋白。由于与野生型相比，rth5 突变体根毛生长尖端中的超氧化物和过氧化氢水平降低，并且已知活性氧 (ROS) 参与尖端生长，因此我们假设 RTH5 蛋白负责在根毛生长尖端建立伸长所需的高水平 ROS。与这一假设一致，对 6 天龄 rth5 与野生型初生根进行的比较 RNA-Seq 分析显示，在 893 个差异表达基因 (FDR) 中，只有两个与生物功能（即氧化/还原和碳水化合物代谢）相关的基因本体 (GO) 类别显着过度表达。
Root hairs are instrumental for nutrient uptake in monocot cereals. The maize (Zea mays L.) roothairless5 (rth5) mutant displays defects in root hair initiation and elongation manifested by a reduced density and length of root hairs. Map-based cloning revealed that the rth5 gene encodes a monocot-specific NADPH oxidase. RNA-Seq, in situ hybridization and qRT-PCR experiments demonstrated that the rth5 gene displays preferential expression in root hairs but also accumulates to low levels in other tissues. Immunolocalization detected RTH5 proteins in the epidermis of the elongation and differentiation zone of primary roots. Because superoxide and hydrogen peroxide levels are reduced in the tips of growing rth5 mutant root hairs as compared with wild-type, and Reactive oxygen species (ROS) is known to be involved in tip growth, we hypothesize that the RTH5 protein is responsible for establishing the high levels of ROS in the tips of growing root hairs required for elongation. Consistent with this hypothesis, a comparative RNA-Seq analysis of 6-day-old rth5 versus wild-type primary roots revealed significant over-representation of only two gene ontology (GO) classes related to the biological functions (i.e. oxidation/reduction and carbohydrate metabolism) among 893 differentially expressed genes (FDR