Global analysis of the root hair morphogenesis transcriptome reveals new candidate genes involved in root hair formation in barley
Global analysis of the root hair morphogenesis transcriptome reveals new candidate genes involved in root hair formation in barley
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DOI：
10.1016/j.jplph.2010.02.009
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发表时间：
2010-01-01
影响因子：
4.3
通讯作者：
Szarejko, Iwona
中科院分区：
文献类型：
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作者：
Kwasniewski, Miroslaw;Janiak, Agnieszka;Szarejko, Iwona
根毛是植物根表皮细胞的长管状突起，在植物的营养和水分吸收中起着重要作用。它们也是研究高等植物细胞分化的重要模型。与模式双子叶植物拟南芥相反，目前对单子叶植物（包括主要谷物）根毛形成的遗传和分子基础知之甚少。为了阐明候选基因控制这一发展过程中的大麦，我们利用最近建立的Affychip大麦1基因组阵列进行全球转录组分析的无毛和根毛原基形成的两个勉强突变株系的根。无根毛突变体rhl1.a及其野生型亲本品种Karat的表达谱分析揭示了10个可能参与大麦根毛形成早期步骤的基因。通过定量逆转录-聚合酶链反应证实了所有鉴定基因的差异表达。所鉴定的基因编码与细胞壁和细胞膜相关的蛋白质，包括木葡聚糖内糖基转移酶的一个基因、过氧化物酶的三个基因和阿拉伯半乳聚糖蛋白、伸展蛋白、富含亮氨酸的重复蛋白、磷脂酰肌醇磷脂酰胆碱转移蛋白和RhoGTdR GDP解离抑制剂的五个基因。其中一个基因的分子功能目前尚不清楚。与亲本品种相比，这些基因的表达水平在无根毛突变体rhl1.a的根中强烈降低，而所有10个基因的表达在另一个突变体即rhp1.b中相似，该突变体已经失去了发育完整根毛的能力，但仍然形成在原基阶段被阻断的毛，以及其野生型相对。这清楚地表明，新的基因鉴定参与启动根毛形态发生在大麦。(C)2010年Elsevier GmbH。All rights reserved.
Root hairs are long tubular outgrowths of specialized root epidermal cells that play an important role in plant nutrition and water uptake. They are also an important model in studies of higher plant cell differentiation. In contrast to the model dicot Arabidopsis thaliana, currently very little is known about the genetic and molecular basis of root hair formation in monocots, including major cereals. To elucidate candidate genes controlling this developmental process in barley, we took advantage of the recently established Affymetrix GeneChip Barley1 Genome Array to carry out global transcriptome analyses of hairless and root hair primordia-forming roots of two barely mutant lines. Expression profiling of the root-hairless mutant rhl1.a and its wild type parent variety 'Karat' revealed 10 genes potentially involved in the early step of root hair formation in barley. Differential expression of all identified genes was confirmed by quantitative reverse transcription-polymerase chain reaction. The genes identified encode proteins associated with the cell wall and membranes, including one gene for xyloglucan endotransglycosylase, three for peroxidase enzymes and five for arabinogalactan protein, extensin, leucine-rich-repeat protein, phosphatidylinositol phosphatidylcholine transfer protein and a RhoGTPase GDP dissociation inhibitor, respectively. The molecular function of one gene is unknown at present. The expression levels of these genes were strongly reduced in roots of the root-hairless mutant rhl1.a compared to the parent variety, while expression of all 10 genes was similar in another mutant, i.e. rhp1.b, that has lost its ability to develop full root hairs but still forms hairs blocked at the primordium stage, and its wild type relative. This clearly indicates that the new genes identified are involved in the initiation of root hair morphogenesis in barley. (C) 2010 Elsevier GmbH. All rights reserved.