Background

Arabidopsis thaliana genome encodes ten DUF640 (short for domain of unknown function 640)/ALOG (short for Arabidopsis LSH1 and Oryza G1) proteins, also known as light-dependent short hypocotyl (LSH) proteins. While some of the LSH genes regulate organ boundary determination and shade avoidance response, the function of most of these genes remains largely unknown.

Objective

In this study, we aimed to characterize the function of AtLSH1 and AtLSH2 in Arabidopsis.

Methods

We overexpressed AtLSH1 and AtLSH2 (with or without the FLAG tag) in Arabidopsis Col-0 plants under the control of the 35S promoter. We also generated knockout or knockdown lines of these genes by miRNA-induced gene silencing (MIGS). We conducted intensive phenotypic analysis of these transgenic lines, and finally performed RNA-seq analysis of two AtLSH2 overexpression (OX) lines.

Results

Although AtLSH1 and AtLSH2 amino acid sequences showed high similarly, AtLSH2-OX lines showed much higher levels of their transcripts than those of AtLSH1-OX lines. Additionally, overexpression of AtLSH1 and AtLSH2 greatly inhibited hypocotyl elongation in a light-independent manner, and reduced both vegetative and reproductive growth. However, knockout or knockdown of both these AtLSH genes did not affect plant phenotype. Gene Ontology (GO) analysis of differentially expressed genes (DEGs) identified by RNA-seq revealed enrichment of the GO term ‘response to stimulus’, included phytohormone-responsive genes; however, genes responsible for the abnormal phenotypes of AtLSH2-OX lines could not be identified.

Conclusion

Although our data revealed no close association between light and phytohormone signaling components, overexpression of AtLSH1 and AtLSH2 greatly reduced vegetative and reproductive growth of Arabidopsis plants. This property could be used to generate new plants by regulating expression of AtLSH1 and AtLSH2.

中文翻译：

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拟南芥 LSH1 和 LSH2 基因的分子特征。

背景

拟南芥基因组编码 10 个 DUF640（功能未知域的简称 640）/ALOG（拟南芥 LSH1和 Oryza G1 的简称）蛋白，也称为光依赖性短下胚轴 (LSH) 蛋白。虽然一些LSH基因调节器官边界确定和避荫反应，但大多数这些基因的功能在很大程度上仍然未知。

客观的

在这项研究中，我们旨在表征AtLSH1和AtLSH2在拟南芥中的功能。

方法

我们在35S启动子的控制下在拟南芥 Col-0 植物中过表达AtLSH1和AtLSH2（带有或不带有 FLAG 标签）。我们还通过 miRNA 诱导的基因沉默 (MIGS) 生成了这些基因的敲除或敲除系。我们对这些转基因品系进行了深入的表型分析，最后对两个AtLSH2过表达 (OX) 品系进行了 RNA-seq 分析。

结果

虽然AtLSH1和AtLSH2氨基表现出较高的相似氨基酸序列，AtLSH2-OX系显示高得多的水平的转录物比那些的AtLSH1-OX线。此外，AtLSH1和AtLSH2 的过表达以不依赖光的方式极大地抑制了下胚轴伸长，并减少了营养和生殖生长。然而，这两个AtLSH基因的敲除或敲低不会影响植物表型。通过 RNA-seq 鉴定的差异表达基因 (DEG) 的基因本体论 (GO) 分析揭示了 GO 术语“对刺激的反应”的富集，包括植物激素反应基因；然而，导致AtLSH2-OX异常表型的基因 无法识别线路。

结论

虽然我们的数据显示光和植物激素信号成分之间没有密切关联，但AtLSH1和AtLSH2 的过度表达大大降低了拟南芥植物的营养和生殖生长。该特性可用于通过调节AtLSH1和AtLSH2 的表达来产生新植物。