State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University, Taicheng Road 3, Yangling, Shaanxi 712100, PR China.
Plant Physiol Biochem. 2013 Oct;71:164-72. doi: 10.1016/j.plaphy.2013.07.009. Epub 2013 Jul 26.
Genetic characterization of the Arabidopsis lesion simulating disease 1 (lsd1) mutant, a lesion mimic mutant (LMM), has revealed the essential role of AtLSD1 in the negative regulation of cell death and disease resistance. The three zinc-finger motifs found in AtLSD1 revealed a novel plant-specific gene family, whose members are significantly related to programmed cell death (PCD). In this study, we characterized a functional homologue to AtLSD1, TaLSD1, in the wheat-stripe rust fungus pathosystem. The expression of TaLSD1 was differentially induced during incompatible and compatible interactions between wheat and Puccinia striiformis f. sp. tritici (Pst) and was up-regulated by oxidative stress generated by methyl viologen (MV). TaLSD1 was found to be predominately localized in the nucleus of onion epidermal cell. Transient overexpression assays in Nicotiana benthamiana demonstrated that TaLSD1 partially inhibited programmed cell death triggered by a mouse Bax protein, whereas expression of TaLSD1 alone had no influence on the phenotype of tobacco. Knocking down the expression of TaLSD1 through virus-induced gene silencing (VIGS) increased wheat resistance against Pst accompanied by an enhanced hypersensitive response (HR), an increase in PR1 gene expression and a reduction in Pst hyphal growth. Our results suggest that TaLSD1 functions negatively in regulating the plant hypersensitive cell death and is involved in disease resistance of wheat against the stripe rust pathogen.
拟南芥病变和类似坏死 1 （lsd1）突变体的遗传特征，是一个病变模拟突变体（LMM），揭示了 AtLSD1 在负调控细胞死亡和抗病性中的重要作用。在 AtLSD1 中发现的三个锌指基序揭示了一个新的植物特异性基因家族，其成员与程序性细胞死亡（PCD）有显著的相关性。在这项研究中，我们在小麦条锈病病原系统中鉴定了 AtLSD1 的一个功能同源物 TaLSD1。TaLSD1 的表达在小麦与条锈菌 Puccinia striiformis f. sp. tritici（Pst）之间的非亲和和亲和互作中被差异诱导，并被甲基紫精（MV）产生的氧化应激上调。TaLSD1 主要定位于洋葱表皮细胞的细胞核中。在 Nicotiana benthamiana 中的瞬时过表达实验表明，TaLSD1 部分抑制了由鼠源 Bax 蛋白引发的程序性细胞死亡，而 TaLSD1 自身的表达对烟草的表型没有影响。通过病毒诱导的基因沉默（VIGS）敲低 TaLSD1 的表达增加了小麦对 Pst 的抗性，伴随着增强的过敏反应（HR）、PR1 基因表达的增加和 Pst 菌丝生长的减少。我们的结果表明，TaLSD1 在负调控植物过敏细胞死亡中起作用，并参与小麦对条锈病病原体的抗病性。
