Leaf abaxial immunity to powdery mildew in Arabidopsis is conferred by multiple defense mechanisms
Leaf abaxial immunity to powdery mildew in Arabidopsis is conferred by multiple defense mechanisms
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DOI：
10.1093/jxb/erad450
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发表时间：
2023-12-05
影响因子：
6.9
通讯作者：
Xiao，Shunyuan
中科院分区：
文献类型：
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作者：
Wu，Ying;Sexton，W. Kyle;Xiao，Shunyuan
白粉病真菌是专性生物营养病原体，只侵入植物表皮细胞。每片植物叶片都有两个表皮面：正面（上）面和背面（下）面。虽然在许多植物物种中，叶片的两个表面都可能对适应性白粉病真菌敏感，但在包括拟南芥在内的一些植物物种中，已经观察到叶片背面免疫。这种叶背面免疫的遗传基础尚不清楚。在这项研究中，我们用适应性白粉病分离物——绿弧菌ucsc1测试了一系列在一种或多种已知防御途径中存在缺陷的拟南芥突变体。我们发现，在EDS1/PAD4-和PEN2/ pen3依赖性防御受损的突变体中，叶片背面免疫显著受损。在s1-2和pen2-1突变体背景下，eds1-黄色荧光蛋白和pen2-绿色荧光蛋白融合体在下表皮细胞中的表达高于在近轴表皮细胞中的表达。总之，我们的研究结果表明，拟南芥叶片对白粉病的背面免疫至少部分是由于EDS1/PAD4-和PEN2/ pen3依赖性防御的增强。这种转录预编程防御机制可能是其他植物（如大麻）叶片背面免疫的基础，并可能被用于作物植物对白粉病真菌的正面免疫工程。
Powdery mildew fungi are obligate biotrophic pathogens that only invade plant epidermal cells. There are two epidermal surfaces in every plant leaf: the adaxial (upper) side and the abaxial (lower) side. While both leaf surfaces can be susceptible to adapted powdery mildew fungi in many plant species, there have been observations of leaf abaxial immunity in some plant species including Arabidopsis. The genetic basis of such leaf abaxial immunity remains unknown. In this study, we tested a series of Arabidopsis mutants defective in one or more known defense pathways with the adapted powdery mildew isolateGolovinomyces cichoracearumUCSC1. We found that leaf abaxial immunity was significantly compromised in mutants impaired for both the EDS1/PAD4- and PEN2/PEN3-dependent defenses. Consistently, expression of EDS1–yellow fluorescent protein and PEN2–green fluorescent protein fusions from their respective native promoters in the respectiveeds1-2andpen2-1mutant backgrounds was higher in the abaxial epidermal cells than in the adaxial epidermal cells. Altogether, our results indicate that leaf abaxial immunity against powdery mildew in Arabidopsis is at least partially due to enhanced EDS1/PAD4- and PEN2/PEN3-dependent defenses. Such transcriptionally pre-programmed defense mechanisms may underlie leaf abaxial immunity in other plant species such as hemp and may be exploited for engineering adaxial immunity against powdery mildew fungi in crop plants.