Arabidopsis phytochelatin synthase 1, but not phytochelatin synthesis, functions in extracellular defense against multiple fungal pathogens
Arabidopsis phytochelatin synthase 1, but not phytochelatin synthesis, functions in extracellular defense against multiple fungal pathogens
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拟南芥植物螯合素合酶 1，但不是植物螯合素合成，在针对多种真菌病原体的细胞外防御中发挥作用
DOI：
10.1101/568113
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
S. Somerville
中科院分区：
文献类型：
--
作者：
Kian Hématy;Melisa T S Lim;Candice Cherk;P. Bednarek;M. Piślewska;Clara Sánchez;Monica Stein;René Fuchs;Christine Klapprodt;V. Lipka;A. Molina;E. Grill;P. Schulze;S. Somerville
植物螯合素合酶（PCS）是植物重金属解毒的关键成分。 PCS 催化从谷胱甘肽合成肽植物螯合剂，以及通过肽酶活性降解谷胱甘肽缀合物。在这里，我们描述了 PCS 在植物病原真菌抗病性中迄今为止未表征的作用。 pen4 突变体是镉不敏感 1 (cad1/pcs1) 突变体的等位基因，是从拟南芥突变体筛选中回收的，该突变体对未适应的大麦真菌病原体 Blumeria graminis f 的抗性降低。 sp。大麦。 PCS1 存在于健康植物细胞的细胞质中，在病原体攻击时易位，并与固定线粒体表面的 PEN2 黑芥子酶共定位。 pcs1和pen2突变体植物在病原体诱导的吲哚芥子油苷衍生化合物的积累中表现出类似的代谢缺陷，表明PEN2和PCS1在相同的代谢途径中发挥作用。 PCS1 在该途径中的功能独立于植物螯合素合成和谷胱甘肽缀合物的脱甘氨酸，因为 PCS1 的催化位点突变体仍然在吲哚芥子油苷代谢中发挥作用。在揭示 PCS1 以前未知的功能时，我们发现这种酶是一种兼职蛋白，对于植物对生物和非生物胁迫的反应非常重要。
Phytochelatin synthase (PCS) is a key component of heavy metal detoxification in plants. PCS catalyzes both the synthesis of the peptide phytochelatin from glutathione as well as the degradation of glutathione conjugates via peptidase activity. Here, we describe a hitherto uncharacterized role for PCS in disease resistance against plant pathogenic fungi. The pen4 mutant, which is allelic to cadmium insensitive 1 (cad1/pcs1) mutants, was recovered from a screen for Arabidopsis mutants with reduced resistance to the non-adapted barley fungal pathogen, Blumeria graminis f. sp. hordei. PCS1, which is found in the cytoplasm of cells of healthy plants, translocates upon pathogen attack and colocalizes with the PEN2 myrosinase on the surface of immobilized mitochondria. pcs1 and pen2 mutant plants exhibit a similar metabolic defect in the accumulation of pathogen-inducible indole glucosinolate-derived compounds, suggesting that PEN2 and PCS1 act in the same metabolic pathway. The function of PCS1 in this pathway is independent of phytochelatin synthesis and deglycination of glutathione conjugates, as catalytic-site mutants of PCS1 are still functional in indole glucosinolate metabolism. In uncovering a previously unknown function for PCS1, we reveal this enzyme to be a moonlighting protein important for plant responses to both biotic and abiotic stresses.