Ethylene-independent signaling by the ethylene precursor ACC in Arabidopsis ovular pollen tube attraction
Ethylene-independent signaling by the ethylene precursor ACC in Arabidopsis ovular pollen tube attraction
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DOI：
10.1038/s41467-020-17819-9
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发表时间：
2020-08-14
影响因子：
16.6
通讯作者：
Chang, Caren
中科院分区：
文献类型：
--
作者：
Mou, Wangshu;Kao, Yun-Ting;Chang, Caren
植物激素乙烯对植物的生长和发育有许多影响。其直接前体1-氨基环丙烷-1-羧酸（ACC）是由ACC合成酶（ACS）产生的一种非蛋白质氨基酸。ACC通常用于诱导乙烯反应。在这里，我们表明，ACC表现出乙烯独立的信号在拟南芥生殖。通过分析acs八倍体突变体与减少结实，我们发现，ACC信号在胚珠孢子体组织参与花粉管吸引，并促进分泌的花粉管化学引诱剂LURE 1.2。ACC通过根原生质体中的谷氨酸受体样（GLR）通道激活含Ca 2+的离子流。在COS-7细胞表达苔藓PpGLR 1，ACC诱导最高的胞质Ca 2+升高相比，所有20个蛋白质氨基酸。在胚珠中，ACC刺激瞬时Ca 2+升高，八倍突变胚珠中的Ca 2+内流拯救LURE 1.2分泌。这些发现揭示了一种新的ACC功能，并为解开ACC在植物中的新生理意义提供了见解。
The phytohormone ethylene has numerous effects on plant growth and development. Its immediate precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), is a non-proteinogenic amino acid produced by ACC SYNTHASE (ACS). ACC is often used to induce ethylene responses. Here, we demonstrate that ACC exhibits ethylene-independent signaling in Arabidopsis thaliana reproduction. By analyzing an acs octuple mutant with reduced seed set, we find that ACC signaling in ovular sporophytic tissue is involved in pollen tube attraction, and promotes secretion of the pollen tube chemoattractant LURE1.2. ACC activates Ca2+-containing ion currents via GLUTAMATE RECEPTOR-LIKE (GLR) channels in root protoplasts. In COS-7 cells expressing moss PpGLR1, ACC induces the highest cytosolic Ca2+ elevation compared to all twenty proteinogenic amino acids. In ovules, ACC stimulates transient Ca2+ elevation, and Ca2+ influx in octuple mutant ovules rescues LURE1.2 secretion. These findings uncover a novel ACC function and provide insights for unraveling new physiological implications of ACC in plants.