Key message

OG1 is involved in JA-regulated anthesis by modulating carbohydrate transport of lodicules in rice.

Abstract

Flowering plants have evolved a sophisticated regulatory network to coordinate anthesis and maximize reproductive success. In addition to various environmental conditions, the plant hormone jasmonic acid and its derivatives (JAs) are involved in anthesis. However, the underlying mechanism remains largely unexplored. Here, we report a JA-defective mutant in rice (Oryza sativa), namely open glume 1, which has dysfunctional lodicules that lead to open glumes following anthesis. Map-based cloning and subsequent complementation tests confirmed that OG1 encodes a peroxisome-localized 12-oxo-phytodienoic acid reductase—a key enzyme that reduces the precursor of JA. Loss-of-function of OG1 resulted in almost no JA accumulation. Exogenous JA treatment completely rescued the defects caused by the og1 mutation. Further studies revealed that intracellular metabolism was disrupted in the lodicules of og1 mutant. At the mature plant stage, most seeds of the mutant were malformed with significantly reduced starch content. We speculate that JA or JA signaling mediates the carbohydrate transport of lodicules during anthesis, and signal the onset of cell degradation in lodicules after anthesis. We conclude that the OPEN GLUME 1 gene that produces a key enzyme involved in reducing the precursor of JA in JA biosynthesis and is involved in carbohydrate transport underlying normal lodicule function during anthesis in rice.

中文翻译：

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OPEN GLUME1：一种减少JA前体的关键酶，参与水稻开花期糖浆的碳水化合物转运

关键信息

OG1通过调节水稻中糖浆的碳水化合物转运参与 JA 调节的开花。

抽象的

开花植物已经进化出一个复杂的调节网络来协调开花并最大限度地提高繁殖成功率。除各种环境条件外，植物激素茉莉酸及其衍生物（JAs）也参与开花。然而，潜在的机制在很大程度上仍未被探索。在这里，我们报告了水稻（ Oryza sativa ）中的一种 JA 缺陷突变体，即开放颖片 1，其具有功能失调的浆片，导致开花后开放颖片。基于图谱的克隆和随后的互补测试证实OG1编码一种定位于过氧化物酶体的 12-氧代植物二烯酸还原酶——一种还原 JA 前体的关键酶。OG1功能丧失导致几乎没有 JA 积累。外源JA处理完全挽救了由og1突变引起的缺陷。进一步的研究表明，og1突变体的细胞内代谢被破坏。在成熟植物阶段，突变体的大多数种子畸形，淀粉含量显着降低。我们推测 JA 或 JA 信号在开花期间介导浆片的碳水化合物转运，并在开花后发出浆片中细胞降解的信号。我们得出结论，产生关键酶的OPEN GLUME 1基因参与减少 JA 生物合成中的 JA 前体，并参与水稻开花期间正常浆液功能的碳水化合物转运。