Ethylene-Inhibited Jasmonic Acid Biosynthesis Promotes Mesocotyl/Coleoptile Elongation of Etiolated Rice Seedlings
Ethylene-Inhibited Jasmonic Acid Biosynthesis Promotes Mesocotyl/Coleoptile Elongation of Etiolated Rice Seedlings
复制标题
乙烯抑制茉莉酸生物合成促进黄化水稻幼苗中胚轴/胚芽鞘伸长
DOI：
10.1105/tpc.16.00981
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发表时间：
2017-05-01
期刊：
影响因子：
11.6
通讯作者：
Zhang, Jin-Song
中科院分区：
文献类型：
--
作者：
Xiong, Qing;Ma, Biao;Zhang, Jin-Song
中胚轴和小叶的伸长有利于水稻（Oryza sativa）幼苗从土壤中萌发，并受到各种遗传和环境因素的影响。这一过程的调控机制在很大程度上仍不清楚。在此，我们通过研究皋姚1号（gy1）突变体的特征，考察了中胚轴和小叶生长的调控机制。皋姚1号突变体的中胚轴和小叶比水稻原种长。GY1 是通过基于图谱的克隆确定的，它编码一种定位于叶绿体的 PLA1 型磷脂酶。GY1 在茉莉酸（JA）生物合成的第一步发挥作用，抑制水稻幼苗中胚轴和小叶的伸长。乙烯会抑制 GY1 和 JA 生物合成途径中其他基因的表达，从而降低 JA 水平，并通过促进细胞伸长来增强中胚轴和小叶的生长。从遗传学角度看，GY1 在 OsEIN2 介导的乙烯信号通路下游发挥作用，调节中胚轴/小球生长。通过分析 3000 个水稻品种的重测序数据，我们发现了 GY1 基因的单个天然变异 GY1376T，它对水稻品种的中胚轴伸长有影响。我们的研究揭示了中胚轴/小穗伸长调控机制的新见解，并将在水稻育种项目中得到实际应用。
Elongation of the mesocotyl and coleoptile facilitates the emergence of rice (Oryza sativa) seedlings from soil and is affected by various genetic and environment factors. The regulatory mechanism underlying this process remains largely unclear. Here, we examined the regulation of mesocotyl and coleoptile growth by characterizing a gaoyao1 (gy1) mutant that exhibits a longer mesocotyl and longer coleoptile than its original variety of rice. GY1 was identified through map-based cloning and encodes a PLA1-type phospholipase that localizes in chloroplasts. GY1 functions at the initial step of jasmonic acid (JA) biosynthesis to repress mesocotyl and coleoptile elongation in etiolated rice seedlings. Ethylene inhibits the expression of GY1 and other genes in the JA biosynthesis pathway to reduce JA levels and enhance mesocotyl and coleoptile growth by promoting cell elongation. Genetically, GY1 acts downstream of the OsEIN2-mediated ethylene signaling pathway to regulate mesocotyl/coleoptile growth. Through analysis of the resequencing data from 3000 rice accessions, we identified a single natural variation of the GY1 gene, GY1376T, which contributes to mesocotyl elongation in rice varieties. Our study reveals novel insights into the regulatory mechanism of mesocotyl/coleoptile elongation and should have practical applications in rice breeding programs.