IRREGULAR POLLEN EXINE1 Is a Novel Factor in Anther Cuticle and Pollen Exine Formation
IRREGULAR POLLEN EXINE1 Is a Novel Factor in Anther Cuticle and Pollen Exine Formation
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不规则花粉外壁1是花药角质层和花粉外壁形成的新因子
DOI：
10.1104/pp.16.00629
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发表时间：
2017-01-01
期刊：
影响因子：
7.4
通讯作者：
Jin, Weiwei
中科院分区：
文献类型：
--
作者：
Chen, Xiaoyang;Zhang, Hua;Jin, Weiwei
花药角质层和花粉外壁是花粉发育和受精的保护屏障。尽管已经鉴定了水稻（Oryza sativa）和拟南芥（Arabidopsis thaliana）中花药角质层和花粉外壁发育的几种调节剂，但是在玉米（Zea mays）中很少有基因被表征，并且潜在的调节机制仍然难以捉摸。在这里，我们报告了一种新的玉米雄性不育突变体，不规则花粉外壁1（ipe 1），表现出有光泽的外花药表面，异常乌氏体，和有缺陷的花粉外壁。使用基于图位的克隆，IPE 1基因被分离为一个假定的葡萄糖-甲醇胆碱氧化还原酶，靶向内质网。在四分体和单核小孢子早期，IPE 1的转录物优先积累在绒毡层中。生化分析表明，ipe 1花药的蜡成分和角质单体和脂肪酸的显着减少。RNA测序数据显示，与蜡和类黄酮代谢，脂肪酸合成和伸长有关的基因在ipe 1突变体花药中差异表达。此外，拟南芥中的orthopeptide基因的转移DNA插入系的分析表明，IPE 1及其直系同源物在雄性器官发育中具有部分保守的功能。我们的研究结果表明，IPE 1参与了C16/C18 ω-羟基脂肪酸的氧化途径，并与玉米雄性不育26和雄性不育45一起控制花药角质层和花粉外壁的发育。
Anther cuticle and pollen exine are protective barriers for pollen development and fertilization. Despite that several regulators have been identified for anther cuticle and pollen exine development in rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana), few genes have been characterized in maize (Zea mays) and the underlying regulatory mechanism remains elusive. Here, we report a novel male-sterile mutant in maize, irregular pollen exine1 (ipe1), which exhibited a glossy outer anther surface, abnormal Ubisch bodies, and defective pollen exine. Using map-based cloning, the IPE1 gene was isolated as a putative glucose-methanolcholine oxidoreductase targeted to the endoplasmic reticulum. Transcripts of IPE1 were preferentially accumulated in the tapetum during the tetrad and early uninucleate microspore stage. A biochemical assay indicated that ipe1 anthers had altered constituents of wax and a significant reduction of cutin monomers and fatty acids. RNA sequencing data revealed that genes implicated in wax and flavonoid metabolism, fatty acid synthesis, and elongation were differentially expressed in ipe1 mutant anthers. In addition, the analysis of transfer DNA insertional lines of the orthologous gene in Arabidopsis suggested that IPE1 and their orthologs have a partially conserved function in male organ development. Our results showed that IPE1 participates in the putative oxidative pathway of C16/C18 omega-hydroxy fatty acids and controls anther cuticle and pollen exine development together with MALE STERILITY26 and MALE STERILITY45 in maize.