Coordination of five class III peroxidase-encoding genes for early germination events of Arabidopsis thaliana
Coordination of five class III peroxidase-encoding genes for early germination events of Arabidopsis thaliana
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DOI：
10.1016/j.plantsci.2020.110565
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发表时间：
2020-09-01
期刊：
影响因子：
5.2
通讯作者：
Dunand, Christophe
中科院分区：
文献类型：
--
作者：
Jemmat, Achraf M.;Ranocha, Philippe;Dunand, Christophe
III类过氧化物酶（CIII Prxs）属于植物特异性的多基因家族。由于它们的双催化循环，它们可以氧化化合物或释放活性氧（ROS）。它们要么参与不同的细胞壁硬化过程，如木质化和超微化，要么参与细胞壁松动或防御机制。发芽是一个重要的发育阶段，需要特定的过氧化物酶活性。然而，对于哪些同工异构体是已知的。从已发表的芯片数据挖掘中鉴定出5个CIII Prx编码基因：AtPrx04、AtPrx16、AtPrx62、AtPrx69和AtPrx71。在相应的CIII Prx突变系中观察到延迟或诱导的睾丸和胚乳破裂，分别表明在萌发过程中具有基因特异性的诱导或抑制作用。通过原位杂交，AtPrx16、AtPrx62、AtPrx69和AtPrx71转录本完全定位于面向胚根的微孔胚乳，转录组学数据分析使这5个CIII Prxs定位在一个富含萌发、细胞壁、细胞壁蛋白和木葡聚糖命中的共表达网络中。结果表明，5个CIII Prxs蛋白是细胞壁靶向蛋白，微孔胚乳具有复杂的细胞壁结构域拓扑化学特征。最后，我们绘制了一个时空模型，突出了精细序列基因表达和可能参与的微孔胚乳细胞壁结构域，以解释CIII Prxs在单一细胞类型中的非冗余细胞壁加固和松动功能。我们还强调了在拟南芥发芽过程中精确控制微孔胚乳细胞壁动态的过氧化物酶稳态的必要性。
The Class III peroxidases (CIII Prxs) belong to a plant-specific multigene family. Thanks to their double catalytic cycle they can oxidize compounds or release reactive oxygen species (ROS). They are either involved in different cell wall stiffening processes such as lignification and suberization, in cell wall loosening or defense mechanisms. Germination is an important developmental stage requiring specific peroxidase activity. However, lithe is known about which isoforms are involved. Five CIII Prx encoding genes: AtPrx04, AtPrx16, AtPrx62, AtPrx69, and AtPrx71 were identified from published microarray data mining. Delayed or induced testa and endosperm rupture were observed for the corresponding CIII Prx mutant lines indicating either a gene-specific inducing or repressing role during germination, respectively. Via in situ hybridization AtPrx16, AtPrx62, AtPrx69 and AtPrx71 transcripts were exclusively localized to the micropylar endosperm facing the radicle, and transcriptomic data analysis enabled positioning the five CIII Prxs in a co-expression network enriched in germination, cell wall, cell wall proteins and xyloglucan hits. Evidence were produced showing that the five CIII Prxs were cell wall-targeted proteins and that the micropylar endosperm displayed a complex cell wall domain topochemistry. Finally, we drew a spatio-temporal model highlighting the fine sequential gene expression and the possible involvement of micropylar endosperm cell wall domains to explain the non-redundant cell wall stiffening and loosening functions of the CIII Prxs in a single cell type. We also highlighted the necessity of a peroxidase homeostasis to accurately control the micropylar endosperm cell wall dynamics during Arabidopsis germination events.