Verdaguer Roger, Soler Marçal, Serra Olga, Garrote Aïda, Fernández Sandra, Company-Arumí Dolors, Anticó Enriqueta, Molinas Marisa, Figueras Mercè
Laboratori del Suro, Biology Department, Campus Montilivi, E-17071 Girona, Catalonia, Spain.
Laboratori del Suro, Biology Department, Campus Montilivi, E-17071 Girona, Catalonia, Spain Laboratoire de Recherche en Sciences Végétales, UMR5546, Université Toulouse III/CNRS, BP 42617, Auzeville, 31326 Castanet Tolosan, France.
J Exp Bot. 2016 Oct;67(18):5415-5427. doi: 10.1093/jxb/erw305. Epub 2016 Aug 12.
Suberin and wax deposited in the cork (phellem) layer of the periderm form the lipophilic barrier that protects mature plant organs. Periderm lipids have been widely studied for their protective function with regards to dehydration and for how they respond to environmental stresses and wounding. However, despite advances in the biosynthetic pathways of suberin and associated wax, little is known about the regulation of their deposition. Here, we report on a potato NAC transcription factor gene, StNAC103, induced in the tuber phellem (skin). The StNAC103 promoter is active in cells undergoing suberization such as in the basal layer of the phellem, but also in the root apical meristem. Gene silencing in potato periderm correlates with an increase in the suberin and wax load, and specifically in alkanes, ω-hydroxyacids, diacids, ferulic acid, and primary alcohols. Concomitantly, silenced lines also showed up-regulation of key genes related to the biosynthesis and transport of suberin and wax in the tuber periderm. Taken together, our results suggest that StNAC103 has a role in the tight regulation of the formation of apoplastic barriers and is, to the best of our knowledge, the first candidate gene to be identified as being involved in the repression of suberin and wax deposition.
沉积在周皮木栓（栓质）层中的木栓质和蜡质形成了保护成熟植物器官的亲脂性屏障。周皮脂质因其在脱水方面的保护功能以及它们对环境胁迫和伤口的反应方式而受到广泛研究。然而，尽管在木栓质和相关蜡质的生物合成途径方面取得了进展，但对它们沉积的调控却知之甚少。在此，我们报道了一个在块茎木栓（表皮）中诱导表达的马铃薯NAC转录因子基因StNAC103。StNAC103启动子在经历栓质化的细胞中具有活性，如在木栓质的基底层，但在根尖分生组织中也有活性。马铃薯周皮中的基因沉默与木栓质和蜡质含量的增加相关，特别是在烷烃、ω-羟基酸、二酸、阿魏酸和伯醇中。同时，沉默株系在块茎周皮中与木栓质和蜡质生物合成及转运相关的关键基因也出现上调。综上所述，我们的结果表明StNAC103在质外体屏障形成的严格调控中发挥作用，据我们所知，它是第一个被鉴定为参与抑制木栓质和蜡质沉积的候选基因。
