Abstract：
The osmotic resistance mechanism has been extensively studied in whole plants or plant tissues. However, little is known about it in embryogenic tissue (ET) which is widely used in plant-based biotechnological systems. Suberin, a cell wall aliphatic and aromatic heteropolymer, plays a critical role in plant cells against osmosis stress. The suberin regulatory biosynthesis has rarely been studied in gymnosperms. Here, PaMYB11, a subgroup 11 R2R3-MYB transcription factor, plays a key role in the osmotic resistance of Norway spruce (Picea abies) ETs during cryoprotectant pretreatment. Thus, RNA-seq, histological, and analytical chemical analyses are performed on the stable transformations of PaMYB11-OE and PaMYB11-SRDX in Norway spruce ETs. DAP-seq, Y1H, and LUC are further combined to explore the PaMYB11 targets. Activation of PaMYB11 is necessary and sufficient for suberin lamellae deposition on Norway spruce embryogenic cell walls, which plays a decisive role in ET survival under osmotic stress. Transcriptome analysis shows that PaMYB11 enhances suberin lamellae monomer synthesis by promoting very long-chain fatty acid (VLCFA) synthesis. PaPOP, PaADH1, and PaTET8L, the first two (PaADH1 and PaPOP, included) involved in VLCFA synthesis, are proved to be the direct targets of PaMYB11. Our study identified a novel osmotic response directed by PaMYB11 in Norway spruce ET, which provides a new understanding of the resistance mechanism against osmosis in gymnosperms.
摘要：
渗透抗性机制已在整个植物或植物组织中进行了广泛的研究。然而,在广泛用于植物生物技术系统的胚胎发生组织（ET）中对此知之甚少。Suberin,细胞壁脂肪族和芳香族杂聚物，在植物细胞抵抗渗透胁迫中起着至关重要的作用。在裸子植物中很少研究木素调节生物合成。这里,PaMYB11,一个亚组11R2R3-MYB转录因子,在冷冻保护剂预处理过程中，挪威云杉（Piceaabies）ET的渗透抗性中起着关键作用。因此，RNA-seq,组织学,并对挪威云杉ET中PaMYB11-OE和PaMYB11-SRDX的稳定转化进行了分析化学分析。DAP-seq,Y1H,和LUC进一步结合探索PaMYB11靶点。PaMYB11的激活对于挪威云杉胚胎发生细胞壁上的细叶沉积是必要且足够的，在渗透胁迫下ET的存活中起着决定性的作用。转录组分析表明，PaMYB11通过促进极长链脂肪酸（VLCFA）的合成来增强薄片单体的合成。PaPOP,PaADH1和PaTET8L,前两个(PaADH1和PaPOP，包括)参与VLCFA合成，被证明是PaMYB11的直接靶标。我们的研究确定了挪威云杉ET中由PaMYB11指导的新型渗透反应，这提供了对裸子植物抗渗作用机制的新认识。
