Very-long-chain fatty acids restrict regeneration capacity by confining pericycle competence for callus formation in Arabidopsis
Very-long-chain fatty acids restrict regeneration capacity by confining pericycle competence for callus formation in Arabidopsis
复制标题
超长链脂肪酸通过限制拟南芥愈伤组织形成的中柱鞘能力来限制再生能力
DOI：
10.1073/pnas.1522466113
复制
发表时间：
2016-05-03
影响因子：
11.1
通讯作者：
Hu, Yuxin
中科院分区：
文献类型：
--
作者：
Shang, Baoshuan;Xu, Chongyi;Hu, Yuxin
愈伤组织诱导是典型植物体外再生的第一步，最近的研究表明，生长素诱导的愈伤组织在多个器官中的形成是通过根的发育途径从中柱细胞或中柱细胞开始的。在此，我们证明了超长链脂肪酸(VLCFAs)或其衍生物在限制轮回愈伤组织形成能力从而限制拟南芥再生能力方面起着关键的信号作用。我们的工作不仅揭示了VLCFAs在定义再生能力方面的未知作用，还揭示了控制植物器官细胞状态的信号。我们的发现也可能与研究VLCFAs在动物细胞状态调节中的可能作用有关。植物中已经分化的器官在培养条件下具有显著的再生新个体的能力。植物的体外再生实际上始于在富含生长素的愈伤组织诱导培养基(CIM)上从分离的器官中诱导出一个多能细胞团--愈伤组织，这通常是随后新实体再生所必需的。最近的研究表明，CIM诱导的愈伤组织形成是通过根发育途径从中柱细胞或类中柱细胞发生的，而调控中柱细胞愈伤组织形成能力的信号尚不清楚。在此，我们报道了极长链脂肪酸(VLCFAs)在限制愈伤组织形成的中柱花序能力，从而限制拟南芥的再生能力方面发挥了关键作用。通过遗传筛选，我们发现了一个突变体cfr1，它绕过了单根对根形成能力的抑制(SLR/iaa14)。我们发现CFR1编码3-酮酰辅酶A合成酶1(KCS1)，它催化VLCFA生物合成的限速步骤。我们的生化和遗传分析表明，VLCFAs至少部分地通过调节异常侧根形成4(ALF4)的转录来限制愈伤组织形成的中柱细胞能力。此外，我们还提供了VLCFAs作为细胞层信号来调节愈伤组织形成的中柱细胞能力的证据。综上所述，我们的结果确定VLCFAs或其衍生物是调节愈伤组织形成的中柱细胞能力从而影响植物器官再生能力的限制信号。
Significance Callus induction is an initial step for typical plant in vitro regeneration, and recent studies show that auxin-induced callus formation in multiple organs occurs from the pericycle or pericycle-like cells via a root developmental pathway. We demonstrate here that very-long-chain fatty acids (VLCFAs) or their derivatives act as the critical signal in restricting the callus-forming capacity of the pericycle and thus the regeneration capability in Arabidopsis. Our work not only discloses an unidentified role of VLCFAs in defining the regeneration capacity, but also sheds light on the signals that govern the cell states in plant organs. Our findings also may have relevance for investigating the possible role of VLCFAs in the regulation of cell states in animals. The already differentiated organs in plants have a remarkable capacity to regenerate new individuals under culture conditions. Plant in vitro regeneration practically starts with the induction of a pluripotent cell mass, the callus, from detached organs on auxin-rich callus-inducing medium (CIM), which is generally required for subsequent regeneration of new bodies. Recent studies show that CIM-induced callus formation occurs from the pericycle or pericycle-like cells through a root developmental pathway, whereas the signals involved in governing callus-forming capacity of pericycle cells remain unknown. Here we report that very-long-chain fatty acids (VLCFAs) play a critical role in confining the pericycle competence for callus formation and thus the regeneration capacity of Arabidopsis. By genetic screening, we identified the callus formation-related 1 (cfr1) mutant, which bypasses the inhibition of callus-forming capacity in roots by solitary-root (slr/iaa14). We show that CFR1 encodes 3-ketoacyl-CoA synthase 1 (KCS1), which catalyzes a rate-limiting step of VLCFA biosynthesis. Our biochemical and genetic analyses demonstrate that VLCFAs restrict the pericycle competence for callus formation, at least in part, by regulating the transcription of Aberrant Lateral Root Formation 4 (ALF4). Moreover, we provide evidence that VLCFAs act as cell layer signals to mediate the pericycle competence for callus formation. Taken together, our results identify VLCFAs or their derivatives as the confining signals for mediating the pericycle competence for callus formation and thus the regeneration capacity of plant organs.