CITAB-UM, Departamento de Biologia, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
Plant Physiol Biochem. 2011 Aug;49(8):835-42. doi: 10.1016/j.plaphy.2011.05.009. Epub 2011 May 31.
Chlorogenic acid (CGA), a product of the phenylpropanoid pathway, is one of the most widespread soluble phenolic compounds in the plant kingdom. Although CGA is known to have important roles in plant function, its relevance in plant de novo organogenesis is not yet understood. With a series of experiments, here we show that CGA has a potential role in shoot, root and root hair development. In the first phase of our investigation, we developed an efficient and novel thin cell layer (TCL) regeneration protocol for Hypericum perforatum which could bridge all the in vitro morphogenetic stages between single cell and complete plant. Tissues at different morphogenetic states were analysed for their phenolic profile which revealed that shoot differentiation from callus tissues of H. perforatum is accompanied by the onset of CGA production. Further, the relevance of CGA in de novo organogenesis was deciphered by culturing highly organogenic root explants on media augmented with various concentrations of CGA. Results of this experiment showed that CGA concentrations lower than 10.0 mg l⁻¹ did not affect shoot organogenesis, whereas, higher concentrations significantly reduced this process in a concentration-dependent manner. In spite of the differential concentration-dependent effects of CGA on shoot regeneration, supplementation of CGA did not have any effect on the production of lateral roots and root hairs. Interestingly, CGA showed a concentration-dependent positive correlation with lateral roots and root hairs production in the presence of α-naphthaleneacetic acid (NAA). When the culture medium was augmented with 2-aminoindane-2-phosphonic acid (AIP), an inhibitor of phenylalanine ammonia lyase (PAL), induction of shoots, lateral roots and root hairs from the explants was significantly affected. Addition of an optimum concentration of CGA in these cultures partially restored all these organogenic processes.
绿原酸（CGA）是苯丙烷途径的产物，是植物界分布最广泛的可溶性酚类化合物之一。尽管 CGA 已知在植物功能中具有重要作用，但它在植物从头器官发生中的相关性尚不清楚。通过一系列实验，我们在这里表明 CGA 可能在芽、根和根毛发育中发挥作用。在我们研究的第一阶段，我们为贯叶连翘开发了一种高效且新颖的薄壁细胞层（TCL）再生方案，该方案可以连接单细胞和完整植物之间的所有体外形态发生阶段。对处于不同形态发生状态的组织进行酚类分析，结果表明贯叶连翘愈伤组织中的芽分化伴随着 CGA 产生的开始。此外，通过在含有不同浓度 CGA 的培养基上培养高器官发生根外植体，解析了 CGA 在从头器官发生中的相关性。该实验结果表明，浓度低于 10.0 mg l⁻¹的 CGA 不会影响芽器官发生，而较高浓度则以浓度依赖的方式显著降低了这一过程。尽管 CGA 对芽再生的浓度依赖性影响不同，但 CGA 的补充对侧根和根毛的产生没有任何影响。有趣的是，在添加α-萘乙酸（NAA）的情况下，CGA 与侧根和根毛的产生呈浓度依赖性正相关。当培养基中添加苯丙氨酸解氨酶（PAL）抑制剂 2-氨基吲哚-2-磷酸（AIP）时，外植体中芽、侧根和根毛的诱导受到显著影响。在这些培养物中添加最佳浓度的 CGA 部分恢复了所有这些器官发生过程。
