Sezione di Biologia Vegetale, Dipartimento Biologia e Protezione delle Piante, Università di Udine, Via delle Scienze 91, I-33100 Udine, Italy.
J Plant Physiol. 2011 Jul 15;168(11):1226-33. doi: 10.1016/j.jplph.2011.01.024. Epub 2011 Apr 2.
Embryogenic cell masses (ECM) of Abies cephalonica were grown on proliferation media in the presence and absence of fulvic acid (FA), whose molecular composition and conformational rigidity were evaluated by CPMAS-¹³C NMR spectroscopy. To assess the physiological effects of this humic material during proliferation and maturation stages of somatic embryogenesis (SE), proliferation rate, proportion of consecutive developmental stages of pro-embryogenic masses (PEM), cellular ATP and glucose-6-phosphate were evaluated at regular intervals. FA increased the proliferation rate, especially during the early sampling days, and the percentage of PEM in their advanced developmental stage. Cellular ATP and glucose-6-phospahte were increased by FA pre-treatment during the maturation phase. Furthermore, the effects of the anti-auxin p-chlorophenoxyisobutyric acid (PCIB), such as a decrease of growth and the enhancement of PEM III induction, were inverted by FA. Proton pumping ATPase and PPase activities were decreased in microsomes from PCIB-treated ECM, while they increased in the presence of FA. This fulvic matter also induced a delay in somatic embryo formation during the maturation phase. Both the improvement of the PEM proliferation and the reduction of the subsequent maturation process of A. cephalonica are explained by a release from the complex humic structure of low molecular-weight molecules, which may interact with the plant hormonal signaling pathway. These effects appear to be related to the hydrophilic and conformationally labile nature of FA. The structure-activity relationship observed here suggests that the influence of FA on ECM may be attributed to specific bioactive molecules that are preferentially released from the FA loose superstructure.
cephalonica 雪松胚性细胞团（ECM）在增殖培养基中生长，存在和不存在富啡酸（FA），其分子组成和构象刚性通过 CPMAS-¹³C NMR 光谱评估。为了评估这种腐殖质在体细胞胚胎发生（SE）增殖和成熟阶段的生理作用，定期评估增殖率、原胚性细胞团（PEM）连续发育阶段的比例、细胞 ATP 和葡萄糖-6-磷酸。FA 增加了增殖率，尤其是在早期采样日，以及 PEM 处于其高级发育阶段的百分比。在成熟阶段，FA 预处理增加了细胞 ATP 和葡萄糖-6-磷酸的含量。此外，抗生长素 p-氯苯氧异丁酸（PCIB）的作用，如生长减少和增强 PEM III 诱导，被 FA 逆转。PCIB 处理的 ECM 中微粒体的质子泵 ATPase 和 PPase 活性降低，而在 FA 存在下它们增加。这种富啡酸物质还在成熟阶段延迟了体细胞胚胎的形成。PEM 增殖的改善和 A.cephalonica 随后成熟过程的减少都可以用从低分子量分子的复杂腐殖质结构中释放出来的物质来解释，这些物质可能与植物激素信号通路相互作用。这些影响似乎与 FA 的亲水性和构象不稳定性质有关。这里观察到的结构-活性关系表明，FA 对 ECM 的影响可能归因于特定的生物活性分子，这些分子优先从 FA 松散的超结构中释放出来。
