Gansu Provincial Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Key Laboratory of Crop Improvement and Germplasm Enhancement, Gansu Agricultural University, Lanzhou, China.
College of Horticulture, Gansu Agricultural University, Lanzhou, China.
Physiol Plant. 2020 Mar;168(3):675-693. doi: 10.1111/ppl.13014. Epub 2019 Aug 12.
Potato tuberization is a complicated biological process regulated by multiple phytohormones, in particular cytokinins (CKs). The information available on the molecular mechanisms regulating tuber development by CKs remains largely unclear. Physiological results initially indicated that low 6-benzylaminopurine (BAP) concentration (3 mg l ) advanced the tuberization beginning time and promoted tuber formation. A comparative proteomics approach was applied to investigate the proteome change of tuber development by two-dimensional gel electrophoresis in vitro, subjected to exogenous BAP treatments (0, 3, 6 and 13 mg l ). Quantitative image analysis showed a total of 83 protein spots with significantly altered abundance (>2.5-fold, P < 0.05), and 55 differentially abundant proteins were identified by MALDI-TOF/TOF MS. Among these proteins, 22 proteins exhibited up-regulation with the increase of exogenous BAP concentration, and 31 proteins were upregulated at 3 mg l BAP whereas being downregulated at higher BAP concentrations. These proteins were involved in metabolism and bioenergy, storage, redox homeostasis, cell defense and rescue, transcription and translation, chaperones, signaling and transport. The favorable effects of low BAP concentrations on tuber development were found in various cellular processes, mainly including the stimulation of starch and storage protein accumulation, the enhancement of the glycolysis pathway and ATP synthesis, the cellular homeostasis maintenance, the activation of pathogen defense, the higher efficiency of transcription and translation, as well as the enhanced metabolite transport. However, higher BAP concentration, especially 13 mg l , showed disadvantageous effects. The proposed hypothetical model would explain the interaction of these proteins associated with CK-induced tuber development in vitro.
块茎形成是一个复杂的生物学过程，受多种植物激素调控，尤其是细胞分裂素（CKs）。关于 CKs 调节块茎发育的分子机制的信息仍然很大程度上不清楚。最初的生理结果表明，低浓度的 6-苄基氨基嘌呤（BAP）（3mg·l-1）会提前块茎形成时间，并促进块茎形成。采用比较蛋白质组学方法，通过体外二维凝胶电泳研究了外源 BAP 处理（0、3、6 和 13mg·l-1）对块茎发育的蛋白质组变化。定量图像分析显示，共有 83 个蛋白质斑点的丰度发生了显著变化（>2.5 倍，P<0.05），并通过 MALDI-TOF/TOF MS 鉴定了 55 个差异丰度蛋白。在这些蛋白质中，有 22 个蛋白质随着外源 BAP 浓度的增加而上调，有 31 个蛋白质在 3mg·l-1 BAP 时上调，而在更高 BAP 浓度时下调。这些蛋白质参与代谢和生物能量、储存、氧化还原稳态、细胞防御和挽救、转录和翻译、伴侣蛋白、信号和运输。低浓度 BAP 对块茎发育的有利影响在各种细胞过程中都有发现，主要包括刺激淀粉和贮藏蛋白积累、增强糖酵解途径和 ATP 合成、维持细胞内稳态、激活病原体防御、提高转录和翻译效率以及增强代谢物运输。然而，较高的 BAP 浓度，特别是 13mg·l-1，表现出不利影响。该假设模型解释了这些与 CK 诱导的体外块茎发育相关的蛋白质之间的相互作用。
