Data_Sheet_4_Pluronic F-68 Improves Callus Proliferation of Recalcitrant Rice Cultivar via Enhanced Carbon and Nitrogen Metabolism and Nutrients Uptake.ZIP

Pluronic F-68 (PF-68) is a non-ionic surfactant used in plant tissue culture as a growth additive. Despite its usage as a plant growth enhancer, the mechanism underlying the growth-promoting effects of PF-68 remains largely unknown. Hence, this study was undertaken to elucidate the growth-promoting mechanism of PF-68 using recalcitrant MR 219 callus as a model. Supplementation of 0.04% PF-68 (optimum concentration) was shown to enhance callus proliferation. The treated callus recorded enhanced sugar content, protein content, and glutamate synthase activity as exemplified in the comparative proteome analysis, showing protein abundance involved in carbohydrate metabolism (alpha amylase), protein biosynthesis (ribosomal proteins), and nitrogen metabolism (glutamate synthase), which are crucial to plant growth and development. Moreover, an increase in nutrients uptake was also noted with potassium topping the list, suggesting a vital role of K in governing plant growth. In contrast, 0.10% PF-68 (high concentration) induced stress response in the callus, revealing an increment in phenylalanine ammonia lyase activity, malondialdehyde content, and peroxidase activity, which were consistent with high abundance of phenylalanine ammonia lyase, peroxidase, and peroxiredoxin proteins detected and concomitant with a reduced level of esterase activity. The data highlighted that incorporation of PF-68 at optimum concentration improved callus proliferation of recalcitrant MR 219 through enhanced carbohydrate metabolism, nitrogen metabolism, and nutrient uptake. However, growth-promoting effects of PF-68 are concentration dependent.

泊洛沙姆F-68（Pluronic F-68，PF-68）是一种非离子型表面活性剂，常作为生长添加剂应用于植物组织培养。尽管PF-68被广泛用作植物生长促进剂，但其促生长效应的分子机制仍未得到充分阐明。为此，本研究以难培养MR 219愈伤组织为模型，旨在阐明PF-68的促生长机制。实验表明，添加0.04% PF-68（最适浓度）可显著促进愈伤组织增殖。通过比较蛋白质组学分析可见，经PF-68处理的愈伤组织中，糖类含量、蛋白质含量及谷氨酸合酶活性均显著提升；其中参与碳水化合物代谢的α-淀粉酶（alpha amylase）、蛋白质生物合成相关的核糖体蛋白，以及氮代谢关键酶谷氨酸合酶的蛋白丰度均显著上调，这些过程均对植物生长发育至关重要。此外，愈伤组织的养分吸收能力也有所增强，其中钾离子吸收增幅最为显著，提示钾离子在调控植物生长中发挥关键作用。与之相反，0.10% PF-68（高浓度）可诱导愈伤组织产生应激反应：苯丙氨酸解氨酶（phenylalanine ammonia lyase）活性、丙二醛（malondialdehyde）含量及过氧化物酶（peroxidase）活性均显著升高，这与检测到的苯丙氨酸解氨酶、过氧化物酶及过氧还蛋白（peroxiredoxin）蛋白丰度上调相一致，同时伴随酯酶（esterase）活性的降低。本研究数据表明，在最适浓度下添加PF-68可通过增强碳水化合物代谢、氮代谢及养分吸收，促进难培养MR 219愈伤组织的增殖。但PF-68的促生长效应具有浓度依赖性。