Plant proteins are suitable and alternative to fish meals (FMs), with less cost compared with that of all other types of fish feeds. In recent years, soy protein concentrate (SPC) has emerged as a cost-effective alternative to FM; however, little is known regarding the effects of dietary SPC on general fish physiology and well-being. This study aimed to perform comprehensive physiological and transcriptomic analysis for testing the applicability of SPC as fish feeds in hybrid grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂) [SPC replaced 0% (CK), 30% (SPC30), and 75% (SPC75) of FM protein]. Generally, SPC30 promoted fish survival and had less effects on the phenotype, while SPC75 reduced fish survival, promoted inflammation, and regulated multiple physiological responses. Thousands of differentially expressed genes (DEGs) by SPC were identified in the intestine, liver, and muscle, which were enriched in biological regulation, cellular process, metabolic process, single-organism process, cell, cell part, membrane, binding, and catalytic activity based on RNA-seq. Notably, some DEGs involved in amino acid and lipid metabolism in the digestive system highlighted the modulatory effect of SPC on these metabolic processes, consistent with the physiological responses including enzyme activities. The enriched aspects of these predominant DEGs might be directly related to the different effects of SPC30 and SPC75 on fish growth, digestibility, and underlying enzyme activities and histology. In conclusion, the comprehensive physiological and transcriptomic comparative analysis of CK, SPC30, and SPC75 was also effective in testing the applicability of SPC as fish feeds and in designing a proper diet with the best impact on the growth performance and health of fish in hybrid grouper.

与所有其他类型的鱼饲料相比，植物蛋白更适合用作鱼粉（FMs）的替代品，且成本较低。近年来，浓缩大豆蛋白（SPC）成为了FM的一种经济高效的替代品。然而，人们对饮食中SPC对鱼类的总体生理和福祉的影响知之甚少。这项研究旨在进行全面的生理和转录组学分析，以测试SPC在杂交石斑鱼（Epinephelusfuscoguttatus♀E.lanceolatus♂）中作为鱼饲料的适用性。）[SPC代替了FM蛋白的0％（CK），30％（SPC30）和75％（SPC75）]。通常，SPC30促进鱼类存活，并且对表型影响较小，而SPC75降低鱼类存活，促进炎症并调节多种生理反应。通过SPC在肠道，肝脏和肌肉中鉴定了成千上万的差异表达基因（DEG），这些基因丰富了生物调控，细胞过程，代谢过程，单一生物过程，细胞，细胞部分，膜，结合和催化作用。基于RNA-seq的活性。值得注意的是，一些参与消化系统氨基酸和脂质代谢的DEG强调了SPC对这些代谢过程的调节作用，这与包括酶活性在内的生理反应是一致的。这些主要DEG的丰富方面可能与SPC30和SPC75对鱼类生长，消化率以及潜在的酶活性和组织学的不同影响直接相关。总之，对CK，SPC30和SPC75的全面生理和转录组比较分析也有效地测试了SPC作为鱼饲料的适用性，并设计了对杂交石斑鱼的生长性能和健康影响最大的适当饮食。