BACKGROUND:The softness of blackberry fruits limits their postharvest shelf-life and commercial use, and abscisic acid (ABA) is considered one of the key hormones involved in fruit ripening. OBJECTIVE:This study aimed to explore the underlying physiological and molecular actions of ABA on blackberry fruit ripening and softening. METHODS:Various physiological indices of and plant hormone levels in treated and untreated blackberry fruits were determined simultaneously. The differentially expressed genes (DEGs) were analyzed by RNA-sequencing, and their expression profiles were detected. The ripening mechanism was elucidated by UHPLC-MS using two groups of fruits at 28 d. RESULTS:After 25 d, the ABA concentration and polygalacturonase (PG) and beta-1,4-endoglucanase (EG) activities in ABA-treated fruits were significantly higher than those in untreated fruits. Large differences in the expression profiles were detected at 28 d. The expression of DEGs related to cell wall softening and ABA synthesis was largely triggered after 25 or 28 d. Sixty-nine differentially accumulated metabolites were ultimately annotated as related to fruit ripening. CONCLUSIONS:ABA stimulates blackberry fruit ripening by promoting cell wall enzyme activities, the expression of various ripening-related genes and metabolite accumulation.

中文翻译：

---

ABA 通过积极影响成熟相关基因的表达和代谢物谱来加速黑莓 (Rubus spp.) 果实的成熟

背景：黑莓果实的柔软性限制了它们的采后保质期和商业用途，脱落酸 (ABA) 被认为是参与果实成熟的关键激素之一。目的：本研究旨在探讨 ABA 对黑莓果实成熟和软化的潜在生理和分子作用。方法：同时测定处理和未处理黑莓果实的各项生理指标和植物激素水平。通过RNA测序分析差异表达基因（DEG），并检测它们的表达谱。UHPLC-MS 使用两组果实在 28 d 阐明了成熟机制。结果：25 d后，ABA浓度和多聚半乳糖醛酸酶（PG）和β-1，ABA 处理果实的 4-内切葡聚糖酶 (EG) 活性显着高于未处理果实。在第 28 天检测到表达谱的巨大差异。与细胞壁软化和 ABA 合成相关的 DEG 的表达主要在 25 或 28 天后触发。69 种差异累积的代谢物最终被注释为与果实成熟有关。结论：ABA通过促进细胞壁酶活性、各种成熟相关基因的表达和代谢物积累来促进黑莓果实的成熟。69 种差异累积的代谢物最终被注释为与果实成熟有关。结论：ABA通过促进细胞壁酶活性、各种成熟相关基因的表达和代谢物积累来促进黑莓果实的成熟。69 种差异累积的代谢物最终被注释为与果实成熟有关。结论：ABA通过促进细胞壁酶活性、各种成熟相关基因的表达和代谢物积累来促进黑莓果实成熟。