Application of γ-aminobutyric acid improves the postharvest marketability of strawberry by maintaining fruit quality and enhancing antioxidant system.

The capability of 5, 10, 15 mM γ-aminobutyric acid (GABA) to improve the postharvest quality and antioxidant system of strawberry was evaluated in this study. The application of GABA had no effect on fruit skin color and firmness. The weight loss in fruits treated with 10 mM GABA was significantly lower than the control. GABA treatments resulted in higher levels of total soluble sugar, titratable acid, SOD and CAT activities with 10 mM being the most significant effect. Specifically, 10 mM GABA significantly induced the accumulation of fructose, oxalic acid, and succinic acid. Besides, GABA application increased the content of total anthocyanins and total flavonoids, and DPPH radical scavenging activity in fruits. The GABA-treated fruits especially at 5 mM and 10 mM displayed less ROS and MDA. These data suggested that application of 10 mM GABA might be a promising strategy to improve the postharvest marketability of strawberry.

Synergistic anti-tumor effects of lenalidomide and gefitinib by upregulating ADRB2 and inactivating the mTOR/PI3K/AKT signaling pathway in lung adenocarcinoma.

Gefitinib is commonly used to be the first-line therapy for advanced non-small cell lung cancer (NSCLC). Therapeutic effect of gefitinib is reduced due to acquired resistance, and combined treatment is recommended. In this research, we planned to explore the impacts of combined treatment of lenalidomide and gefitinib on gefitinib-sensitive or -resistant NSCLC cells. The co-treatment results demonstrated that enhanced antitumor impact on NSCLC cell growth, migration, invasion, cell cycle process and apoptosis. The tumor-bearing mouse models were established using PC9/GR cells. In vivo assays also showed that lenalidomide and gefitinib synergistically inhibited mouse tumor growth along increased the survival of mice. ADRB2 was identified as a lowly expressed gene in PC9/GR cells and LUAD tumor tissues. LUAD patients with high ADRB2 expression were indicated with favorable survival outcomes. Moreover, ADRB2 was upregulated in lenalidomide and/or gefitinib-treated PC9/GR cells. ADRB2 deficiency partially offsets the suppressive impacts of lenalidomide and gefitinib co-treatment on the viability and proliferation of PC9/GR cells. Additionally, lenalidomide and gefitinib cotreatment significantly inactivated the mTOR/PI3K/AKT signaling pathway compared with each treatment alone. Rescue assays were performed to explore whether lenalidomide and gefitinib synergistically inhibited the growth of PC9/GR cells via the PI3K/AKT pathway. PI3K activator SC79 significantly restored reduced cell proliferation, migration and invasion along with elevated cell cycle arrest and apoptosis caused by lenalidomide and gefitinib cotreatment. In conclusion, lenalidomide and gefitinib synergistically suppressed LUAD progression and attenuated gefitinib resistance by upregulating ADRB2 and inactivating the mTOR/PI3K/AKT signaling pathway in lung adenocarcinoma.

Light Quality and Sucrose-Regulated Detached Ripening of Strawberry with Possible Involvement of Abscisic Acid and Auxin Signaling.

The regulation of detached ripening is significant for prolonging fruit shelf life. Although light quality and sucrose affecting strawberry fruit ripening have been widely reported, little information is available about how they co-regulate the strawberry detached ripening process. In this study, different light qualities (red light-RL, blue light-BL, and white light-WL) and 100 mM sucrose were applied to regulate the ripening of initial red fruits detached from the plant. The results showed RL-treated samples (RL + H2O, RL + 100 mM sucrose) had brighter and purer skin color with a higher L*, b*, and C* value, and promoted the ascorbic acid. Almost all light treatments significantly decreased TSS/TA (total soluble solid/titratable acid) and soluble sugar/TA ratio, which is exacerbated by the addition of sucrose. Blue or red light in combination with sucrose notably increased total phenolic content and decreased malondialdehyde (MDA) accumulation. In addition, blue or red light combined with sucrose increased abscisic acid (ABA) content and promoted ABA signaling by inducing ABA-INSENSITIVE 4 (ABI4) expression and inhibiting SUCROSE NONFERMENTING1-RELATED PROTEIN KINASE 2.6 (SnRK2.6) expression. The strawberries exposed to blue and red light significantly improved auxin (IAA) content compared to the control (0 d), whereas the addition of sucrose inhibited IAA accumulation. Moreover, sucrose treatment suppressed the AUXIN/INDOLE-3-ACETIC ACID 11 (AUX/IAA11) and AUXIN RESPONSE FACTOR 6 (ARF6) expression under different light qualities. Overall, these results indicated that RL/BL + 100 mM sucrose might promote the detached ripening of strawberries by regulating abscisic acid and auxin signaling.

Blue light combined with salicylic acid treatment maintained the postharvest quality of strawberry fruit during refrigerated storage.

Strawberry is a high economic and nutritional value fruit, but marketing is limited by a short postharvest life. The objective of this work is to assess the influence of blue light (BL) and salicylic acid (SA, 2 mM) on strawberry postharvest quality during cold storage. The results showed that the combination of BL and SA noticeably delayed weight loss, prevented decay, improved fruit skin brightness, and increased soluble protein. Strawberries treated with BL + SA had lower total soluble solids and titratable acidity contents among treatments but had no significant change during the entire storage. Additionally, contents of total flavonoids, phenolics, anthocyanins and proanthocyanidins, activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) and total antioxidant capacities in BL + SA-treated fruit were kept at stable levels throughout the entire storage. Collectively, these findings suggest that BL + SA treatment exhibits a high potential in maintaining postharvest fruit quality of strawberry fruit.

Genome-Wide Analysis of the ERF Family and Identification of Potential Genes Involved in Fruit Ripening in Octoploid Strawberry.

Ethylene response factors (ERFs) belonging to the APETALA2/ERF superfamily acted at the end of the ethylene signaling pathway, and they were found to play important roles in plant growth and development. However, the information of ERF genes in strawberry and their involvement in fruit ripening have been limited. Here, a total of 235 ERF members were identified from 426 AP2/ERF genes at octoploid strawberry genome level and classified into six subgroups according to their sequence characteristics and phylogenetic relationship. Conserved motif and gene structure analysis supported the evolutionary conservation of FaERFs. Syntenic analysis showed that four types of duplication events occurred during the expansion of FaERF gene family. Of these, WGD/segmental duplication played a major role. Transcriptomic data of FaERF genes during fruit ripening and in response to abscisic acid screened one activator (FaERF316) and one repressor (FaERF118) that were involved in fruit ripening. Transcriptional regulation analysis showed some transcription factors related to ripening such as ABI4, TCP15, and GLK1 could bind to FaERF316 or FaERF118 promoters, while protein-protein interaction analysis displayed some proteins associated with plant growth and development could interact with FaERF118 or FaERF316. These results suggested that FaERF118 and FaERF316 were potential genes to regulate strawberry ripening. In summary, the present study provides the comprehensive and systematic information on FaERF family evolution and gains insights into FaERF's potential regulatory mechanism in strawberry ripening.