FaAKR23 Modulates Ascorbic Acid and Anthocyanin Accumulation in Strawberry (Fragaria × ananassa) Fruits

Abstract

Strawberry (Fragaria × ananassa) fruits are rich in ascorbic acid (AsA) and anthocyanin, which are essential antioxidants for human health. However, the underlying regulatory mechanism of these antioxidant accumulation, especially AsA accumulation in strawberry fruits, remains largely unknown. In this study, we identified FaAKR23 was a regulator of AsA and anthocyanin accumulation. We transiently expressed FaAKR23 in strawberry fruits and conducted metabolic and molecular analyses to explore the role of FaAKR23 in AsA and anthocyanin accumulation. Transient silencing of FaAKR23 (FaAKR23-RNAi) in strawberry fruits significantly decreased the AsA and anthocyanin contents compared with control (empty vector-RNAi, EV-RNAi). Correspondingly, expression of some structural genes and regulatory factors involved in these two antioxidants’ accumulation was dramatically repressed. In addition, transcriptome analysis of EV-RNAi and FaAKR23-RNAi fruits suggested that FaAKR23 was also involved in starch and sucrose metabolism as well as plant–pathogen interaction. Overall, these results not only provide the coordinated regulatory function of FaAKR23 on AsA and anthocyanin accumulation but also offer a promising candidate gene for strawberry breeding with high antioxidants.

Biofortification as a solution for addressing nutrient deficiencies and malnutrition

“…Stimulating findings have been reported by maneuvering the galacturonate pathway. Overcountenance of the strawberry FaGalUR gene in potatoes resulted in a two-fold enhancement in ascorbic acid content; moreover, this increment resulted in abiotic stress tolerance in transgenic lines [ 150 ]. Comparable progressive findings have also been described in the case of tomatoes; although a reasonable increment in ascorbic acid amount was observed, total antioxidants were reported to increase, which was connected to the regulation of the redox state [ 151 ] and overexpression of the FaGalUR gene in tomato plants was reported to be more resistant to abiotic pressures [ 143 ].…”

Genome-Wide Identification and Characterization of Aldo-Keto Reductase (AKR) Gene Family in Response to Abiotic Stresses in Solanum lycopersicum

“…Plants inevitably encounter biotic and abiotic stresses, such as salt and alkali stresses in soil, extreme temperatures (heat or cold), drought, diseases, and insect pests [ 9 ]. A large number of REDOX enzymes are activated in plants to be against the superfluous acetaldehyde and reactive oxygen species (ROS), which decompose toxic substances, such as the AKR family involved in the degradation of ROS and active acetaldehyde to detoxification, to resist adverse environment [ 10 , 11 , 12 , 13 , 14 , 15 ]. With the rapid development of genomics in recent years, AKR families are increasingly identified and even cloned in different species of plants, such as Arabidopsis thaliana [ 10 ], rice [ 11 ], Hordeum vulgare [ 12 ], Medicago truncatula [ 13 ], and strawberry [ 14 ], for further research.…”

“…A large number of REDOX enzymes are activated in plants to be against the superfluous acetaldehyde and reactive oxygen species (ROS), which decompose toxic substances, such as the AKR family involved in the degradation of ROS and active acetaldehyde to detoxification, to resist adverse environment [ 10 , 11 , 12 , 13 , 14 , 15 ]. With the rapid development of genomics in recent years, AKR families are increasingly identified and even cloned in different species of plants, such as Arabidopsis thaliana [ 10 ], rice [ 11 ], Hordeum vulgare [ 12 ], Medicago truncatula [ 13 ], and strawberry [ 14 ], for further research. AKR genes play roles in promoting resistance to stresses in the plant by detoxifying reactive aldehydes and in many redox reactions [ 8 , 15 ].…”

Transcriptome analysis of fruit development and identification of key transcription factors related to anthocyanin pathway in cultivated octoploid strawberry

“…In agriculture, the color of strawberries is a critical agronomic trait that receives considerable attention. Anthocyanin is the primary factor contributing to strawberry color and is crucial in enhancing stress resistance and human health (Mattioli et al 2020; Wei et al 2022). Therefore, identifying key regulators involved in the anthocyanin pathway is essential for breeding high-quality strawberry cultivars.…”