Insights into the senescent mechanisms of harvested strawberry fruit at the physiological, molecular and metabolic levels

Abstract

Strawberry (Fragaria × ananassa) is a worldwide cultivated horticultural crop, however, its short preservative life of the harvested fruit remains a challenge to be addressed. Currently, although much progress has been made toward understanding the senescence of harvested strawberry fruit, the defined mechanisms remain unclear. Therefore, we performed a series of morphological, physiological and biochemical, as well as transcriptome and proteome analyses using the widely-cultivated strawberry 'Benihoppe' during 0−8 d at room temperature. The results showed not only the shorter storage of harvested strawberry fruit resulted from the rapid perishability, softening, and water loss, but also an increase in soluble sugars within 2 d and a coordination of ABA with JA at the early stage, BR at the middle stage and ethylene at the later stage, respectively. The RNA-seq data highlighted on ABA with NCEDs and PYLs, auxin with IAAs and AUXs, ethylene with ACSs, EIN3 and ERFs, BR with BZRs, and JA with JMTs; while proteome data highlighted on ABA with PYL/SnRK2/ABF, JA with JAR1/JAZ, GA with GID1, BR with BSK, and ethylene with ETR/CTR/EIN2, suggesting an important role of ABA, JA, and ethylene in the senescence of harvested strawberries. Interestingly, higher contents of nerolidalyl caproate and threonine represented characteristic signs of ripening and senescence. Finally, a physiological, molecular and metabolic model for strawberry fruit senescence is proposed, providing comprehensive insights into the preservative mechanisms.

Keywords

• strawberry fruit
• postharvest
• senescence
• phytohormone