Abstract
European pear requires inter-cultivar cross-pollination by insects to develop fertilized fruits. However, some European pear cultivars such as ‘Conference’ naturally produce parthenocarpic seedless fruits. To better understand the hormonal regulation of fruit set and early fruit development in this European pear cultivar, the phytohormone and polyamine profiles in ‘Conference’ flowers and fruits resulting from both fertilization and parthenocarpic processes were analyzed. The expression of genes involved in phytohormone metabolism and signaling were also investigated. Phytohormone profiles differed more at flower stage 3 days after treatment than in 15 day- and 30-day-old fruits in response to fertilization and parthenocarpy. An increase in auxins, abscisic acid, ethylene precursor, and spermine, and a decrease in putrescine were recorded in the fertilized flowers as compared to the parthenocarpic flowers. Fertilization also upregulated genes involved in gibberellin synthesis and down-regulated genes involved in gibberellin catabolism although the total gibberellin content was not modified. Moreover, exogenous gibberellin (GA3, GA4/7) and cytokinin (6BA) applications did not increase parthenocarpic induction in ‘Conference’ as observed in other European and Asian pear cultivars. We hypothesize that the intrinsic parthenocarpy of ‘Conference’ could be related to a high gibberellin level in the flowers explaining why exogenous gibberellin application did not increase parthenocarpy as observed in other pear cultivars and species.
Highlights
Fruit set and fruit development are complex developmental processes which need the coordination of different phytohormones [1,2,3,4,5,6,7]
There were no differences in fruit weight but parthenocarpic fruit were more elongated than the cross-pollinated fruit
Our study showed that intrinsic parthenocarpy occured in the European pear cv
Summary
Fruit set and fruit development are complex developmental processes which need the coordination of different phytohormones [1,2,3,4,5,6,7]. Growth factors by which pollen influence fruit set include auxins and gibberellins (GAs) [9,10,11]. Gibberellins produced by the pollen may increase auxin production in the ovary, which in turn may act as a signal for fruit set and subsequent activation of cell division [9,12]. Active fruit growth by pericarp cell division and elongation is due to the synthesis of auxins in the developing seeds and of GAs in the pericarp [13]. Fruit set relies on the concerted action of auxins and/or GAs and/or CKs depending on the species [7,13]. A GA-auxin crosstalk is involved in early fruit development while each phytohormone seems to play a specific
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
