RT article
T1 Gibberellin reactivates and maintains ovary-wall cell division causing fruit set in parthenocarpic Citrus species
A1 Mesejo, Carlos
A1 Yuste, Roberto
A1 Reig, Carmina
A1 Martínez-Fuentes, Amparo
A1 Iglesias, Domingo J.
A1 Munoz-Fambuena, Natalia
A1 Bermejo, Almudena
A1 Germana, Maria Antonietta
A1 Primo-Millo, Eduardo
A1 Agustí, Manuel
K1 F63  Plant physiology - Reproduction
K1 F60  Plant physiology and biochemistry
K1 Citrus
K1 Flowers
K1 Fruit set
K1 Fruit trees
K1 Gibberellins
K1 Parthenocarpy
AB Citrus is a wide genus in which most of the cultivated species and cultivars are natural parthenocarpic mutants or hybrids (i.e. orange, mandarin, tangerine, grapefruit). The autonomous increase in GA1 ovary concentration during anthesis was suggested as being the stimulus responsible for parthenocarpy in Citrus regardless of the species. To determine the exact GA-role in parthenocarpic fruit set, the following hypothesis was tested: GA triggers and maintains cell division in ovary walls causing fruit set. Obligate and facultative parthenocarpic Citrus species were used as a model system because obligate parthenocarpic Citrus sp (i.e. Citrus unshiu) have higher GA levels and better natural parthenocarpic fruit set compared to other facultative parthenocarpic Citrus (i.e. Citrus clementina).The autonomous activation of GA synthesis in C. unshiu ovary preceded cell division and CYCA1.1 up-regulation (a G2-stage cell cycle regulator) at anthesis setting a high proportion of fruits, whereas C. clementina lacked this GA-biosynthesis and CYCA1.1 up-regulation failing in fruit set. In situ hybridization experiments revealed a tissue-specific expression of GA20ox2 only in the dividing tissues of the pericarp. Furthermore, CYCA1.1 expression correlated endogenous GA1 content with GA3 treatment, which stimulated cell division and ovary growth, mostly in C. clementina. Instead, paclobutrazol (GA biosynthesis inhibitor) negated cell division and reduced fruit set.Results suggest that in parthenocarpic citrus the specific GA synthesis in the ovary walls at anthesis triggers cell division and, thus, the necessary ovary growth rate to set fruit.
PB Elsevier
SN 0168-9452
YR 2016
FD 2016
LK http://hdl.handle.net/20.500.11939/6913
UL http://hdl.handle.net/20.500.11939/6913
LA en
NO Mesejo, C., Yuste, R., Reig, C., Martínez-Fuentes, A., Iglesias, D. J., Muñoz-Fambuena, N. et al. (2016). Gibberellin reactivates and maintains ovary-wall cell division causing fruit set in parthenocarpic Citrus species. Plant Science, 247, 13-24.
DS MINDS@UW
RD Aug 18, 2022