Function of gibberellins VideoBiosynthesis of Gibberelins function of gibberellins
Development 1 December ; 23 : — Gibberellins GAs are hormones that control many aspects of plant development, including flowering.
It is well known that stamen is the source of GAs that regulate male and bisexual flower development. However, little is known about the role of GAs in female flower development.
Transient expression of a catabolic Funftion 2-oxidase from pumpkin in cucumber ovaries decreases GA 9 and GA 4 levels and arrests the development of female flowers, and this can be restored by application of GA 9 function of gibberellins petals thus confirming its function. Given that bioactive GAs can promote sex reversion of female flowers, movement of biologically inactive precursors, instead of the hormone itself, might help to maintain floral organ identity, ensuring fruit and seed production. In higher plants, the final part of the GA biosynthetic pathway is catalysed by enzymes encoded by small multigene bibberellins that belong to the class of 2-oxoglutarate-dependent dioxygenases 2-ODDs Hedden and Phillips, The hydroxylation pathway is introduced by an function of gibberellins hydroxylation step, by which GA 12 is converted to GA The GA oxidases involved belong to the class of cytochrome P monooxygenases Magome et al.
Cucurbits form a large plant family, the members of which mostly develop unisexual flowers. Many are important crops, such as cucumber, that frequently serve as model plants for studying hormonal regulation of reproductive development Pimenta Lange et al.
RESULTS AND DISCUSSION
Sex determination and flower development are largely under the control of the plant hormones ethylene and GA, respectively Cheng et al. Bioactive GA from stamen of bisexual and male flowers is translocated to, and controls the development of, the other floral function of gibberellins Koornneef and van der Veen, ; Nester and Zeevaart, ; Weiss and Halevy, ; Goto and Pharis, ; Hu et al. This implies that hormonal control of floral organ development in female flowers is regulated differently than in male flowers, http://rectoria.unal.edu.co/uploads/tx_felogin/art-therapy-and-the-creative-process/aboriginal-art-lessons.php surprisingly little is known about this process.
To address this question, function of gibberellins investigated GA signalling during female flower development in cucumber Fig. Under our growth conditions, cucumber female flowers appear approximately 5 weeks after sowing. From the day of appearance until fully open, flower development is divided into four stages Fig.
Approximately 6 days after appearance, flowers reach developmental stage I, when flower buds contain greenish floral organs.]