Biology subjects

Madueno, F.

Publications and source records attributed to Madueno, F..

4 recordsLinked to original sources

bioRxiv2024

A reduced vernalization requirement is a key component of the early-bolting trait in globe artichoke (Cynara cardunculus var. scolymus)

Early-bolting is a major breeding objective for globe artichoke (Cynara cardunculus var. scolymus L.). It has been suggested that globe artichoke bolting time is linked to a vernalization requirement, although environmental conditions under which vernalized plants and controls have been grown may not always allow for proper comparison. Here, we defined morphological markers to monitor the vegetative-to- reproductive phase transition at the shoot apex and linked these to expression changes of homologues of key Arabidopsis flowering regulators SOC1, FUL, and AP1. Importantly, we developed an experimental setup where control and vernalized plants grow under comparable conditions. These tools together allowed for comparison of the vegetative-to-reproductive phase transition between early- and late-bolting genotypes and how they respond to vernalization. Our results show that vernalization requirement is significantly lower in early-bolting genotypes, supporting the view that the early-bolting trait is partly underlain by alterations in the network controlling vernalization response.

plant biology↗

bioRxiv2022

Characterization of metabolic changes associated with floral transition in Arabidopsis: RAFFINOSE SYNTHASE 5 contributes to determine the timing of floral transition

Integration of environmental and endogenous cues triggers floral induction at the optimal time during the plant life cycle. Flowering is a tightly regulated process, which involves an intricated genetic network, as expected for a process crucial for plant fitness and survival. Individual metabolites are known to contribute to the determination of flowering time, including carbohydrates and hormones. However, a global analysis of metabolic changes associated with flowering was still lacking. We performed a metabolomic study to characterize global metabolic changes associated with photoperiodic floral induction. By using an inducible system, with the CONSTANS (CO) promoter driving the expression of CO fused to the rat glucocorticoid receptor (CO::GR), we induce flowering and identify metabolites that increase or decrease in leaves and apices during floral induction. Combining metabolomic with transcriptomic data, we identify that raffinose metabolism was altered in apices that are induced to flower. Loss-of-function mutants affecting RAFFINOSE SYNTHASE 5 (RS5), a key enzyme of the raffinose metabolism, show an early flowering phenotype. Also, RS5 expression changes during floral transition, suggesting a role for raffinose catabolism on the release of simple sugars at the apex. We propose that variation on the differential accumulation of raffinose and mono- and disaccharides during floral transition contributes to the induction of floral transition, by influencing expression of THEHALOSE-6-PHOSPHATE SYNTHASE 1 (TPS1) and SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 3 (SPL3), which affect expression of the florigen FLOWERING LOCUS T (FT).

plant biology↗

bioRxiv2021

The making of cauliflowers: the story of unsuccessful flowers

The arrangement of plant organs, called phyllotaxis, produce remarkable spiral or whorled patterns. Cauliflowers present a unique phyllotaxis with a multitude of spirals over a wide range of scales. How such a self-similar fractal organization emerges from developmental mechanisms has remained elusive. Combining experimental assays with modeling, we found that cauliflowers arise due to the hysteresis of the bistable floral network that generates inflorescences imprinted by a transient floral state. We further show how additional mutations affecting meristem growth dynamics can induce the production of conical phyllotactic structures reminiscent of the conspicuous fractal Romanesco shape. This study reveals how the spectacular morphological modification of the inflorescences in cauliflower and Romanesco shape arises from the hysteresis of the genetic programs controlling inflorescence development. One Sentence SummaryThe molecular making of cauliflowers

plant biology↗

bioRxiv2020

The SINGLE FLOWER (SFL) gene encodes a MYB transcription factor that regulates the number of flowers produced by the inflorescence of chickpea.

research conducted & rationaleLegume species usually have compound inflorescences, where flowers appear in secondary inflorescences (I2), at lateral positions of the primary inflorescence (I1), in contrast to simple inflorescences, as in Arabidopsis, where flowers are formed in the primary inflorescence stem. The number of flowers per I2, characteristic of each legume species, determines inflorescence diversity, and the number of pods produced, which can affect yield. Gene Regulatory Network that controls the activity of I2 meristems, and therefore the number of flowers per secondary inflorescence is mostly unknown, as well as how specific are factors controlling this trait and whether they share this function in other meristems. methodsChickpea produces one flower per I2 but single flower (sfl) mutants produce two (double-pod phenotype). By mapping the sfl-d mutation and identification and analysis of a second mutant allele we have isolated SFL. We used scanning electron microscopy to study the effect of sfl mutations on inflorescence ontogeny and in situ hybridization to study the expression of SFL and of meristem identity genes in the developing chickpea inflorescence. key resultWe show that the SFL gene corresponds to CaRAX1/2a, encoding a MYB transcription factor. Our results show that CaRAX1/2a / SFL is specifically expressed in the I2 meristem, possibly activated by CaVEGETATIVE1. main conclusion & key points for discussionOur findings reveal that SFL plays a central role in the control of chickpea inflorescence architecture, specifically acting in the I2 meristem to control the time length for which it is active, and therefore determining the number of floral meristems that it can produce.

plant biology↗