marzo15Referencia

Plant Cell. 2014 Feb;26(2):565-84. doi: 10.1105/tpc.114.122721. Epub 2014 Feb 21

Autores

Ortiz-Marchena MI1, Albi T, Lucas-Reina E, Said FE, Romero- Campero FJ, Cano B, Ruiz MT, Romero JM, Valverde F.

Resumen

Flowering is a crucial process that demands substantial resources. Carbon metabolism must be coordinated with development through a control mechanism that optimizes fitness for any physiological need and growth stage of the plant. However, how sugar allocation is controlled during the floral transition is unknown. Recently, the role of a CONSTANS (CO) ortholog (Cr-CO) in the control of the photoperiod response in the green alga Chlamydomonas reinhardtii and its influence on starch metabolism was demonstrated. In this work, we show that transitory starch accumulation and glycan composition during the floral transition in Arabidopsis thaliana are regulated by photoperiod. Employing a multidisciplinary approach, we demonstrate a role for CO in regulating the level and timing of expression of the GRANULE BOUND STARCH SYNTHASE (GBSS) gene. Furthermore, we provide a detailed characterization of a GBSS mutant involved in transitory starch synthesis and analyze its flowering time phenotype in relation to its altered capacity to synthesize amylose and to modify the plant free sugar content. Photoperiod modification of starch homeostasis by CO may be crucial for increasing the sugar mobilization demanded by the floral transition. This finding contributes to our understanding of the flowering process.

Descripción

En este trabajo se ha descubierto una relación entre la movilización del carbono y el fotoperiodo analizándose la capacidad de liberar azúcares a partir de la amilosa y en concreto de la actividad de la almidón sintasa unida a gránulo (GBSS). De este modo, la amilosa generada antes de florecer podría utilizarse durante la transición floral como una fuente de azúcares necesarios para este proceso. En este sentido, en este trabajo se propone un mecanismo por el cual CONSTANS (CO) alteraría la expresión de GBSS ayudando a liberar grandes cantidades de azúcares durante la transición floral. Así, la misma señal fotoperiódica que activa la expresión de FT a través del regulador central CO es también responsable de la movilización de azúcares durante la transición floral. La GBSS, por tanto, tiene una gran influencia en la composición del gránulo de almidón y en su estructura, además de en la capacidad de las plantas de acumular y movilizar azúcares a partir de él.

grupo

REFERENCIA DEL GRUPO INVESTIGADOR

La Unidad de Desarrollo Vegetal está constituida por un grupo de investigadores del CSIC y de la Universidad de Sevilla que combinan diferentes aproximaciones para estudiar los mecanismos moleculares que controlan el desarrollo vegetal. La línea de investigación del Dr. Valverde se centra en los mecanismos que rigen el proceso de floración, en particular aquellos aspectos relacionados con la floración dependiente de la longitud del día o fotoperiodo y señales metabólicas. El grupo del Prof. Romero investiga los mecanismos que controlan la biosíntesis de almidón y azúcar y el papel del metabolismo de carbono en el desarrollo vegetal. Finalmente, las investigaciones del grupo de la Dra. Calonje se centran en esclarecer los mecanismos epigenéticos que controlan las distintas fases del desarrollo vegetal, en particular el papel que desempeñan las proteínas del grupo Polycomb (PcG) en este proceso. Para estos estudios, resulta crucial el uso de técnicas masivas de adquisición de datos (ómicas), por lo que se ha iniciado una estrecha colaboración con el Departamento de Informática e Inteligencia Artificial de la Universidad de Sevilla.

Descárgate este artículo aquí.
Más artículos en la revista SEBBM.

Did you publish an interesting article recently?

Send it through our application form and we will contact you. Age limit: 32.

The selected articles will participate at the Award to the best article of young people of the SEBBM which will be given during SEBBM conference, that will take place at Spain (free registration, travel and accommodation).

More articles of the month

Mechanisms of autoregulation of C3G, activator of the GTPase Rap1, and its catalytic deregulation in lymphomas

01-10-2020

C3G is a guanine nucleotide exchange factor (GEF) that regulates cell adhesion and migration by activating the GTPase Rap1. The GEF activity of C3G is stimulated by the adaptor proteins...

Read more

Expression of the long non-coding RNA TCL6 is associated with clinical outcome in pediatric B-cell acute lymphoblastic leukemia

31-08-2020

The reciprocal translocation t(12;21)(p13;q22)[ETV6/RUNX1] is the most frequent chromosomal rearrangement in pediatric B-cell acute lymphoblastic leukemia(B-ALL). Long non-coding RNAs (lncRNAs) play important roles in numerous diseases and they represent an...

Read more

Evaluation of different approaches used to study membrane permeabilization by actinoporins on model lipid vesicles

30-07-2020

Release of aqueous contents from model lipid vesicles has been a standard procedure to evaluate pore formation efficiency by actinoporins, such as sticholysin II (StnII), for the last few decades...

Read more

ADAR1-mediated RNA editing is a novel oncogenic process in thyroid cancer and regulates miR-200 activity

01-07-2020

Adenosine deaminases acting on RNA (ADARs) convert adenosine to inosine in double-stranded RNA. A-to-I editing of RNA is a widespread posttranscriptional process that has recently emerged as an important mechanism...

Read more

Sarcoplasmic reticulum Ca2+ decreases with age and correlates with the decline in muscle function in Drosophila

29-05-2020

Sarcopenia, the loss of muscle mass and strength associated with age, has been linked to impairment of the cytosolic Ca2+ peak that triggers muscle contraction, but mechanistic details remain unknown...

Read more

Structural basis for substrate specificity and catalysis of α1,6-fucosyltransferase

30-04-2020

Core-fucosylation is an essential biological modification by which a fucose is transferred from GDP-β-L-fucose to the innermost N-acetylglucosamine residue of N-linked glycans. A single human enzyme α1,6-fucosyltransferase (FUT8) is the...

Read more

Molecular basis for fibroblast growth factor 23 O-glycosylation by GalNAc-T3

31-03-2020

Polypeptide GalNAc-transferase T3 (GalNAc-T3) regulates fibroblast growth factor 23 (FGF23) by O-glycosylating Thr178 in a furin proprotein processing motif RHT 178R ↓S. FGF23 regulates phosphate homeostasis and deficiency in GALNT3...

Read more

Identification of distinct maturation steps involved in human 40S ribosomal subunit biosynthesis

29-02-2020

Technical problems intrinsic to the purification of preribosome intermediates have limited our understanding of ribosome biosynthesis in humans. Addressing this issue is important given the implication of this biological process...

Read more

Unraveling the cellular origin and clinical prognostic markers of infant B-cell acute lymphoblastic leukemia using genome-wide analysis

23-01-2020

B-cell acute lymphoblastic leukemia is the commonest childhood cancer. In infants, B-cell acute lymphoblastic leukemia remains fatal, especially in patients with t(4;11), present in ~80% of cases. The pathogenesis of...

Read more

Mip6 binds directly to the Mex67 UBA domainto maintain low levels of Msn2/4 stress-dependent mRNAs

23-12-2019

RNA-binding proteins (RBPs) participate in all steps of gene expression, underscoring their potential as regulators of RNA homeostasis. We structurally and functionally characterize Mip6, a four-RNA recognition motif (RRM)-containing RBP...

Read more

Protector Members