title: Seed abscission and fruit dehiscence required for seed dispersal rely on similar genetic networks.
abstract: Seed dispersal is an essential trait that enables colonization of new favorable habitats, ensuring species survival. In plants with dehiscent fruits, such as Arabidopsis, seed dispersal depends on two processes: the separation of the fruit valves that protect the seeds (fruit dehiscence) and the detachment of the seeds from the funiculus connecting them to the mother plant (seed abscission). The key factors required to establish a proper lignin pattern for fruit dehiscence are SHATTERPROOF 1 and 2 (SHP1 and SHP2). Here, we demonstrate that the SHP-related gene SEEDSTICK (STK) is a key factor required to establish the proper lignin pattern in the seed abscission zone but in an opposite way. We show that STK acts as a repressor of lignin deposition in the seed abscission zone through the direct repression of HECATE3, whereas the SHP proteins promote lignin deposition in the valve margins by activating INDEHISCENT. The interaction of STK with the SEUSS co-repressor determines the difference in the way STK and SHP proteins control the lignification patterns. Despite this difference in the molecular control of lignification during seed abscission and fruit dehiscence, we show that the genetic networks regulating these two developmental pathways are highly conserved.
authors: Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, Milan 20133, Italy.
authors: Vicente
authors: V
authors: Balanzà
authors: Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, Milan 20133, Italy.
authors: Irma
authors: I
authors: Roig-Villanova
authors: Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, Milan 20133, Italy.
authors: Maurizio
authors: M
authors: Di Marzo
authors: Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, Milan 20133, Italy.
authors: Simona
authors: S
authors: Masiero
authors: Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, Milan 20133, Italy Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Milano 08193, Italy lucia.colombo@unimi.it.
authors: Lucia
authors: 0000-0001-8415-1399
authors: L
authors: Colombo
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D005638:Fruit / Q000378:metabolism* / Q000502:physiology; D053263:Gene Regulatory Networks / Q000235:genetics / Q000502:physiology; D026161:MADS Domain Proteins / Q000235:genetics / Q000378:metabolism; D058614:Seed Dispersal / Q000235:genetics / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D026161:MADS Domain Proteins; C484035:INDEHISCENT protein, Arabidopsis; C476012:SEEDSTICK protein, Arabidopsis; C445880:SEUSS protein, Arabidopsis; C419044:SHP1 protein, Arabidopsis; C419045:SHP2 protein, Arabidopsis
keywords: Arabidopsis; Fruit dehiscence; Lignin; MADS-box genes; Seed abscission