Fleshy Fruit Expansion and Ripening Are Regulated by the Tomato SHATTERPROOF Gene TAGL1    

Abstract

The maturation and ripening of fleshy fruits is a developmental program that synchronizes seed maturation with metabolism, rendering fruit tissues desirable to seed dispersing organisms. Through RNA interference repression, we show that Tomato AGAMOUS-LIKE1 (TAGL1), the tomato (Solanum lycopersicum) ortholog of the duplicated SHATTERPROOF (SHP) MADS box genes of Arabidopsis thaliana, is necessary for fruit ripening. Tomato plants with reduced TAGL1 mRNA produced yelloworange fruit with reduced carotenoids and thin pericarps. These fruit are also decreased in ethylene, indicating a comprehensive inhibition of maturation mediated through reduced ACC Synthase 2 expression. Furthermore, ectopic expression of TAGL1 in tomato resulted in expansion of sepals and accumulation of lycopene, supporting the role of TAGL1 in ripening. In Arabidopsis, the duplicate SHP1 and SHP2 MADS box genes regulate the development of separation layers essential for pod shatter. Expression of TAGL1 in Arabidopsis failed to completely rescue the shp1 shp2 mutant phenotypes, indicating that TAGL1 has evolved distinct molecular functions compared with its Arabidopsis counterparts. These analyses demonstrate that TAGL1 plays an important role in regulating both fleshy fruit expansion and the ripening process that together are necessary to promote seed dispersal of fleshy fruit. From this broad perspective, SHP1/2 and TAGL1, while distinct in molecular function, regulate similar activities via their necessity for seed dispersal in Arabidopsis and tomato, respectively.

Genome sequence of the hot pepper provides insights into the evolution of pungency in Capsicum species

“…Expression of transcription factor genes (RIN 43 , TAGL1 (ref. 44) and NOR 45 ) and genes involved in ethylene signaling pathways (NR 46 , ETR4 (ref. 47), EIN2 (ref.…”

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Gr and hp-1 tomato mutants unveil unprecedented interactions between arbuscular mycorrhizal symbiosis and fruit ripening

“…We selected Gr, Nr, Nor and Rin, altered in ET metabolism, hp-1, altered in light signaling and pigment production and Tagl1-1 and Tagl1-11, silenced in two TOMATO AGAMOUS-LIKE (TAGL) MADS box genes (Vrebalov et al 2009). Mutants were grown in parallel to their isogenic line ''Ailsa Craig'' under mycorrhizal colonization, inoculated with the AM fungus F. mosseae, and a control treatment.…”

The Tomato FRUITFULL Homologs TDR4/FUL1 and MBP7/FUL2 Regulate Ethylene-Independent Aspects of Fruit Ripening

“…Moreover, the binding of RIN to its target promoters was shown to be dependent on CNR activity, suggesting that CNR or one of its targets is required in a functional complex with RIN (Martel et al, 2011). The SHP1 ortholog TAGL1 has been reported to play an important role in tomato fruit development and ripening (Itkin et al, 2009;Vrebalov et al, 2009). TAGL1 knockdown plants were found to produce yelloworange fruits with reduced carotenoids and thin pericarps.…”