Regulatory change in YABBY-like transcription factor led to evolution of extreme fruit size during tomato domestication

Abstract

Plant domestication represents an accelerated form of evolution, resulting in exaggerated changes in the tissues and organs of greatest interest to humans (for example, seeds, roots and tubers). One of the most extreme cases has been the evolution of tomato fruit. Cultivated tomato plants produce fruit as much as 1,000 times larger than those of their wild progenitors. Quantitative trait mapping studies have shown that a relatively small number of genes were involved in this dramatic transition, and these genes control two processes: cell cycle and organ number determination. The key gene in the first process has been isolated and corresponds to fw2.2, a negative regulator of cell division. However, until now, nothing was known about the molecular basis of the second process. Here, we show that the second major step in the evolution of extreme fruit size was the result of a regulatory change of a YABBY-like transcription factor (fasciated) that controls carpel number during flower and/or fruit development.

Citogenética de genotipos de uchuva, Physalis peruviana L., y Physalis floridana Rydb., con respuesta diferencial a Fusarium oxysporum

“…En el presente estudio, según los datos de pasaporte, la accesión 09U216 pertenece al ecotipo Colombia, lo cual indica variación en el número cromosómico en accesiones de este ecotipo cultivado. Estos resultados sugieren que P. peruviana está definiendo su complemento cromosó-mico, en concordancia con Lagos (2006), posiblemente en relación con el hecho de que pasó de ser una especie silvestre a cultivada, sin experimentar un proceso de domesticación como la especie relacionada Solanum lycopersicum (Cong et al, 2008). Dada la reproducción mixta de P. peruviana con más de 50% de alogamia (Lagos et al, 2008), se podría, además, suponer la existencia de cruzamientos naturales que podrían haber conducido a la generación de dotaciones cromosómicas variables para la especie, incluso en materiales del mismo ecotipo.…”

Regulatory change at Physalis Organ Size 1 correlates to natural variation in tomatillo reproductive organ size

“…FW2.2 is a plasma membrane-anchored protein, which is involved in the cell cycle pathway for ovary size control 16 . Another two cloned loci namely fasciated (fas) and locule number (lc) mainly control the locule number of ovary 17,18 . FAS encodes a YABBY-like transcription factor, and the mutation that increases the locule number and fruit weight resulted from an insertion knocking out the gene 17 .…”

“…Another two cloned loci namely fasciated (fas) and locule number (lc) mainly control the locule number of ovary 17,18 . FAS encodes a YABBY-like transcription factor, and the mutation that increases the locule number and fruit weight resulted from an insertion knocking out the gene 17 . The molecular nature of LC is two single-nucleotide polymorphisms located B1,200 bp downstream of the stop codon of the tomato orthologue of WUSCHEL, a gene encoding a homeodomain protein regulating stem cell fate in plants 18 .…”

The tomato genome: implications for plant breeding, genomics and evolution

“…Classical breeding and marker analysis has also made remarkable contributions to improve various yield traits of tomato. For example, the fruit size QTL fasciated , initially identified using a cross between S. lycopersicum and S. pimpenellifolium , has recently been characterized [56]. The first example of yield improvement by a single overdominant gene ( SINGLE FLOWER TRUSS ) through heterosis has been demonstrated in tomato [57].…”

“…For example, genome-wide association studies (GWAS) will allow detection and fine mapping of QTLs in the post-genome era, given the high phenotypic diversity among various tomato wild relatives [61,62]. QTL analyses will also help to investigate the process of domestication and associated yield increase [56,63]. Additionally, millions of informative markers (SNPs/InDels) and structural variations, such as duplications, inversions, transpositions, and so on, identified through comparison of genome sequences of domesticated and wild tomatoes will promote investigations into the genetic and molecular basis of the process of domestication and crop improvement.…”