Gene regulation in parthenocarpic tomato fruit

Abstract

Parthenocarpy is potentially a desirable trait for many commercially grown fruits if undesirable changes to structure, flavour, or nutrition can be avoided. Parthenocarpic transgenic tomato plants (cv MicroTom) were obtained by the regulation of genes for auxin synthesis (iaaM) or responsiveness (rolB) driven by DefH9 or the INNER NO OUTER (INO) promoter from Arabidopsis thaliana. Fruits at a breaker stage were analysed at a transcriptomic and metabolomic level using microarrays, real-time reverse transcription-polymerase chain reaction (RT-PCR) and a Pegasus III TOF (time of flight) mass spectrometer. Although differences were observed in the shape of fully ripe fruits, no clear correlation could be made between the number of seeds, transgene, and fruit size. Expression of auxin synthesis or responsiveness genes by both of these promoters produced seedless parthenocarpic fruits. Eighty-three percent of the genes measured showed no significant differences in expression due to parthenocarpy. The remaining 17% with significant variation (P <0.05) (1748 genes) were studied by assigning a predicted function (when known) based on BLAST to the TAIR database. Among them several genes belong to cell wall, hormone metabolism and response (auxin in particular), and metabolism of sugars and lipids. Up-regulation of lipid transfer proteins and differential expression of several indole-3-acetic acid (IAA)- and ethylene-associated genes were observed in transgenic parthenocarpic fruits. Despite differences in several fatty acids, amino acids, and other metabolites, the fundamental metabolic profile remains unchanged. This work showed that parthenocarpy with ovule-specific alteration of auxin synthesis or response driven by the INO promoter could be effectively applied where such changes are commercially desirable.

Microarray Analysis of the Abscission-Related Transcriptome in the Tomato Flower Abscission Zone in Response to Auxin Depletion

“…AF416289.1), which is expressed in tomato ovary (Vriezen et al, 2008) and fruit (Martinelli et al, 2009), was found in our analysis to be transiently up-regulated 2 h after flower removal in both AZ and NAZ samples (Fig. 6H).…”

Transient Silencing of CHALCONE SYNTHASE during Fruit Ripening Modifies Tomato Epidermal Cells and Cuticle Properties

“…Schijlen et al (2007) constitutively suppressed CHS expression in tomato via RNA interference and obtained pink tomatoes due to a reduction of cuticle flavonoids. However, the alteration of plant reproduction due to pollen growth impairment present in these plants led to the development of parthenocarpic fruits, which are known to have altered hormone levels as well as several genes involved in cell wall, sugars, and lipid metabolism (Martinelli et al, 2009).…”

Proposal of a Genome Editing System for Genetic Resistance to Tomato Spotted Wilt Virus

“…The strategy is to focus on tomato genes that were differentially regulated by TSWV infections, previously identified by published works. Molecular markers commonly used for phylogenetic studies (Martinelli et al, 2008;Martinelli et al, 2009b;Minnocci et al, 2010) maybe also employed to determine untargeted effects on genomic structure. The analysis of the phenotype will be performed measuring key morphological parameters such as leaf, stem, whole plant dimension, length, size and health.…”