Genetically modified parthenocarpic eggplants: improved fruit productivity under both greenhouse and open field cultivation.

Abstract

BackgroundParthenocarpy, or fruit development in the absence of fertilization, has been genetically engineered in eggplant and in other horticultural species by using the DefH9-iaaM gene. The iaaM gene codes for tryptophan monoxygenase and confers auxin synthesis, while the DefH9 controlling regions drive expression of the gene specifically in the ovules and placenta. A previous greenhouse trial for winter production of genetically engineered (GM) parthenocarpic eggplants demonstrated a significant increase (an average of 33% increase) in fruit production concomitant with a reduction in cultivation costs.ResultsGM parthenocarpic eggplants have been evaluated in three field trials. Two greenhouse spring trials have shown that these plants outyielded the corresponding untransformed genotypes, while a summer trial has shown that improved fruit productivity in GM eggplants can also be achieved in open field cultivation. Since the fruits were always seedless, the quality of GM eggplant fruits was improved as well. RT-PCR analysis demonstrated that the DefH9-iaaM gene is expressed during late stages of fruit development.ConclusionsThe DefH9-iaaM parthenocarpic gene is a biotechnological tool that enhances the agronomic value of all eggplant genotypes tested. The main advantages of DefH9-iaaM eggplants are: i) improved fruit productivity (at least 30–35%) under both greenhouse and open field cultivation; ii) production of good quality (marketable) fruits during different types of cultivation; iii) seedless fruit with improved quality. Such advantages have been achieved without the use of either male or female sterility genes.

Transcriptome analysis of oil palm inflorescences revealed candidate genes for an auxin signaling pathway involved in parthenocarpy

“…The treatment was performed on commercial oil palm, named as Surat Thani 2 because of its long bunch stalk, causing high female flower visibility. Auxin is the predominant hormone inducing parthenocarpy in many plant species, including Arabidopsis, tomatoes and eggplant (Acciarri et al, 2002; Ficcadenti et al, 1999; Goetz et al, 2007; Gorguet et al, 2008; Ingrosso et al, 2011; Klap et al, 2017; Martí et al, 2007; Martinelli et al, 2009; Molesini et al, 2009; Serrani et al, 2007; Wang et al, 2005). GAs, Ethylene and cytokinin were also reported to induce parthenocarpy in tomatoes, and cucumber (Ding et al, 2013; Fos, Nuez & García-Martínez, 2000; Lin et al, 2008; Martí et al, 2007; Pandolfini, 2009; Wang et al, 2005).…”

“…The potential genes above could help to fill in some of these gaps, especially concerning fruit set initiation and development, both of which are tightly regulated in a complex network. Furthermore, these genes could be targeted for the development of transgenic parthenocarpic fruits, like in the previous work done in eggplant and tomato (Acciarri et al, 2002; Rotino et al, 2005, 1998). Consequently, this work can add to basic knowledge of auxin regulating genes involved in the fruit development process and perhaps these genes may be exploited for parthenocarpic fruit production in the near future.…”

Comparative transcriptome analysis provides insights into molecular mechanisms for parthenocarpic fruit development in eggplant (Solanum melongena L.)

“…Parthenocarpic varieties exhibit tolerance to unfavorable environmental stresses [7], have improved fruit set, yield and quality [8, 9]. Parthenocarpic fruit development can be achieved by many methods, e .…”

“…Parthenocarpy, a highly desirable trait in horticultural plant breeding, is characterized as that ovary can development into seedless fruit without pollination and fertilization [ 6 ]. Parthenocarpic varieties exhibit tolerance to unfavorable environmental stresses [ 7 ], have improved fruit set, yield and quality [ 8 , 9 ]. Parthenocarpic fruit development can be achieved by many methods, e .…”

Comparative transcriptome analysis during early fruit development between three seedy citrus genotypes and their seedless mutants

“… 10 The DefH9::iaaM expression promotes the synthesis of auxin (IAA) specifically in the placenta, ovules and tissues derived therefrom. 11 The agronomical advantages of DefH9::iaaM genetically modified plants have been assessed in greenhouse and field trials using transgenic eggplant, 12 strawberry and raspberry 13 and cucumber ( Cucumis sativus ). 14 Goetz et al 15 demonstrated that AUXIN RESPONSE FACTOR 8 (ARF8) is a negative regulator of fruit initiation in the absence of fertilization in Arabidopsis .…”