The expression of cell proliferation-related genes in early developing flowers is affected by a fruit load reduction in tomato plants

Abstract

Changes in photoassimilate partitioning between source and sink organs significantly affect fruit development and size. In this study, a comparison was made of tomato plants (Solanum lycopersicum L.) grown under a low fruit load (one fruit per truss, L1 plants) and under a standard fruit load (five fruits per truss, L5 plants), at morphological, biochemical, and molecular levels. Fruit load reduction resulted in increased photoassimilate availability in the plant and in increased growth rates in all plant organs analysed (root, stem, leaf, flower, and fruit). Larger flower and fruit size in L1 plants were correlated with higher cell number in the pre-anthesis ovary. This was probably due to the acceleration of the flower growth rate since other flower developmental parameters (schedule and time-course) remained otherwise unaffected. Using RT-PCR, it was shown that the transcript levels of CYCB2;1 (cyclin) and CDKB2;1 (cyclin-dependent kinase), two mitosis-specific genes, strongly increased early in developing flower buds. Remarkably, the transcript abundance of CYCD3;1, a D-type cyclin potentially involved in cell cycle regulation in response to mitogenic signals, also increased by more than 5-fold at very early stages of L1 flower development. By contrast, transcripts from fw2.2, a putative negative regulator of cell division in tomato fruit, strongly decreased in developing flower bud, as confirmed by in situ hybridization studies. Taken together, these results suggest that changes in carbohydrate partitioning could control fruit size through the regulation of cell proliferation-related genes at very early stages of flower development.

Producción y calidad poscosecha de tomate (Solanum lycopersicum L.) larga vida sometido a la aplicación de ácido giberélico

“…Al respecto, se entiende que la habilidad de un órgano vertedero para importar asimilados es conocida como fuerza de vertedero (Ho, 1988), esta fuerza es producto del tamaño y la actividad del vertedero (Ho, 1988;Baldet et al, 2006). Se podría pensar que el ácido giberélico al menos aumentaría el tamaño de los frutos de tomate y de esta manera incrementaría la fuerza de vertedero.…”

The impact of different thermal processing of tomato to its antioxidant activity, vitamin E, dry matter and sugar content

“…The intensity of color was determined spectrophotometrically at 520-525 nm. 100 g of samples were measured and volume was made up to 100 cm 3 by absolute ethanol in a volumetric flask. 5 cm 3 of this solution was transferred to a volumetric flask and made up to 100 cm 3 by absolute ethanol.…”

“…Besides that, phenolic acids and minerals in fruit impact the total flavor (Kader, 2008). Sugar content in tomato fruits is a result of physiological, metabolic and genetic processes that control the plant growth (Baldet et al, 2006, Mounet et al, 2009, Wang et al, 2009). Its accumulation in fruit is important both for nutritive value and for taste.…”

The Effect of Potassium Biofortification Over Yield and Nutritional Quality of Cherry Tomato Fruits

“…Tomato-fruit sugar content is the outcome of fruit physiological, metabolic, and genetic processes that are under developmental control (Baldet et al, 2006;Wang et al, 2009). Sugar production begins with leaf photosynthesis, the product of which is translocated to developing fruits.…”