Spatiotemporal transcriptome provides insights into early fruit development of tomato (Solanum lycopersicum)

Abstract

Early fruit development is crucial for crop production in tomato. After fertilization, the ovary undergoes cell division and cell expansion before maturation. Although the roles of regulatory signals such as hormone and carbohydrate during early fruit development have been studied, the spatial distribution and the sequential initiation of these regulatory signals still need to be explored. Using the tomato cultivar ‘Moneymaker’, we analyzed the transcriptome of the ovule and the ovary wall/pericarp dissected from four different stages of the early developing fruits by stereoscope. These datasets give us the whole picture about the spatial and temporal signal distribution in early development of ovule and pericarp. Our results indicate that the hormone signal was initiated in both ovule and pericarp after fertilization. After that, different signals were activated in ovule and pericarp due to their distinct developmental processes. Our study provides spatiotemporal regulatory landscape of gene expression with sequential information which was not studied by previous work and further strengthens the comprehension of the regulatory and metabolic events controlling early fruit development.

Tomato facultative parthenocarpy results from SlAGAMOUS‐LIKE6loss of function

“…In agreement with the Expression Atlas of Tomato Tissues, four transcriptomic analyses concerning tomato fruit set reported that relative to pre‐anthesis (−2 days postanthesis, DPA) (Tang et al ., ; Wang et al ., ) or anthesis (Pattison et al ., ; Zhang et al ., ), Sl AGL6 expression sharply declines in fertilized fruit at 4‐5DPA (Figure S4b,c,d). However, in unpollinated emasculated ovaries, it scarcely declined (by 1.4‐fold only, Figure S4b), suggesting that its decline following fertilization is inherent to fruit set.…”

“…Yet 5DPA it sharply declines to the level found in ovaries of the young 4-mm-long flower buds, hence associating 'ovary arrest' with elevated SlAGL6 expression and fruit set with its decline. Genetic variation between M82 and Micro Tom or Solanum pimpinellifolium might explain the higher fold decline between anthesis and 4DPA reported before (Pattison et al, 2015;Tang et al, 2015;Wang et al, 2009), whereas smaller variation between M82 and Moneymaker could account for the observed similarity in fold decline (Figure 7 vs. Figure S4d, queried from Zhang et al, 2016). Evidence for preferential sublocalization of the SlAGL6 transcript within the ovules of the mature arrested ovary was provided by Pattison et al (2015).…”

“…Genetic variation between M82 and Micro Tom or Solanum pimpinellifolium might explain the higher fold decline between anthesis and 4DPA reported before (Pattison et al ., ; Tang et al ., ; Wang et al ., ), whereas smaller variation between M82 and Moneymaker could account for the observed similarity in fold decline (Figure vs . Figure S4d, queried from Zhang et al ., ).…”

“…Comprehensive transcriptomic studies of tomato fruit set found significant changes in the expression of hundreds of genes, including several down-regulated MADS-box genes (e.g. Pattison et al, 2015;Tang et al, 2015;Wang et al, 2009;Zhang et al, 2016). Among them, SlAG1 and SlAGL6 were suggested to play an important role in fruit set (Wang et al, 2009), and so was also the tomato MADS-box 29 (TM29) (Ruan et al, 2012).…”

Genetic Analysis and QTL Mapping of Fruit Peduncle Length in Cucumber (Cucumis sativus L.)

“…Xylene was replaced gradually with paraffin (Paraplast Plus, Sigma, P3683) at 60°C for two nights with four times replacement of paraffin. Ten μm sections were made using a HEISTION ERM3000 microtome and stained with Toluidine Blue O [23], and examined at x100 in a light microscope.…”